Datasets:

VatsaDev
/

worldbuild

Dataset card Data Studio Files Files and versions Community

Split (1)

train · 67.3k rows

text stringlengths 22 2.11M
[Question] [ In this world, there exist a race of humanoid people which, for simplicity, we'll call Rockfolk. Their skin is grey, and visually resembles stone. It is also exceptionally tough and durable, to the point where it cannot be pierced by modern firearms, even if such weapons actually could damage an equivalent mass of inert normal stone. Bullets hit their flesh and are flattened on impact or richochet off, without harming the individual in any meaningful way. On top of this, their flesh is flexible enough for them to still be mobile and live out normal lives in the same fashion as humans would. Other than this one major feature, Rockfolk resemble humans as closely as is physically possible for a race with such a feature. The question is: How closely is that? Assuming their bodies function in such a way that having such skin is helpful, or at least not actively detrimental to their health, what other features or qualities would they necessarily have (or lack) that would differ from a human? For example, I imagine they would not have any body hair, as it could not pierce through their own skin, and thus they would be vulnerable to cold when exposed. Note: This is not a question about whether or not having bulletproof skin is possible or plausible. Assuming it is, and this is what it looks like, I'm interested in possible and plausible side effects. [Answer] If we look at what skin does we can figure out how changing it will impact things. 1. Temperature Regulation The skin regulates our temperature, both in cold and hot conditions. Blood vessels contract and expand to release and retain heat. The included fat also acts as an imperfect thermal barrier. 2. Creates a sealed environment The skin keeps out toxins, germs and really anything else that exists in our environment. Yet it is light and flexible enough that we are still pretty agile creatures. 3. Touch receptors We feel stuff via nerves in our skin. 4. Storage System Or skin stores water and fat and other metabolic products. What happens when we make our skin bullet-proof? Well it sort of depends on how you want to do that. You can either make the skin more dense, make it thicker, or since you want to stop bullets, likely a combination of the two. Thicker, denser skin will make temperature regulation a challenge. Either your rock men should live in a colder climate, that is less prone to temperature swings or you are going to have to hand-wave this. Alternatively you could alter the method of heat reduction, dogs as the obvious example pant to reduce their body temperature. This may still require a bit of hand-waving, I am not sure but I would hazard a guess that panting becomes less effective/efficient as the size of the animal increases. When you increase the density and thickness of a substance you make it stronger but you also make it more inflexible. Odds are these humanoids of yours are not going to be as agile as a regular human. Conversely they will likely be stronger. As one other post mentioned they are going to need to be stronger to support the additional weight of their armored skin. The additional weight reduces their agility as well...momentum and all that. I suppose this would also lead to reduced touch sensitivity, which considering the skin is much tougher isn't a huge problem in a lot of ways. It would be a problem when it comes to fine motor skills and you are probably going to want to make the skin thinner where need be to account for that. On a side note, facial expressions are going to be pretty drastically subdued if they exist at all, its tough to emote if your skin doesn't want to move. As far as the point on storage goes I don't see any problems in the cross over. If anything you would probably want to make this system more robust as getting hit in un-padded armor will still hurt pretty bad. Final notes: Keep in mind that if this evolved via natural means you won't have uniform thickness. Having the core and perhaps upper legs and arms armored would provide protection and help maintain agility, plus the resources to armor everything are biologically expensive...best survival wins. When it comes to survival really tough skin is good, but so is mobility. Rhinos and Elephants have super thick skin sure...but they also don't have fingers. Maintaining a decent level of mobility is going to be important for your humanoids, if you want them to in fact be humanoid. As someone else mentioned you can have hair if you want to, it doesn't technically grow through the skin, but out of little holes. [Answer] Let's assume their bullet resistance comes from an ability to resist rapid compression (think [oobleck](https://sciencebob.com/oobleck-the-corn-starch-and-water-experiment/)) or "shear thickening". This would allow "their flesh is flexible enough for them to still be mobile and live out normal lives". That being the case, they could still get cut (though not as easily) by a sharp but slow moving blade (think [Dune's slow shield](http://dune.wikia.com/wiki/Shield)). This would drastically change combat styles. Another cool effect would be dealing with space: Rapid decompression due to cabin breach? Not a problem...for a few minutes at least. Physical contact sports would require little if any padding. If Rockfolk get to interact with other species like humans, I would expect their hides/bodies to be highly sought after for its [uses](https://en.wikipedia.org/wiki/Dilatant#Applications). [Answer] Kevlar skin! Cool! So, point of order here-- you specifically said bullet proof, but bulletproof is not knife proof. It's not at all the same kind of durability. The most heavy duty kevlar for bullets works by spreading the impact stress in combination with ceramic plates. So it's not that the skin has to be strong exactly, but that it can spread that stress and might have impact bones over vital areas. Bottom line is that you need layers to get what you want, and depending on the type of bullet (because there are many out there that are designed to shred through anything). Knives are sharper and pointier than bullets. A good knife can pierce and cut through the weaved kevlar fibers made for bullets. Bullets crash into the vest with a quick, powerful shove, spreading their energy throughout the vest and stretching the fibers rather than breaking them. So you'd want not hardness like a rock (even if it looks rocky), but some FLEXIBILITY to distribute the energy. Weaved and layered kevlar fabric is basically like some kind of net: it has high tensile strength and can stretch and "catch" a bullet. Too many bullets or the wrong kind (pointy armor piercing) and yes, it will break, doesn't do well against slashing or piercing weapons comparatively. If you want them stab resistant as well, that's more about layering to catch the knife. > > It’s true that both types of body armor consist of strong materials like Kevlar, but it’s the way those materials are used that matters. > With a ballistics vest, energy is redirected across the armor. A stab vest is less concerned about redirecting energy, and instead allows the edged weapon to penetrate into the material (that’s a critical detail). That’s where the stab vest nestles the weapon in strong materials that the edge or point can’t completely cut through. > > > Allowing for a little bit of penetration goes a long way when you’re talking about stopping a bullet. Sure, a stab vest might stop some of the lighter calibers on a good day. But the intermediate and larger calibers? Forget it. > > > Bottom line: Stab vests aren’t designed for the kind of energy > dispersal that’s key to stopping a bullet. > > > And Vice Versa The opposite is true when it’s a ballistics vest up > against a knife. That type of armor isn’t designed to trap an edge or > point in its fibers. Yeah, it offers a degree of protection that could > prevent injury, but don’t bank on it. [SOURCE](https://crimefictionbook.com/2015/06/17/can-a-bulletproof-vest-also-stop-a-knife/) > > > To stop a knife you want to trap and grab. To stop a bullet you want to redistribute energy. In both cases, layered material is key. If you design the skin specifically for bullet proofness, it's actually going to have to have immense bounce and the ability to redistribute energy without breaking. Rock-like skin isn't necessarily going to cut it, but a system of skin with kevlar-like properties, combined with plating UNDER the skin to protect vital parts could be the way to go here. No doubt you are hoping for ricochet as a cool effect, so if you wanted to, you could put some outer plates on your creature but I would not put them on the inside of their hands. So what do we have on the planet that is bullet proof? There are many legends of alligators being bullet proof. They aren't but it takes more than a .22 to penetrate their hide. Take a look at [this question](https://worldbuilding.stackexchange.com/questions/33364/could-a-creature-evolve-a-biological-bulletproof-vest) that's right here on stack exchange. In it, there are a bunch of biologic answers to how that would evolve and what on the planet is close to that. What you'd want is polymers probably, and a layering system like one user described as in abalone shells. Your rock people have to have in their skin a) flexibility b) a series of layered protection and possibly c) curved or sloped armor. > > Firstly, a projectile hitting a plate at an angle other than 90° has to move through a greater thickness of armour, compared to hitting the same plate at a right-angle. In the latter case only the plate thickness (the normal to the surface of the armour) has to be pierced; increasing the armour slope improves, for a given plate thickness, the armour's level of protection at the point of impact by increasing the thickness measured in the horizontal plane, the angle of attack of the projectile. The protection of an area, instead of just a single point, is indicated by the average horizontal thickness, which is identical to the area density (in this case relative to the horizontal): the relative armour mass used to protect that area. [SOURCE](https://en.wikipedia.org/wiki/Sloped_armour) > > > Angles are one more defense. Put that altogether, and what are the side effects? * Most animals with armor-like skin are invertebrates, and even those that are not are super-heavy (armadillos aren't but their shells aren't close to what you want). So no spine might be a side effect, with more of an exoskeleton deal. * So your guys would have to be really strong to carry around that armor, and they would likely have to consume more food than us, pound for pound and/or a very efficient digestive system. * Heat loss and gain. Shells can absorb heat to be used and keep it, but doesn't necessarily mean they are cold-blooded. There's at [one sea turtle](http://www.iflscience.com/plants-and-animals/how-leatherback-sea-turtles-keep-their-muscles-warm-frigid-waters/) that is, in fact warm blooded, but their system of keeping warm is worth looking at because it is much different than our own: > > The closely bundled arrangement of veins and arteries at the base of the legs, the researchers found, have a counter-current function that's the opposite as that of aquatic mammals and birds exposed to similarly cold conditions. Rather than transfer heat from (outgoing) arterial blood to (incoming) venous blood in order to maintain elevated core body temperatures while the limbs are kept cool, leatherback heat exchangers maintain higher temperatures within their limb muscles. > > > Their body core temperatures are typically lower than that of their > muscles, and their endless amount of exercise – they’re always > swimming – transfers some heat to the insulated core. This system > keeps sea turtle muscles warm enough to work effectively in the cold. > Leatherbacks are the sole living species of the family Dermochelyidae, > which has a 50-million-year history of foraging in cool water. > > > Keeping heat in the muscles (and outside of the core) is especially > important for nesting females, who use their legs for locomotion as > well as nest digging; otherwise, they’d overheat. > > > If you go with that model, then your rock dudes and dudettes might be in near constant motion, using muscles as a heat sink and transference system, with a regulated core under all those layers. Overheating and overcooling might still be an issue--I don't think that they will actually be good with the extremes of either. But it's an interesting biologic twist that might be good to use. [Answer] Side effects: * some medical procedures, not only surgeries, but even simple injections would become quite tricky (actually in modern society it may negatively influence life expectancy) * this race would presumably not use tatoos... * their pelts would be quite valuable on black market * if they share environment with humans, they would presumably end up as a warrior caste (or just overlords) [Answer] They might well require stronger skeletons and bigger muscles than your average human in order to carry their natural 'armour'. While lighter materials do exist that meet your bulletproof criteria it seems unlikely that evolution would produce an organism able to produce them in sufficient quantities to cover a humanoid creature. Their sensory organs (assuming that these are squishy and not hardened) would need to be further from the internal components of the body. Therefore they would have longer nerve connections to them which might increase the risks of damage or sensory disruption. As already indicated in the comments they would not necessarily be hairless. Plenty of animals with tough skin have hair - e.g. elephants or rhinos. However, based on these examples it is plausible to think that their hair might be quite sparse. [Answer] 1. If their skin is grey, it probably doesn't have melanin, meaning they might be more strongly affected by ultraviolet rays and more at risk for skin cancer, unless their skin has a substance which fulfils the same roles as melanin, just grey in colour. They also wouldn't get tan lines. (Probably. They might just go from darker to paler from sun exposure, and not the other way round.) 2. They might be unable to produce vitamin D. 3. Ingrown hairs are a pain to deal with. 4. They couldn't get tattoos or at least not the kind with a tattoo gun. I guess it depends on how resistant their skins are for those. Same with piercings. You'd need to decide whether they would develop different methods for tattooing and piercing, or just not bother. 5. Do they have fingerprints? And does their skin produce oils? 6. Would they get wrinkles as they age? It seems to me that wrinkled skin might not be that good at repelling gunshots. 7. Would their skin bruise? The discolouration might not be visible under the grey layer. They might be unable to blush or pale, so they may appear more stoic and emotionally less accessible to other people. 8. Would their facial muscles be able to express emotions to the same degree as humans? 9. Are their skins also the texture of rock? If yes then their clothes may need to be designed from more resistant materials. Also furniture and whatever objects they need to touch constantly. Think of touch screens being scratched up by rocky skins. On the bright side, they might be highly sought after in the pedicure industry! 10. The fashion and cosmetics industry would probably develop products specifically to fit their needs/skin tone. [Answer] All the other answers are good, but they've missed this: Surgery If the Rockfolk suffer from internal bleeding, they die. If your Rockfolk have cancers, they die. If your Rockfolk have any internal problems, they die. Pregnancy If your Rockfolk need a C-section, they die. Note: It would be pretty cool if their unborn children can survive inside their dead mothers. If so, you could have some spooky unborn children wreaking havoc in your world :) [Answer] You need to define "tough" first. Obviously, "tough" does not mean rigid, since you said the skin was flexible. If that is the case, then the underlying tissue would still take the impact force, even if the skin does not break. "Tough" also cannot mean inelastic, because otherwise movement would be very difficult. Again, the tough-but-elastic skin would allow the impact forces to be felt by the underlying tissue. Basically, I don't see how you can protect the underlying tissue unless the skin is rigid -- which you said it is not. So, I am suggesting that you cannot have what you want: flexible yet rigid enough to be bullet proof. If you want flexibility, then the skin may be bullet proof, but the tissue underneath will suffer nonetheless. And that't not really bulletproof, is it? Some people have suggested non-Newtonian, dynamic substances that resist rapid changes in shape. Great idea! This has actually been used in bulletproof vests, filled with shear-resistance fluid chambers or something similar. But this would make the skin bulletproof, but not slow-knife-proof. Is that what you want? It's still a pretty good trick, but not very rock-like for your Rockfolk. As others have said (a la Nick Cage) if you're skin is too tough, you cannot undergo surgery or be injected with hypodermic needles -- or any number of desirable actions that involve piercing the skin followed by healing. Does your bullet proof skin grow as the Rockfolk mature? If so, then that introduces the possibility that the skin can be breached: The adjacent molecules that make up the skin, or the cells that are its building blocks, must be able to separate to allow for new material to be added. How does that occur? Can a chemical mean me used to hijack this mechanism, to weaken the skin? [Answer] I'd make it so that their skin is much more rigid, so it is a problem when they grow and they need to shed once a year like a snake does. [Answer] Personally, I feel like there are more strengths then weaknesses. Strengths: * Knives, guns, and impact are trivial to the Rockfolk * Being able to carry all that armor 24/7 requires thicker bones and stronger muscles, which add to physical force and durability * No need to be careful when fighting a regular human * Assuming these people can withstand explosions, they would be the ultimate soldier Weaknesses: * Surgery would be a pain in the ass * Any internal problems would be very hard to treat * The color of their skin would make them dull and unrecognizable Overall, I think it would be better to have this skin because of its utility, and I generally disregard cosmetics, so this would not be an issue for me. ]
[Question] [ I understand that in order to compress and expand spacetime, an [Alcubierre drive](https://en.wikipedia.org/wiki/Alcubierre_drive) would require some sort of "exotic matter" with a negative energy density. Is that sort of exotic matter purely hypothetical? If not, what would it look like? How would it behave? Is it related in any way to antimatter? Lastly, would that the exotic matter either fill or form the rings that surround the ship? (as seen in various conceptual designs from NASA) And am I right in assuming that it would be wrong to treat the exotic matter as some sort of fuel that's depleted, rather than as an integral part of the ship itself? Thanks in advance for any pointers. This is my first question, so I apologize if it's too broad or if it overlaps with any others I may have overlooked. [Answer] It is important to note that you do not need negative mass for an Alcubierre drive to work, but negative mass density.** The difference is subtle, but important for actually being able to build a warp drive. Essentially what the equations say is that to bend space in the appropriate manner for a warp drive (i.e. to expand space behind your spacecraft and compress it in front), you need to be able to sum up all of the matter in a given portion of space and get something along the lines of "-10 kg / m3." Space-time curvature is caused not simply by the mass of matter, but also by how compact it is in a given volume, and what we're trying to do with a warp drive is to curve space in a very specific way, so it doesn't matter what we're doing with the matter-energy in a given volume, so long as we can make its mass density appear to be negative. The easiest way to do this is to just take a lump of matter that weighs -10 kg, and put it in your space. This however, doesn't make sense, since how can something "weigh" negative 10 kilos? That's like saying I have negative 3 apples. This is why it is sometimes said we need "exotic matter" to make warp drives work, however, there are a few examples of ways to cheat this. I'll start with an analog in silicon doping. In order to create integrated circuits, bulk silicon is doped to either be positive or negative charged. The way you do this is by adding impurities to pure silicon to change the number of valence electrons in its structure. To make positively charged silicon, boron is added. Because boron has one fewer valence electron vs. silicon, this results in a deficiency in electrons. Similarly, to make negatively charged silicon, phosphorus is added. Because phosphorus has an extra valence electron vs. silicon, there is a surplus of electrons, leading to a negative charge. Because these electrons are surplus, they're free to move around the silicon lattice, and controlling this flow is how circuits work. The more interesting thing here, however, is what happens when you consider not the electrons as a particle, but the absence of electrons. In circuit design, we call this a hole, and we *treat it as a positively charged particle,* one that doesn't actually exist. In this way, you can actually view this as a negative electron density. Essentially, we have created a positively charged particle using only negatively charged matter! This is very similar to what we want for our warp drive if you think of mass not as an electrical charge, but instead a sort of gravitational charge. There are many equations that treat mass like a [gravitational charge](https://en.wikipedia.org/wiki/Gauss%27s_law_for_gravity), and it's telling that gravity is unique among the fundamental forces in that it does not, to our knowledge, have opposite charges. This means gravity forms monopoles, and everything we've seen about monopoles suggests that nature abhors them. Really it makes no sense, when viewing mass as a kind of charge, for there to not be the concept of an opposite charge. This probably indicates our models are incomplete with respect to how we view mass and gravity, and indeed, we are unable to combine gravity with quantum mechanics. So can we find a little more concrete example of negative mass density? Yes, actually, we can find a few. The first, as others have mentioned, is the Casimir effect. In a nutshell, what happens in the Casimir effect is that two plates close together are pulled together with an extra, anomalous force (i.e. not due to charge or gravity). The reason for this comes when we look at empty space from a quantum point of view. Quantum physics says that vacuum isn't really empty, but is a seething mass of "virtual particles" constantly popping into existence in pairs then combining with each other and annihilating. Because they recombine, the energy density of the vacuum balances back out to zero (in fact, that it exactly cancels out to zero is considered one of the great unsolved mysteries of physics). So what does this have to do with the Casimir effect? Well, if space is empty, the vacuum energy can easily cancel back out to zero as virtual particles pop into existence, do their thing, and pop out of existence. However, things change once we add mass (i.e. our two plates). Virtual particles are treated as a spectrum. As far as the math is concerned, we treat it as an infinite sum of particles that all exactly cancel out to zero. Because the virtual particle spectrum has infinite energies, per De Broglie it also has infinite wavelengths. This is where things start to get interesting once we add our plates. For a particle to fit between those plates, it must have a wavelength smaller than the distance between them. Now, because our plates are close together, they block some of these virtual particles from popping into existence, namely those with a larger wavelength than the gap between them. Now, more particles of the larger wavelength are forming outside the plates than in between them. What this ultimately means is we've altered the density of virtual particles in space. Because we can say these virtual particles have mass (even if it is short-lived), we have now changed the *mass density* of the space in between and around the plates. So if normal, empty space has a mass density of zero, what does that mean for the mass density between the plates? Because it has less of a density than the space outside the plates, and that space has a density of essentially zero, it must, for all intents and purposes have negative mass density. We've just created a form of negative mass! The Casimir force however, is incredibly weak, as a particle's energy is directly related to its wavelength. In order to increase the Casimir force, you must decrease the separation of the plates (and thus block shorter wavelength, higher energy virtual particles), and so you can only create very small amounts of negative mass density with it. Just like our silicon doping example, we've created a negatively charged attribute just from manipulating the distribution of a positively charged one. We have, in effect, "doped the vacuum." Unfortunately, we can't really use this for creating our warp drive, but it does at least show us that negative mass density is possible. As a sidenote, this "pairing" of positive and negative attributes cancelling out to zero was first envisioned in a vacuum model known as the [Dirac Sea](https://en.wikipedia.org/wiki/Dirac_sea). This model basically states that the vacuum is an infinite sea of negative energy particles (hey, that's exactly what we want), and although it turned out to be not true, it did make valuable scientific predictions that were later confirmed, namely the existence of antimatter. Even though the Dirac Sea view is incomplete with regards to the vacuum, it is directly analogous to our silicon doping example. So are there more useful examples of negative mass density in nature we can use? Yes, it turns out there are. Two of them, in fact. I will start with the more scientifically accepted version first, one that we can see all around us: The accelerating expansion of the Universe. It is generally agreed, based on astronomical observations, that the Universe's expansion is accelerating. This creates a bit of a problem: something must power this acceleration, and that means energy. So to make our equations match our observation, we add some energy to the vacuum, making it expand faster. We treat this as an intrinsic property of space, so as space expands, its density doesn't decrease. That means adding more space is also adding more energy! This creates a new problem: energy means mass, and mass means gravity. If we're adding more and more energy to the Universe as it expands, we're adding more and more mass! The Universe shouldn't be expanding at all then, the energy making it expand faster and faster should itself generate gravity that slows the expansion!! We call this strange energy that seems to come from nowhere "dark energy" because we don't understand what it is at all. So what do we do about this problem? Mass and energy curve space, so adding more energy should curve space more, and indeed it does (the Universe accelerates faster), but the space is curving in the wrong direction since the Universe is speeding up, not slowing down! Clearly whatever "dark energy" is, it's not "normal" energy in any way. Looking at things from a general relativity standpoint, the accelerating expansion means that empty space has negative curvature. This may not sound weird, but what it's basically saying is that the negatively-curving space has a negative mass-energy density! All of our data is telling us at every point in the entire Universe, we have negative-mass! We have exactly what we need to build our warp-drive, everywhere, but we don't have the slightest clue what it is! It's like the Universe itself is taunting us! But once again, it shows us that negative mass is, in fact, a real, natural thing. The only question is how do we create this negative mass in the configuration we need to go really fast? Our last, best hope lies in a very controversial conjecture of physics: The Woodward effect. Essentially, the Woodward effect says that if you accelerate any object that is absorbing or discharging energy, that you can create a transient change in the mass of that object. In fact, it is theorized that this transient change can even be negative! So what kinds of systems can absorb energy and release it that we can also easily accelerate? Well, one of the simplest ways to model such a system is using capacitors and inductors. These are objects that are simple, cheap, and can absorb and discharge energy rapidly without relying on mechanical components. This leads us to our modern day research into warp fields. Nearly every warp field experiment is using capacitors in some kind of configuration designed to make use of the Woodward effect. Often these capacitor banks take the form of a ring, this is because you can maximize the bending of space inside the ring, thus making it easier to detect. It is perhaps also telling that fringe theories such as the EmDrive rely on microwave resonant cavities, which themselves behave as a capacitor and inductor tied together. In other words, an EmDrive can be modeled as the exact system predicted to create negative mass by the Woodward effect! In the end, if it turns out the Woodward effect is real (big if), then we have a way of generating negative mass density, and interestingly enough, you can probably do it with a microwave resonant cavity (which is essentially what an EmDrive is). I find it interesting how all of these seemingly unrelated fringe ideas seem to be converging at the same point. ## So why do NASA's artistic depictions of Alcubierre drive spaceships use rings? This is a very different question, but one still related to negative mass density. When the Alcubierre drive was first proposed, many scientists did some calculations and decided that even if it were possible to construct negative mass, that you'd need planet-sized amounts of this negative mass to create a warp field (on the order of the mass of Jupiter). This is clearly unrealistic, and seemed to mean bad news for our plans to go fast, but some other scientists did more calculations and determined that no, you don't need planet-sized amounts of negative mass, you can just do it with less than a metric ton. So why the huge discrepancy? It all boils down to the topology of your warp field. The scientists who came up with the planetary mass estimate created a warp field that was essentially spherical in shape, whereas the scientists who came up with the much smaller estimate devised a warp field that is toroidal shaped. But it gets more interesting than that: the speed at which you can travel faster than light, known in warp research fields as the boost velocity, is directly proportional to how thick your warp bubble is. It becomes very difficult to shrink the thickness of your warp bubble since it requires increasing the mass density along the edge of your warp bubble. But in doing so, you minimize the amount of exotic mass you need while maximizing the amount of boost you can get. It turns out the easiest way to create a thin, yet dense edge to your warp bubble like this is to make your bubble the shape of a torus. Since the warp field is a function of how you arrange your negative mass density, that's where your rings come from. So do the rings contain the exotic matter? Well, yes and no. As we've already established, you don't need actual matter weighing negative 10 kilos, you need negative mass density, and as we've shown before, it should be possible to create such a mass density using normal matter. It is therefore more appropriate to say that the rings contain the mechanism for creating negative mass density, and most likely that negative mass density exists as a field around the rings. To finish my answer, I will leave you with a world-building scenario that allows you to create a warp-drive with minimum hand-waving: Let's say your warp drive works by taking energy and using it to boost the appropriate type of virtual particle into existence. The how it does this is the only hand-waving part we have. Virtual particles are everywhere in empty space. They are represented as an infinite spectrum of properties, and always appear in pairs and annihilate, returning the average energy density of the vaccuum to zero. So long as the particles "pay back" the energy for their existence by recombining, they can literally have any characteristics, as long as the pair allows them to combine back to zero. In general, we might say the pair have opposite charges, but the equations work just as well to say the particles have "opposite masses," so long as everything sums up to zero energy in the end. What our warp drive does then is use energy to force virtual particles that have negative mass into existence. It does this by "paying" for the energy that would have otherwise been paid by the virtual particles annihilating. This is analogous to Hawking radiation, where a black hole "pays" the Universe for a particle in a virtual particle pair, causing one of the virtual particles to be boosted into reality. This particle then escapes the black hole, carrying energy away from it. So by specifically tuning how we move energy around our spaceship (hand-wave part), like a black hole, we too boost virtual particles into existence, but only those with negative-mass, and use them to form our warp bubble. This warp bubble causes space in front of our ship to compress, and space behind it to expand in a manner similar to how the Universe expands. Because there is no limit to how fast space can expand, there is essentially no limit to how fast we can go. Inside our warp bubble, everything is stationary, but to an outside observer, we seem to be moving faster than light. Because we aren't actually moving, time dilation is only a problem at the infinitesimally small edge of our warp bubble. This process takes constant energy input, as these negative mass particles want to decay to more stable forms (and in the process presumably acquire positive mass), but they exist on timescales long enough for us to create a warp bubble. Without that energy input, our warp field collapses, and we're stuck at sublight speeds. [Answer] An Alcubierre drive can't exist at all, if by "drive" you mean something analogous to what you find in Star Trek/Wars: you have a region of your ship filled with some unspecified phlebotinum, you send a go signal to it, it powers up and you go zipping off in whatever direction you want. This is impossible because the exterior part of the Alcubierre warp bubble is a spacelike surface: no part of it lies in the future light cone of any other part. So nothing you do at the start point of your journey can cause the correct spacetime geometry to exist at later points of the journey. Either you have to happen upon existing infrastructure, or you have to start preparing your own infrastructure at a point whose future light cone includes the entire trip. (So, for example, you have to start preparing at least 1000 years in advance if you want to travel 1000 light years.) The Wikipedia article briefly discusses this in the section [Alcubierre drive#Placement of matter](https://en.wikipedia.org/wiki/Alcubierre_drive#Placement_of_matter). That aside, the main problem is that the "exotic matter" in the solution doesn't follow any physical laws. The field equation of general relativity has the basic form $$\textit{complicated function of second-order derivatives of the metric} = \textit{mass/energy distribution}$$ Finding exact solutions to the field equation for realistic mass/energy distributions is extremely difficult. But finding a solution with no constraint on the mass/energy distribution is trivial: any twice-differentiable spacetime metric is a solution. Alcubierre's warp drive is in the trivial no-constraints category. And, in fact, the mass/energy distribution that you get from it makes no sense. I don't just mean that the energy density is negative; I mean that there's no cause and effect. The exotic matter just appears from nowhere when it's needed and disappears into nowhere when it's not. In principle one could invent a hypothetical form of matter, invent some plausible physical laws for it to follow, and then find a warpy solution to GR in which the stress-energy tensor actually reflected your exotic matter behaving according to the laws you invented. That would be an interesting theoretical accomplishment. As far as I know no one has succeeded in doing that. So at the moment there is no warp drive physics. There is just warp drive magic, with a false veneer of respectability from the use of the GR field equation. [Answer] > > Is that sort of exotic matter purely hypothetical? > > > Mostly. There appear to be things that might be suitable... Alcubierre suggested the [Casimir effect](https://en.wikipedia.org/wiki/Casimir_effect), but that's pretty weedy. [Dark energy](https://publicintelligence.net/dia-warp-drives/) might also fit the bill, but as to how you'd actually make it do what you want it to do, instead of appearing out of nowhere and blowing up your universe... your guess is as good as mine. [Negative mass cosmic strings](https://en.wikipedia.org/wiki/Cosmic_string#Negative_mass_cosmic_string) may also fit the bill. > > If not, what would it look like? How would it behave? Is it related in any way to antimatter? > > > It almost certainly wouldn't behave or look like matter. Calling it matter is probably something of a misnomer. I expect you wouldn't be able to see it at all as it would be unlikely to interact electromagnetically (though you might get some gravitational lensing effects), and (aside from the associated space-time warping and resulting mangling of you and your ship) you'd probably be able to fly right through a cloud of the stuff without crashing into it as it. As to the rest of its behaviour, who knows? For specific examples... we don't really have a handle on dark energy, but you probably can't see it or feel it , other than by inferring its presence from accelerating inflation. Cosmic strings aren't made of "stuff" at all, but are interestingly warped regions of space that can't simply unkink. You can't see it directly, but it will strongly bend light that passes close to it, similar to gravitational lensing. The casimir effect is an artefact of the quantum vacuum, and so isn't really made of "stuff" either. > > Lastly, would that the exotic matter either fill or form the rings that surround the ship? (as seen in various conceptual designs from NASA) > > > In those designs, probably yes. However. Many of the problems with existing warp metrics boil down to needing unbelievably colossal amounts of exotic handwavium to make a warp that could encompass an entire spacecraft. One solution to this is to make a region of warped space that's small on the outside and large on the inside (not really a tardis, because you have to expand and collapse the whole thing to get out). There are a few [interesting papers on this](https://arxiv.org/abs/gr-qc/9905084) (with a few more at the bottom of this Orion's Arm page on [reactionless drives](https://www.orionsarm.com/eg-article/493f29cc472f0)) which may or may not interest you. To avoid crunching and uncrunching space every time you want to get out (which may be risky), and to handle the fact that superluminal travel doesn't appear to be possible with an alcubierre-type drive anyway, the Orion's Arm creators construct a warp drive, crunch it up into a warp bubble and then use it to tow or push a regular spacecraft. The big lumpy things and rings on the outside of their ships are the connecting mechanisms, with all the interesting stuff folded up in a picometre-sized bubble. > > And am I right in assuming that it would be wrong to treat the exotic matter as some sort of fuel that's depleted, rather than as an integral part of the ship itself? > > > As no-one really knows what the stuff would actually be, or how you'd get it, or manipulate it, there's no good answer to this question. Maybe the stuff evaporates when you unclench your warp fields. Maybe the stuff isn't stable. Maybe keeping the stuff in one place is so hard that you just can't help but have it leak out over time, requiring new stuff to be pumped back in to stop your warps going flat. The hands are yours to wave; it seems unlikely that anyone will prove your fictional statements on this matter wrong in your lifetime. And if they do, it'll probably be for awesome real-life-warp-drive reasons anyway, so its kind of a win-win. [Answer] As far as I'm aware (I'm neither an astrophysicist, nor do I play one on television, and I didn't sleep at a particular hotel chain last night), that's been one of the perceived sticking points for construction of an actual Alcubierre drive -- the inability to even define what exotic matter is, never mind say for certain how to obtain or create it. In order to have negative energy, you'd need to have negative mass, and to a layman, it's not at all clear what that actually means -- since both normal and antimatter have positive mass (i.e. are gravitationally attracted by other masses). It might require a local reversal of the Higgs Field, if that even makes sense (I'm not a particle physicist, either). Or it might require some unfamiliar arrangement of quarks (though I believe I've read that all the possible combinations of two or three of the known quarks and antiquarks -- up, down, and strange and their counterparts -- still produce positive mass). In the end, for worldbuilding purposes, you can treat "exotic matter" as just another form of handwavium -- something your characters or their culture have discovered how to obtain or make, in order for their warp drives to work, without the need for the reader to know the actual details of what it is, where it's found, or how it's made. As far as the rings in illustrations of Alcubierre warp ships, I believe you have it exactly right -- the exotic matter is in the rings, and is (in current iterations of the theory) vibrated radially to produce the warp effect, then the warp field somehow offset so that space ahead of the ship shrinks, while that behind expands, carrying the ship (protected by the bubble of the warp field) forward at potentially superluminal speeds. [Answer] The answer offered by Zeiss is well-put-together, and so I avoid repeating those thoughts and instead offer another potential solution. The man behind the Alcubierre drive, Miguel Alcubierre, realized that his demand for a matter with negative energy may not ever be feasible, so he proposed an alternative: a [Casimir vacuum](https://en.wikipedia.org/wiki/Casimir_effect). Just as the other answerer, I am nowhere near a proper physicist, much less a quantum physicist -- but in essence, it has to do with the way vacuums interact. The idea at the core of the Alcubierre drive is to contract the space in front of it, and expand the space behind it, in order to travel faster than light without breaking the laws of relativity. With space mostly being a vacuum, Alcubierre saw potential in the Casimir effect to achieve these ends. How, exactly, is either up to quantum physicists, or in the case of your world, to you. [Answer] I came here because the title says "what could power an Alcubierre drive", although you actually want to know what drives it. Still, I'll quickly give you my thoughts on the power question. The power for an Alcubierre drive would have to come from antimatter or black holes because no other known source of energy would be plentiful enough. With black holes there are basically two ways of producing energy: Evaporating small black holes, or throwing matter into black holes and using the resulting radiation. Throwing matter into black hole has a terrible efficiency: Most of the matter ends up in the black hole which gets heavier in the process. By contrast, evaporation, like matter-antimatter annihilation, has 100% efficiency — all the mass is turned into radiation. Because only microscopic black holes radiate at all significantly, one would need a huge number of them. The evaporation can be slowed down by throwing mass into the holes (which, as a side effect, also produces some radiation) because larger holes do not radiate much. But there is no way to re-start a large black hole, which is a big disadvantage compared to antimatter which can readily be annihilated. Ideally on would always feed fast-burning black holes at a steady state just below "criticality" and somehow dispose of the energy produced. Overall it seems that antimatter is easier to handle and use. (I didn't think I'd ever write that sentence.) ]
[Question] [ Closed. This question is [opinion-based](/help/closed-questions). It is not currently accepting answers. --- Want to improve this question? Update the question so it can be answered with facts and citations by [editing this post](/posts/45680/edit). Closed 7 years ago. [Improve this question](/posts/45680/edit) Story: I am a evil necromancer Overlord who has many evil minions loyal to me. However a hero has greatly wounded me, and I have to go into deep sleep in order to heal and regain my dark energy. My minions remain loyal to me (no worries there) but I have to leave quickly before my enemies find me. How do I hide myself in such a manner that only my evil minions will able to find me? What is the best place to hide ? I don't want to leave some obvious clue that will get me ambushed by a bunch of annoying heroes. Background: My world is like a magical-Earth, with the most common magic types being - elemental and necromancy. Spirits can be summoned, but they can't find people. I am a evil Overlord with 3 powerful minions (they are the most loyal) and a evil army. I have some time to prepare before going into hiding. Question: Where is the best place I should hide ? Since I have some time (but not that much) to prepare before going into a deep sleep, it is possible to create artificial places with traps and all. But my evil minions have to be able to find me in order to awaken me at the appropriate time, when good is at its weakest etc. So the second question is, what clues (if any) do I leave behind ? I can't just tell my minions, "I'm going to this and this place" because it is possible to force clues out of them if they get captured. A subtle hint would be enough. Note : For leaving behind clues, I can use code words, or hide in a place only my minions know about. Enemies cannot read minds , but they can get some clues (magically listening in etc) [Answer] In order to outwit a hero, one must think like a hero. So in order to hide from said hero, where would be the last place a hero would think of looking? I would say the most holy place imaginable, such as a great temple or revered statue. Whilst the hero is delving into dungeons and searching through barrows and graveyards, I shall be slumbering beneath those who will worship this hero readily. They would not know that their doom lays beneath their feet! Then, even if the hero does manage to discover my location, he would have to dig up a holy place, something he may not be willing to do unless he is fully certain. Even then, he would have to convince the worshippers at that site to let him defile it and destroy it, something my minions would have no such qualms about. For the second point, I would tell my loyal minions exactly where to go. However, that is not exactly where I am. That would be simply the first step in an elaborate treasure hunt to find my true location. This means that even if my minions are tortured and reveal the information, that would not help the hero in finding me. Indeed, only the minions would be able to complete the quest when the time is right, and the only way the hero could complete it would be to subdue one of the minions throughout the entire journey, and force it to answer the riddles/ puzzles or decipher the codes they are given correctly at every step of the journey. Much more difficult than simply forcing the information out of them on a single occasion. These could include really evil things, such as summoning another spirit that will only give the next clue if it is presented the blood of an innocent (say a child). Even if the hero gets that far, would they be willing to perform the task and taint their soul to find me? [Answer] Hide in the crowd. Choose some minion, preferably the one that lives in a big city, with a spotless reputation (hope you're smart enough NOT to mark your minions with "I'm evil" tattoos). Let the minion declare that his dad or granddad got sick and needs a better care, so the "granddad" will move to him. Fake the required documents, and just sleep in the minion's spare room. Unless your "grandson" annoys the neighbors with a loud music, no one would even remember that you exist. I really doubt any Legendary Hero would bother meticulously checking the papers of every Average Joe that appeared in a new place after the Bad Guy disappeared. They'll have more exciting things to check, like powerful artifacts, magical anomalies and elaborate quests. Actually, ask your smartest minions to create a couple of "cool" artifacts, set up some puzzles, draw maps and spread rumors - it'll keep the Heroes distracted for a while. As for keeping it secret: only one minion knows your true location, and after you've settled the details, no magical eavesdropping can discover the truth - you're just his comatose granddad. You need to select some other minions for backup (again, only the ones with a perfect reputation), and, again, they'll be talking about "taking care of a friend's grandpa", not about "hiding the Evil Overlord in a spare room". [Answer] ## Regarding the minions If the minions can be broken, your hiding is pretty much required to be magically linked to certain events in the realm. No matter how cryptic or scattered the information, if the knowledge can be forced from the most loyal of subjects, and the life of the villain depends on it, I wouldn't recommend trusting them with the information. A solution could be a means to contact the Overlord, but the location is not revealed in this method of contact. Like a summoning ritual that merely opens a channel to the mind of the Overlord. But onward to the suggestions of locations ## Pocket dimension Create a rift in the fabric of reality, hiding yourself in a dimensional pocket that can be accessed via some means. Non-Euclidian reality would be a tricky space to traverse for mere mortals that are accustomed to the laws of physics. ## Magical domes Impassable shields of natural or unnatural variety. Wild magic, electricity, a vacuum. There's a number of different means that would shield from most lifeforms. A spheroid vacuum with several minutes of traverse time to get to the villain would negate most lifeforms, provided the minions are undead. ## Outside the world Practical immortality and lich-like features make possible to create a space for yourself on celestial objects, or simply on orbit. This pretty much unifies the first two ideas into one: The location is for all intents and purposes impossible to get to, and if someone were to get close, lack of breathable atmosphere would hinder any intruders. ## "The Voldemort" Provided the Overlord is able to possess people, have it latch on to living beings. Powerful enough they could leech lifeforce from Dragons, basically zombifying a big brood mother for example. This could be mistaken by the people as just some random pestilence that plagues the land, not necessarily the Overlord. It would also create a possibility for a more accelerated timeframe for the evil to rise again, provided your world has powerful magical creatures to drain life from. ## "The Sauron" Like Sauron survived via the small token - ring, this Overlord could simply use mundane, yet precious objects as his phylactery. Perhaps a jewel in a crown of royals or a gem in a signet ring. This would also provide with a plothole for how the big evil stayed on top of current events during their absence. [Answer] The trick here is that the Hero has to think he has utterly defeated you, so you need a little stagecraft. Find a minion that resembles you somewhat, and perform surgery and other manipulations to make him resemble you perfectly. Dress him up in your finest robes and stick him at the end of a dungeon somewhere with a perfect escape route. Bonus points if you brainwash him to believe he is you trying to enact one of your B plans for world domination (be sure to add in a keyword that is unlikely to be spoken to him to remove the brainwashing in case he succeeds). Next, have your three, probably well-known, lieutenants guard and protect him (alternatively, if you want to keep said lieutenants around, repeat the first step with minions that look like them). You can brainwash them too if you want to make sure they don't let it slip that he's not their real boss. You have now set up a situation that, in every way, looks like what the hero expects (BBEG in a lair, threatening to take over the world). If he defeats him, then the hero gets what he wants, and stops hunting you. If he fails, that's one less hero to bother you (and potentially the world might be conquered while you sleep). As to you sleeping it off, you have a lot of options. I like the "pretend to be a prisoner in your own dungeon" approach. You might have to change your appearance to make that work, but when the hero finds you, you can wake up and be grateful, and tell a terrible story about how Lord Evilton was torturing you so you'd reveal where Plot McGuffin #3 was hidden, but you resisted, knowing some brave hero would come to save you. Feel free to give the hero additional information, like Lord Evilton boasted to you about how he couldn't be killed, and only a sword coated in the blood of a pure maiden thrust into the heart of his corpse could keep him dead (or something equally funny to see if the Hero will do it). In either case, you probably want to invest in some spells to misdirect any scrying done on you, and prevent mind reading and other pesky problems. [Answer] Try hiding in a statue. (Preferable one immune to Detect Life kind spells if you are alive enough). The statue of yourself wouldn't be the best choice (heroes who lost loved ones or friends might relieve their anger on your statue => they will discover you too soon), so I would suggest a statue of some noble hero. Hide it in your treasury so it would look like you/your minions stole it somewhere. When the time comes, all your minions have to do is to break a statue and take your body away. [Answer] ## The same way it's always been done At the back of a cave system behind hundreds of minions (in easily pulled groups who apparently can't see each other across a room). You need to make sure that each of your progressively tougher trusted lieutenants has a part of the key needed to waken you from your long slumber and that they will hold that key on their person until death. After all, why break with such a fine old tradition and if nothing else, necromancers love to cling on to the past. [Answer] Go on the sea floor, perhaps the [Mariana Trench, the deepest part of the world's oceans.](https://en.wikipedia.org/wiki/Mariana_Trench) It's super difficult to get to, even with magic? Unless it isn't? [Answer] Every respectable fantasy villain needs a dungeon. If the term D&D rings a bell, remember that each and every RPG or RPG like game, be it video or board game, could maybe never have existed if Gary Gygax et al hadn't been so addicted to villains hidden in dungeons. It's what the first D stands for. Dungeons may take many forms - they may be spires, cave systems, lairs inside castles or churches, etc. But at the end of the day, they are just that - dungeons. I am trying to come up with some examples of villains waiting for heroes for a final clash in a dungeon, or just living in a dungeon when they are the protagonists. Some examples that come to my mind: Diablo (and his brothers), almost every single dragon and lich in every single D&D videogame ever, the Overlord from the Overlord series, Zemus & Zeromus from Final Fantasy, the japanese queen from Tomb Raider, Satan in Dante's Inferno, Magneto in his asteroid, Dr. Doom in his castle, Juno in Assassin's Creed III, Smaug, the uber Ethereal from X-Com, Ch'Tullu, Bowser, Dr. Weird... And these are just off the top of my head. Sure, the alternative of hiding in plain sight is smart and all, but it takes away all the fun of traps, epic monster battles, hidden treasures and a sense of exploration. I say stick with dungeons all the way. ]
[Question] [ Wanting to keep my writing realistic, I try to keep distances traveled in the humanely possible range. The current setting is thus: * Medieval style world, roads available, they are travelling north, climate like Germany/Holland/Scandinavia * A group of mostly military (only one not-experienced rider among them) horsemen travelling as fast as they can because their life depends on it need to cross a windswept plain. About 12-15 persons plus horses. * They ride light (light armour) but heavily armed (everyone carries either one or two swords or a bow with full quiver and a shortsword, and an occasional axe or warhammer present). * They have pack-horses for supplies and enough mounts. Rations are simple dry rations for the men and oats for the horses. Water is available on the plain. * The not-experienced rider is a thin woman, but she is a magic healer (magic does come at a cost in the form of energy drains). * They are being followed and they know that. The windswept plain houses many nasties and you don’t want to be there for much longer than you need. How far could they have traveled in two days and three nights, taking minimal breaks and only one longer rest due to extreme fatigue? [Answer] The answer to this depends on the rider's preference: do they want to travel "AS FAST" as they can or do they need to travel "AS FAR" as they can. Riding a horse in medieval times didn't meant that the rider was constantly on the horse. Going as fast as you can meant that you could travel 80-100 km with the horse cantering but that also meant that after two hours of constant effort the horse would just drop dead. Going as far as you can (or going as far as you can in the shortest time) would mean that you are constantly on the move. Riders don't ride the horses all the time but they are walking with them. A horse is an unusual animal in that after 4 hours of constant moving they will stop. It don't matter how fast or how overladen they were, they just need to rest. A few examples: * James Mowat - 350 km in 36 hours. Edit based on info from a Canadian site - Mowat did in fact change horses during his trip and it took him 3 days. (I assume it's because he started late on the first one and finished on third day) * Ashgabat – Moscow horse ride by Turkish horsemen in 1935 - 4128 km (of which around 900 were through a desert) in 84 days. Traveling at night, without lights (to not attract nasties) would require riders to walk beside horses. Maximum speed of 4 km/h. So I would say that 400 kilometres is a safe distance to assume. Maybe 600 if you don't want to keep the horses and can ride them to their death at the end. Horse distance trivia: Crusaders in Prussia built castles separated by a distance that a rider could travel in one day (from dawn till dusk). As you can see from this picture [Crusaders' castles in Prussia](https://pl.wikipedia.org/wiki/Zamek_krzy%C5%BCacki#/media/File:Ordensburgen_Ausschnitt.jpg) the distance was different depending on roads, geography and ease of travel (barbarians, big forests and so forth). [Answer] > > How far can you travel on horseback [...] > > > traveling as fast as they can > > > At full speed ([gallop](http://www.luckypony.com/articles/horse_long_gallop.htm)): about 2-3 km. Horse gallops at about 40 km/h so that would be about 5 minutes. Maximizing distance: about 50-60 km per day. 40km is the largest distance that separated [Pony Express](https://en.wikipedia.org/wiki/Pony_Express) stations. At the station the rider would change to a fresh horse. A single rider, weighting max 57kg with 9kg of mail, rode about 120 km per day - that's only relevant in showing that such figure is impossible with one horse instead of 5. Middle Ages horses were not as good, their saddles were not up to par and your riders are much heavier. Wikipedia says about Middle Ages horse riding that ["Small mounted companies might travel 30 miles (50km) a day."](https://en.wikipedia.org/wiki/Horses_in_the_Middle_Ages#Transportation) Both horses and men needs rest. Riding at night on dangerous plains is simply not practical, the best you can hope for is horse breaking a leg and leaving your stranded there. [Answer] <https://en.wikipedia.org/wiki/Endurance_riding> > > Endurance riding is an equestrian sport based on controlled long-distance races. It is one of the international competitions > recognized by the FEI. There are endurance rides worldwide. Endurance > rides can be any distance, though they are rarely over 160 km for a > one-day competition. > > > There are two main types of long-distance riding, competitive trail > riding and endurance rides. In an endurance ride, discussed in this > article, the winning horse is the first one to cross the finish line > while stopping periodically to pass a veterinary check that deems the > animal in good health and fit to continue. As with human marathon > running, many riders will participate to improve their horse's > personal best performance and consider finishing the distance with a > proper vet completion record to be a "win". > > > In the United States, most endurance rides are either 50 or 100 miles > (160 km) long. Shorter rides, called Limited Distance rides (LD), are > organized for new riders to the sport or young horses being trained. > However, LD's have evolved into a competition of their own, in which > more experienced riders and horses also participate. There are also > longer, usually multi-day, rides as well. In the USA, the American > Endurance Ride Conference (AERC) sanctions endurance rides. In the UK, > Endurance GB is the governing body. Winning riders can complete > 100-mile (160 km) rides in 14 to 15 hours.[1](https://en.wikipedia.org/wiki/Endurance_riding) > > > Any breed can compete, but the Arabian generally dominates the top > levels because of the breed's stamina and natural endurance abilities. > > > Readded as a quote. SO if 160km in 14 to 15 hours in race conditions I would say the horse wouldn't be able to be used that night and little the next day. So if you wanted to keep your horses I would say it would be around the 300km mark. If you didn't want to keep the horses then you could probably get this up to 450km but that would mean a hard ride at the end and your riders would arrive very tired. [Answer] I think the most relevant point is that your party's speed will be limited by the slowest members... it's all well and good how far a conditioned endurance horse might travel in a day, but let's talk about those pack animals. :D The inexperienced rider is one thing -- if she can stick to the horse well enough, she could probably keep up with a faster pace -- but the pack horses are quite another. How much weight are they carrying, and what kind of cargo? A fully laden pony carrying over 200 pounds is not going to be going anywhere in a real big hurry. And the kind of cargo matters, too. An animal with an unwieldy load, like fence posts or an artillery piece, won't be capable of moving faster than a walk. Even going up to a trot, that gait has a lot of up-and-down movement and bounce to it, which is very likely to unbalance or even completely unravel the load the horse is carrying; and then even if the load remained 100% secure, the pounding the horse's back and joints would take would sore him pretty quickly. With a lighter load, closer to 100 pounds, the pack animal is a lot more maneuverable, and if his cargo is properly hitched and not too bulky he might be able to keep up with a more brisk pace, but he's probably going to have an unhappy time with it. A stiff, dead weight is a lot more difficult and awkward to carry than a living rider, even an inexperienced rider like your healer. If your characters really want to get somewhere fast, I'd recommend they leave the pack animals behind. I'm sure there are some circumstances I don't know about from your question of why they have the pack animals (it's sensible in general for a group that large, if they're not staying at an inn or something every night), but for two days travel, assuming there's grazing available, I'd think they would be able to carry all they need with them on their saddle horses. Perhaps a member of the party can take a longer (and safer) alternate route with the pack animals and meet up with the main group again later, when matters are less urgent, or they could sell their pack animals at one end of the journey and buy new packers and supplies when they reach the other side of the perilous plain. But if the group is going exactly as you've laid it out, count on a walking pace of around 4mph. ]
[Question] [ I'm interested in the technical feasibility of a rifle that fires a lightning bolt. Typical lightning requires a large difference in electrical potential, and something that prevents equalizing this difference. In lightning storms the ground and clouds (in normal cloud-to-ground scenarios) the "polarities" of our difference in charge. The air itself insulates the exchange of electricity to balance out these charges. Lightning produces "leaders" prior to the actual flash of electrical discharge we see. Leaders are Channels of ionized air that effectively seek out shortest path (and produce the zig-zag pattern of the bolts). Wikipedia's article on Lightning tells us that normal negative lightning contains "carries an electric current of 30,000 amperes (30 kA), and transfers 15 coulombs of electric charge and 500 megajoules of energy" it also mentions that positive lightning is about 10 times this powerful. Questions the rifle needs to overcome: The rifle would have a difficult time producing an opposite charge in the target, as opposed to just holding a huge capacitive type charge. Will this matter? Would the rifle be able to use a short range "laser" that would produce a straight channel of ionized air to the target? Would this channel be sufficient to keep the lightning on track to hit the target instead of jumping to other nearby grounding sources? Given the absolute best capacitors/batteries/etc. can a rifle sized/weight object contain the energy of a negative bolt? Positive bolt? I'm assuming cost is no problem here but feel free to ball park a cost. Could this rifle switch between negative/positive bolts like the weapons in sci-fi movies (i.e. "set your lasers to stun")? [Answer] [The US has already done it.](http://www.popsci.com/technology/article/2012-06/armys-laser-guided-lightning-weapon-delivers-high-voltage-through-air) At the moment, the gun shoots lightning down a laser beam. Essentially, what it does is it uses a laser to carve an electromagnetic pathway through the air, so that the high voltage beam will use it. A very very very short pulse of laser that's high intensity will be shot, and that creates an electromagnetic field around itself so powerful that it rips out the electrons from the air, creating a pathway of plasma. Since plasma is a better medium than the air around it, the lightning travels through that instead. However, this is not a very feasible weapon. Not only is a ton of hardware required for it, the shelf life likely isn't very long. Compared to a normal gun, which has bullets that fire straight, easy maintenance and long shelf life, this gun is likely to melt itself after a while, and would be hard to maintain. I couldn't find the actual technical aspects of the US designed weapon (I doubt they'd release those to the public anyways), but I'll try to answer your requirements anyways. > > The rifle would have a difficult time producing an opposite charge in the target, as opposed to just holding a huge capacitive type charge. Will this matter? > > > It won't matter since you don't need to produce a charge in the target. You just provide a path. > > Would the rifle be able to use a short range "laser" that would produce a straight channel of ionized air to the target? > > > Yes. That's exactly how it's done. > > Would this channel be sufficient to keep the lightning on track to hit the target instead of jumping to other nearby grounding sources? > > > Yes. > > Given the absolute best capacitors/batteries/etc. can a rifle sized/weight object contain the energy of a negative bolt? Positive bolt? I'm assuming cost is no problem here but feel free to ball park a cost. > > > It's been done, so with enough hardware, yes, either the negative or positive, but I'm not sure which - I'm pretty sure lightning is just... lightning. Also, very very expensive. > > Could this rifle switch between negative/positive bolts like the weapons in sci-fi movies (i.e. "set your lasers to stun")? > > > Probably not. Lightning the way you described it will never be able to "stun" (Too much power involved) - you're always going to be in kill mode, regardless of negative/positive mode, so why bother swapping to a more expensive mode? It's been noted that this weapon is easily disrupted by insulation. To that, I point towards [Samuel's](https://worldbuilding.stackexchange.com/a/22358/6453) answer for a more effective version of the gun which provides it's own grounding path. [Answer] The basis for this technology already exists, it is called an Electrolaser and it works as follows: You fire a laser into the air, and take advantage of the fact that lasers diffuse in air by stripping electrons free of any atoms that they come into contact with. This creates a directed channel of free electrons, also known as Plasma, which is one of the best electrical conductors in existence. You then create a surge of electricity at one end of the plasma channel, which conducts down said channel like it was a live wire. Applied Energistics is the primary US contractor working on this technology, and they are currently working on designs for everything from portal denial (a stationary system that can remotely shock people trying to pass through a door) to a handheld variant. Another company working on the same sort of thing is HSV Technologies. The voltage requirements to replicate lightning with this system are well known, and are currently around $10^8$ to $10^9$ volts. Right now, this is a tremendous amount of power, but can be obtained by using step-up transformers to trade current for voltage. (Ideal 'stun gun' uses high voltage low amperage anyway) Seeing as lightning has a typical voltage of only $10^8$ volts, this is to be expected. However, you can dial back to only ten to twenty thousand volts if you are aiming it at a person with intent to stun, not kill. That's easy, we put that in hand-held stun guns all the time. The challenge remaining is not so much 'can we produce a strong enough voltage to drop someone.' Plasma is a reasonably good conductor with very low resistance. Much of the energy released into the beam will strike the target. The challenge is 'can we power a strong enough laser to create the plasma channel.' Again, the answer is 'yes.' The power of the laser would dictate the range it could fire before completely falling apart, but you could throw a strong enough laser for a 'pistol-range' shot pretty easily. You aren't trying to burn anyone with the laser, just ionize the air. It doesn't take too much to do that. To address a few of your other questions. There would be a small amount of scattering, but electricity prefers to follow the path of least resistance...and plasma is an awesome conductor. There is no such thing as 'positive' or 'negative' electricity. Electricity which is the movement of electrons, which only carry a negative charge. If you want something that behaves like electricity but has a positive charge, you need positrons. But then you are playing with antimatter, thus boom. If you want to vary the lethality of the bolt, adjust the voltage or amperage (an amperage between 100 and 200 mA will stop your heart). It's the same way you can taze someone to disable them, or electric-chair someone to kill them. A few notes of caution... Be careful using such a weapon during a storm, as the Plasma Channel created is very friendly to natural lightning, and may invite a bolt to jump down into the channel. Be careful using this weapon near high voltage power lines, the presence of such a strong conductor may cause power to arc out of the lines and jump into the plasma channel. Ensure the weapon is well insulated so that it cannot ground itself out through you, and must ground itself through the target. Ensure proper timing of the laser/electrical pulse, otherwise the beam may not have sufficiently ionized the air, and the surge of electricity will behave according to physics (and might jump back at the gunner). All that taken into consideration, here are a few other things an Electrolaser is capable of. Burning out electronics, including the ignition and alternator systems of an automobile. To control natural lightning strikes: there are designs out there for firing a high power laser through a thunderhead to 'aim' natural lightning strikes at targets. [Answer] You need to provide a grounding path. The other answers are on the right track. However, they're missing an important component. They rely on generating a path from the gun to the target and the return path through the ground. This is folly, because all the person needs to do is insulate themselves from the ground. The obvious answer and addition my answer brings to to create two plasma paths with the lightning gun. Call it the Double Tap. If you create two paths from the gun to the target you have effectively created a complete circuit with the target. You can now send variable currents up one path, through the target, and down the return path. You also have the option still to use both paths for sending current and using the ground as a return path or you can use one to the target and one as a return path aimed at the ground further away from you. > > The rifle would have a difficult time producing an opposite charge in > the target, as opposed to just holding a huge capacitive type charge. > Will this matter? > > > This doesn't matter. The target is simply a part of the complete circuit. You don't need to rely on them providing a charge. > > Would the rifle be able to use a short range "laser" that would > produce a straight channel of ionized air to the target? > > > This rifle would use two lasers to create a complete circuit with the target through the air. > > Would this channel be sufficient to keep the lightning on track to hit > the target instead of jumping to other nearby grounding sources? > > > No grounding source required! You provide the grounding path. > > Given the absolute best capacitors/batteries/etc. Can a rifle > sized/weight object contain the energy of a negative bolt? Positive > bolt? I'm assuming cost is no problem here but feel free to ball park > a cost. > > > You would use capacitors for this, but they can only contain the energy, you'll need to increase the voltage after it leaves the capacitors. There are no capacitors which can contain both the energy and the high voltage. This is because a very high voltage requires a significant amount of insulation between plates. You can fit more surface area inside a capacitor when it has much thinner plates (lower voltage). > > Could this rifle switch between negative/positive bolts like the > weapons in sci-fi movies (i.e. "set your lasers to stun")? > > > Yes, though there is no difference to the target. A positive bolt vs a negative bolt just describes the origin of the bolt from clouds to Earth and in this case the direction a charge flow through the target. It doesn't matter which direction a few amps goes through a person, it does the same damage. This particular gun, because it supplies the return path can therefore adjust the current through the gun and target from a lethal bolt to a stunning shock. ]
[Question] [ Would it be possible for a corporeal alien with a solid physical body (it must be able to touch and interact with the world) to exist but remain invisible to humans? My understanding of optics is that if a material doesn't absorb or reflect light in the visible range, it would be invisible to humans. Is this correct? If so, what sort of alien alien anatomy and biology would enable this? [Answer] In a science-based setting without using technology, the answer is "Probably Not" for alien beings that live in the air, and "Perhaps" for beings that live in water. Consider glass for a moment. It doesn't absorb or reflect much light in the visible range, yet as long as we can see an edge or a curved surface, then we can tell that it is there. Why? Because of refraction. Every transparent or translucent substance has a property called [Refractive Index](http://en.wikipedia.org/wiki/Refractive_index), which defines how much the boundary of substance refracts light. Where a transparent object is immersed in another transparent substance, such as air or water, the degree to which light is refracted depends on the difference between the refractive index of the object and the refractive index of the medium. As the refractive index of the object and medium approach one-another, the object becomes progressively harder to see, until the point where the refractive indexes match, at which point the object is effectively invisible (unless it has a different colour to the medium). The problem with having an invisible alien in air is that there are no known solid or liquid substances that have a refractive index as low as that of air, thus no matter how transparent the alien, you would be able to see its edges and the distortion of objects through its body. In water is another matter, It is conceivable that a colourless transparent alien may have a refractive index equal to that of water under certain conditions of temperature and pressure, so under these circumstances, the alien could conceivable be "invisible", or at the very least, very hard to see. However, varying the conditions would probably make the alien visible again unless it could also vary its own refractive index. There are some species of water-dwelling life that are transparent and difficult to see because of this, however their eyes and abdominal organs tend to be visible, somewhat spoiling the effect. So, Yes, an alien may be able to be "invisible" in water, but it is unlikely that it would be totally invisible. It probably wouldn't be able to photosynthesise, and given that it would probably have to eat to survive, it is also probable that its food would not be invisible, and therefore a gut-full of food would be a bit of a giveaway. [Answer] Since the creature is solid then just making it transparent is very hard, for the reasons already discussed. That leaves two options: Bending Light The creature could somehow bend light around itself, as is being experimented with in various labs around the world right now. We already have materials that are invisible to some frequencies, so it's theoretically possible to do the same with visible light. Active Camouflage This is not true invisibility as it has to present the same image to all observers but it would be effective at reasonable distance. You re-colour yourself dynamically to match your background. The chameleon does this but quite slowly, there are much faster and more dynamic examples though. For example check out this animal: ![Mimic Octopus (Credit: Wikipedia)](https://i.stack.imgur.com/igBJH.jpg) To see it in action watch this video: <https://www.youtube.com/watch?v=t-LTWFnGmeg> It's not "invisibility" but it can make itself look like a wide range of different other animals. [Answer] Not only would the material the aliens are made of have to be transparent (neither absorbing nor reflecting), it would have to have the same index of refraction as the medium they inhabit, with no internal variation. For a liquid medium, this seems implausible but not completely impossible. There are some transparent aquatic organisms on Earth which are fairly hard to see, but not outright invisible. They aren't perfectly match to the refractive index of water and the material that makes them "work" isn't quite perfectly clear. The size of the organism is also going to be a factor. The bigger something is, the more of it there is to bend, absorb, or scatter light and the more angular area it occupies at a given distance. For something like ordinary air, it's much harder. Density is a big factor in refraction, and liquids and solids are just much denser than air. The only way around this is with porous structures like aerogel, which has many internal surfaces to refract light (the solid parts of it are still much more dense than air and refract light each time it passes between that solid and the bubbles of gas or vacuum trapped within it) A different index of refraction while otherwise being transparent will result in a creature that looks like it's make of glass or pure water. [Answer] A short addition to the other Answers: ## If your life form is Invisible it cannot see itself in conventional ways. The Theoretically impossible Creature needs to have some psychic ability or senses that are not about "seeing". If you imagine your eyeballs and the iris / lens / retina is invisible how could it react to light? Also if it is temperature sensitive keep in mind that temperature is visible in some other kind´s of light spectrum, this would also make a reaction with light. And to a good end. If your creature has mass, it reacts with light. So to make it Invisible you just have do eliminate the mass. Don't know if the mass of a creature is big enough to bend light but i can imagine it is enough. EDIT: ok the i checked the Last paragraph. I found [This](http://van.physics.illinois.edu/qa/listing.php?id=25475) on the Internet. > > The mass of the sun is enormous but the measured angular deviation was only about 1.5 arc seconds, 0.0004 degree. > > > So the light bending by Mass of a creature is not really measurable. [Answer] It looks like everyone else has used the usual definition of "see" - using reflected light to visually locate an object. There are many other ways that animals "see" the world around them, though: bats and dolphins, for instance, use echolocation; snakes have a type of heat-vision; spiders use tiny vibrations in the earth (or their web); many predators use their sense of smell to locate prey. Visually, to become truly invisible (that is, unable to be seen in front of a variety of backgrounds, even when moving), a creature would need to bend light around itself. Even then, any distortion from refraction or absorption of light would cause shadows or edges that could be easy to detect. Furthermore, if an animal is truly invisible, then no light can reach its eyes; it would be permanently blind. Some sea creatures manage to be nearly invisible in water, but even then, their eyes and some organs are visible. However, there are many other ways to become invisible. Sonar or echolocation use bursts of reflected sound to locate objects. There are two ways to appear invisible in that situation: absorb the sound waves, or cancel out the sound waves. Specially-engineered foam can absorb nearly 100% of sound, from almost any angle; that would provide passive invisibility. Active sound-canceling headphones record ambient sounds and play inverse waves to cancel them out. While sound absorption can (and is) used in nature, sound cancellation is much more complex, and unlikely to be used. However, neither of these would provide true invisibility; an echo against a wall will show an obvious "hole" where you have absorbed or canceled the sound. It may be enough to confuse some predators, but it wouldn't be true invisibility. For a snake's heat-vision, you must be the same temperature as your surroundings; in warm weather, cold-blooded animals can approach ambient temperature. Warm-blooded creatures can mask a heat signature by sweating, or exterior cooling methods like submerging themselves in a cool liquid. The key is to match the ambient temperature exactly - even the smallest temperature difference is enough to break invisibility. Being invisible to a spider's vibration-sense is much more difficult. Flying above the ground will cause drafts of air to make the ground move; even the beating heart of a tiny mammal provides enough vibration for a spider to pick up on it. Snails and slugs move very slowly, using fluid movements and minimizing impacts, and are probably best equipped to avoid vibration-sense. Even if a creature managed to be truly invisible to light, they may still be completely visible through sound, smell, heat, or vibration, which means predators will simply use alternate means to hunt them. Invisibility is hard - but there are a lot of shortcuts. Instead of invisibility, most creatures rely on passive or active camouflage, or by "jamming the signal": squid squirt jets of ink to muddy the water, [Bertholdia Trigona](http://en.wikipedia.org/wiki/Bertholdia_trigona) actively jam bat's echolocation, and many creatures mask their scent by rolling in dirt or all manner of other things. When it comes down to it, camouflage is a lot easier than true invisibility. [Answer] I would like to add another option to circumvent the problems depicted in the other answers: ### The creature is not compact For starters, think of thin cobwebs. They certainly match your definition of solid, as they are able to interact with the human world, but they are very difficult to see from most angles (which I can imagine to be important to their success). The reason is that the amount of light refracted or blocked per area is often below our threshold of perception. All you have to do to achieve de-facto invisibility is take this approach to extremes with a creature that consists of sufficiently thin wires. Of course, this creature needs to be rather large in general, if it shall plausibly be able to do certain things. Also you need sufficiently strong components for it to not collapse under its own weight, but the [cube–square law](http://en.wikipedia.org/wiki/Square-cube_law) is in favour of this and let’s not forget about nanotubes. Another similar approach would be a [colonial organism](http://en.wikipedia.org/wiki/Colonial_organism), i.e., the creature is plainly not contiguous but consists of many very small components – think of an ant colony as a single organism. [Answer] ## Truly invisible NO, but... But your creature could be nearly there if covered in lenticular lenses. It is a neat optical trick and perhaps will be enough to suit your needs. [![enter image description here](https://i.stack.imgur.com/1E75o.png)](https://i.stack.imgur.com/1E75o.png) See this article: <https://hackaday.com/2021/01/25/lenticular-lens-makes-things-invisible/> ]
[Question] [ In various fantasy stories I have read and seen there is a trope known as [Eye Colour Change](http://tvtropes.org/pmwiki/pmwiki.php/Main/EyeColourChange) Warning: TV Tropes!. In many cases the person or creature's eyes change color as a sign that they are activating their super powers. What I am curious about is: Could a creature have eyes that rapidly change color based on their mood? For example a character gets mad and their eyes turn red. [Answer] ## You are designing the creature, so yes There is a [skeptics SE question](https://skeptics.stackexchange.com/questions/6766/can-mental-state-affect-eye-color) on this subject, relating to humans. This seems to support the claim that mental state can have some difference on an eye colour - mostly through anecdotal 'evidence' though. It doesn't necessarily mean human eyes can have rapid drastic changes though (blue to red instantly, for example, would require a very fast change in the amount of melanin and may not be healthy). You could, however, have a different structure to your creatures entirely. Perhaps the chemicals that drive emotions, once in the blood stream, refract light differently and make the colours. Perhaps your creatures have various protective filters on their eyes - under stress a creature on a desert planet may have an automatic dust filter which comes down and this scatters or reflects red light more - making the eyes appear red. There are many methods you could apply. Your question only asks for if they could, not how they would though so I won't go into that too much here. Edit to add the how: There are lots of ways to do this: * Moisture traps: This idea comes from the Charidotella egregia which traps water between different layers of thin reflective surfaces [as described in this paper](https://www.researchgate.net/publication/5915487_Switchable_reflector_in_the_Panamanian_tortoise_beetle_Charidotella_egregia_Chrysomelidae_Cassidinae) (even if only the abstract is available it describes this process fairly simply). The moisture changes the distance between these reflective films and, by varying the amount of moisture, the distance between reflective films can be controlled. + I like this method because it gives fine control over colour change and can be related to something more human - crying. Interestingly we have [different types of tears](http://www.independent.co.uk/life-style/health-and-families/features/why-do-we-cry-the-science-of-tears-9741287.html) I would imagine the salinity of your creatures tears could effect how easily the porous layers of film absorb and, therefore, produce different colours. + This is a very fast acting method. + This also requires little effort (no producing complicated dyes or such that this may be an evolutionary disadvantage). * Colour cells: Cuttlefish are, I've been finding out, rather amazing [colour changers](http://news.nationalgeographic.com/news/2008/08/080608-cuttlefish-camouflage-missions_2.html). Here is a quote from that article: > > Cuttlefish skin has been likened to a color television—it has a way of combining basic colors to form more complex hues and dynamic patterns. "It really is electric skin," Hanlon said, because it's all controlled by neurons in the brain that transmit impulses and information to the rest of the body. > "A cuttlefish has maybe ten million little color cells in its skin, and each one of them is controlled by a neuron. If you turn some on, but leave others switched off, you can create patterns," Hanlon explained. > > > + This method is brilliant colour control, fast acting and we can link it into the brain fairly easily since it is controlled by electrical impulses. It would require having these colour cells in the iris (perhaps as a method to better see in different lights). These could be related to emotion in many different ways but a few that occurred to me: + When sad humans often look down where we receive fewer distractions as we look inside ourselves. This could be substituted by a darker pigment blocking out more light. + [Anger in humans can cause dilated pupils](http://www.coolhealthtips.com/dilated-pupil-definition-symptoms-causes-and-treatment.html), perhaps to take in more light. In our creatures they could do this by changing to lighter irises, revealing the crisscross of blood-vessels behind the eye and creating a red eye look (as with albinos). Those last couple of points could apply to either technique or any of those other answers have mentioned. [Answer] Some Chameleons change the colour of their skin to reflect their mood. For example: Darker colours mean that the chameleon is angry whilst lighter colours may be used to attract mates. They have a specialised layer of cells to allow them to do this so there is no reason why a creature couldn't have a layer of cells over their eyes to allow them to do the same thing. [Answer] Yes. There are many animals on Earth that can and do change color (though not eye color specifically, I think). It wouldn't be a stretch at all to extend this to eyes (and/or patches around the eyes, maybe, to enhance the idea). The interesting thing would be to explain how and why this change happens. (I'm assuming, since this is Worldbuilding, that you're thinking of building a world with creatures like these yourself.) * Is it universal? Do some members of the species not change eye color, or change to different colors than most others? * Is it voluntary? Can they cheat? Can an individual force itself to change eye color even though it doesn't feel the associated emotion, or to suppress the change even though the emotion is present? * Is it used for other purposes besides showing emotion? Artistically, erotically? * Can it be suppressed or damaged permanently by accidents, surgery, etc.? * How did it evolve? Was it a useful trait to signal emotion in a social species? Was it a form of mating display? Was it a (maybe undesirable) side consequence of another biological process? The detailed mechanism need not be explained, but as I seem to remember, in general there are ways for color to appear in a living organism: * Structures can be colored by pigments inside cells (and [these cells](https://en.wikipedia.org/wiki/Chromatophore) can expand or contract to spread or mute a given color). * Structures can contain reflective surfaces that appear to change color as they face light at different angles ([iridescence](https://en.wikipedia.org/wiki/Iridescence)). Either of these could very well work inside eyes, though vision can be impaired if the coloring structures stand between the retina and the incoming light, of course. [Answer] Yes. You don't even have to look that hard to find examples. Personally my eyes shift from brown to green based on my blood pressure/stress level. My optometrist finds it to be fascinating, apparently it's not that common, but I share the trait with a few family members. My mother's eyes, for example, manage to throw a blue-grey color into the mix. Changing eye color isn't any more unbelievable in a story than changing skin color and there are lots of creatures that can do the latter. [Answer] [Heterochromia iridum](https://en.wikipedia.org/wiki/Heterochromia_iridum) which is where one eye colour is different from the other can be acquired after birth due to injury or sickness. The colour change can be caused by deposits in the eye such as iron from an injury or sickness So you could use a similar mechanism to change eye colour due to mood without it sounding far-fetched. [Answer] Is it something that happens in the real world? No, but many people think it does because they are translating "my eye appear to be a different color" to "my eyes are a different color". Those things may seem alike, but they're different. The basics of how it happens that when we're in this or that mood we hold our head in different ways and it can effect things like how blood shot our eyes are or the direction of light/shadow hitting our eyes. The result is that that Eyes can appear to change color, because of the colors around them. Is it something that could be possible? Yes indeedy it can be done. How? Basically the same way pupils can dilate. Just have a similar thing that comes over the pupil (in the standard 3 colors) that developed to be able to modify what light goes in the eye so that some things will stand out more or less because certain wave patterns will be blocked out. It would be a rather useful trait for a predator on Earth... but I don't know how the prey would evolve to counter it. You could say that it is controllable in wild animals, but in the humanoid animals you could say that they lost the ability to actively control it resulting in the various lenses closing/opening when they are focused, in a rage, etc. [Answer] To add another possibility: Many animals have a ["third eyelid"](https://en.m.wikipedia.org/wiki/Nictitating_membrane). Perhaps this creature has one which carries some color, and in some moods holds it closed. You could even speculate that the filtering or protection might be functional to justify this behavior. [Answer] In terms of creating a creature, I'd say you likely can. However, going through examples in our world (aka the more boring side of the spectrum), I'd suggest instead to have either special rings or patterns around the eyes, since eyes are very delicate and specialized organs, while the skin would likely be a better point to change, or at least easier to do so. The trait could've appeared as a way to scare predators (tigers have "fake eyes" on the back of their heads, so I think it's plausible) and ended up as something linked solely to the individual's subconscious, directly connected to the parts of the brain responsible for emotions and mood. Such patterns/rings/regions would be rich in chromatophores and, being linked to the subconscious, would change color similarly to how chameleons change their skin according to mood. Also, one could be born with a mutation that allowed them to control these regions to an extent (just like how some people can flap their ears). ]
[Question] [ How plausible would buildings made inside of, or made using, giant mushrooms be?[![A series of giant nail-like mushroom towers stand on the top of a moutain with doors, windows and balconies carved into the mushrooms](https://i.stack.imgur.com/KTcia.jpg)](https://i.stack.imgur.com/KTcia.jpg) Copyright [Raphael Lacoste](https://www.deviantart.com/raphael-lacoste) 2018 A staple of the fantasy genre, mushrooms have commonly been seen as magical and unusual. Often we see houses and structures made inside of these mushrooms by magical or nature-loving individuals, but how possible would this be? If we assume that they could grow (either through magical or natural means) could you make a house inside of, or using, the giant mushrooms? To qualify as a house, it needs to be someone’s permanent place of residence and contain at least one room. Assume that the structure is meant to be inhabited by a human. Edit: As several answers pointed out, mushrooms may be too soft to be suitable as housing. To counter this, i will clarify that when i used the term ‘mushroom’ i meant any fungal or fungal-like organic. Plants that are naturally visually similar to a fugus may also be acceptable answers. [Answer] Prototaxites! Fossil mushrooms are rarities. Mushrooms are the fungal equivalent of flowers - spongy, ephemeral, disposable bodies generated to serve a reproductive need. You could not use mushrooms for wood. The prototaxites were not mushrooms. They were large and substantial; up to 7 meters high. [![prototaxite fossil](https://i.stack.imgur.com/HNn0N.jpg)](https://i.stack.imgur.com/HNn0N.jpg) <https://www.smithsonianmag.com/smart-news/long-before-trees-overtook-the-land-earth-was-covered-by-giant-mushrooms-13709647/> They were not temporary structures like mushrooms, but perennial like trees. I deduce this from the presence of growth rings in the fossil prototaxites. [![growth rings in fossil prototaxite](https://i.stack.imgur.com/kSaIi.jpg)](https://i.stack.imgur.com/kSaIi.jpg) <https://www.researchgate.net/figure/Transversely-sectioned-Prototaxites-fossil-This-overview-image-originating-from-a_fig1_51174561> The presence of rings means this structure endured shifts in growing conditions over time. This thing was there for many seasons. On earth, that means it weathered storms and wind: no small feat for an upright thing this size. There is an analogous modern fungus: the [bracket fungus](http://www2.palomar.edu/users/warmstrong/bracfung.htm) aka "shelf fungus". [![shelf fungus](https://i.stack.imgur.com/CTPPJ.jpg)](https://i.stack.imgur.com/CTPPJ.jpg) The shelf is also a spore-making body but a permanent one, and it also can persist many seasons, laying down growth rings with the seasons. Bracket fungi are as tough as wood. <https://herbarium.usu.edu/fun-with-fungi/shelf-fungi> > > Woody shelves may be several years old. They add a new layer of spore > tissue every growing season. The old layer is covered by the new one. > These layers look like growth rings in a tree. One author reported > counting 37 rings. Ten layers may mean the shelf is 10 years-old if > there is only one growing season (spring). If there are two growing > seasons per year (spring and fall), it may only be 5 years-old. > > > One of the largest shelves weighs 300 pounds… > > > Woody shelves are impossible to break with your hands and difficult to > cut. This toughness results from the kinds of hyphae (filaments) that > are used to construct the shelf. Easily crushed mushrooms are made of > thin-walled hyphae. Some of the hyphae in woody shelves are > thick-walled and the hyphae are interwoven making them tougher. They > resist tearing or splitting because there are no planes to split along > in the tissue. > > > A bracket fungus large enough could be used for wood. The medium to small ones are used to make real shelves and durable beads. It is reasonable to assume the prototaxites were of a composition similar to modern bracket fungi and so suitable for use as a wood equivalent. A redwood-sized Prototaxite could be hollowed out and used as a dwelling. [Answer] [Buildings made out of mushrooms](https://www.bbc.com/news/magazine-28712940) already exist, so I would say that the plausibility is very high. The vegetative part of the fungus, called mycelium, can be fashioned into to "bricks" by growing them in brick shaped molds and adding in some corn husks. Using these "bricks" a builder can construct many different types of buildings. [Answer] The thing about mushrooms is that they grow on decay; on dead wood, plant matter and organic waste. They require either the fuel of other plants, or the symbiosis with them. In the latter case, there would either have to be millennia of cultivation and harmony between the humans and mushrooms, allowing for enough food to be provided to the mushrooms to allow for them to grow and be relatively stable. Or, trees that are large enough to support mushroom tree-houses. So to try and answer your question, I think growing house sized mushrooms is out of the question, especially with regards to their decay cycles and relative softness. However, mushroom mattresses growing on trees could be a nice substitute. [Answer] It doesn't have to be mushrooms, but it can be one. Prototaxites have just been mentioned. One would go further and propose a giant prototaxite species which survived to this day. Another option is a plant akin the [Myrmecodia (ant-plant)](https://en.wikipedia.org/wiki/Myrmecodia) which swells its trunk to accommodate the ants which inhabit it. The giant plant may have a trunk wide enough to harbor large cavities. Some cavities may be merged into larger "rooms" by carving-out some of the wooden material and leave walls strong enough to support the "house". Some of the material is left to make the inner walls and stairs. [Answer] If we look at the example of houses built from within trees as a baseline, it's certainly possible in terms of space. Now, of course mushrooms are softer and more compressible than trees are, so we'd have to assume it'd take time to compact before being ready to move in furniture and the floors would need to be thicker to keep from ripping, but given sufficient size requirements are met, that shouldn't be an issue, especially if you only need one room. The biggest problem is the Spores though. If you have a large mushroom, when it distributes its spores, they will go EVERYWHERE. Improper hygiene (even if it's just cleaning with water that happened to get contaminated by the spores) is a sure way to break out in an all-over fungal infection. The areas all around your home would be flush with mushrooms. If the mushrooms are edible, it'd be an excellent food source to look into, but the mushroom spores and reproductive process introduce too great of a risk to truly feel safe and comfortable unless you have some industrial fungicide on-hand. [![Tree House](https://i.stack.imgur.com/YVpWG.jpg)](https://i.stack.imgur.com/YVpWG.jpg) ]
[Question] [ Let's pretend for a moment that, right now, everybody on Earth was given the ability of flight. What new legislation would have to be passed to regulate this ability? Physical restrictions on the ability of flight: * Maximum altitude is based on existing human limits (no more than 26,000 feet / 8,000 meters) * Maximum air time is around 30 minutes * Maximum speed is around 30 mph / 48 kmh * Maximum distance is around 15 miles * Roughly the same amount of physical exertion as running at a brisk pace [Answer] Laws, rules and regulations vary country by country according to the needs of the people or whims of the rulers. Hence no hard and fast legislation can be mentioned to have been imposed by all the countries. However, a general sketch would be something like this: * In several Western countries, it would be illegal to fly above the airspace of other people's homes. I'm mentioning Western countries for this only because individual rights (in general, with several exceptions) are included in legislation in Western countries. * Military installments would be fitted with computer-controlled guns to shoot down any and all personnel flight in their airspace without a digital identity. * It would be illegal in almost all countries to fly with a weapon. Flying with handguns would result in least punishment while caught flying with a sniper rifle might end up with maximum punishment. * Flying within a radius of 1 km around airports would be a crime and punished heavily. * There might be a speed regulation for intra-city flights (in order to minimize in-flight accidents). * Only paramedics, firemen and policemen would be allowed to fly above certain roads and commute routes. * It would be illegal to fly within a building in most government offices and military bases. # Edit To Add Explanation On Point 2 It appears that the idea of military bases having automated guns has led to some controversy here. First, I should mention that this setup (where guns are programmed to immediately shoot any intruder) would/can be implemented if a few preliminary actions are taken. 1. Military bases are located outside the reach of human flight distance from all cities. That is, all military bases are located more than 15 miles from all cities. It is beyond the reach of all curious children. If you are on a road trip and you allow your children to take flight from an unknown location to an unknown destination, you are clearly a careless parent. 2. Warnings are issued to any unknown approaching flying person to stop and land. If the person repetitively ignores these warnings, they would be shot. 3. Lethal force is not used. Instead, rubber bullets are used to incapacitate the intruder and force him/her to land. The last thing about it is that collective interest is usually more important than individual interest. If you use emotional argument of "No, you can't program your guns to shoot at my kids", you are neglecting that people already have the right to shoot trespassers in their properties. Why should the military not have this right? Furthermore, you are also shielding terrorists, enemy spies/assassins and criminals from being shot. Not shooting at unknown intruders and building passive defenses might save your child's life, but it will result in the loss of 30 or more soldiers. [Answer] Disabled people Other answers mentioned restrictions on flying indoors and in government buildings but I don't think that's going to fly in almost any western country. Most western countries have pretty strong regulations on discrimination against disabled people. Suddenly being able to fly is going to be a massive boon for a big chunk of the disabled population. Elderly people without the strength to walk might not be able to fly far or fast but they can probably float enough to grant them a hell of a lot of extra mobility even if it's only for a few minutes at a time. If flying inside a government building was banned the state would immediately (rightly) get slapped with dozens of discrimination lawsuits. They could change the rules allowing only disabled people to fly but if it's an ability everyone has I'm imagining that would be unlikely. Far more likely they'll simply introduce height and/or speed limits for flight inside buildings. Toddlers Toddlers are going to be in mortal peril in this world since they can wander hundreds of meters up before falling. There's probably going to be a lot of new laws effectively requiring that all children under a certain age be kept on leashes if the parents want to avoid negligence charges. Building regulations It's likely that people are going to start building far more highrise properties where the main mode of entry is simply flying up to the side of the building and entering(perhaps with one slow heavy goods evelvator). After some less-fit people fall to their deaths when trying to enter a door with no ledge there's going to be a lot of new rules added requiring that buildings have ledges so many meters apart and nets or platforms bellow any primary entrances to catch people who fall while trying to open doors. Employee safety regulations A lot of high-altitude jobs are going to suddenly become dramatically safer. If you fall off while doing this: <https://www.youtube.com/watch?v=yDa6nM0o5JU> It's suddenly not a big deal. Many OSHA rules about safety lines can be quickly repealed but with the time limits on flight there's also going to have to be new safety laws making it clear that employers cannot require employees to hover more than a few feet up for more than a very short period of time. Wildlife Suddenly a lot more wildlife will be getting disturbed by humans. Birds nests up in high trees are no longer an arduous climb away, they're a few seconds flight. Hunting will also be easier when humans can suddenly drop nets from the air. This is likely to lead to some stricter wildlife protection rules related to disturbing wild animals from the air. [Answer] So, there are already laws in place that would likely be applicable, plus some new ones we are going to need. Humans would most likely be restricted to Class G and Class E (lower-tier) Airspace...This is, essentially, all airspace below 18,000 feet that is not close to an airport or otherwise restricted airspace. This is the areas in which things are permitted to fly without regulation by the FAA (this may be changing in the future with regards to drones). This is where hot air balloons, hobbyist helicopters, and most civilian drones stay. It is possible that they may be restricted to MUCH lower in the name of safety. As implied by the first point, humans would face No-Fly-Zone restrictions in certain places. Near airports, for sure...because getting hit by an airliner could not only kill the flier, but damage the aircraft enough to cause it to crash. Other places would include government facilities and military bases. there may be a special exception allowed for low-altitude human flight in some No-Fly-Zones, such as allowing flight in New York City, despite the presence of a very large airport-based chunk of restricted airspace. The exact altitude permissions would be determined based on numerous factors...but at the simplest, just keep people below the level of the tops of buildings. We would need to step up the pace at which we figure out how 'high' private property extends. This is already being debated in some ways in regards to drones. In essence, they need to figure out how high humans would have to fly in order to not be trespassing on privately owned property. (An example of where this came up was a case where a homeowner shot down a drone that was hovering over his property...purportedly 'snooping' on his sunbathing daughters) Once that was figured out, they'd need to work out new rules for posting No Trespassing signage. The current rules (with variation by state) mandate that signs be posted all along the perimeter of the property at eye level, and spaced no more than 500 feet apart. Once we have to consider people approaching from the sky, those rules will need to be revised. Aerial Traffic Laws may need to be implemented on a city-level to prevent collisions. It's one thing when two people collide while walking at 3mph...it's quite another when they collide at 35mph. The exact specifics of these would need to be messed with to find a 'good solution,' but would be created on the same justification that ruled that pedestrians need to stay on the sidewalk or in crosswalks. These rules would be less important in suburban and rural areas where fliers are not dense enough to really have to worry about collision Medical Insurance Laws may need some updating in order to properly manage assignation of fault in event of an aerial collision or in event of being struck by a dropped object. Flight within structures may be restricted due to close quarters and the risks of a high-speed collision. Or, at least, businesses would be given permission to determine this for themselves. Laws regarding carrying weapons while in flight may be addressed in some countries, but others may stick to their current rules regarding transport and usage of a weapon. [Answer] It would quickly become illegal to not bury power lines. Laws regarding drones would be forgotten as people simply pluck offending drones from the sky. Civil aviation undergoes a huge transformation as people realize it's cool to thumb a ride at 10,000 feet. Cessna pooling becomes a thing. Soon laws crop up trying to stop it from being a thing. People get around the laws, claiming they're only going sky diving. Just in reverse. Whole new kinds of ultra light aircraft are developed to exploit the fact that dropping people at altitude is no longer a death sentence. A few people die anyway. So laws are created to reflect the new realities of air safety. I start building something that looks suspiciously like a human cannon ball cannon in my backyard. New laws regarding fraud are considered but rejected when someone starts selling hover boards that are just skateboards with foot straps and no wheels. [Answer] It depends what you mean by "maximum airtime" and "maximum speed". Is 30 minutes at 30 mph something that the average person can do, or is that something for top athletes? Today, some top athletes can run at maybe 13 miles per hour for 30 minutes. The average person doesn't get near that. The average person can't do a "brisk run" for 5 minutes. If many people could fly at a mile per two minutes for a few minutes, in normal street clothing and perhaps with a little back pack, that would make commuting into London for example a lot easier. A huge part of the city is within 3 miles of a major train station. If I could fly 3 miles in 6 minutes, I could go from the nearest train station straight to work. If I couldn't but many physically fitter people could (maybe 1/3rd of all commuters), that would take a lot of pressure off public transport. I'm not sure what to think about the proposed 8,000 meters maximum height. If I can fly 15 miles in 30 minutes, there is no way I could reach a height of 8,000 meters. I would assume that the laws of physics still apply and I can't fly upwards quicker than I can walk up the stairs. One horse power is defined as the power that you need to lift 75 kg up one meter in one second. Another thing that needs clarification is the required area for takeoff and landing. How much clear space do I need to start or land safely? [Answer] The Talking Heads will launch a comeback tour, opening each performance with "And She was". The Airborne Civil Liberties Union will successfully appeal to natural law and claim flight to be an inalienable human right. Widespread civil disobedience will make all attempts at legislation futile - except limits during hunting season, because of the NRA. [Answer] If humans could fly - 99% of the time it would be illegal, only in "fly" zones, here's why: 1. You could easily get to many places you cant now, so could illegally cross borders. AA gun galore. 2. Mid flight collisions in cities would wreck havoc! 3. Imagine if terrorists could fly - they could be able to hit so many more targets, no planes needed. [Answer] # Laws In the US we would have the National Flight Legislations or NFL for short, the NFL would create flight laws for humans without violating the 11th Amendment in the original Bill of Rights: *"The right of the people to fly shall not be infringed", so the work done by NFL would be to "regulate"* Infringe the flight right, constituted by ten simple laws: 1. None is allowed to fly over buildings unless one has a justifiable reason. 2. One shall not fly within flight free zones defined by local laws 3. One shall not fly one mile away or less from airports 4. One flying a mile or less from a military building can be considered a threat and shot down 5. While flying, one shall not carry any kind of firearm or explosive material 6. One shall not fly under the influence of drugs that alter one's ability to fly 7. One can fly carrying objects which weight does not exceed five pounds 8. Objects carried during flight should be carried inside a sealed container and attached to one's body 9. The limit speed one can fly is twenty miles per hour 10. The maximum altitude one can fly is five thousand feet The infringement of the laws above shall result in lawful penalty defined by the local laws # Just a few bad things... Just imagine how many violent people we have right now, now add "wings" to those same violent people, it would be a total chaos, a lot of people could pass out and freefall to their death, terrorists would hit buildings just like birds with C4 strapped to them, airstrikes wouldn't be as effective against personnel, so the military would bomb places at night to cause maximum damage, killing disabled people who can't fly and women and children who can't move as fast as fit men. A lot o people would be hit by lightning strikes if flying when raining. The plane that bombed Hiroshima and Nagasaki would have been a freshman from San Francisco with a smaller nuke. Wars in general would still be almost the same, because humans can't fly so high and could be shot down, but I don't know, the soldiers could wear some bird camo so they could sneak into the enemy's aerospace and drop bombs/grenades. We could be robbed anywhere, every police pursuit would most likely cause death, because tackling a flying object with another flying object is not that smooth. # But... We would move from place to place in a cool way, no ladders, some stairs, fewer cars, less traffic, a lot of people would try to do the "deed" in the air, no bird poop. We would most likely be attracted to people with better wings because of natural selection, people would take dumps over buildings and houses, no bicycles because it's lame. # Sentences that would be widely used "Dude, check that chick's ;) wings, so feathery" "Don't be such a chicken" "Look at him, he's a penguin, hahahah" "Fly me Bruh, fly me now, come on bruh!" "Man, don't clip my wings" "OMG, staaahp plucking me, mooom!" "I believe I can fly!" [Answer] Other answers have covered most things, but not clothing. For instance, barely anyone would wear a dress without pants, leggings, shorts, etc. underneath. For the flight restriction laws: likely there'd be a limit set on how close to private property you can fly, such as making it the height equivalent to the weigth and length of the property. And there would be extra weather warnings for weather in which it's unsafe to fly, such as wind, rain, thunder/lightning, etc. [Answer] I am surprised no one thought of much simpler things : 1. Its illegal to spit, vomit, urinate, defecate etc, while flying. 2. Its illegal to throw cigar butts, and lighten matches while flying. 3. No flying while drunk. 4. Etc. ]
[Question] [ Various futuristic novels and movies have posited the existence of the mega-city; a city in the clouds built up hundreds if not thousands of meters above the surface area below. Examples are Coruscant from Star Wars or New York City from The Fifth Element. [![enter image description here](https://i.stack.imgur.com/X7VJX.jpg)](https://i.stack.imgur.com/X7VJX.jpg) When your city is miles high, how do you get running water? Where does the sewage go? ### Considerations * Assume that replicators don't exist. [Answer] ## Sewers still work the way they always did The DWV (drain-waste-vent) system in a high-rise building is actually quite similar to that found in a house -- it's simply bigger! The principles (gravity flow, mostly) that make a building's DWV system work scale quite beautifully with the size of the building. As to the sewers under the streets, you'll have separated sewers for sure in a city like this -- you simply have too much sanitary flow to afford spilling raw sewage due to rain-induced sewer overflow events. Your buildings will have roof drain systems that simply tie into downpipes to the storm drain system, while their DWV system ties into the sanitary sewers. Both of these systems will be underground rivers, basically -- at its most extreme, you get a "river atop a river" effect, with the storm drain system built atop the sanitary sewer system, and your streets built over the storm drains, with utility ducts/tunnels flanking them for other utilities. ## Pump up the pressure to get water to go where you want In order to get water to the tops of such high buildings, high-performance pumps are mandatory, both for fire suppression and domestic service. These superbuildings will have redundant fire pumps (due to the criticality of the service involved) feeding combination wet head sprinkler/wet standpipe systems (there is no other way to control a fire in an Earth-sized high-rise, never mind a Coruscant-sized one -- One Meridian Plaza and First Interstate Bank taught us that already), in addition to a pump dedicated to providing enough domestic water pressure to reach the top of the building. Pressure-reducing valves will be needed on each floor to prevent the high standpipe/vertical main pressures from reaching fixtures and damaging them, while the pumps themselves will need to achieve pressures likely into the thousands of PSI (such pressures are more typical for motive hydraulics than water service), and you will need break tanks every so often to keep the pump pressures from becoming totally unreasonable. A good break tank setup would pump up to the tank and then gravity feed down, by the way -- this way, redundant pumps can be used easily, and even if all the pumps fail, a limited supply of water will be available. ## Evening out hot and cold The square-cube law works in our favor here -- enlarging a building is beneficial from a thermal performance standpoint as the marginal heat loss goes down as you further increase size. However, the heating and cooling loads are going to be high, still. A high-performance, lightly glazed envelope (vs. the glazing-everywhere postmodern high-rise aesthetic) is going to be a necessity in these superbuildings, and they will likely be forced to rely on distributed ventilation in order to allow the structural design to prevent stack effects by placing air barriers between floors, with either mechanical floors feeding transfer media (steam, water, refrigerant) to air handlers in each compartment, or complete HVAC on a per-compartment basis. Domestic water heating will be handled the same way -- either by indirect tanks off the HVAC heat loops, or by per-compartment hot water heaters. ## Big power means big problems Last but not least, we have the electrical and communications infrastructure needed in such a megabuilding -- a set of medium voltage "trunks" with accompanying fiber optics will be run in heavily firestopped vertical shafts in the building core along with the other building services, with dry-type transformers on each floor to provide low voltages for lighting, receptacles, and appliances. Said transformers will likely be tied together in what's called a secondary network to bolster the reliability of the electrical service, while the fiber optics will feed distribution nodes on each floor (similar to a cable-TV hybrid fiber coaxial node, or a passive optical network splitter for that matter, with primary voice service being provided via some type of Voice over IP setup). Redundant trunking will be provided for both power and communications in order to prevent a single failure from knocking out power or voice/data services to the whole building, while secondary systems may also be present for power (such as a low voltage auxiliary communications power system to play the role of the 48V central office batteries in a POTS system) and communications (a firefighter's telephone system will be needed as handheld radios are no good for a fire crew working in a highrise). In addition, key services (fire/life safety) will have their own backups for power and the likes (including dedicated generators or engine drives). ## Oh. Egress. All of this discussion ignores one utility that is necessary for every high-rise, though, and that's egress. Your superbuildings will need a high-capacity, high-performance egress system in order to get people out safely in case a fire, chemical release, or other emergency makes part of the building untenable. While total evacuation isn't generally required in high-rises thanks to modern sprinklering and fire-resistive construction, egress in a Coruscant-sized building becomes much more challenging. In addition to the pressurized, smokeproof tower stairshafts used in today's high-rise design, such a megabuilding will likely need to use smoke-protected occupant evacuation elevators in order to get people out from a "safe" floor one or two floors away from the emergency situation to a designated point of refuge or further exit means, as well as using any skybridges present as horizontal exits so that evacuees can seek refuge in neighboring buildings. Exit capacity will be another issue as well. Occupant evacuation elevators, while providing accessibility and a degree of speed over long vertical distances, struggle with moving large crowds in a smoothly flowing fashion. Stairs provide high capacity and smooth flow at the cost of space and physical fitness requirements; even then, though, you will likely need more than a typical high-rise core's set of stairwells to provide for full capacity egress, especially if high-density occupancies such as assembly halls are present on upper floors. What are called scissor stairs can provide a useful boost to capacity per unit volume of space, although they have the downside that whatever renders one uninhabitable will likely render the other stair in the scissor-stairs uninhabitable as well. And that's before you get into the challenges that pressurization zones would add to this all! Putting airlocks in egress paths is a major obstacle to mass egress, never mind pressure differences acting on exit doors to the point where without careful engineering, exits may become utterly inoperable. [Answer] Regular domiciles have 3 pipes: water, sewer, gas... and 2-3 wires: electrical and comms (phone and/or cable TV). For a skyscraper, the wires are simply more and bigger, and a superskyscraper won't have gas. ## All the adventure will be in fresh water In Earth gravity, a column of water 2 feet high weighs 1 pound per square inch. The bottom of that column will be at about 1 pound per square inch (PSI) of pressure. That's British PSI, so that should be a galactic unit, via the [same mechanism that aliens speak English](https://polandball.cc/wp-content/uploads/2014/11/ZQtBK77.png). So a column of water 100' high will generate 50 PSI of head. Now, your household plumbing is happy at around 35-70 PSI, and water towers provide that passively. The Burj Khalifa's top floor is 1918 feet, or about 1000 psi to push water up there. 2000 psi pipe is readily available (not cheap). How do you push water to the top of a 20,000 foot high Coruscant skyscraper? *Not* by developing 10,000 psi of pressure - any leak would become a waterknife that could slice through the structure of the building like a lightsaber. Instead you have reservoirs every 1000' up the building, and push from pool to pool - only 500 psi needed. Have distribution reservoirs every 70 feet or so, each reservoir serving the customers below the next reservoir, so everyone gets 35-70 psi passively. ## Sewer - don't let it fill up Pressure only develops if a pipe entirely fills. Usually a sewer pipe is just an air-filled chute, and does not fill up solid except at the very bottom, and only develops just enough pressure to move things along out the sewer lateral to the street. So a 20,000 foot tall sewer stack is not an engineering problem... unless city services have a problem. Then you do too. ## Oh. Pressurization. On Earth, a 20,000 foot skyscraper would have one serious problem. Much above 10,000 feet above sea level, people couldn't breathe. Realistically you would have to pressurize the upper floors (to about 8000' elevation, as jetliners do), or lease them to species who prefer those altitudes on this planet. The pressurization will play havoc on how the sewers operate. You'll probably need to have a mechanism at the end of each pressurization zone to deal with that, to prevent all the pressurization from blowing out the sewer pipe. Simply having their own pipe down to their pressurization altitude should suffice. [Answer] I could see miles high buildings with tens of thousands of occupants being largely self contained. As has been stated, sewage and water systems would remain the same just larger. But instead of going to a centralized location in the city, which risks spilling tens of thousands of tonnes of raw sewage if there is a leak, it would go to a sewage plant in the basement. The sewage could be treated normally, with the water being reclaimed for later use as it is today. The [sludge](https://www.scientificamerican.com/article/the-future-of-sewage-is-power-and-profits/) would be separated, with phosphorous compounds sent to nearby farms for fertilizer, while the methane gas and whatever sludge remains would be burned and turned into electricity for the building. This extra power would be used to support the main power system also in the lower levels. This system would help reduce the amount of water and energy coming from the city to a minimum. Another benefit is that a break in the grid would not shut the city down, but merely the one building. With backup generators and a large septic system, the building could keep functioning until repairs were made. [Answer] Assuming energy is cheap, you can always beam it. For waste, again if energy is practical free ( like unlimited fusion power ), just incinerate it with a small electric arc furnace. You would still need water lines. But you could store rain water on various levels of your buildings, recycling it on the way down. Letting gravity do it's thing. Or pump it to the upper levels in stages with holding tanks between. Clean water goes up, bad water goes down. Living on the bottom floors would be a real joy in that case.... [Answer] Make recycling local. In the sequence that frame comes from the action shortly visits some lower unused areas, that might be called the bowels of the city. I suggest that's exactly what they would be. Transportation is pretty clearly close to capacity, anything you don't have to ship any distance would be a win. Water, air, power are all totally fungible and while they do benefit from scale the volumes required might make transportation costs cancel any benefits beyond a certain point. If ten thousand people live in a tower you probably save on pipes and pumps by putting a moderately sized water reclamation plant in it than pumping stuff out to a huge plant miles away and then back in. Especially if co-ordinating infrastructure is hard, like say the if service to the next tower over needed to be disrupted to connect your line, or you would have to pay to add the needed capacity to the municipal processing center when building a tower it might make sense to make them more or less self sufficient. [Answer] # The sky does not depend on the ground! If you change your perspective there is another potential solution. How do you manage a city that is miles WIDE... you don't put all your resources one one end and pipe them all from that location to every building on the grid, you distribute them THROUGHOUT your city. A city that is miles high can extend that paradigm to the third dimension... * Every n stories you have a wastewater processing plant... why send it all the way back down? * Every few floors you have water collection, why wait for the rain to get to the ground? * Electricity is generated (wind, nuclear, maybe hydroelectric from falling gray water) * Telecom is distributed more or less this way even in moderately smaller buildings already. * Agriculuture is distributed on new modern buildings, at the "miles high" scale this could become farming. This opens up fantastic opportunities for cultural and social differences as well. [Answer] # The Buildings Are Self-Contained For an in-depth discussion I recommend the Isaac Arthur episode on [arcologies](https://www.youtube.com/watch?v=TqKQ94DtS54) - self-sufficient structures with all their utilities, and most of their own economy, built in. In essence, an arcology is a space habitat constructed on the ground. Another way to think of it is a city in a can. Waste is recycled internally so water supply is not an issue, food is often grown internally (this only needs fusion power or sufficiently advanced bioengineering, not magic tech), and everything that can be provided inside the building is. You don't need Star Trek style replicators - just living space for the people who work there, a reasonable supply of commonly needed technicians, tools, and spare parts, and the equivalent of an Amazon fulfillment center in there somewhere. Compared to a space habitat, an arcology doesn't have to be quite so self-sufficient, and at least it doesn't have to be airtight. But much of the design is similar, because you don't want too many people or goods coming and going. Just as you can live your entire life inside a city today without really having to leave, you would be able to live your entire life inside an arcology if you wanted to. The essential problem with traditional skyscrapers at extremely large scale is that the consumption requirements of the building increase with the building's volume, but the ability to get material in and out of the building increases only with the building's surface area. Forget the view from the top floor - the entire outer shell of the building has to be a loading dock or a garage! In concepts that don't involve ubiquitous flying vehicles, everything going in and out of the building has to pass through not only the edge of the building but the ground floor, so the available rate of material flow is essentially fixed, and buildings can't get much bigger than they are now. We already have trouble with traffic getting in and out of skyscrapers during rush hour periods. The design of elevator shafts for supertall buildings is already a serious problem and designers are [inventing new ways](https://www.citylab.com/design/2017/07/elevator-of-the-future-travels-sideways/533316/) to deal with it. So you keep everything inside the building that you can. A facility for disposal of waste heat becomes the main external utility that an arcology must connect to, especially one that has its own fusion power plant. Even present-day skyscrapers have to run their air conditioners in the dead of winter, and city centers are hotter than the surrounding environments, in part [because of heat generated in large buildings](https://en.wikipedia.org/wiki/Urban_heat_island#Causes). For arcologies, air-cooled heat pumps aren't going to cut it. Something like a molten sodium cooling loop would be more useful. In some ways the construction architecture of arcologies parallels computer architecture. Early computers (say 1970s to mid-1980s) handled relatively little data and the CPU could communicate with memory and peripherals at its own speed. CPUs got faster and RAM cache had to be invented so the CPU didn't spend most of its time waiting on system RAM. Later CPUs got more and more levels of RAM cache of varying speeds because the cache needed its own cache. Eventually RAM and peripherals started to move directly onto the CPU itself and we now have integrated systems-on-chips including everything but the power and human interface components. Most of the actual space inside the chip is used just for storage or moving signals from place to place, not actual computations. And the essential limiting factor on performance is power in and heat out. The development of arcologies can be evolutionary, not revolutionary. One example of something that's on the path to an arcology is the [MIT campus](http://archive.boston.com/lifestyle/blogs/thenextgreatgeneration/2012/03/school_secrets_5_things_to_kno_4.html). It's possible to travel almost anywhere on campus without going outside, like most universities it provides basic living needs to the students, and it even has its own power plant. Of course, it's not really self sufficient - they still need to bring in almost everything from outside - but it probably feels self-sufficient to the students that live there. Arcology-like architecture has also [been proposed](https://www.citylab.com/design/2018/01/the-case-for-putting-hq2-in-the-suburbs/551108/) for the upcoming Amazon HQ2 - even if it's not contained in a single tall building. ]
[Question] [ Scenario: The Moon disappears slowly -- within 3 days. It is a result of natural causes and we don't have any control over this disaster. What will be the Major Effects On Earth and life on Earth? [Answer] Tides will still exist from the sun's pull, though they would be smaller. Solar tides are 44% of the current total and lunar tides 56%. Tides would occur at roughly noon and midnight every day. Probably some impact on life, weaker tides would stir up less nutrients, etc. Due to how tides are a drag on the earth's rotation, the earth's spin is gradually slowing down -- days are getting longer. Without the moon, this slowdown would be even more gradual. This effect is not noticeable unless you consider thousands of centuries though. The earth and moon co-orbit about their combined center of mass which is still inside the earth. No moon means that the earth would lose this wobble. Hard to see any impact on life from this. Nights would be a great deal darker -- at least compared to those nights other than new moon. Even at new moon, the moon is still a significant source of nighttime illumination due to earthshine. Human eyesight perceives it as dark, but some animals can see quite well in this light. With only the stars and planets nocturnal animals would have a more difficult time, however they would not be as blind as you might suspect. Brightness is measured in magnitude, lower numbers are brighter. The scale is logarithmic because vision response is approximately logarithmic. These are average figures Sun: -26.74 Full Moon: -12.74 New Moon: -2.50 The integrated night sky: -6.5 So, the new moon is considerably darker than the rest of the sky combined. In terms of total light, the new moon is about 2.5% of the total. It is still an important contributor, though less than you might think because it is not diffused over the whole sky and still appears relatively bright. Because of cloud cover, many nights are much darker than they would otherwise be. Since nocturnal animals are used to these conditions as well as the nights when the moon is below the horizon, I can confidently say that though without the moon it would be more difficult to see at night, the animals would still get by, though it might be a little more of a struggle -- every bit counts in a hunter/prey situation and they would never get the bright nights. Some animals would be adversely affected though as they restrict their activities on the especially dark nights and are more active on the normal nights. Other animals are the reverse, they avoid the full moon and are more active on the darker nights. Some animals also appear to respond the moons cycle in unexpected ways, e.g., spawning only on a full moon. Clearly, this could be potentially disastrous for them. The earth's axial tilt is about 23.4 degrees and varies over the course of thousands of year between 22 and 25 degrees. The missing moon would destabilize the earth axial tilt. Over millions of years the tilt would vary from 0 to 45 degrees, some sources suggest that the range would be 0 to 85 degrees. In either case, very massive climate changes would occur. Due to fact that the moon in receding, this process is already very slowly underway -- at least hundreds of million years to be really noticeable. The effect of solar changes is expected to be a much bigger problem first as is becomes hotter over time. Earth would lose a convenient source of building raw materials for future exploration. Some suggest the the moon and the human menstrual cycles are related. Given that other mammals have different periods lengths, this is likely no more than coincidence, but we really don't know for sure. Romance will take a hit. And the ever popular eclipse will be no more. Finally -- werewolves would not be nearly as much of a problem. At least, no more full moons to set them off. It occurred to me later, that there will also be a world-wide panic as the moon disappears. Certainly, anything that makes the moon disappear will be very energetic. Just to knock the moon out of the neighborhood, i.e., reach solar escape velocity you would need around 3.8E28 Joules or 9.1E18 tons of TNT worth of energy. That is a 1 megaton bomb every second for 288 thousand years worth of energy, ignoring the fact that Orion pulse rockets are not perfectly efficient. I did not use the [Tsiolkovsky rocket equation](http://en.wikipedia.org/wiki/Tsiolkovsky_rocket_equation) though. Since there are details I don't know (such as nature of the event) and given the ridiculousness of the answer I figure I am close enough (solely considering kinetic energy change required). I certainly remember laughing at the [intro of Space 1999](https://www.youtube.com/watch?t=12&v=8WZW4groJro). ADDED Earth's wobble around the earth/lunar barycenter is actually a minor consideration. The barycenter is 4641 km from the center of the earth. The earth orbits around the barycenter once every 27.322 days (the lunar sidereal month). This means the earth orbits the barycenter at about 44.47 km/hr -- 4641 km radius \* 2 \* pi / 27.322 days / 24 hours/day. The earth orbital velocity around the sun is frequently given as 30 km / sec or 108,000 km / hr -- this number is slightly high, but close enough. Removing the moon instantly would thus change the orbital velocity by about 0.041 percent -- as a vector quantity it could be faster or slower as well as in a different direction. The earth's orbit already changes by a similar amount in natural orbital variation. Depending upon where the moon was in its orbit when it disappeared the earth's orbit could either become more circular or more elliptical. A more elliptical orbit would result in more climate variation, but the earth orbit would not be quickly destabilized by this catastrophe. Since the earth's orbit is more circular than average at the moment, the resulting orbit would still be similar to natural orbital variation. Over millions of years, the effect is not predictable (n-body stability is unproved) and you get into the realm of butterfly effects. Over hundreds of years Earth would be essentially unaffected in terms of a stable orbit because of the sun that is so massive compared to Earth. I failed to include this effect and Dan Smolinki did, but I am certain he overstated the impact re: orbital stability. Definitely a good catch though as greater climate variation would be a bad thing. --- ADDED -- Now with catastrophes 3 days to disappear is certainly not slowly disappearing in my mind, but I think there are other effects that I did not consider before. Lunar tides means water is pulled up by about 0.4 meters / 1.5 feet in mid-ocean (considering just the lunar component). If the moon disappeared instantly, that would likely result in fairly large tsunamis at the shore at this kind of water displacement is similar to that caused by major earthquakes. If the moon accelerates away from the Earth relatively slowly, this would spread out the water displacement effect over time. Considering that lunar tidal effects result in 2 sets of high/lower tides every day, there would be little change noticed from the moon leaving slowly. If the moon departed to do a sudden velocity change, the effects would be intermediate, but unlikely to be dangerous. It is really the near instant change in the water displacement that would cause large tsunamis. The "natural causes" for moon leaving in 3 days are fairly limited in terms of likely causes, the most obvious being an impact or near miss event. Impact would be catastrophic for Earth as debris rains down on the Earth over time (many years in fact), but the heaviest debris would start within hours of the impact. Something massive enough to de-orbit the moon in a near passage could also affect Earth orbit noticeably as the passive object would have to be very massive -- did not do the math, but I would expect the passing object would have to be considerably more Earth mass to steal or simply de-orbit the moon in a single quick pass -- a wandering black hole being the likely candidate. Since Earth's mass is 81 times as much, the delta v would likely be 81 times less +/- a considerable factor as the distance at which it passed Earth could be considerably larger or smaller than the distance from which it passed the moon. For example, earth moon distance is about 385,000 km if object passed 38,500 km from moon, the gravitational effect would be 100 times stronger. Thus the net effect on Earth orbit could be relatively minor or major depending upon the particulars. Of course, we would detect such an object well in advance due to the gravitational anomalies and we could begin the world-wide panic before the actual loss of the moon. End of the Earth riots could cause major damage even if the black hole passage does not by itself. But now we have to consider that our wandering black hole would result in some seriously strong tides that should guarantee some pretty catastrophic tsunamis and floods. The crustal strain would probably trigger some earthquakes and volcanoes too at a minimum. In any case, those disappointed by the lack of catastrophic effect can take comfort in having at least some catastrophes deriving from the direct effects on Earth that would occur at the same time. [Answer] * The moon is in fact important because it stabilizes the Earth axis. Without the moon, the Earth Axis would slowly (we are talking about geological timeframes, thousand of years) change their orientation, making life on Earth much more difficult: [Laskar,Joutel,Robutel: Stabilization of the Earth's obliquity by the Moon](http://www.nature.com/nature/journal/v361/n6413/abs/361615a0.html) * Muslims would be quite aghast because their calendar, the Islamic Calendar is based on the moon. The beginning of a month is defined by the first sighting of the crescent moon after new moon (رؤية الهلال: hilāl ) and the holidays are based on the Calendar. [Answer] Losing the moon would perturb Earth's orbit. It would cause it to become significantly more elliptical, and almost certainly would put us in a non-stable orbit. Over time (possibly as short as 100-1,000 years?), this would likely render Earth uninhabitable. We might end up further or closer to the sun, in a very elliptical orbit that alternately freezes and then burns the Earth, captured as a new moon of one of the gas giant's, or even ejected from the solar system. It's possible that it would stabilize back into an orbit that's conducive to life, but unlikely - orbits are tricky. If you've ever played with a solar system simulator, you'll know orbits are very easy to screw up if you introduce or change current masses. [Answer] A minor change would be waves. The big change is the ecosystem. Without the moon, animals cannot see well at night. Without this light, they cannot hunt at night (which many animals do). They will either adapt, or they die. [Answer] The importance of moon for the stability of the earth axis should be considered when investigating the prospects of intelligent life in other planetary Systems: While there may be many earth-like plantes in the habituable climate zones, only quite few are expected to have a companion similar to the moon, i.e. quite large. The moon may have contributed to a more stable climate suitable for life and, even more, for agriculture. I would also like to raise the question whether there may be some correlation betweeen the moon and tectonic activities, in the long run. ]
[Question] [ I'm curious what it would take to get a planet with so much free fluorine that you can have an atmosphere of predominantly or purely fluorine. I realize how improbable a planet like this is, so I'm looking for the long set of perhaps contradictory conditions that would lead to a hellscape planet like this. How do I get a planet sized ball of fluorine ash products and an atmosphere of fluorine to go with it? Planet parameters: 1. Earth-like in mass. 2. Surface atmosphere of one bar 3. Atmosphere is >70% fluorine Points in a good answer : 1. Organization and evolution of the proto planetary disk. 2. Processes required to concentrate enough fluorine in one place to get a fluorine planet and fluorine atmosphere. ## Out of Scope 1. Questioning the question :) I know this planet is crazy and highly improbable. Don't tell me why it can't work. Tell me why it can and what it would take. 2. Life. Whether this planet will support life doesn't matter to this question. 3. Evolution of the planet past initial formation. [Answer] ## Here goes nothing Firstly, fluorine is not particularly abundant in the universe so you need a large source in order to get an atmosphere of it. Additionally, fluorine is easily consumed in [stellar nucleosynthesis](https://en.wikipedia.org/wiki/Stellar_nucleosynthesis) so it's hard to encounter a significant concentration for your planet forming. Anyway, let's begin! ## A Star Dies In a [Red Giant](https://en.wikipedia.org/wiki/Red_giant) star at the end of its life, it's inside is stratified with different layers of fusion occurring. In these different layers, you get different elements.Lighter in the outer layers, heavier in the center. The Star Dies in a core collapse supernova or [Type II](https://en.wikipedia.org/wiki/Type_II_supernova) blasting its layers outward and releasing a ridiculous amount of [neutrinos](https://icecube.wisc.edu/info/neutrinos). [![really, you should enter image description here](https://upload.wikimedia.org/wikipedia/commons/f/f3/Nucleosynthesis_in_a_star.gif)](https://commons.m.wikimedia.org/wiki/File:Nucleosynthesis_in_a_star.gif#mw-jump-to-license) ## Deadly Neutrino Radiation Relevant [XKCD comic](https://what-if.xkcd.com/73/). Now the outflow of neutrino radiation is so great that it [may](http://kencroswell.com/fluorine.html) be enough to knock a proton off Neon or Neutron to make Neon-19 which decays into fluorine. This process is currently speculation. The result is an expanding fluorine rich shell of gas. For the sake of argument, let's say there is a whole bunch of it. The whole system falls into a disk around the supernova remnant. ## Planet-forming Planets start forming during your standard process: [accretion](https://en.wikipedia.org/wiki/Accretion_(astrophysics)). These planets form in the heavy element-rich layers with no abnormalities. Except two relatively large planetesimals form and collide with each other. These two planets were not so dissimilar from Earth during the early [Haden Eon](https://en.wikipedia.org/wiki/Hadean). So violent is the collision that the metal-rich cores of the planets are knocked out and form a new planetesimal rich in metal. ## The burning Our new planet drifts out into the fluorine rich part of the disk and begins gathering it due to its gravity. The planet has a surface rich in nickel and iron with much fewer [silicates](https://en.wikipedia.org/wiki/Silicate) than earth. As the planet begins to gather fluorine the surface burns. But the metal rich surface reacts with the fluorine and produces a nonreactive passive layer. The silicates burn and react and form their own layers or there is not enough silicate to react with the fluorine. As such the planet is able to keep a fluorine atmosphere for a geological period of time. ## Results A dense (why not venus atmospheric density for good measure) fluorine rich atmosphere with a whole bunch of other nasty compounds on its surface. Even More Hardcore it's also orbiting a neutron star or black hole. [Answer] # Problem The problem here is not the reactivity of fluorine - you can make a planet out of fluorine compounds that will be stable wrt fluorine by definition. The problem is how we concentrate enough of the stuff in one place to make it dominant. # Concentrating F Now, what we could imagine is a highly magnetic object acting as a particle accelerator and also banding the paths of released particles - not dissimilar to a mass spectrometer on earth. So imagine a spinning neutron star ploughing through a cloud of dust released by a supernova, throwing off atoms at different angles according to their mass. These particles then impact a dense region of dust and gas, forming zones of differently concentrated elements. # Making a Planet Now we have a freakishly fluorine-rich area, which collapses into a star and protoplanetary disk by the normal mechanisms; there is further differentiation within this disk - because the F-rich minerals have chemical properties that have them condensing at a certain distance from the new star (just as the solar system has an ice line) so we concentrate the F-containing compounds into a smaller band; this turns into a planet with a very high percentage of fluorine. We can also deliver more fluorine from icy objects outside of this band. # Planet Composition Common elements such as silicon, carbon, and hydrogen wil be present; we'd want to minimize oxygen. We might propose that there is an iron core and silicate layer at depth in this planet, with a fluorosilicate layer above that, an ocean of HF and an atmosphere of F2. [Answer] Read until the end, I do has he asks. Sorry but this is in a real danger of becoming bad fiction. You don't let a baby win the Olympic marathon in a book either. Fluorine isn't created in large quantities by stars so you won't find large quantities in space. In addition to that, fluorine reacts with basically anything - even some noble gases. It's way more reactive than oxygen. Look, you not only need a rare element to form a planet, you also need common elements to be absent from said planet - like hydrogen for example (or else you would have an hydrogen fluoride atmosphere). Let's not say it was created like oxygen on this planet because 70% is way too high for that. I had a whole passage about why life can't exist on that planet and this option is out of the question, but I deleted it - felt out of place. Basic thing is: It can't happen. Just wanting it to work doesn't make it a good idea. So here are possible solutions: The planet has been created by a super advanced civilization as a joke and any possible life has been designed by them as well with materials we do not know of yet. The planet was inhabited by a civilization that created fluorine as industrial waste, even collecting it throughout their star system. This ended in catastrophe. [Answer] Related to Raditz\_35's answer: There is a superadvanced race that is able to manipulate space to build what is in effect a cavatron that can process a whole star at once (Obviously it's working on something other than an electric current!) They haul the machine to stars that are just about to die and toss them in, the matter is scattered across space by it's charge and atomic mass. They scoop up everything of value. They do not consider the fluorine of value. (For those who haven't heard of them: You ionize the input material, subject it to a fixed voltage, deflect it with a magnet and catch it. The deflection is based on charge/mass, so long as you are precise enough and the buckets are placed appropriately it's quite capable of doing things like U-235/U-238 separation--and with a machine a good engineer might be able to build in his garage. We aren't buried in engineers building nukes because the power requirements are incredible--we even tried that route in the Manhattan project, it was abandoned as impractical.) [Answer] Highly reactive species, like oxygen or fluorine, need to have some sort of cycle freeing them back in the atmosphere. Therefore if there was some form of life which used oxydation by fluorine as energy source and some sort of plants using photosynthesis based on fluorine instead of oxygen, you could get quite some free fluorine in the atmosphere. [Answer] This answer is going to be long and rambly because I'm writing it on my phone and I just wanted to throw all the thoughts I had out there. Maybe it should be edited later though to make it easier to read and/or to add sources for claims. Also, I may stray a bit away from your specifications for the planet at times. First of all, O2 is a high energy molecule that can only be present in the Earth's atmosphere because it is created by life. Life is kind of like the opposite of chemical equilibrium and often pumps systems away from chemical equilibrium when it stores energy in itself by methods like photosynthesis. If a planet has an F2 rich atmosphere, it's probably biogenic, because otherwise it would have to just have so much fluorine that it ran out of things to react to (which is really weird) or it would have to be at extreme temperature-pressure condition where that was part of the equilibrium (?really high temperatures or low pressures, but not enough for atomic F), or there is some non-biogenic process pumping this disequilibribrium, like ultrahot volcanic eruptions, lightning, or radiation\* breaking things up. \EDIT: Daniel Joyce made a good point by mentioning radiation. Neutron star planets are definitely a real thing, and even include the first confirmed exoplanets. I have no idea how likely it is for a planet to be close enough to a neutron star to be heated to Earth-like temperatures, but any star heated my neutron-star-light would be heated mostly by x-rays and very hard UV. These are energetic enough to break up and ionize pretty much anything, so the chemical composition of the surface and atmosphere of such a planet would be very different from normal "chemical equilibrium" that's based on just pressure, temperature, and composition, even without life. If such a planet's surface was rich in fluorine, then atomic F, F2, and many other bizarre things, including ions (i.e. the atmosphere might be plasma even at rather low temperatures), could be major parts of the atmosphere. These x-rays would also lead to ridiculous rates of atmospheric loss, too, perhaps removing all volatiles (substances likely to become gases) from the planet on astronomically short timescales which may or may not be good for your idea. Ways to get more moderate, but still large, amounts of x-rays are with tiny flare stars like Proxima Centauri, other rarer types of flare stars like some RS Canum Venaticorum variables (close binaries), stars that are just massive and hot, and so bluer, and parasitic binaries (x-ray binaries). An black hole/neutron star/white dwarf accretion disc outside of a parasitic binary would be very x-ray or even gamma-ray heavy, but would probably be short lived.* Personally, I think the idea that a life-form might release F2 into the atmosphere is quite plausible, but only if fluorine is particularly common in it's environment in some other form. Thus, large parts of your planet need to be rich in both fluorine (probably fluorides of some kind), and energy that is accessible to autotrophs (likely sunlight, but not necessarily). The key issue is getting enough fluorine on the surface, in any form. There are probably astrophysical processes that could produce particularly fluorine-rich parts of the universe, but I don't know how fluorine rich. Fluorine has only one stable isotope: Fluorine-19. F-19 is generally easily destroyed in environments where fusion can occur and it is not directly produced by the alpha-process, (which makes the even numbered elements from carbon to nickel). F-19 is produced in a couple variants of the CNO cycle that are somewhat important in heating large stars (CNO-III and HCNO-III), but it is quickly and easily destroyed by the following fusion reactions in those cycles. Apparently the fact that there is as much fluorine as there is is a bit of a mystery, so that leaves hope that there might be some process that isn't well studied that's very good at making it. Also, I really don't know at all, but maybe some kind of neutron- or proton- capturing process that either happened really quickly and the stopped or happened in a low energy environment might make a slightly more favorable amount of fluorine. Look up the s-process, p-process, r-process, and rp-process to see if any work. I know special astrophysical environments can make some extremely strange balances of isotopes, like how the r-process of simulated neutron-star mergers makes more noble metals, elements around caesium, and lanthanides than anything else and a weird balance of the lighter elements. EDIT: For probably much more accurate and useful information about fluorine and it's mysterious creation, see [Origin and Occurrence of Fluorine](https://en.wikipedia.org/wiki/Origin_and_occurrence_of_fluorine), and it's two sources, [Fluorine: An Element-ary Mystery](http://kencroswell.com/fluorine.html) and [On the origin of fluorine in the Milky Way](http://doi.org/10.1111/j.1365-2966.2004.08215.x), as well as [The thermonuclear production of 19F by Wolf-Rayet stars revisited](https://doi.org/10.1051/0004-6361:20053323), [The origin of fluorine: abundances in AGB carbon stars revisited](https://doi.org/10.1051/0004-6361/201526586), and [FLUORINE IN THE SOLAR NEIGHBORHOOD: NO EVIDENCE FOR THE NEUTRINO PROCESS](http://dx.doi.org/10.3847/1538-4357/835/1/50). I doubt astrophysics will solve all your problems, but it could be a good first step. My first guess as to what the most important factor in getting a fluorine-rich environment would be is that some chemical process is concentrating fluorine near the surface, pulling it out of the mantle. I believe that fluorine is slightly enriched in the Earth's crust, but there is still a lot more of it in the mantle that we could take out. In fact, the increase in the amount of fluorides in water is one of the major threats of volcanic eruptions, and HF and SiF4 are notable components of volcanic gasses. It's also important to just remember that planets have way more mass in there interior than near their surface. I've heard that even gold could completely cover the surface of the Earth as a thin layer of coins if you took all of it out of the Earth's interior. Enrichment based on chemical and physical properties already do wonders towards making rare elements common in some environments. Consider how silicon is the 2nd most common element in rocky planets while helium barely present at all, how the Earth's oceans have so much chlorine (as chloride) in them because it concentrates on the surface and in water rather than in the mantle, how the Earth's atmosphere is mostly nitrogen because close to half of all the Earth's nitrogen is in the atmosphere while most of the oxygen, carbon, hydrogen, and sulfur are in in the crust, mantle, core, and oceans, or how ore deposits and crystals of rare elements like HgS deposits can form. I'm not sure what could preferentially enrich fluorine so much to the exclusion of other elements. Fluorine is usually found as HF in the interstellar medium, which is more volatile than H2O, but not as volatile as NH3. On Earth and probably on other planets, it exists mostly in the form of metal fluorides like CaF2 and Ca5(PO4)3F (the latter of which contains most of the fluorine in Earth's crust). I think that fluoride salts are not very soluble in silicate mantles like that of the Earth, since it is enriched in the crust relative to the upper mantle and is thus classified as a "lithophile" element. I'm not sure how deep the depletion in the mantle goes, though. I think it may be that only the upper mantle is strongly depleted in lithophile elements and the lower mantle is not. (I'll have to check back with data\* on the composition of magmas from plate boundaries vs magmas from hot-spots, the latter likely being volatile-rich magma from deeper in the mantle.) If this is true, then increasing the level of convective mixing between the upper and lower mantles of a planet might help, but be careful, because heating up mantle so more of it is molten (the most obvious way to do this) might increase the solubility of fluorides in it. \EDIT: "My data" is mostly [Composition of the Depleted Mantle](https://doi.org/10.1029/2003GC000597), [The composition of mantle plumes and the deep Earth](https://doi.org/10.1016/j.epsl.2016.03.023), and [Identifying volatile mantle trend with the water–fluorine–cerium systematics of basaltic glass](https://doi.org/10.1016/j.chemgeo.2019.06.014). I haven't actually checked it yet, but one complication I'm concerned about is that, although hot-spot lavas are believed to come from the deep mantle via mantle plumes, the fact that they rise could be partially BECAUSE they are richer in volatiles than the rest of the mantle, and so not representative of the lower mantle in that regard.* Something you may want to look into is the chemical speciation of fluorine in the interiors of carbon planets. (The term "carbon planet" generally means terrestrial planets that have more carbon than oxygen, but there is also an in-between category, as rocky planets with >~1% carbon will likely have graphite crusts according to a paper I read most of.) Ionic compounds like fluoride salts can't dissolve very well into solid carbon, and carbon is likely to be solid all the way down to the core in a carbon planet, due to its hot melting curve, high thermal conductivity (cooling the interior) and the fact that carbon planets have too much carbon to react to form more volatile compounds, though it will likely form other refractory carbides like SiC if there is more C than O. If fluoride salts are lighter than graphite, and crucially are able to collect into separate fluid or maybe even solid phases that are lighter than graphite (noting that solids can sometimes act somewhat fluid over geologic time-scales), then these fluoride salts might reach the surface as diapirs. From there, they may dissolve in water or, on a very hot planet, form lakes or seas of molten salt. EDIT: The above is particularly relevant, since the most likely largest astrophysical sources of fluorine often produce more carbon than oxygen, particularly AGB carbon stars, but sometimes also Wolf-Rayet stars. In addition, SiF4, fluorocarbons (and hydrofluorocarbons, chlorofluorocarbons, etc.) like CF4, HF, and sulfur fluorides like SF6 are all quite volatile substances (gasses at room temperature, except for some fluorocarbons, though HF melts at 19.5°C). These could be formed in some highe temperature low-pressure environments (like how SiF4 and HF can be formed from Earthly volcanism) and could help spread fluorine into the atmosphere. I think that carbon planets, with substances like elemental carbon, SiC, and sulfides floating around, which are more reactive than oxides and oxoanion minerals like silicates and SiO2, might be more conducive to the generally endothermic reactions that produce these volatile fluorides from the relatively more refractory ionic fluoride salts. Melting points and density are one way to enrich the surface of a planet in certain elements. Perhaps the most useful property to exploit, though is solubility. The Earth's oceans are full of sodium chloride, despite the fact that chlorine is not much more common than fluorine, and actually less common in the Earth's crust (though that's probably because the ocean is not counted as part of the crust). Why is there so much chloride rather than sulfates, carbonates, silicates, etc, because chlorides are much more soluble in water than those things. Many fluorides are also very soluble. The problem is calcium (and somewhat other Alkali Earth metals like strontium and barium). There is more calcium on Earth's surface than fluorine, and fluorine prefers to bond to Ca to make CaF2 and Ca5(PO4)3F than to bond to anything that's as common, and alkali-Earth fluorides like this have extremely low solubilities in water until you get to the extreme pressure-temperature conditions when all sorts of things, including silicates, are highly soluble in water (ruining the ability of solubility to enrich fluorine effectively). If a planet had way more potassium than Earth, however, than the fluorine might form highly soluble KF. Similarly, if a planet had less calciu than fluorine on it's surface (perhaps due to being particularly deficient in calcium), then the excess fluorine might mostly bond to sodium to make highly soluble NaF. Either way (or both ways), you could get planets where fluorides partitioned into the oceans as much as chlorides, potentially leading fluorine being similarly or perhaps more common than chloride in the world's seas. This enrichment of Na and K and/or depletion of Ca, need not be due to astrophysical processes (although forming a planet out of material that the alpa-process or at least it's late stages did not contribute much to could easily help), but could be due to the melting points of Na and K compounds vs Ca ones. This exact composition difference is part of what differentiates felsic from mafic rocks on Earth, and similar differences could be formed due to the lower melting points of Na2S and K2S vs CaS and I think Na2O and K2O are less stable than CaO. (Note, enriching a planet in sulfur relative to Earth is easy by just having it form further out in the protoplanetary disc where FeS can form, c.f., Io. Also, perhaps collisions with S-containing comets might be common furthur out.) Maybe if you can get an ocean full of fluoride salts and/or a non-trivial amount of volcanically-originated fluorine compounds like the quite stable SiF4 and CF4 into the atmosphere than it might be plausible for life-forms to be surrounded by enough fluorine that storing energy through endothermic reactions that produce F2 might be viable. About oceans, though: The planet probably shouldn't have too much liquid water to start out with. F2 reacts pretty quickly with H2O, so turning all the H2O into HF and O2 will increase it's lifetime in the atmosphere a lot. Life could perhaps adapt to using liquid HF as a solvent instead of water if the change was very slow and the conditions cold and/or high-pressure enough. (Pure HF is liquid -83.6°C~19.5°C at 1 atm.) Interestingly, apparently many organic compounds including proteins and carbohydrates can dissolve in HF without reacting (although they do react with F2) because C-F bonds aren't any more stable than H-F bonds. HF is less stable than other fluorine compounds the life-forms that originally made the F2 likely started out decomposing, so the autotrophs could probably adapt to make what water their biochemistry still needs, and store energy at the same time, by using the endothermic reaction: 4HF + O2 → 2H2O + F2. F2 also reacts with rock-forming oxides, but since the these are solid and so are many of the reaction products (AlF3, NaF, MgF2, CaF2, KF, FeF2, FeF3, but not SiF4), they may form a thin surface fluoride layer before too much F2 is used up. Once there are no liquids or gases on the surface that react with water, and the solids are all covered with a thin layer of fluorides, F2 will have a much longer life-time in the atmosphere and will have at least a chance of accumulating. I should also mention atmospheric loss as a way to affect a the composition of a planets atmosphere. Maybe if a lot of the lighter elements in an atmosphere are lost over the first billion years or so, then heavy fluorine compounds like SiF4, CF4, and, SF6 might a lot of what remains. Based on the idea of [Jean's escape], where lighter molecules are lost more easily due to thermal vibrations, this result you would probably need to get rid of CO2 in order for these fluorine molecules to become dominant in the atmosphere. CO2 is heavier than F2, so this would also prevent F2 buildup. However, if the planet then cooled, reducing the amount of Jean's escape, then, after loosing all gases up to CO2 in atomic mass, it could build up F2 again due to autotrophs endothermically breaking them down and releasing F2 to store energy and access the carbon, silicon, etc. stored in them. (There are other types of atmospheric loss than Jean's escape, which are often more important. Radiation based methods have to contend with the fact that CO and N2 are harder to dissociate than these fluorine compounds, although the high electronegativity of fluorine does mean that it would be very difficult for radiation to ionize, likely more difficult than anything except noble gases, and this property would somewhat be donated to fluorine molecules, though not entirely, since fluorine-containing cations can exist even in stable compounds.) Also, I'm going to repost this comment I made here: Have you seen either of these: [Alien Atmospheres: How to Make Plastic Trees](https://youtu.be/fwauz9uIl9M) (or the fiction it is referring to and links in the description) or this 2014 paper: [Fluorine-Rich Planetary Environments as Possible Habitats for Life](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4206852/)? [Answer] First problem is to get a fluorine rich planet at all. Stellar nucleosynthesis is working against this, and the remaining possibility is an engineered planet with unusual elemental composition. So as a starter, you have an advanced civilisation that builds a fluorine rich planet as kind of laboratory for planet evolution. Second, what will the atmosphere of fluorine rich planet contain? Most probably, predominantly HF. $CF\_4$ will polymerise over time giving solid teflon. Probably some $SF\_6$ and some $NF\_3$ will be in the atmosphere, too. They are a very strong greenhouse gases leading to a heat up of the planet: Your hell will probably have Venus-like temperatures! I don't expect free $F\_2$ to be a major component of the atmosphere unless there is some biological activity on the planet. It will be very strange and unlikely lifeforms, but I can imagine exotic life based on carbofluorides. [Answer] Ionizing radiation can release fluorine from rocks. CF "Stinking Fluorite" which is Fluorite contaminated with Uranium, in which beta particles break apart fluorite into calcium and fluorine. <https://en.wikipedia.org/wiki/Antozonite> So your hellscape just got more hellish. To keep fluorine in the atmosphere there has to be enough beta emitters in the crust and fluorites comingled to trigger its release. So its not just poisonous but radioactive too. The necessary beta particles could also come solar wind. Maybe the planet has a dead core and weak magnetic, so solar radiation impinges the surface unheeded. Even more hellish. ]
[Question] [ Closed. This question is [off-topic](/help/closed-questions). It is not currently accepting answers. --- You are asking questions about a story set in a world instead of about building a world. For more information, see [Why is my question "Too Story Based" and how do I get it opened?](https://worldbuilding.meta.stackexchange.com/q/3300/49). Closed 3 years ago. [Improve this question](/posts/188930/edit) The aliens arrived in secret and hide on the blue side of the moon. And as they scanned our internet, they decided that Felis catus is the dominant species on Earth, as Homo sapiens sapiens clearly does their bidding all the time. Now, the aliens do have some odd streak in that they seek out other planets to find a worthy overlord, and they believe this time they might have managed it! Now, their search for the perfect overlord species to themselves prevents them to ever discuss terms with other subservient species, which means they can't contact humanity - even the idea of trying to decipher the language and glyphs humans use to describe things are so alien to them that they will not do so. They also can't just abduct any member of the overlord species Felis catus, because that would be sacrilege and even thinking about it makes them commit suicide. They can't pass for humans even passingly as they are [Starfish Aliens](https://tvtropes.org/pmwiki/pmwiki.php/Main/StarfishAliens) of truly non-humanoid design. They can't also just use an invisibility technology or psi, as such doesn't exist. How might the aliens still get in contact with a representative cat? Of course, eradicating humans would be a way to not need to contact humans, but glassing the surface also burns Felis catus. [Answer] ## Finding a cat without a human is easy A "representative cat" is a feral cat; [the world has over twice as many strays as it does "owned" cats](http://carocat.eu/statistics-on-cats-and-dogs/). So just find a stray living at a remove from humans, and you're done. Offer them some food, maybe keep some actual mice in a box to attract the cat (cats can hear into the ultrasonic range to track mice), and bam, first contact made. Even if you insist on a cat that humans take care of (it's a status symbol, clearly the feral cats are the peasantry of cats), a non-trivial percentage of the 220 million "owned" cats are barn cats on farms. Humans still feed them (because cats hunt for pleasure, and feeding them ensures they do their hunting near the barn, rather than travelling further afield to hunt/beg for food), but the cats are left alone, away from humans, all night long. Just meet them inside the barn so no one abroad after dark would see you. Cats that don't live in a human's house tend to gravitate to a nocturnal existence anyway (as opposed to house cats, which tend to be crepuscular, matching the apparent activity cycle of their humans), and you want to make contact when they're awake. [Answer] # Cat Toys Obviously one of the prime functions of the subservient Homo Sapiens is to assist their overlord in the pursuit of physical purr-fection. This is done with strings, mechanical rodents, and laser pointers. This provides the aliens with not only a way to make contact with their new overlords, but also to prove that they are better servants. Make a perfect cat toy, and the world will beat a path to your door. [Answer] ### Offerings suitable for their royal highnesses With the average cat travelling [200 meters from homes](https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.petplan.co.uk/amp/pet-information/cat/advice/roaming/&ved=2ahUKEwjf1K2ph9HsAhXymeYKHRLpBewQFjATegQITRAB&usg=AOvVaw2mej6aAXEWvsJnyx00Vve8&ampcf=1) in an average day, it’s quite easy to get a neighbourhood cat to regularly grace you with their presence in return for some offerings of the tinned variety. The aliens are forbidden from reading or talking to humans, but that doesn’t mean they're forbidden from a smash and grab of cat food from the local shop (the cans have pictures of cats on it — easy to find). Failing that, they're also not forbidden from abducting lower creatures and grinding them up into mince meat. (If the mincer is loud enough you can’t hear them talk / scream). Park your UFO on the outskirts of a town late at night, and prepare your offerings. Once they have judged your offerings as suitable, cats will think you worthy of an audience. ]
[Question] [ In the sci-fi role playing game setting I'm working on, there is a religion, which believes that they actually live in a role playing game. They believe in a single, omnipotent god, the 'Game master', and claim that some people have personal gods, called 'Players'. Others are regarded as less worthy NPC's. They imagine, that in a divine dimension there is a room, where the gods are sitting with notes, between snacks, and are playing the great Game. The Game master is omnipotent, but in-universe causality is not violated. If he says that X happens, it also implies that its Z, Q and F causes also happened in-universe. If the GM says something, that contradicts his previous statements, the Players correct him. What could this cult use to prove its truth? Could they eventually convince the skeptical in universe scientist? Could they have fragments of the rule book in their sacred scriptures, making prophecies with them? Or will they claim that some coincidences are not random, but arise because of the cooperation of the players? [Answer] This religious sect documents suspected cases of [metagaming](https://en.wikipedia.org/wiki/Metagaming_(role-playing_games)). The practice is basically analogous to Catholic canonization: to be considered for sainthood, evidence of reported miracles should be collected and analyzed. The person in question is probably fairly pious or seen as a vessel of God, and the merit of their case is weighed. If a "player" evidences some of the omniscience of the "game master," it would appear in-universe to be basically miraculous. Now that's cheating, so the person would probably suffer some sort of catastrophe or hardship soon thereafter, but this is basically in line with the stereotype, and it would make the faithful even more sure of themselves to witness this cause & effect in so many cases of suspected metagaming. A wizard peered into a dense fog, unable to see anything five feet in front of him. He cast fireball and fifty flaming kobolds fled in terror. To this day, the wizard maintains he didn't know they were there... and that he doesn't know why he cast Fireball. Naturally, it will rarely be the most convincing evidence in the world, and there are all sorts of built-in logical escape routes for the skeptical, but that's the double-edge of the entire fiasco. I think this scheme would work well narratively. Lots of opportunity for dramatic irony. EDIT: I Share the sentiment at the top of Sazanami's answer, that real evidence would be impossible, and these cases could be explained in science by coincidence (improbable things happen very regularly in our universe). However, in-universe, a relgion's search for truth would look a lot like any of our religions' searches for truth, whether that be very philosophical or more practical and faith-based, like my example. [Answer] Proving the existence of a GM is not possible, unless that's what the GM wants. The cult can, however, make it somewhat plausible that a GM exists. The thing with GMs is, they may have the power of gods, but they still have the personality of a human. I invite you to look around on the internet for GM horror stories. There are plenty about, for example, powerplayers that drive the GM crazy, players that keep bending the rules, players that enrage a GM by doing stupid things, and there plenty about horrible GMs doing similar things as well. Bottomline is, as a player, it is fairly easy to trigger a GM response. A player could try some of the following: * Ask the GM for a minor favor. Players often forget to buy basic gear, such as camping supplies and reagents for magic spells. More often than not, those supplies magically appear in the player's inventory as soon as they are remembered. This method usually fails while adventuring. Better try this while in town. * Voice corrections for the inconsistencies in the observable world. World's governed by creatures with merely human intellect are imperfect, and even if they are not, a GM may be tricked into thinking that the world is inconsistent and subsequently make some alterations. * Make fun of the GMs mother. In a GMless world, nothing happens. In a world where a GM rules, just about anything could happen. The GM may decide to transform the player into a frog if he's in a good mood. He might have rocks fall down on the player (some GMs will even do this if the sky is clear). You're basically looking for signs of karma here. * Incessantly invoke rules that are in your favor and conveniently forget those that that aren't. A.k.a. rules lawyering. This requires a lot of experience, especially if any knowledge of the rules is obtained with practical experience, as opposed to rulebook's once could reference. Given enough experience though, rules lawyering has proven to be a great way to get ahead in the world. This is suprising, because the GM has the power to overrule everything. The reason that rules lawyering works, is because GMs don't want to be unfair: Once they have set a rule, they try to stick to it. Additionally, human psychology is such that they don't want to let a player down if the player is expecting something that appears perfectly reasonable. Among other things, rules lawyering can be used to improve the effectiveness of skills beyond their original intention or to gain knowledge you were not supposed to have access to. Invoking rules grants the practitioner more control over the outcome than pointing out inconsistencies (see above), but does so at the risk of frustrating the GM. If a GM is pushed too much, he may become resistant to rules lawyers and invoking rules will subsequently have greatly diminished effect. What would you do if you're an NPC and don't know any players? They are pretty rare after all. Well, you go and find plot hooks. In a GMed world, there should be plenty. The Players use them to find adventure after all. When you have found a plot hook, make sure that the area or person of interest is observed. You can expect the status quo to hold until a group of people comes along that disturbs it. It might be a coincidence, but you'll know soon enough if you have that particular group of people followed. They'll probably behave a little odd, and are inexplicable magnets to trouble. A word of warning: Follow them around long enough, and it's likely that they'll confront you or your spy, but fear not! As long as the adventures are grouped together, the consensus is probably that they won't kill you if you are good at heart. Just by following around the players you'll find plenty of support for your theory. Just remember that you'll never find any actual evidence. [Answer] ## Look for quantisation For the sake of argument, I'll assume The Game uses something like the D&D system of levels, skill points, and d20s. That gives us a pretty interesting lever to get into the rules of the universe. Does an individual's performance in a certain area scale in an analogue progression, getting slowly better as they practice and improve, or is their performance quantised - average ability suddenly jumping from one level to the next? Do people identified as "Players" suddenly become more effective at certain apparently unrelated tasks immediately after a traumatic experience? Do Players lose skills they don't practice with, or are gains effectively permanent? Do people suffer from decreased effectiveness when they're wounded, or do they operate at full strength until they suffer enough damage to kill them? Once you have the rules figured out, you can start making predictions. Person A has no attack bonus; his chance of hitting this target, which has an AC of 10, is exactly 50-50. Person B's ability to charm the opposite sex was measured before and after going into combat; their success spiked 25% after combat, suggesting they leveled up and put skills into Seduction. Essentially, you're looking for digital or quantised effects in situations you would expect to be analogue. Sudden changes instead of steady progression. Of course, if your players are sufficiently god-like, they may be playing with rules far too complex for mere humans to understand, rules which would effectively mimic analogue change. Which means... ## Look for Plots Does the world appear to run on Narrativium? Even if the players' actions don't produce quantised effects in the universe, they're still going to need compelling storylines to keep people playing. So find out - do people identified as "Players" keep finding themselves in unusual and challenging situations with a defined plot that they can follow? And, more importantly, does this happen to a statistically significant degree? Are they regularly put in situations where they need to kill large numbers of people single-handed, without apparent remorse? In Terry Pratchett's [Discworld](https://en.wikipedia.org/wiki/Discworld) series, there's actually an element that causes storylines to happen - Narrativium. It's the element or property that all things have that tells them what they are, and what they are supposed to be. You can look for a similar element, and demonstrate that it favours some individuals (the Players) over others. [Answer] If a GMless world is indistinguishable from one ruled by a GM. By definition there is no way to distinguish between the two. This makes the question of the existence of a GM unproveable. It is an interesting theory, but it is equally possible that instead of a tabletop game the world is the dream of a butterfly, a story told by an invisible pink unicorn, was brought into existence by the noodly appendage of the flying spaghetti monster, or that what we observe is all there is. They could certainly have fragments of a rulebook, or claim that things happened by DM fiat instead of some other phenomena. There are similar books and claims in this world. Often these claims are contradicted by other similar claims. Your cult could use any of the existing [arguments for the existence of god](https://en.wikipedia.org/wiki/Existence_of_God#Arguments_for_the_existence_of_God) however like in the real world the skeptical would probably remain skeptical. [Answer] ## Any coincidence can be considered as a "proof" retroactively We can find many "evidences" that Players exist, but all of them will be based on the [Texas sharpshooter fallacy](https://en.wikipedia.org/wiki/Texas_sharpshooter_fallacy). Since there is no way to determine if a person has or has not their Player god, you can always find a convenient coincidence, and then say "that happened because they were special people". Now that they are special, all that things happened to them actually were the Player (or the GM) intervention. [Answer] I doubt this would be fun. Sorry op that I had to break it to you. Could they convince scientists? How high is their charisma? Proof? It's religion. You are the game master though if you want this to be a PITA for your players then nothing is stopping you at all. You can give them whatever you want, however you want. I just doubt that it will be fun. There's also a stack exchange site for this sort of thing specifically. You might get better answers on how to be GM of your own game there. ]
[Question] [ So there's been some industrial espionage committed against T-Rex Forever LLC. The method for how they acquired their T-Rexes has been stolen. Terrible Lizards Inc has acquired a mated pair of [Velociraptors](https://en.wikipedia.org/wiki/Velociraptor) and a mated pair of [Deinonychus](https://en.wikipedia.org/wiki/Deinonychus) using the same mysterious technique. Note that the Jurrasic Park depiction of Velociraptors are actually Deinonychus in everything but name. We'll be using the scientifically accurate names and description in this question. Given that the T-Rex' from T-Rex Forever died out because the [juveniles couldn't reach maturity fast enough](https://worldbuilding.stackexchange.com/a/99859/10364) to compete with other apex predators, the owners of Terrible Lizards believe that Velociraptors and Deinonychus could survive in a modern ecosystem. They reason that the smaller size compared to a T-Rex will help them get to maturity faster and thus compete with comparable predators in that size bracket. Which species is more likely to survive and become invasive when released into the wilds of Costa Rica; a small group of Velociraptor mongoliensis or a single pack of Deinonychus antirrhopus? If these species would die out as well, why? The velociraptors have an advantage in their smaller size and reproduction rate but Deinonychus have an advantage in their pack behaviors. Worrying about metabolic or infectious diseases that these dinosaurs might catch or infect modern animals with is out of scope. Whatever group behaviors and instincts these dinosaurs had in the Cretaceous Period, they have them now. Humans are hands-off thus far. [Answer] # What are these dinosaur's competitors? According to Wikipedia, a velociraptor is up to 2m long and 15 kg. A Deinonychus is up to 3.5m long and 75kg. I'm going to assume that those masses are the upper range for a large, healthy specimen, and [compare to modern species](https://en.wikipedia.org/wiki/List_of_mammals_of_Costa_Rica#Order:_Carnivora_.28carnivorans.29) accordingly. Deinonychus is in a weight class with only the Jaguar (100 kg) and Cougar (80 kg). Velociraptor has a wider range of competitors, including the Ocelot (15kg), Jaguarundi (10kg), Coyote (12 kg), Racoons (12 kg), Coati (12 kg) and Otters (15kg). # What are a dinosaur's characteristics relative to its competitors? * Family care and growth: Here mammals like the cats a have an unmistakable advantage. Milk allows them to provide a highly nutrient dense food source to their offspring, speeding growth. Mammalian growth rates [are significantly higher](http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0088834) than all other groups for body masses greater than 10 kg. Birds can exceed mammal growth up to about 5 kg; but [growth rates for an ostrich](https://www.ncbi.nlm.nih.gov/pubmed/9719849) are in the 200g per day range up to 20kg, which is about average for a mammal that size. Velociraptor might come out as a wash against similar sized mammals, but Deinonychus is almost certainly going to develop more slowly than a big cat cub. Advantage: Mammals * Intelligence: Velociraptor has [come](http://ircamera.as.arizona.edu/Astr2016/text/extvelrapt.htm) [under](http://www.caspercollege.edu/sites/default/files/documents/tate/edres-prefaq-07.pdf) [extensive](http://www.geo.arizona.edu/~rwright/abs2002.html) scrutiny, what with the opening of doors in Jurassic park and all. However, it appears that a raptor's ecephalization level is below that of cats and dogs, and its brain may have had a more primitive structure, with more space less efficiently allocated to sensory inputs. Also relevant is rate of intelligence growth. Milk's big advantage is its high fat content, which is critical for early, rapid brain development. Even if dinos get to be a smart as cats one day, a cat's brain has the raw materials to develop faster. Advantage: Mammals * Vision: A primary advantage of bipedalism is height of eye. The higher up you are, the more you can see. This is particularly important for seeing over tall grass. It might also be important in ability to chase prey into water. For the larger, taller Deinonychus, this might allow it to be a better hunter of capybara than the jaguar, for example Advantage: Dinos * Endurance: One proposed advantage of bipedalism is [increased endurance](https://en.wikipedia.org/wiki/Endurance_running_hypothesis). There is, for example, evidence that humans are better endurance runners than horses. This is hypothetical, but we'll score it Advantage: Dinos * Agility: Bipeds are fundamentally limited by rotational inertia. Therapod dinosaurs are further limited by a relatively rigid spine to help keep their body efficiently balanced on two legs. Cats, on the other hand, have very flexible spines. If a dino wants to change direction, it must swing its head and tail both around, generating torque around the axis of the two rear legs with the same legs that must be used for running. A cat, on the other hand can use its abdominal muscles to bend its entire body, so that its front legs start applying force in a different direction from its rear legs. Thus, a cat can generate torque from the same motion that it uses to run, while a therapod must use a different motion. Quadrupedal mammalian carnivores are more agile that bipedal therapod dinosaurs. Advantage: Mammals * Climbing: The cats in particular are good climbers, and the coatis are semi-arboreal. Despite being feather covered, Deinonychus is certainly too heavy to be able to get any lift; a jaguar's climbing ability is probably superior. Velociraptor might to better, but the manipulative hands of a coati will put it far ahead in a climbing competition. Advantage: Mammals * Swimming: Neither dino appears to be optimized for swimming. However, the otter is. It is highly unlikely that velociraptor could compete with an otter in the water. Advantage: Mammals ### How does Deinonychus match up? Not very well. First off, neither the Jaguar or Cougar is a cursorial (running and chasing) predator, instead they are ambush hunters. Deinonychus seems to have several disadvantages as an ambusher. First, as a poor climber it will have a hard time jumping out of trees. Second, being taller, it will likely have a harder time stalking its prey. Third, there is an open question about how effective its 'attack' would be. I know they made a big deal out of the claws in Jurassic Park, but no animal that large today kills with a single disemboweling thrust. If a jaguar hunts a tapir, it has to tackle it and choke the life out of it. I don't see even a foot long sickle doing that much damage to a thick, muscled tapir hide. Jaguars can put crushing bites on animal skulls, with [bite forces](https://en.wikipedia.org/wiki/Jaguar#Characteristics) around 5000 N, while musculo-skeletal [estimates of a Deinonychus](https://en.wikipedia.org/wiki/Deinonychus#Bite_force) are more like 1500 N (the 4000-8000 N estimates come from tooth indentations, and I consider them highly suspect). The advantage of endurance could be significant in open terrain, but open areas for long chases are going to be limited in Costa Rica. This is an environment with lots of trees and tall grasses (taller than a Deinonychus, at least). In most parts of the country, a chase that lasts for multiple minutes will give the chased animal somewhere to run through for cover. Here, the superior agility of quadrupedal prey items will come into play. Finally, and most damningly, there is no modern analogue for a bipedal big game hunter (unless you are using a bow and arrows). Ostriches and ratites are mostly herbivores or frugivores, and nothing else is that close in size. Deinonychus won't make it. ### How does Velociraptor match up? Velociraptor's disadvantage is that it is competing with a wide variety of mammals specialized for different habitats. It is tough to compete with otters in the water, coati in the trees, and ocelots and coyotes on the ground. Fortunately, since we can assume velociraptor will survive on much smaller prey, it has a lot more options for niches. The upright vision aspect gives velociraptor a significant advantage in hunting small animals in open clearings. It will be able to spot prey from farther away, and track it better while running. Its smaller size will minimized the negative effects of rotational inertia on its ability to turn. In addition, it may be able to use its feathers to perform a leaping/gliding attack to surprise small burrowing prey (like gophers) from above. The best point in its favor is that there exists an analogue on Earth, in a niche currently unoccupied in Costa Rica. The [secretary bird](https://en.wikipedia.org/wiki/Secretarybird) is a mostly terrestrial, avian, dedicated carnivore. That is, unlike most other birds in its niche, it is not a primary insectivore. It eats a lot of lizards, rodents, snakes, tortoises, small birds, and even small predators like mongoose. The secretary bird is capable of full flight, so its mass is limited to 5 kg, but a larger, non-flying, more-Velociraptor-ish variant is feasible. The larger velociraptor would be able to expand the secretary bird's dietary range by tackling the young of larger prey mammals (peccary piglets, deer fawns, etc) as well as the variety of medium-small animals like rabbits, opossum, paca and agouti. The velociraptor's closest competitor in this niche would be the raccoon, but the raccoon is nocturnal and tends to stay in areas of heavy cover, since it depends on hiding to escape predation. The velociraptor, on the other hand, would operate during the day in open clearings, and use speed and endurance to escape things big enough to kill it, like a jaguar. # Conclusion Velociraptor seem like they have an available niche, so they might be here to stay. They would probably be strongly selected at first in the direction of the secretary bird: longer legs, more relative wing power for gliding attacks, and keen daytime vision (if they don't have that already). [Answer] Given that a population of massive, cold-blooded constrictors [Python bivittatus](https://en.wikipedia.org/wiki/Burmese_python) (aka Burmese python) has successfully established itself in Florida, I would say that it's quite plausible for a population of of small and agile [velociraptors](https://en.wikipedia.org/wiki/Velociraptor) to establish itself in [Costa Rica](https://en.wikipedia.org/wiki/Costa_Rica), giving a strong boost to the tourism industry of that splendiferous jewel of biodiversity. After all, the [colorful TV documentaries](https://www.youtube.com/watch?v=ckA8CIsuWqg) (YouTube) and [promotional brochures](https://www.youtube.com/watch?v=6J3aBk9Sgv4) (YouTube) show that Costa Rica is full of suitable prey, including tapirs, peccaris, deer, monkeys, hares, rabbits, iguanas, and of course frogs and birds suitable as practice targets for young and aspiring velociraptors. Wise velociraptors would be well advised to keep the number of eaten tourists low, and avoid [WEIRD](https://en.wikipedia.org/wiki/Psychology#Contemporary_issues_in_methodology_and_practice) tourists altogether. [Deinonychus](https://en.wikipedia.org/wiki/Deinonychus) was a much larger predator, which would scare off the tourists and their money; so no, no Deinonychus please. [Answer] Historical fact with humans The larger a species is the least invasive it can be, because its more likely to be wiped out by humans. The larger it is the easier it is to be found by humans. Any foreign organism released into an ecosystem is invasive however its effect can be regulated by human interference which is made easier by its size. If humans aren't involved then it comes down to: * available food sources in the ecosystem * interpretative ability of competing invading organisms. in this case, since local fauna is small and limited, if D cannot eat V then V will prevail as it is smaller allowing it to need less food and survive off smaller food sources. If D can eat V then they system would eventually reach a balance with D as an apex predator. This would likely follow the progression between dire wolves and gray wolves. Note: if this is a comparative question asking which species would essentially thrive better in the environment without the other present. I would say the answer is negligible as you are essentially releasing apex predators into a new ecosystem. The only factor that would determine its success is its ability to control its population (like wolves) and not over predate its ecosystem. There isn't enough data about these creatures to answer this perspective. ]
[Question] [ A staple of both fantasy and science fiction literature is the long-vanished Ancients, who left nothing but their buildings (or devices) behind. Somehow, these (usually) decrepit structures still work to some extent when discovered and activated by the protagonists. Doors open when their mechanisms are triggered, power sources still have a bit of juice, sometimes mechanical and/or triggered guardians are still active, and so on. Rarely is it in perfect working order, but there's usually still some functionality left. On the flip side, our modern technology is so fragile that very little of is expected to last a lifetime, let alone hundreds or thousands of years un-cared-for... How can these two be reconciled? What practical features would a device or building need in order to survive a long period of disuse and still be able to function? I'm primarily interested in complex machinery, rather than computers and other electronics, but since so many of our machines are "smart" these days, I don't know if they can be separated. [Answer] Two important points need to be made about the sort of technology usually being left behind in these settings. The first is the type of technology: for the most part, this is stuff that was important before it was abandoned, like space ships or military defense systems, and thus is built to a higher standard than a computer or cell phone. The second is the level of technology: these devices are usually built by civilizations with far greater technical development than we currently have, meaning that they would have more options for constructing lasting devices, especially if they knew there was a potential for them needing to be used thousands of years later. Military systems are already much more resilient and long-lasting than common, general-purpose technology. For example, the Atlantis space shuttle was used from 1985 to 2011, which is substantially longer than most people consider car life to extend. Many command and control systems for nuclear missiles have been in operation for long periods, one specific example of which is Dead Hand, which may or may not still be in use. Further, it’s no secret the technology used by the military is generally outdated, but reliable. That leads into the other point, that a civilization with greater technology can accomplish more. It depends specifically on the setting how much that applies, but being able to FTL travel is definitely a huge advance over our current state of technology, and would certainly carry with it technological advances we lack, like control over gravity and reliable fusion power. At the extreme, a group like Mass Effect’s Protheans would presumably be advanced enough that even their tried-and-true technology would be enough to get what needed to be done done. There are some technologies we have now that are more likely to survive long periods of time, and ways that others can have their life extended. Standard chemical batteries tend to not last long due to the corrosive nature of the acids within them, but lithium ion batteries and capacitors can last effectively forever. While capacitors are prone to losing charge over long periods of time, if extended life were a goal, they could be housed and insulated in such a way that they could likely hold enough power to get a ship started. Either of these could serve now as a means to power something long after it was abandoned. Some sources of power could even be run without much involvement, and often in science fiction fusion is posed as one of these. How likely it is for a fusion reactor to be able to run constantly for thousands of years I cannot say; it is doubtful, but it is occasionally given as the reason for the extended life of the technology. For the general components of a ship, it’s more complicated. The inside could be sealed, considering a space-going vessel needs to be completely air-tight, meaning that moisture could be totally removed. That would go a long way towards keeping things working for long periods of time. On the other hand, anything on the outside, like engines, would be a much bigger issue. Indeed, I’m not convinced that without extremely large technological advances, an engine on the outside of a ship, no matter the type of engine, would still work after more than 30 years. That would be even less for hostile environments. This would be less an issue if the ship/station were in space, where there would be little to harm the outside of the ship. To summarize, it has a lot to do with having more advanced technology and higher standards for its construction. I’m not entirely convinced by some of the portrayals in media, but it could be done to some degree given the level of technology common in science fiction, and more would naturally be possible with the extremes of technology sometimes shown. To summarize what I think would help make something last: reliable power source capable of running startup (LiIon/capacitors); air-tight hull and dry interior; being able to retract external parts of the ship like engines inside, where they could be protected by the hull itself. Of course, nothing is ever a guarantee, but it isn't too far off to assume that the people building this technology would know how to keep it running if they chose to, much like we do with our level of technology. [Answer] First of all, the comparison with consumer-grade products is flawed: consumers want the most complex systems at the best prices; that gives little room for manufacturers to provide ruggedized, durable hardware $^1$. The exception would be with vehicles, but those are subject to heavier workloads. Second, intent. Even if a civilization is very advanced, making hardware that lasts so long without maintenance is a effort that needs to be justified. They would need to have a reason to design hardware that way. In other words, I would not expect everything from such a civilization to be still working after hundreds of years; only items designed and stored for that purpose. For example, the office kitchen will not work, but the bunch of robots that were being prepared and packed for a transtellar expedition could have survived. As to how it could be achieved, two ways: * Some items could be packaged/sealed off to maximize their endurance (powered down, no oxidizers) * Robotic maintenance. Of course, this will mean that the system would need the ability to repair and ever recycle robots. Also, it requires a functional power supply. * A mix of both (robotic maintenance of a small core that is always active, packaged hardware ready to be activated). As for the energy issue, two ways: * For "packaged" units, thermoelectric nuclear. Store radioactive materials with long half-lives isolated one from the others. When you activate the unit, put those materials in the power unit of the hardware. The increased amount of radioactive nuclear would increase the rate of nuclear disintegration, increasing the power output (try to avoid a runaway chain reaction, though). * For robotic-maintained systems, you can use nuclear fusion. The combustible (let's say Hydrogen $^2$) does not decay, so you could just have a BIG tank of it and just spend it little by little. Additionally, you could filter it off from the environment. $^1$ Would you buy nowadays a Nokia 6110 for US$200, even if it was guaranteed to work for 50 years? $^2$ We would have issues storing Hydrogen for so long because it leaks, but maybe an advanced technology would not have such issue. Or you can use other elements like Helium. [Answer] The Ancient [Sons of Merk](http://wot.wikia.com/wiki/Mosk_the_Giant) had used their knowledge of Pshysik and the Dark Arts of peering into the bodies of dead men to extend their lives to unnatural length. While lesser Merkans could live for ten times the span of a normal man and remain unwearied, the higher among them, the sons of Buffet and Walton, could live for untold Aeons without showing outward signs of age. However, the weight of the ages grew on their weary shoulders, some among these princes would build massive complexes and undergo a dreaded ritual called [Uthenera](http://dragonage.wikia.com/wiki/Codex_entry:_Uthenera) where they would lay down to sleep for an age. Others, wrought with wanderlust, took to traveling the untold distances in the skies, seeking the homes of the angels, to places so far away that Earthen-time lost all meaning to them. Thus it was that for them, a thousand years was but the blink of an eye, and husband and wife would plan to meet millenia in the future like us mere mortals would plan meeting for a cup of nesqiq in the long red evenings. Their dwellings were great and lasting, on the earth and their Great Depots in the sky, where the [Cargo](http://en.wikipedia.org/wiki/Cargo_cult) came from, and many became great temples of worship for us, the sons of Moroni, Amesh and Hassid and for the other men of the world. After age upon age, their weariness grew, and many never awoke from Uthenera or never returned from their wanderings. No more Cargo arrived, and the great Spaceports of old were slowly overrun with weeds and age. It is said that the Buffeti princes waged a great war against the Angels in the sky, and were crushed, and the Angles laid down the [Kessler Curse](http://en.wikipedia.org/wiki/Kessler_syndrome), a sword of flame in the skies to prevent men from ever rising to the heavens and challenging them again. Every now and then, on dark and clear nights you can see the sword slashing across the sky over and over again. --- TLDR: So, the Precurors engage in relativistic travel, and want to make sure the idiots they left behind don't run out of hot chocolate in 20,000 years when they'll come back, 10 or so of their subjective years later, due to silly things like nuclear war, the occasional dark age or ecological collapse. Solution: build Great Depots in space (stuff them full of cocoa, and glass beads for the prols), where there is no weathering aside from micrometeors. Planetside, go for monolithic style bulk diamond or somesuch material. With Zero-point-energy drives, you can have powered nanites going around eating dust and healing microcracks. Electromagnetic fields keep away dirt and maintain a good seal inside. Might get a little stuffy, but hopefully you've vacuumed it first. That still leaves you vulnerable to 9.0+ Earthquakes, but with a proper reactive foundation and heliotropic gyros for stabilization, you can probably get a decent life expectancy. Coco powder will be waiting patiently. Eventually, enough junk accumulates in LEO (low earth orbit) that coming back becomes such a bother, and the Precursors simply move on to bigger better things. Or die off of boredom. Big hulking relics (with surprising amounts of cocoa powder) litter then landscape. See, easy. [Answer] Something to keep in mind: Those long-working things in the stories are almost inevitably sealed away somewhere where they are shielded from the elements. Generally no water, almost always minimal temperature changes, no UV from the sun eating things. Very often the power source is gravity--a weight on a pulley doesn't lose power over time. [Answer] In the book Sphere by Michael Crichton, there was a spaceship which survived crashing into an ocean and was there for centuries. It was in deep water, and had little signs of decay. The majority of the systems inside operated just about flawlessly. This scenario is pretty believable because objects can survive deep underwater for a very long time because the environment has very little oxygen in it which tends to break down anything metallic fairly quickly in the water. There are also few organisms at extreme depths which will attack the exterior. If the hull remained in tact, then something like this could survive in tact for thousands of years. The problem with having technology like this above ground is that it has a high likelihood of being tampered with. Nearly every metal object made by humans in deep antiquity no longer exists, regardless of the type of metal they are made with. Most of these objects are destroyed by natural decay, etc. If you study ancient stone buildings, there is evidence of them being held together with metal rods and clamps. The only thing remaining is the holes that were left behind. There are some objects that still exist which are made out of gold and other precious metals. However, there is a high likelihood that the objects will be stolen by treasure hunters and melted down, or removed from the context sufficiently that people would not be able to recognize these objects as technology. There are two main things you would need to keep in mind when designing something that will last for centuries. The first is make sure that the material itself is durable enough to survive the wear and tear of time. The second is to conceal it to avoid tampering by people who aren't yet ready to use or understand the technology. I think the best way the preserve technology for the distant future is to encode all the information needed to recreate it in the future on objects which have very little value in them such as clay or stone tablets. These materials can survive for many thousands of years. [Answer] First a background on our disposable society > > <http://www.investopedia.com/articles/pf/07/disposablesociety.asp> > > > ...Creating products that aren't meant to last is a very viable business strategy as this means that consumers will need to buy replacement products. > > > <http://knowledge.wharton.upenn.edu/article/made-to-break-are-we-sinking-under-the-weight-of-our-disposable-society/> > Long before factories across the globe began churning out disposable razors, diapers, and soda cans, American businessmen worried about overstocked warehouses and strategized ways to keep people buying. America’s “throwaway ethic” began in the mid-19th century > > > ...American business actively resisted the Treasury Department’s national frugality campaign during World War I, with stores across the nation displaying signs that read, “Business as Usual. Beware of Thrift and Unwise Economy.” Local newspapers, eager to coddle their largest advertisers, wrote editorials in support of shopping, while in 1921, New York retailers launched the National Prosperity Committee to combat thrift. Articles written about thriftiness from this time period, Slade found, were combative in their language: “Miserliness is despicable, hoarding is vulgar; both are selfish, fatal to character and a danger to the community and the nation,” wrote C.W. Taber, author of The Business of the Household. > > > Fortunately some things still last: calculators from the 1970's one year warranty but still working after thirty years (as long as it is stored long term without batteries) * calculators <http://www.mrmartinweb.com/calculator.html> * <http://www.vintagecalculators.com/html/the_pocket_calculator_race.html> * <http://www.vintagecalculators.com/html/calculator_displays.html> * <http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv019.cgi?read=157392> * electronic calculators <https://www.youtube.com/watch?v=AaLPT0G32MY> How about products old and new with attached 25year or 50 year warranties to them. <http://www.reddit.com/r/BuyItForLife/comments/1tgx37/new_lifetime_warranty_thread_post_any_items_you/> * foot powered or Treadle sewing machines <http://beforeitsnews.com/self-sufficiency/2013/02/treadle-sewing-machine-advice-2453546.html> * Mechanical typewriters * Wristwatches <http://www.moneysense.ca/spend/watches-with-lifetime-warranties-make-timeless-gifts> and <http://www.ablogtowatch.com/watch-choice-for-survival-top-pick-for-deserted-island-scenario/> * Grandfather clocks Simple items * mercury thermometers * Fisher Space pen <http://en.wikipedia.org/wiki/Space_Pen> * Fisher space pen working after 38 years in storage <http://fisherspacepen.com/pages/testimonials> * Leatherman * coleman lanterns or petromax lanterns * Zippo lighters [Answer] I will enforce other's answers that what you're looking for is military grade equipment, or an equivalent. Per unit cost is high and it is made in relatively small numbers (hundreds or thousands compared to millions for consumer models). It must take a beating in harsh environments: hot, cold, wet or dry. It must be rugged and easy to maintain in the field, critical components such as engines must be accessible without special parts or jacks. Parts should be interchangeable from left side to right, and from one unit to the other (no custom built vehicles). [The A-10](https://en.wikipedia.org/wiki/Fairchild_Republic_A-10_Thunderbolt_II#Overview) is an excellent example of this design philosophy. Military equipment has another advantage, its technology can plateau. Consumer equipment is continuously pressured to be better and cheaper. Military equipment only has to be better than your enemy's. If, as happened at the end of the Cold War, your enemy can no longer sustain their military, there's little pressure to spend the excessive amounts of money for an upgrade. Much of the standard US equipment was designed in the 60s to 80s: the M16 rifle, the M2 heavy machine gun, the M1 tank, the M2 fighting vehicle, the F-15, F-16 and F-18 fighter-bombers, the B-52 bomber, the A-10 attack aircraft... with help from a small number of more advanced weapons, they're all good enough to provide the bulk of the armed forces to take on their expected enemies and will continue to serve with upgrades for decades to come. As it becomes too expensive, and as opponents fall behind in the arms race, military technology can also backslide. An example is the 60s race for faster and faster aircraft, culminating in the [Mach 3+ XB-70 Valkyrie Bomber](https://en.wikipedia.org/wiki/North_American_XB-70_Valkyrie). The incredible cost of this bomber, and its vulnerability compared to cheaper ballistic missiles, lead to its cancellation. Modern military aircraft fly at a more sedate and affordable Mach 1.5 and our defenses are tuned to match. I could see a future where a old Mach 3 aircraft could prove untouchable, at least for a little while. I will also enforce storage. If the equipment is properly drained of fluids, sealed and stored in a controlled environment it could last for centuries. One such example are [aircraft boneyards](https://en.wikipedia.org/wiki/Aircraft_boneyard) usually located in very dry deserts. In addition to [being specially sealed](https://www.flickr.com/photos/xwrn/8845400464/in/set-72157633720110276/), the dry conditions and hard ground protect aircraft from decay. Some are cannibalized for spare parts. Some are meant to be ready to fly in a few days. Another element is an explanation why nobody else has already plundered this cache. It could be hidden or obscured. As in the case of the boneyards, it could be in a very remote or hostile area. It could be protected. It could be made out of materials worthless as scrap, such as the [Clock of the Long Now](https://en.wikipedia.org/wiki/Clock_of_the_Long_Now#Design). Batteries are a problem. You can hand wave this away with advanced technology. You could require your discoverers to give it a jump start. You could provide a trickle power source such as solar, or an RTG. An [RTG using a fuel such as Plutonium or Americium](https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator#Criteria_for_selection_of_isotopes), with no moving parts to wear out, could provide a basic power source for centuries. [Answer] In modern society, we design a vast majority of our products to do well within a small range of operation, with little care to how well it operates outside that range. Compare that with organic life, which to this day astounds us by its ability to operate outside of "spec range." If a society ceases to focus so much on the narrow capabilities, and begins considering the broader operating range, it would begin designing things which can continue functioning much longer. Interestingly enough, in many Sci Fi books, this jump from "do what I say really well" to "do the right thing" often occurs near the cusp of a society being annihilated by its creations [Answer] It is a sad fact that [no ancient ruins have ever been found full of working traps](http://www.straightdope.com/columns/read/2217/were-ancient-tombs-really-booby-trapped) and with good reason. However, if you did want to leave something somewhere that it might endure for a long period, there is one place that you could be reasonably confident that things will last: Space. There is some risk of damage from meteorite collisions but space is very big and so the chances are relatively small. With no atmosphere to provoke destructive chemical reactions and no sources of dust or other solids to jam up workings, there are few reasons that anything that could successfully be put in space - assuming it is far enough out to avoid falling out of orbit or colliding with another body - could not stay there indefinitely. If you are on a planetary surface you might be able to preserve equipment well by taking something from this philosophy and sealing it in an artificial vacuum. Whatever you had sealed away should stay in good condition until the seal failed at least, which could be a very long time if you made it from durable materials ( maybe a glass-lined bubble of granite? ) and they were not exposed to erosion. Eventually the vacuum would fail, but it would take a very long time and even once it did, the environment might be sufficiently protected to preserve it for a long time anyway. [Answer] Also, Ancients might just added General AI with goal maintain that system, build robots to fix any problems and mine resources to provide energy and necessary raw materials. [Answer] First of all, current technology's fragileness is a bad reference, as the technology is now designed to break after some chosen period, to let people buy a new phone / car / whatever, unless it is really designed to last. The old pieces of technology don't last so long because 'they did it better once'. They simply didn't got the idea of making things which had to break: they simpy had to work. And I think that some ancients won't leave mechanical guardians, etc. which would break after guarantee period. :) ]
[Question] [ So, somewhere around one hundred years from now, a terrible - and unexpected - disaster strikes Earth, most of humanity dies off, yadda yadda yadda. Luckily, secret-lab-dwelling scientists had stashed tons of knowledge about a lot of probably important stuff (test data ! everybody loves tests !) inside a super-computer. Unluckily for them though, they all die, and the secret lab's power supply shuts down. Four hundred years later, a bunch of explorers stumble upon our secret lab, and manage to turn the power back on. As the lights illuminate the lab, they hear a "Hello, World !" resounding throught the facilities. It seems our computer is still alive ! Now my question is, if we assume that our computer is safe from any environmental harm, and take only the main parts (cpu, etc...) into account, is there any existing or theorised way to build a computer that would still function after centuries ? I've read in [this answer](https://superuser.com/a/312764) that even with extreme luck we couldn't really expect much from hard drives past a few decades and from what (little, admittedly) I know, computers can't really run on an optical drive (then again, I may be wrong, I didn't manage to find anything about that), even though [some of them](https://en.wikipedia.org/wiki/M-DISC) could theorically store data for a millenia . So is this theorically possible, or will I have to handwave my way through with a magnificient "Future YO ! Look, there ! hoverboards !" ? --- EDIT : Hello again everyone ! Tanks a lot for all your answers and ideas ! A little update on what I decided I'd go with so far, based on your answers and my own research. 1. How to store the data ? This is pretty much covered : either [DNA Data Storage](https://en.wikipedia.org/wiki/DNA_digital_data_storage) or [neronix17's Data Crystals](https://worldbuilding.stackexchange.com/a/28576/14831) with the corresponding reading/writing devices, potentially accompanied by more conventionnal drives for quicker access once data has been restored. 2. How to preserve usable boot and restoration programs ? If the above-mentionned techniques can't fill this specific role (and I'm not even sure we can determine this yet, given the early stage these technologies are at), [Jim2B's answer](https://worldbuilding.stackexchange.com/a/28520/14831) provides extensive information about all this, so I'd most likely go for magnetic core memory. 3. How to deal with components decay ? This is where I'm kinda stuck. [Ville Niemi mentioned](https://worldbuilding.stackexchange.com/a/28587/14831) that some of the computer's components will be degraded as time passes while Monty Wild affirms the opposite in the comments. Now I'm expecting that the components would suffer at least some kind of degradation over 400 years, but would it really be all that catastrophic if they are kept unused and in an optimal environment ? By the way, I'm kinda new to this site so please do tell if I need to mark the current question as answered and/or ask this in a separate question, I'm kinda confused .\_. [Answer] ## We don't really know The recent development of our current digital environment (commercial use of the internet dates back to roughly 1980 - which also coincides for the approximate start of home computing), means that we haven't really had an opportunity to test their long-term viability (essentially we can't even test the digital data standards & storage methods for more than about 35 years because they simply haven't been around longer than that). But, currently all of the standard storage mechanisms that we use today are only expected to remain viable for from a few years to a few decades (this includes so-called archival media like optical disks and data tapes). So far we've never encountered a need for extremely long duration archiving of data, so no one has ever bothered to design a system to work for that situation. If the scientists and engineers in your story had a few years of warning, they could probably develop something that would work. I do not know how it would look but, based upon experience with various methods, I can guess. ## But maybe we can guess The F-15 originally was built with "primitive" [magnetic core memory](https://en.wikipedia.org/wiki/Magnetic-core_memory). This type of memory is non-volatile and highly resistant to EMP and other things (like cosmic rays) that can damage the data stored in modern memory. However, it is much slower and bulkier than modern memory. [![Magnetic Core Memory](https://i.stack.imgur.com/A3rJK.jpg)](https://i.stack.imgur.com/A3rJK.jpg) [Magnetic Core Memory Durability](https://en.wikipedia.org/wiki/Magnetic-core_memory#Physical_characteristics) > > Core memory is non-volatile storage—it can retain its contents > indefinitely without power. It is also relatively unaffected by EMP > and radiation. These were important advantages for some applications > like first-generation industrial programmable controllers, military > installations and vehicles like fighter aircraft, as well as > spacecraft, and led to core being used for a number of years after > availability of semiconductor MOS memory (see also MOSFET). For > example, the Space Shuttle flight computers initially used core > memory, which preserved the contents of memory even through the > Challenger's disintegration and subsequent plunge into the sea in > 1986. > > > ### POST I imagine your computer's bootstrap would be composed of similar bulky but reliable and non-volatile memory. This basic bootstrap functionality, perhaps similar to your computer's POST (power on self-test), would ensure important portions of the computer still worked and would then (slowly) load the actual operating system for the device. ### Flag failed components/use good ones Because I would expect many of the bits of the computer to have degraded enough to be unusable, the overall system probably would provide massive redundancy for each critical component. As the POST operations encounter failing components, it'd automatically switch to testing the next redundant component in lines. Since the POST operations would likely be fairly elementary, the overall system would likely flag the "failed" component for re-evaluation by the full-up OS once the boot cycle completed. A more thorough mapping of the essential components (e.g. CPUs might reveal just certain portions of the chip failed and that the CPU was otherwise OK). The OS would use this map of its redundant components to ensure it could keep operating as long as a complete set of essential functions remained operational. ### After boot up cycle This computer system would probably fall back on a bank of relatively modern memory chips for actual operations after the initial bootstrap. It'd be up to the original POST operations to initially determine which banks of modern memory were still viable and then (like with the CPU), a more sophisticated utility in the OS would perform a more thorough mapping of the memory to see how much of it remained usable. ### Data recovery After the basic OS and self-check programming began operating, the computer would begin to activate its many RAID (redundant array of independent disks) like data storage systems. The "drives" in the system would be special low density (and probably solid state) memory drives. The RAID system would verify the bit states across multiple drives and slowly reconstitute any damage data in the storage systems. ### Slow and reliable (tortoise) performance In your scenario, the primary goal of the hardware would be reliability and data redundancy so the storage arrays for your data would be quite large and probably not all that fast. A set of fast "working" hard drive storage might be provided for daily operations. The time it took for the RAID like systems to perform the data validation checks and/or rebuild damaged sections could be quite lengthy (days, weeks, or substantially longer - depending upon the speed of the devices and amount of data we're discussing). From a dramatic perspective this might allow the author to perform a variety of reveals through the course of the book as different sections of the data storage are flagged as "ready for use", loaded into the faster systems, and made available to the characters in the story. If the data reconstruction was imperfect it might allow the computer to provide false information too... ## All good things come to an end All hardware eventually fails. Meaning even if your computer booted perfectly upon the application of power, mechanical hard drives fail, solid state drives fail, memory fails, etc. Your computer that survived the centuries would eventually wear out and stop working. It should make that point to the inheritors of the system as soon as possible. ## And another thing Richard Feynman sponsored some prizes to groups that could write data (["There's Plenty of Room at the Bottom"](https://en.wikipedia.org/wiki/There%27s_Plenty_of_Room_at_the_Bottom), in conventional analog form, in the highest density. For instance trying to print the Encyclopedia Britannica on the head of a pin. The only thing you'd need to read the data is a really good microscope. This sort of data's shelf life is potentially MUCH higher than that of digitally stored data and you wouldn't have to worry about computer interoperability and changes in encoding standards as a condition of data retrieval! > > "There's Plenty of Room at the Bottom" was a lecture given by > physicist Richard Feynman at an American Physical Society meeting at > Caltech on December 29, 1959.[1](https://i.stack.imgur.com/A3rJK.jpg) Feynman considered the possibility of > direct manipulation of individual atoms as a more powerful form of > synthetic chemistry than those used at the time. The talk went > unnoticed and it didn't inspire the conceptual beginnings of the > field. In the 1990s it was rediscovered and publicised as a seminal > event in the field, probably to boost the history of nanotechnology > with Feynman's reputation. > > > ... > > > At the meeting, Feynman concluded his talk with two challenges, and he > offered a prize of $1000 for the first individuals to solve each one. > The first challenge involved the construction of a tiny motor, which, > to Feynman's surprise, was achieved by November 1960 by William > McLellan, a meticulous craftsman, using conventional tools. The motor > met the conditions, but did not advance the art. The second challenge > involved the possibility of scaling down letters small enough so as to > be able to fit the entire Encyclopædia Britannica on the head of a > pin, by writing the information from a book page on a surface 1/25,000 > smaller in linear scale. In 1985, Tom Newman, a Stanford graduate > student, successfully reduced the first paragraph of A Tale of Two > Cities by 1/25,000, and collected the second Feynman prize. > > > [Answer] I'm a little surprised nobody brought up the quartz glass storage device that was talked about the past couple of years, I couldn't find if anything came of it but there's a few articles about it [here](http://physicsworld.com/cws/article/news/2013/jul/17/5d-superman-memory-crystal-heralds-unlimited-lifetime-data-storage), [here](http://www.scientificamerican.com/article/data-saved-quartz-glass-might-last-300-million-years/) and [here](http://inhabitat.com/revolutionary-superman-memory-crystals-can-store-data-virtually-forever/). As the last one point out it sounds like something out of Superman or some other sci-fi shows/movies, but it makes sense. I mean we have had the technology to etch crystals with drawings and 3D 'sculptures' inside of them so it seems perfectly reasonable to think we could do that and have a computer read it as information. The length of time these could last appears to vary quite a bit but I'm sure millions of years is considerably longer than you need. [Answer] You may want to check out <http://longnow.org/essays/written-wind/> for issues with retrieving archives over long periods of time. > > To keep a digital artifact perpetually accessible, record the current version of it on a physically permanent medium, such as silicon disks microetched by Norsam Technologies in New Mexico, then go ahead and let users, robot or human, migrate the artifact through generations of versions and platforms, pausing from time to time to record the new manifestation on a Norsam disk. One path is slow, periodic and conservative; the other, fast, constant and adaptive. When the chain of use is eventually broken, it leaves a permanent record of the chain until then, so the artifact can be revived to begin the chain anew. > > > The Norsam disk is supposed to be good for a minimum of 1000 years (cite: <https://en.wikipedia.org/wiki/HD-Rosetta>). If you're looking into a computer system, you'd want a bootstrapped system where it could build itself. [Answer] I think computer components should decay with a half-life just like radioactive materials. Assuming half-life of 5 years after 400 years you would have left... not that much of the original components. Having a secure location and being in deep sleep mode should help significantly. I think you could realistically expect the system to still have between one billionth and one trillionth of its original capacity. So I don't think we can assume any current or projected technology to cover this. But you say this would happen one hundred years in the future. They might have developed such technology. They certainly would have if they had expected the end to be near. The simplest rubber-science (best that can be provided for "computers century from now" category) solution would be for the computing systems to have self-repair capability. If the system also had high level of redundancy and a secure supply of power, both of which are reasonable possibilities, it could feasibly survive for a long time. It would still have much less capacity than it used to have, but chatting up some explorers should not really require that large a portion of capacity to survive, if the system was originally designed to support cutting edge research. Unfortunately the only way to build a self-repairing computer with massive redundancy we can currently theorize is bio-mimicry. That is, to create an artificial organism that supports a very large brain modelled after the human brain. Probably it would be more like an entire colony of interconnected brains. Possibly suspended in a container of nutrient fluid with an entire artificial ecosystem. I guess it would be like a large aquarium with "brain-coral" in it. Radio-thermal or geothermal power could support the ecosystem for a few centuries despite what happens on the surface. And you might be able to justify that by desire not to have an energy trail that can be used to locate the lab on the surface. Note that with a persistent power source and continuous activity needed for the self-repair and memory refresh, the computer would have been awake and aware for the entire 400 years. It might be confused by visitors after such a long time and suffer severe culture shock. So full ability, but difficulty to communicate? It might appear to suffer from mental issues and general weirdness to the explorers. [Answer] Perhaps long-lived computers will be created for use in space probes. Just as Galileo operated for years in transit and then the harsh radiation environment near Jupiter, an interstellar probe would need to be built to last. Even if only meant for (say) 50 years, if left in a calm environment rather than the radiation of space, it may last much longer. So, it is conceivable that such a computer will be built and available for use in such a lab. [Answer] # Easily (mostly) If we build for that purpose only and not to maximize cost efficiency, speed, size, or any of the "normal" criteria. Instead of making each semiconductor junction a few dozen atoms wide, make them 100000 atoms in size. Think microprocessors built using today's technology, but on 1970's scale of miniaturization. With each transistor being 1000^3 = 1 billion times as large, your computer will be 1/1000th the speed. SO WHAT! It will also be 1 billion times more resistant to damage from radioactive events, crystal deformation, and oxidizing factors. Build the hard drive with stonking huge overpowered motors. With physically separate magnetic domains, not tiny little deviations in a smooth magnetic plain like we normally do. Built your driver with RAID-plaid. (That's raid mirroring taken past ludicrous level). Build every device, every data channel with quadruple or better redundancy. Get rid of all components that have a built-in lifespan limitation of less than millenia. This especially means to get rid of all electrolytic capacitors. Yes, this is very inconvenient, and will cause the engineers to have fits. But it can be done. Pay attention to what materials you build it from. For example, do NOT use aluminium and gold junctions. Because, over time, they rot. For that matter, do not use aluminium in its construction at al. That stuff just loves to oxydize. Ditto for copper. And don't even think about using steel as construction material, that stuff is useless! All of this we can do. Easily. Not cheaply! And good grief the resultant computer will be SLOW, and will consume a mountain of power compared to the task it performs. But we can do it. And, as long as it is protected from physical damage, and shielded from extremes of environment, it will remain functional for a long, long, looong time. Unsolved problems. I'm not sure what to do about display. Both CRT screens and LCD are not suitable for multi-century storage, and cannot easily be made so. Can a crt be made without a vacuum inside, but with inert gas? I don't think so. Not can i visualize any way to keep a vacuum component retain its vacuum over centuries. Even many cm-thick glass leaks air eventually. Glass is porous, you know. slightly You might even have to revert to glowing-filament-in-inert-gas tubes for display? Almost any mechanical switch or relay will become untrustworthy after a few centuries. Possibly if made out of inert material such as gold, and kept in a neutral gas to prevent surface deposits? [Answer] One possible solution to data decay would be a mirrored array of data storage devices (possibly hard drives or flash memory). You would probably need an array of four or eight drives (possibly with some mirrored parity drives) to maintain data for centuries if not millennia. Flash memory would probably be best, since it's non-magnetic and the main limitation on its lifespan is read / write cycles. Even if there is significant data corruption on all the drives, you should be able to restore most if not all the data. At that point, you're dealing with physical breakdown of the device, not decay of the data itself. An optimal climate controlled environment would probably protect the data storage devices themselves for 400 years. If you're looking for longer-term storage and not concerned about cost or capacity, you can use gold leaf punchcards - which will last pretty much indefinitely. The computer itself probably wouldn't be in great shape after 400 years. Modern electronics simply aren't designed to last that long - a few decades at most. With careful consideration and design - as well as an ideal environment - would probably let you work around those problems. A sealed inert gas environment might do the trick there. [Answer] Try some wooden computer powered by mechanical energy. Really, computers are just some really fast [Abacus](https://en.wikipedia.org/wiki/Abacus) And it's state can last for centuries ! Really, I think a pure mechanical computer is possible. Useless because of electricity, but it could be powered by fuel. [Answer] Blueprint, Large Parts, Redundancy Why not split the problem into three easier ones: Firstly, prototyping a simple computer that can be maintained by the crudest crafting. It would only need the simplest operations, such as displaying raw text files with a series of large 26-digit alphabet spinners (rather than screens, relying on mostly analog parts, 36 if you want the numbers too), and operating on a large keyboard. Everything about it should be massive, so that it is easier to assemble and replace parts. There should be as much analog, moving parts made of normal materials, and if possible, no electrical parts, (like Charles Babbage's [differential engine](https://en.wikipedia.org/wiki/Difference_engine#Charles_Babbage's_difference_engines)). Secondly, a storage medium that works with the simple computer, created with materials designed to last for thousands of years. Thirdly, the blueprints for the simple computer can be placed with the storage medium, and etched onto some material that can last for hundreds of years ([mineral](https://www.wired.com/2016/10/want-tombstone-last-forever-make-quartzite/) or corrosive-resistant metal will probably work, taking into account tombstones). The materials for making the computer will be made of components that can also conceivably last many years without corrosion, so that whoever finds the blueprints can re-assemble them into the simple computer. A deactivated, working computer can also be placed in the room as well, created with the same blueprint. This way, should it break down, not only will the finder have the blueprints, but also have a way to maintain, repair, and create said computer, to access the storage mediums that will last a long, long, time. This will allow your computer to be used for as long as the storage medium can last for, since we do not rely on the computer to be functioning immediately after countless years, just on it being reliable enough to be easily repaired after countless years. Who knows, if it's found long enough afterwards, the incredible size of the computer and its all-knowing nature might have the finders worship it as a deity! [Answer] One approach that hasn't been mentioned yet is that the computers could repair themselves. That is how DNA data survives for millions of years. The DNA is carried in organisms which reproduce, replacing any dying ones. Similarly a computer equipped with a suitable 3d printer and robotic appendages could replace any failing part of itself. This can't be done in real life yet because some components, especially the chips, cannot be 3d printed yet in the size at which they are made. But there is no reason in principle why this couldn't be done. Chips are made by chip making machines, and your computer could be equipped with a few. [Answer] I am in two minds on this. Either you go all solid state with flash drives and as few moving parts as possible OR you go steampunk and have a completely mechanical computer similar to Babbage's [Difference Engine](https://en.wikipedia.org/wiki/Difference_engine). The level of technology required to maintain it is very low. You could even have a order of monks who maintain it over the centuries without knowlegde of what it actually does. [Answer] There are new technologies being developed and tested nowadays, for example the 5-dimensional computer 'memory crystal' that according to the scientists the Information encoded with lasers, has a thermal stability of up to 1000°C and a practically unlimited shelf life. There are a couple of links bellow with news about it. [Like this](http://www.independent.co.uk/news/science/the-superman-of-hard-drives-new-5-dimensional-computer-memory-crystal-will-survive-the-human-race-8700319.html) [And this](http://www.dailytech.com/Scientists+Create+360+TB+Superman+Crystal+Discs/article31933.html) [Answer] Here is my description of the technology, it was created specifically for computing systems that required durability above all. Palantir ( not spherical, but cubic ) When you first look at it, you can not help but think that the developers of this device were clearly big fans of Tolkien, which can already be judged by the name of the device itself. Imagine a block of solid diamond with a side of exactly twenty-five centimeters. And this is a computer. A single-crystal computer is a monoblock in the most literal sense of the word. Any of the six faces can serve as a monitor, contact keyboard, scanner, and solar battery. All the computer circuits, the power supply, the storage device-all embedded directly in the crystal, almost all of different forms of carbon, with minor additions of other substances. No moving parts. There are no cavities. Each module is duplicated three times. Fullerene inserts allow you to hold quite strong shocks, so if an ordinary diamond can be broken with a hammer, this one is like hell. And on top of everything else, this shit is also able to self - repair-growing new transistors and memory cells to replace those damaged by friction and wear, as well as ultraviolet rays and other types of ionizing radiation. The process of creating memory cells can be described as follows: Under the influence of very short laser pulses, the necessary multilayer self-organizing nanostructure is created in the glass. Such pulses are called femtoseconds, and their duration is equal to one quadrillionth (one millionth of one billionth) of a second. Information is recorded using three layers of voxels (volume pixels) located at a distance of 5 micrometers (one millionth of a meter) from each other. These points change the polarization of light passing through the disk, which allows you to read the state of the structure using a microscope and a polarizer-similar to the one used in Polaroid sunglasses. Developers call this technology 5D-memory, because each unit of information (bit) has five different characteristics. This includes the three spatial coordinates of points in the nanostructure, as well as the size and orientation — a total of five possible parameters. Due to this, the new technology provides a huge density of information recording compared to conventional CD-ROMs running on 2D memory technology. This technique allows you to achieve a huge recording density: 360 terabytes of data can be written to a disk made of quartz glass with a diameter of several centimeters. For a minute, in order to record this amount of information, you would need about seven thousand modern 50-Gigabyte double-layer Blu-Ray discs. Since glass is used as the material, data can be stored at temperatures up to 1000°C. the Durability of such a storage device will be, according to scientists, 13.8 billion years at an operating temperature of 190°C. So this "cube" is the most durable computer and data storage ever created. The only problem is that due to the incredible durability, we had to pay with computing power. For this reason, the average "Palantir" in terms of computing power is comparable to conventional PCs of the 2010s. ]
[Question] [ Given the approximate technology level of us Humans today. Is there enough of each material needed by our modern civilization in Asteroids to make this economic? And would the materials be used for stuff in space or brought down to the surface? Consider the following/take as given: 1. No human is needed to directly supervise the mining process. Engineers came up with a set-and-forget mining facility, which just needs some commands from Home-Control from time to time. 2. It is possible to bring the mining facility to any place in the solar-system. I'm interested in the process of shipping resources around, not setting up the system. 3. Cargo-Vessels can be built in space, but only under direct supervision (Humans need to be around, the perfect space dock needs yet to be built), and it is not necessary that the vessel that transports the cargo to Earth also brings it down to Earth. To summarize: Does it make sense to start harvesting asteroids in the next 100 years? [Answer] The economics of mining in space are hotly contested, with some estimates claiming as much as US$20 trillion worth of precious and industrial metals in a single asteroid, while others point out that any efforts to extract these materials and bring them back to Earth en masse will necessarily flood the market and cause prices to crash, potentially (or probably, or even definitively, depending on who you ask) making the whole endeavor self-defeating. Frankly, if the experts can't even agree on whether or not it could be economically feasible to mine asteroids and bring the materials back to Earth, I doubt we'll be able to give a solid answer either way. Where space mining could come into its own, however, is in space-based industry. Currently, [according to NASA](http://www.nasa.gov/centers/marshall/news/background/facts/astp.html_prt.htm), it costs US\$10,000 per pound to put anything into space. While NASA's goal is to reduce that to around \$100 per pound by 2025, they don't yet have anything that could do that, and even if they do manage that let's put it into perspective: at that lower, post-2025 cost, it would cost over \$81.6 million to put the [ISS](http://www.space.com/8876-international-space-station-numbers.html) into orbit, which while an impressive feat itself is quite limited in its scale, and much too small for anything even remotely considered "industrial". Given such high overhead, it's really no surprise then that we really are not doing a whole lot out there. But if we can bring raw materials into orbit for cheaper, then suddenly the economics of space-based industry become a lot friendlier: It's a lot cheaper to move around in space than it is to fight against gravity and escape Earth's surface. Just look at the Apollo missions: Compare how big the Saturn V rocket was that had to get the CSM/LM into space, versus how small the CSM/LM were for getting all the way out to the moon, landing on it, getting back into lunar orbit (into a retrograde orbit at that (a consequence of the free-return trajectory Apollo took out to the moon), much more costly than prograde!), and then returning to Earth. Solid numbers: 1,000 times more mass required to go 2,000Km than needed to go almost 800,000Km! So what would we do with space-based industry? While there are a few super-high-tech things that simply work better to manufacture in micro-gravity than here on Earth, for the most part anything made in space would suffer the same self-defeating diminishing returns if we try and manufacture it for the purpose of bringing it back to Earth. That doesn't mean it won't be done -- could be a good way for some manufacturers to get a leg up on their competition -- space-based industry would most likely exist to service space, not Earth. Which means we probably won't have it until we have a need for it, i.e. we won't have space-based industry until we're doing things in space that would benefit from it (living in space stations, extra-terrestrial colonization, space tourism, etc.); the Catch-22 is that we (probably) won't be doing things in space that would benefit from space-based industry until it's economically feasible to do without space-based industry, though granted even then space-based industry would probably be cheaper than flying things up from Earth. If you really want to bring stuff down to Earth from space, you could always build cheap, single-use "dropship"-style pods in space and literally drop them down to Earth. The cost is fighting against gravity; using it as your version of a FedEx driver is actually quite cost-effective! Just beware of the fundamental law of economics: As you increase the supply of some product/material, unless you also increase the demand by the same proportion (unlikely), prices will necessarily drop, which will of course cut into any profits you might otherwise have gained. [Answer] Kromey's answer was a very good treatise on the unlikelihood of using asteroid mining to bring materials or products back to Earth. One quick-and-dirty method to get at the contents of a mineral-rich asteroid would be to redirect it to the planet where we wanted the minerals and just let it crash on its own. That might be a problem almost anywhere on Earth, but not on other planets/moons. Suppose one day we have a permanent Mars colony, but Mars is lacking in certain heavy elements we take for granted in Earth manufacturing. Instead of sending regular care packages of these Earth-mined substances, we might redirect (for example) a nickel-rich asteroid to slam into Mars a few hundred/thousand miles away from any current human settlements and give the colonists a semi-artificial nickel mine. After a one-time care package full of mining and ore-refining equipment the Martians can get their own metal and build their own machines out of it. [Answer] Good answer in space stackexchange by @PearsonArtPhoto: Most interesting part imho: > > So, what does it take to make a space mining operation profitable? > Manufacturing. If you can develop an autonomous set of manufacturing > robots, then you might be able to make something work. There is a > number often quoted of $2.6 billion to break even, but that depends on > making these advanced robotics work. It could work, but I think only > time will tell. > > > There is also a whole world of microgravity manufacturing > possibilities which has barely been touched. It's far easier to make > some things in microgravity, but we haven't really explored that space > very much yet. > > > <https://space.stackexchange.com/questions/633/what-resources-could-be-gained-from-asteroid-mining-that-would-be-worth-the-effo> [Answer] The major cost in moving freight around the Solar System is fighting the gravity wells of planets. Moving material from the asteroid belt to Earth orbit is relatively cheap in terms of fuel, if you have the technology. Dragging material from the Earth's surface is expensive, as is dragging it down to the surface. If the idea is to bring the material to Earth's surface, the cost will probably be prohibitive. The advantage would come if you needed it in Earth orbit. [Answer] In general the primary benefit of mining asteroids in space would be for building things in space, such as space stations and ships. Once we can mine asteroids and process the raw materials into space ship pieces etc., it will dramatically reduce the cost of making a space station of a reasonable size, say one that is a couple Km across so it can turn and have decent gravity. [Answer] It's an area of active research: <http://www.bbc.co.uk/news/science-environment-25716103> Gold and related precious metals are particularly interesting. They have good value density, usefulness in space, and are iron-soluble so they tend to end up in planetary cores. On earth they are thinly distributed across the surface. Iridium and rhodium are even rarer, and have industrial use. Gold mining tends to be environmentally destructive; mines can leak mercury and arsenic into surrounding water tables. This isn't an issue in space, although you will need a good reagent reprocessing system as there's no additional water available. Nobody will really complain if you replace an asteroid with a toxic debris field. [Answer] "Down is easy", but I wonder if the delivery of astrogoods will become a source of pollution in itself? Imagine refined ore shaped into a capsule and use slag as an ablative heatshield. The slag burns off on the way down, so eventually they'll be wanting to keep various elements out of it, or push for more eco-friendly solutions like aeroglides or future tech like superconducting magnet skylanes. [Answer] I think this is only a cost-effective solution under a few circumstances. 1. The initial mining rig must be tiny, and used to build the rest of the mining apparatus. * You send up a small, cheap mission to construct the big monstrosity that will be the permanent mining operation. This cuts down on the real costs of shipping things from earth against gravity * You use the same manufacturing techniques to exponentially build more until you are mining as much as you can handle * You establish a shipyard near these supplies that can manufacture every component you need. * This whole thing is very tricky, and would require a good deal of human intervention to get set up. Manufacturing delicate components for spacecraft would be especially difficult as we haven't done this in low gravity and would have to have some very delicate refining processes. With enough research it should be doable. 2. Phase 2 involves the building of your transport vessels. You build several of these, put them on an orbital trajectory that minimizes the need for fuel, and use gravity to drop packages of materials to earth/other colonies. 3. The real value in all of this is the spaceyard. If you can build spacecraft without the need to fight against Earth's gravity, you've drastically reduces the cost of space missions. The hard part becomes getting the humans there, but you can build a deep space exploration vessel that isn't restricted by the weight of what can escape Earth. [Answer] Make it economic: Step 1: Set it up. The cost is really high, but presumably after you're set up the marginal cost of an extra tonne of ore is minimal. Step 2: Flood the market with ultra-cheap ore. Making all terestial based mining go out of business (not even a bad idea given the polution effect of earth-based mines). You now have a monopoly. Step 3: Rack up prices again to earn back your initial investment (plus a bit on the side of course). (Repeat step 2 and 3 if anybody tries to re-open a mine. Do this a few times and people (companies) will get the message.) For extra profit: Refuse to supply to anybody that might be working on setting up a similar space-based mining complex. This would be hard to do perfectly, but even done imperfectly, it would further increase the cost competition. And as a special bonus: Use your relatively large presence in space to have "accidents" happen to anybody that does manage to get started on competition. ]
[Question] [ Is there any software tool for quickly prototyping a planetary system? Ideally this should: * Allow for placement of planets of different sizes and masses around a star. * Allow for examination of the interactions of the planets caused by gravity. * Allow for examination of day and night on the planets and eclipses. [Answer] There's [Universe Sandbox](http://universesandbox.com/2/), which while considered and marketed as a game and using some orbital calculation approaches that are outdated by modern astronomical standards, should work great for worldbuilding and simulating celestial bodies and events. It's paid software, but it does allow you to simulate the Solar System, albeit without much accuracy very far into the future. The current version is Windows only, with the next one being made for OSX and Linux apparently. There's a free version but you can't add objects. > > edit - Taemyr mentions that Universe Sandbox will not* model day and night, so if you need that, you might have to look elsewhere or wing it.* > > > edit - Having recently acquired and played Universe Sandbox, I want to add that while it's ok to use when you want to answer some abstract question ("What if Jupiter disappeared?") it really isn't very good for a realistic and detailed analysis (not to mention, it is quite buggy and not very fun). From what I gather, you really need to perform some simulations on a computational math package if you want something like that. > > > [Answer] When I was in the university physics program I was given a Physics simulator package called [CUPS](http://perso.utinam.cnrs.fr/~cordier/index.php?pw=cupslinux), it contained many packages (electrodynamics, quantum mechanics, classical mechanics, and astrophysics). The astrophysics package contained a planetary orbital dynamics simulator that would suit your requirements. All of the CUPS packages came with PASCAL source code, so you should be able to run them on your favorite OS, if you can program in PASCAL [Answer] To some extent, you can create your own star system also in [Space Engine](http://en.spaceengine.org/). It has beatiful graphics, it allows you to make videos or photos from the surfaces of planets in various angles, but it is not so interactive as the [Universe Sandbox](http://universesandbox.com/2/). This basically means that you have to input the parameters in text format and you cannot just add them by clicking. The Space Engine is free. I have also heard that [AstroSynthesis](http://www.nbos.com/products/astro/astro-new.htm) is quite good, but I have no experience with it myself. [Answer] My personal favorite is [My Solar System](http://phet.colorado.edu/en/simulation/my-solar-system), by the University of Colorado-Boulder. You can also access version 2.04 directly [here](http://phet.colorado.edu/sims/my-solar-system/my-solar-system_en.html). It's pretty basic, but it has some cool features. You can choose to view from the perspective of the system's center of mass, of that of a hypothetical stationary observer. Other features include tracing orbits of the objects. You can adjust a few different quantities: * Number of objects (up to 4) * Mass of objects * Position of objects * Velocity (magnitude and direction) of objects These can give a pretty good description of a system of bodies. You can't model day and night, but you can satisfy your other criteria. By the way, the system is free. ]
[Question] [ How would avians build a defensive structure? What would be the equivalent of walls, a drawbridge, a dungeon, etc. If two avian / arial cultures were at war, say birds vs. dragonflies, how and where would they construct their defensive strongholds? Would a siege be possible? Siege engines? A human stronghold typically requires a wall or moat to slow the attacker, giving the archers a chance to cut them down. Could there be any equivalent for an arial species? Assume mixed level technology, medieval level weaponry bows, bladed weapons, wooden structures, etc, with some advanced materials. [Answer] Castles built to defend Avians from other Avian races would likely be built below ground. Either in cliff sides or in mountain crevices. However, these natural terrain formations will not always be options. Depending on the terrain, the Avians may build their fortifications as great shafts cut through the earth into bedrock. Lined with either cut stone or the existing smoothed rock, these holes would have shafts leading into the inhabited parts of the fortification. ![Super Colliding Super Collider!](https://i.stack.imgur.com/DQj9o.jpg) Attackers would be forced to dive into a deep hole, ringed with firing loops manned by archers (or gunners) and attempt to breach one of the side passages recessed into the shaft walls. This would be a nearly insurmountable obstacle, and even a successful assault would entail incredible loss of life on the part of the attackers. Sieges would be the natural solution to this design. As would attempting to breach the fortress via tunnel. Any fortress of this type would have to be designed with the understanding that the enemy may tunnel in from above or the side, and be laid out accordingly. The defenders, on the other hand, will likely have sally ports scattered around the surrounding countryside, accessed by tunnels from the main fortress. These would allow the defenders to harry the besieging army and make contact with the outside. Remember that many of these suggestions become immaterial if the Avians must also contend with land-bound races. In that case, the traditional "Tower on a Mountain" design becomes the most practical for the sheer difficulty of assailing it from the ground as well as its good command of the surrounding airspace. ![Castle in Slovakia](https://i.stack.imgur.com/SZxZC.jpg) [Answer] This question is very difficult to answer without knowing more details: technologicl levels/capabilities (do they have projectile weapons? How fast/dangerous/speed-of-firy are they?) Engineering levels/capabilities? Aerobatic characteristics of the species? (e.g. slow flying birds can be defended against by small movable walls, ala ping-pong paddle blocking). A couple of generic points can be made (some shamelessly stolen from Bean of Orson Scott Card's Ender's Game series): * In true 3-d, far forts and in general perimeter defenses are practically meaningless outside the effective coverage range of ranged weapons. Reason: Surface area to be covered increases as a square of distance; the volume as a cube of distance. For the same reason, sieges are far less effective without VERY good (fast rate of fire, auto-aiming, fast-to-aim) ranged weapons able to cover TONS of area/volume. That's why most spaceship SciFi has point defense lasers. * As with regular 2-d surface warfare, tactical and strategic use of terrain as defense is critical (even more so). + Your avian species, presumably, still have planet surface. So building a castle in a crevice of a mountain, so you're protected by earth below, and 2 sides of the mountain from the sides, is a major advantage. + Not all 2D stuff is applicable. "High Ground" becomes LESS defensible instead of more defensible, for obvious geometric and physics reasons. - Picking a windy area benefits the defenders against avian species, however, in a way that picking higher ground helps pedestrian defenders due to gravity. [Answer] I would think that it would not look like any sort of castle that we're used to seeing. Birds have to think in three dimensions because they can move in three dimensions - as can their opponents. There's no sense in building a ring-shaped castle when your enemy can simply fly over the top and land right on you. So what shape would it be? I'd assume a sphere. Spheres have no edges or corners, and so it would be hard for attacking birds to identify its orientation. It would also be hard to land on, because, ideally, its surface would be so flat that nobody could land on it without slipping. Coat it with, say, oil, and you've got a place that would be very hard to breach. This does leave the issue of how you're going to keep the whole thing in the air. You probably wouldn't be able to, so it could rest on a surface, like the ground. It would still be fully enclosed, though. So it would not be aerial, because any bits intended to keep it in the air would become easy targets. * Walls - These would, of course, be the outer edge of the sphere. These would probably be thick, like a conventional castle - many feet deep. They have to be strong and hard to break. Steel might be a good choice, as would iron. Advanced composites would have some merit if the society was duly advanced. * Drawbridge - Why would you want a drawbridge? There's no way you could create a three-dimensional moat, unless the sphere was at the bottom of an ocean (in which case everyone's in trouble). No moat means no drawbridge. Several doors would be necessary, though, complete with iron bars and all the other guarding regalia from the Middle Ages. * Dungeon - Just like a normal dungeon, I would think. Chuck an enemy in an enclosed room and lock them in, preferably with chains. * Keep - The castle keep is important; it's the central area where the king can be found. I'd embed a smaller sphere inside the big sphere, with some support columns between the two. You wouldn't need bridges because these things can fly. * Defenses - These depend on just how advanced these birds are. Obviously, guns can make a big difference over bows and arrows. Either way, though, expect to see versions of crenelations. Also, catapults would be difficult because there wouldn't be an open top to launch them off of. * "Moat" - You can't have a castle without a moat or other obstacle, but, as superluminary pointed out to me, there's not a whole lot of obstacles you can put around a large sphere. So we'll have to be creative. What would deter a flock of large, angry birds attacking a spherical castle containing other angry birds? Well, barbed wire is an idea. Let's have a whole bunch of large columns stick out at regular intervals along the sphere. Now string webs of barbed wire between them, so that the only gaps are smaller than a bird. This would take a lot or barbed wire and an elaborate system of support structures, but it would make it impossible for the enemy to get in while allowing defenders to safely fire weapons from [arrowslit](http://en.wikipedia.org/wiki/Arrowslit) ports in the castle's sides - like this (viewed from the inside): [![enter image description here](https://upload.wikimedia.org/wikipedia/commons/6/66/Arrow_slat_corfe_castle.jpg)](https://upload.wikimedia.org/wikipedia/commons/6/66/Arrow_slat_corfe_castle.jpg) Image originally from Wikipedia user Bkwillwm, licensed under the under the [Creative Commons Attribution 2.0 Generic license](https://creativecommons.org/licenses/by/2.0/deed.en). So perhaps a shell of barbed wire around the castle could act as a moat defending against the attackers. You could also attach automatic or remote-controlled weapons on the columns to defend them from the attackers. [Answer] The answer by HDE 226868 already provides some great ideas about how the fortress itself would be designed. I would like to write about another aspect: Location. Medieval castles are built on mountains, because this makes them hard to reach. The access routes are few and narrow, making it impossible for attackers with superior number to attack all at once. When transferring this logic to an aerial attack, the opposite becomes true: The amount of airspace needs to be limited as much as possible, so placing the castle on a mountain would be a weak location. The enemy could easily surround it and assault it from all sides at once, from above and from below. It would be a better idea to place the castle at the foot of a mountain, because this reduces possible attack vectors. The defenders can concentrate their anti-air fire on a smaller part of the sky. An even better location would be beneath an overhang, in a cenote or inside a large cave, because that way it could only be attacked from a single direction which might even be small enough to block with a gate. [Answer] Tons of good answers already, but I can't help myself but try to my hand too. In terms of passive defense mechanisms, regardless of 2d/3d, you basically have to think of how you (or rather your avian species) can: * slow/fatigue the enemy * funnel the enemy * stop the enemy These same things can happen far from the fortification, nearer the fortification, and even inside the fortification. Below are a bunch of ideas (got carried away), but the point is really the above: Slow, funnel, stop. --- As already mentioned, tunnelling or burrowing would be obvious solutions for an avian species (indeed many birds in our world burrow or tunnel). You're protected on most sides, and funnel an attacking force quite naturally. One could also consider burrowing upwards. A cliff by the sea could easily have some caves worn by water. From there you might burrow upwards into the cave's ceiling, and (given time), you'd have an upside-down mine. It might be a pretty natural idea for an avian species, just like digging downwards is for us. ### Natural obstacles The trick, though, for any of those structures would probably be in generally slowing an advancing enemy when that enemy can fly. A human castle might be near a river - or even swampland - which is difficult to ford or cross. And it also make it easy to spot attackers. It's harder to think of something that would do the same in an airspace. Giant trees or floating rocks might work if your world otherwise allows for such contrivances. But it would also hide attackers. Giant cobwebs would be neat, though. Or: Large panes of clear glass. Many a bird have fallen victim to that. But there are some naturally occurring things that could hinder flight: * A smoking/ash-spewing volcano is basically a vertical river that'd be hard/dangerous to "cross". (And it's a pretty dramatic visual, if nothing else) * Hot springs or giant geysers producing a lot of steam might work too. * Natural wind tunnels, and places with vicious currents, like those between tall buildings or near mountains. * Really tall mountains. Low temperatures and thin air affect any living being. (See also: False sense of security. Hannibal crossed the Alps in winter, after all.) * An area with near-constant precipitation and/or fog making flight difficult. Swimming birds have feathers that repel water, but other birds aren't so lucky, and can't fly if they get soaked. * Conversely, an arid desert area might have a perpetual sandstorm - not something you'd want to fly through. Plains might have tornados and lightning storms. None of these will stop an army, but it could wear it down, and make an ordered advance impossible. Speaking of precipitation: The good ol' cave-hidden-behind-a-waterfall. The defenders could have a retractable "tunnel" (or just a big awning) that would part the waterfall from inside the cave. Once retracted, attackers would be flying into a moving wall consisting of a few tons of falling water. (Though if I were attacking, I'd think about diverting the water somewhere upriver, if possible. Doing so for something the size of Niagara Falls would be pretty difficult, though.) ### Passive defenses In terms of more purpose-made passive defenses, smoke is a good option if you've burrowed into the ground, because smoke rises. It could make the dive into a shaft even more difficult. Any type of fire, with or without smoke, could also cause strong updrafts that might be considered "difficult terrain" for anyone flying. A hole in the ground like that proposed by Danny Reagan could be ringed by fire at the top: Not only would you have to dive into a heavily defended shaft that you can't see clearly, you'd also have to pass through dense smoke and updrafts first, and avoid getting singed on the way in. A really devious (and pretty Looney Toons'y) idea would be to camouflage the real entrance, and light a ring of fire somewhere else. Brave attackers would dive for the center... and faceplant (beakplant?) into solid rock. A horizontal tunnel could be blocked with a literal trap, like you see under a sink: A place where the tunnel "bucks" up or down. A low part could be flooded with water. The defenders would also be locking themselves in, of course, but unlike a cave-in, it'd be reversible. A really cruel idea: Heavier than air gasses. Perhaps your world has a natural spring of sulfur hexafluoride or something. Fill the trap with that, and make flight really difficult - maybe even asphyxiate attackers, drowning them in "air". Of course a similar thing could be used by the attackers if the fortification is lower than its entrance. Defenders at the bottom of a shaft might try the opposite: Lighter than air gasses. Though you'd need a lot you could create pockets of "light air" where the attackers wings won't carry them. Hydrogen balloons could work as floating mines. Poke one and it'd (somehow) ignite. The fireball, while maybe not deadly, could singe feathers and prevent flight. ### Weaponry As for actual weaponry, others have already mentioned that your defenders might want to use ranged weapons with large cones of fire (e.g. birdshot) or AA-weapons like flak cannons. It may not be necessary to kill if your defenders can simply make flight impossible. Slinging tar or pitch could also interfere with flight by gumming up plumage. It's like anti-personnel mines, if less visually horrific. Still, removing a creature's main means of transportation is a horrible thing, regardless of how you do it, but that's why it'd be effective. [Answer] Once again cliff faces make a good defensive position. Hard to drop something from above and door ways can be blocked. Scatter weapons would be very useful on defense, either large flights of arrows or later tech using gun powder, shotguns with "buck shot" or cannon with 'grape shot' would be very effective since it covers an area and requires less accuracy. Though with a cliff face you'd want to keep heavy enemy weapons out of range, if all they need to do is point at your cliff 'wall' and cause damage. Having good overhead protection becomes much more important with the ability to have more accurate projectiles dropped from on high. This might be very steep roofs to help deflect rocks. (assuming generally rocks small enough to be carried by one and still allowing them to actually fly) Using multiple avians to carry larger stones would require a lot more training to fly in synch and they would be a larger, slower target, so would be easier to defend from the attempted attack but harder to deflect a successful drop. [Answer] I'd have difficulties seeing a castle in a traditional sense...In day to day life, most activity occurs outside the castle walls. It's when an enemy approaches that people relocate themselves in to the safety of the walls. In a "3d" world, walls don't do as much, you'd need a roof as well. In the case of a bird or species that inhabits the ground (builds nests and other structures on land or in trees), I suspect a castle would be very unassuming...simply a cave entrance or hole in the ground. When an enemy comes, the majority of the population would enter the cave 'castle' to protect themselves from the flyers above. A drawbridge here is simply blocking the entrance from the inside. Defensive 'turrets' as bunkers dug into the ground (possibly not even connected to the main castle' cave) with some capability of firing into the sky would likely be the best defence (scattered through the town/village, camouflaged when possible). Roman style artillery would be a good choice (ballista's, Onagers, Scorpio's). In a completely ideal setting, the narrow entrance to the cave castle would open up into a large cavern...gives a narrow opening for the enemy to cram through while the defense is well spread out and focused on the narrow choke point that the invaders must enter. An insect species might be a bit different. Bird-like still has a heavy ground component where it nests and lives on ground while not in flight...insects are different as they don't need this component and are more likely to build in the air. I wonder if a giant 'bees nest' structure would became the dominating 'castle' image. ]
[Question] [ ## Eureka! I have a time machine in my garage and it works. I put an apple in it, close the door, set the timer, open the door to an empty machine, wait five minutes and the apple reappears. (Still tastes great too! Gotta love [Honeycrisps](https://en.wikipedia.org/wiki/Honeycrisp).) I haven't sent anything back in time because that's more risk than I want to take on just yet. Help me out, please. At this point, I just want to test my machine to see that it works beyond trivial examples. (To use industry parlance, I've moved beyond unit testing and want to start user acceptance testing.) ## Things to test There's a couple of things I want to find out before I put my poor fragile body into this machine to see where it goes. I don't mind testing with live animals but want to avoid cruelty to animals if at all possible. * Is there a way for me to discover, non-destructively, how my universe will resolve or prevent any paradoxes? I'm aware that there's potential for "[earth shattering kabooms](https://www.youtube.com/watch?v=z8rYotiiFP8)" which I would like to avoid since I, and the people I care about, live here. * Is there a limit to how far forward or backward I can go? * Can I or anything else go backward? * How could I tell whether I live in a multiverse, single timeline or diverging timeline universe? (This is the subject of [a previous question](https://worldbuilding.stackexchange.com/questions/20371/determining-your-universes-time-travel-paradigm)) * Is the past inviolate or can I remember more than one version? I'm looking for a checklist that will help me test my time machine. I'll discover the results for myself, I just want to know how I should go about getting them. Recommendations to just destroy that machine will be flatly refused. What kind of a mad engineer do you think I am to build something and not test it? Seriously. --- Note to those tempted to vote to close for "actions of a single person": While the question is written in first person, the underlying question is generic to all time-machines. [Answer] What do you need is a series of experiments. Sending small, unconsequential things are best. For the fourth point (multiverse or not), I have two experiments (there can be more). Both require generating a random digit sequence using random.org, writing it in a scrap of paper, and folding the paper. * Send the digit sequence a minute into the future. If the digit sequence received is different, definitely multiverse, otherwise inconclusive. * Make sure that the time machine is empty. Promise to yourself to generate and send, 1 minute in the future, a digit sequence 1 minute to the past. Check the time machine, pick the paper if there's one, but don't read it. Generate and send the digit sequence as promised. Now compare the digit sequences (sent and received). There are a few possible results: + There was no paper waiting for you. Either it was lost on the travel, or it created an alternative future to be sent into (multiverse valid). + There was a paper, and the digits were the same. Either single universe or divergence universe is valid. + There was a paper, and the digits were different. Definitely not single universe. An alternative to the previous experiment is to generate the digits before promising to send them. I don't know what difference it makes, though. [Answer] Most of the answers to date have dealt with single timelines or a multiverse. Actually the multiverse concept needs further refining because there a variety of multiverse concepts. This answer will deal with what the OP calls the "diverging timeline universe". This is more correctly called the branching timeline universe. It's also the most difficult time-travel friendly universe to test and be assured time-travel is safe. This form of time-travel forms a timeline whenever a time-traveller arrives anywhere in time. Past, future or present, it doesn't matter. History branches from the time-traveller has arrived and presumably continues onwards until the end of time. Testing this time-machine by sending anything into the past or the future, it result in precisely nothing. No slips of paper with random numbers, lottery tickets, apples or mangoes (some examples were in alternative timeline versions of this question) will materialize before or after being dispatched by the time-machine. This does mean the operator of a time-machine cannot distinguish things are travelling into branching timelines or what they thought was a time-machine is a perfect disintegration machine. The only way a time-traveller can be sure they exist in branching timeline universe is to travel in their own time-machine and see where it takes them. if it works, the time-traveller will be visiting different past and futures to his merry content. Until he decides to go home. One consequence of this kind of time-travel is that it is effectively impossible to return to your timeline of origin. Return to your initial present and a new branch timeline will be created. It may look like home, but it won't be, and people in that initial present will never see a returning time-traveller. Yes the time-traveller will experience many alternative branching timelines and many alternative versions of his initial present. But anyone in his genuine initial present he never see him return. Also, those branching timelines may only visited by one time-traveller in their entire existence. This is one form of time-ravel that can never be tested in advance of taking the plunge and the time-traveller does it himself. The positive side is that there is no possibility of any form of causality violation. Time-travellers can never their own actual past. They enter other versions of their own past and make whatever changes they like, but this won't violate their own history. Time-travel in a branching timeline universe will be soon discontinued. Time-machines will leave and never return. The probability of time-travellers arriving from other timelines, branching or not, practically zero. There may be time-travellers wandering like transtemporal Flying Dutchmen (irrespective of gender) who never return to their actual points of origin. This answer has addressed one form of time-travel neglected by commentators and other answers. This form of time-travel is highly resistant to testing. Time-travellers be warned! What look's like a time-machine may, in fact, be a very effective and practical disintegration machine. There's no way of knowing in advance. Prepared to take a chance? [Answer] Digital camera tests: Use a digital camera take photos around your laboratory, house, and outside. Download copies and then send the camera forward. After you receive the camera 1 minute in the future, examine the photos side by side and look for any discrepancies. If there are any discrepancies, this means that your camera came from a divergent timeline and that your original camera was sent elsewhere. If there are no discrepancies, I suggest you repeat this test a few times with various photos from around the world, just to be certain. Maybe even sent a video forward. Sending things backwards makes my brain hurt. You could send the camera back with a note saying "take a photo, save a copy and send the camera forward", but then you would remember receiving that message in the past. You would have to promise yourself to send the camera backwards whether you remember receiving it or not, and hope that a new photo appears on the camera after you put it in the time machine. For you, no time will have passed at all, and there are a few possibilities for what your will find: a) There is no photo on the camera and you don't remember receiving a note, meaning it didn't go backwards. b) You remember the message, and there is a photo on the camera that matches the one you saved a copy of...proof that you sent the camera back to the same reality. c) You remember the note, and there is a photo that does not match the photo you have saved, meaning it could be from another multiverse. These are just the tests I can think of off the top of my head. You would probably want to do each test several times to ensure that you're absolutely positive of a non-divergent timeline. You probably would want to try sending the camera over increasing lengths of time to play with the possibility that things change more drastically over longer lengths of time. [Answer] Attend Stephen Hawking Time-Travellers Party. To test moving forward in time without possibility of destruction take 3 weeks holidays. Say to everyone you will go to the desert for 5 days without access to phone, internet, mail, humans or any form of communication (not even a telegraph). Then on the first day of the trip travel those said 5 days. There shouldn't be any repercussion as you was supposed to be "missing" for those days anyway. Now - if you go by "everything that is in history happened" then you can't change anything. If you go by multiverse you need to reconcile with the fact that anything/everything create/move you to another universe so there is no coming back. If you go by "one timeline to change as you wish" with the moment of inventing working timemachine you can see what the changes would be. If anything changes rapidly around you it means the machine is working and you or somebody else changed time. If nothing change then you can assume you died and no one else used or discovered a time machine. But the most critical question is: Did you invented time machine or space-time machine? [Answer] Sigh. Your mad engineer had some actual reason to invent and build this contraption. He had some actual theory it is build on. And, lo and behold, since the machine works, the theory probably has some resemblance to the reality in your purely fictional universe. So what your engineer would actually be doing would be to either work on achieving his actual goals or in fine tuning or falsifying his actual theory. The two might be the same, of course. So you need to start by working out a draft of the engineers goals and theories then plan his actions accordingly. He might want to be rich. Buying two newspapers every morning and sending one of them back in time a set number of days would be a good start. A comparison of the differences between the copies would give you more information than random numbers can. And if stuff like sports results or stock values stays similar, you should be quite lucky with your finances. If the future is mutable, it would be fairly trivial to become very rich with patent applications. Famous too. You might be able to significantly accelerate the rate of technological innovation by sending yourself scientific papers and patent applications from few years ahead. This kind of meddling would also enable you to see if the changes propagate ahead. And yes, you can do this stuff with random numbers but why would you? Not only is actual information more valuable, but different kinds of information should have different "temporal inertia", so you'd get more information out of it. ]
[Question] [ New here! Now let me be clear: I'm well aware that telekinesis and pyrokinesis are both impossible, as I've been rudely informed on every science forum. Nonetheless, I don't just want to "make it up" either, as every fantasy forum has suggested. I write science-fantasy, neither hard sci-fi or high fantasy. While I'd like the magic system in my story to be as closely based on real physics as possible, I am willing to fudge some numbers for the sake of bigger booms, but I'd really like to handwave as little as possible. Because I'm sure I'll still have to handwave a lot. So to be more specific: What known scientific mechanisms could levitate objects, remotely ignite objects, and manipulate any subsequent flames? I've heard of magnetic levitation being used for trains and frogs,microwave radiation to heat objects, and EM fields for containing plasmas. But I'm not sure how far I could stretch that into levitating other objects, manipulating flames, etc because I suck at physics and math. As for how the brains of my characters would produce such energy....Well that's a problem for a different time, one which will probably require the most handwavium. All the more reason to avoid the h-word as much as I can. As fantastical as my world is, I'd like it to be as "realistic" as possible. There's already enough in Ea that can't be explained. Sorry if this post is too long and I need to break it up, or if these questions are otherwise inappropriate; I can and will edit however necessary to get the answers I seek. And to reiterate, please no "that's impossible" or "use your imagination", I'm just looking for that sweet spot between physics and handwavium. The in-story obstacles presented by scientific limitations are a fun challenge, such as the massive caloric requirements for magic, but it just isn't fantasy if earth physics are follow to the letter. Since magic is impossible and all. I also only write as a hobby, a very very serious hobby, so whatever any audience might think is irrelevant. That's another thing I get a lot too, variants on "just worry about suspending the audience's disbelief". I write as a mental exercise, and that includes both thinking outside the box and thinking INSIDE a box. This particular box being physics. [Answer] Use nanotech. The atmosphere is saturated with tiny, flying nanomachines that are powered by sunlight and can respond to commands, allowing people to manipulate objects from far away. Some people have devices in their brains that let them command said machines at will. Perhaps Ea is actually our Earth in the far future. Humanity had created these nanomachines and also infused certain people with other nanomachines that produce the control devices, which are passed from mother to child. (Or they could be genetically modified with the ability to naturally have control devices). Civilization collapsed and people forgot this technology (perhaps it was deliberately hidden), but the atmospheric nanos and the descendants of their controllers still remain. Maybe the nanos were almost all wiped out, but a few remained and it took them hundreds of years to restore their population and allow the "magic" to come back. [Answer] Let's start with the much maligned Schrodinger's Cat, which has become a science-fiction trope for justifying a causal relationship between observation and physical effect. Assume that Schrodinger was a closet telekinetic with a sporadic and unreliable talent. From his own experiences with his gift, he knew that telekinesis was real, but could not personally provide a repeatable experimental method to satisfy the scientific method. Realizing Tesla's mistake and knowing that the scientific community would laugh at him for even suggesting the existence of another fundamental force, Schrodinger created the cat thought experiment. The purpose of the experiment was not only demonstrate how weird quantum mechanics can be. It also served to soften intellectual skepticism and prepare the next generation of scientists for an even more complicated physical world. Expectation is a fundamental force which can affect the strength with which molecular bonds resist other forces such as heat. A watched pot actually does take longer to boil; but only if none of the observers are scientists. Scientists come with a predefined set of expectations which cancel out the "less informed" expectations of the other observers. They strongly expect that observer expectation will have no effect in the physical world. As with other fanatical believers across history, their strongly held expectations overwhelm the wills of mere laymen. So how does all of this heresy get us to telekinesis and pyrokinesis? The answer is in those molecular bonds. Weaken the bonds in some object enough and the surrounding oxygen will overwhelm the existing pairings, causing the object to oxidize and spontaneously combustion. Strength the attraction between adjacent air molecules enough and you can create invisible funnels which focus and direct existing winds enough to move small objects. When there is enough wind available, you can even levitate an object by directing the moving air to strike it from below, lifting and suspending it without any visible means of support. [Answer] Let's assume telekinesis and pyrokinesis are impossible. Despite parapsychology, there is no known mechanism for either psychic ability. There is no scientific explanation for anything like the phenomena. This takes care of the situation in our universe. So let's postulate there exists a universe where telekinesis and pyrokinesis are possible. What then would nature look like to produce these abilities in biological organisms? I say biological organisms because it is quite likely these parapsychic abilities will be manifest in animals as well as humans. Firstly, there needs to be organs of perception in either the nervous system or the brain proper so the organism can manipulate whatever forces it needs to manipulate to move or ignite objects. Secondly, there needs to be organs of manipulation so the organism can manipulate whatever forces it needs to manipulate to move or ignite objects. Thirdly, there needs to be a medium to project these forces from organism to object. I will assume the medium is provided by the physical nature of this alternative universe being more strongly coupled than is the case in our universe. To such an extent that even biological organisms can interact with the physical vacuum, in effect they move through it like fish move through or we land animals move through air. The brains of organisms in this alternative universe have developed (OK, evolved) parts of their nervous systems (which includes their brains) that perceive aspects of the quantum vacuum such as the virtual particles bubbling in and out of it and organs that can manipulate them too. This manipulation propagates through the vacuum like sound waves which influences the levels of virtual particles emerging from it. The really tricky bit is how this influence emerges only at a distance from the manipulating organism at the pace where the target object is located. Perhaps it doesn't need to? Pyrokinesis then is easy. The pyrokinetic activates her fire-power and projects a 'force' that causes virtual infrared photons to emerge along that line of 'force' with sufficient thermal energy to ignite the target. This also means that anything in the line of 'force' will be heated too. Telekinesis isn't very much different. Our telekinetic causes virtual photons to rise in a more or less coherent volume inducing the [Compton Effect](http://physics.about.com/od/quantumphysics/a/comptoneffect.htm) on the particles of matter in the target. The transfer of momentum to target matter will make it move in the direction wanted by the telekinetic. The incident virtual photons will disappear back into the vacuum. Just don't stand in the way of telekinetic or pyrokinetic when they work their magic. You be moved in ways you don't want or get burnt. If the lines of power can be refracted or bent in a way that they only emerge where the target is, then these powers could act at a distance (so to speak). This is, of course, making assumptions about nature that are wholly unjustified about nature as we know it and accompanied by hurricane-force handwaving. But it does sketch a hypothetical alternative universe designed to accommodate psychic abilities. To make them even remotely possible definitely involves massively rewriting nature as we know it. [Answer] I would've liked to post this as a comment, as this is just fruit for thought, but I have no privilege to do so. The following is strictly simplified, but maybe that's enough inspiration to come up with something useful. Some details might be not quite the newest physical knowledge. If we are talking about telekinesis first. Telekinesis is all about exerting a force on something. The question is what is force. In classical newtonion mechanics force equals mass times acceleration and has some properties or laws it follows. One of them is the famous action equals reaction, which essentially says that each action will create an equal and opposite reaction. So far so easy. Now, in quantum mechanics you find a very similar concept except, although your mass and acceleration are not simple variables but fields. Think for example of the electrical field of an electron, another charged particle will have a potential generated in that field (hence fields are also called potentials) and will act accordingly (i.e. be attracted or repelled). The important point now is, that these reactions are governed by the properties of the particles and the fields they generate. There are physical principles governing these properties. There can be different variables, for example momentum and space. If for example for two identical particles the momentum or spin is parallel, the spatial variable is not parallel, which translates to a repelling force between the particles. You can also turn this around, where the spin is not parallel, the spatial variables become so called symmetric, which translates into an attracting force. See also: <https://en.wikipedia.org/wiki/Exchange_interaction> Force itself is expressed or transported via force carriers. These are for example photons for the electromagnetic forces or the Gluon for gluon gauge field (forces in atomic nucleus). These particles do not have mass in and of itself, but carry energy which is equivalent to mass. With that in mind, you can establish Telekinesis as a way/technology/ability to manipulate quantum fields and create and manipulate those force carriers. The energy required to do so, is available in todays particle accelerators, so you might get a hint on what energy is required to achieve anything like that. Pyrokinesis is in my opinion a special case of telekinesis. Flames are oxidating gases, that can be moved by the same principle everything else is moved. I do not have an idea how to "create" flames out of thin air. Heat itself is just the movement of atoms/molecules/particles. In thermodynamics the heat or temperature of a fluid/object is the average kinetic energy of its particles. But flames and fire require fuel by design. Flames or burning in general is Oxidation and Reduction, therefore you always have an oxidizer and a reductant. [Answer] I am a newbie here too. I think I may write similar to you in respect to not wanting the reader to constantly have to suspend their disbelief. For instance I desire a certain level of realism to be retained, where the powers of characters are not purely supernatural in nature, instead having its explanation done up in fancy sci-fi or pseudoscience. This may not be necessarily what you are looking for but it kinda fits in with your goal of "that sweet spot between physics and handwavium". Pyrokinesis (The power gifted upon character A). 1. In multiverse theory, an infinite amount universes similar and dissimilar to our own exist. In one case Universe A will have a set of physical law that are the direct inverse of the laws of physics that make up Universe B, where matter from Universe A would destabilise in a fission event the moment it came through into Universe B from a handwavium wormhole Character A can create. Effectively only a very small amount of matter needs to be transported through said wormhole in order to produce a level of energy that would set something ablaze or just plain incinerate it. 2. Perhaps Chacter A has a handwavium set of processes that allow them to absorb a potentially limitless amount of energy and retain it in a state of metastability. When necessary, Character A could disrupt the metastable state that the stored energy is in, causing it to gush forward in a form of infrared radiation. This one I got the idea from an answer to the question [Realistic perspective on "shadow/void/darkness"?](https://worldbuilding.stackexchange.com/questions/46568/realistic-perspective-on-shadow-void-darkness-powers). I do not really have any ideas for telekinesis except for being able to induce gravitational fields of their own, however I do not know any ways you could come up with pseudoscience to make the reader go "Oh OK" and just accept it. However with the discovery gravity waves, perhaps there are theories on manipulating gravity that are now more plausible for a reader to accept. [Answer] So... a couple of answers, a weekend to think about it and a tiny bit of time to spare did yield something the answers are still missing. But how to start... well, if you want to stick to reality, first thing you need to take care of is the most beloved argument of "that can't work" screamers: Conservation of energy: So every force needs energy, to put it simple, right? Lets scramble through my favorite source of useful explanations for off-this-world-things: games and tv! And thankfully Star Gate and the X-Files offer two interesting examples right off the start. First, in Star Gate there was that girl... something with C... Cassandra! Anyway, she was a - beside being a bomb - super human experiment of... Neferti (?)... some Indian looking female member of the never ending cast of Goua'uld. When getting older some nasty stuff caused a high fever, which she could expel from her body by channeling this heat inside iron stuff lying around, which made her levitate chess pins by electromagnetism. Okay, thats maybe not the most day-to-day-friendly way of transferring energy for the sake of telekinesis. So than look over to the X-files. Hell, they do have several cases of this. One of the last episodes was about a guy which was a prime telekinet as a child but ended up manifesting a strange soap-opera to make him feel ok when he was grown up. In that case electro-magnetism and... spectral matter (?) were used to explain this. But thats not the case I was looking for. Yes, they do have a telepath (that chess playing kid), but I was going for The Pusher. I can't recall his movie-name, but the Pusher was able to talk people into any stuff he wanted by forced suggestion. Unfortunately (for him) he had to pay for this: a tumor in his head at the first place, and extreme exhaustion at the second place. So, in this last example the body himself was used to create the excess energy needed to do some paranormal stuff. That is something you could use after all - your paranormal people would suffer from extreme exhaustion if they use their abilities in great quantities. On problem still persists: Appliance of Force: So... you have a source of energy, bu no way to apply it to a target. Its like a spacecraft in space that produces way to much heat without being able to radiate it. So you need a medium to transfer this energy. What do we have? Air? Water? Hm... could work, but would need fancy telling to make it sound plausible. What else do we have? Ah... the Aura. Subject of controversy first class. What it is and how it does work is not entirely sure at the moment. Going the more scientific approach would lead to something like "the electromagnetic field the body radiates", which isn't as implausible as one might think at the first moment, because our brains, muscles and nerves working by applying electric currents at the right destination. Going more spiritual would lead to words like "Ki" and "Chi", which come from the far eastern religions... and here we are back to the esoteric guys, which tell you that you need to meditate to ... I don't know, sometimes I think its their way to force away others by keep on claiming "you are doing it wrong" when their explanations wont work after all... Anyway. If you want your Aura to lift cookies, you need to know how to use it. Applying extreme magnetic fields will lift anything - even insulators - but thats out of question. Right here the science ends and the narrative steps in, gently taking the "why" to realms where the answer is "I can't explain... its like describing a blind guy how a field of flowers does look during a solar eclipse below an aurora". But still, using your own magnetic belt to influence stuff around you isn't such a blind shot. After all, we all did feel the pressure a old monitor could apply to you fingers when charged. it wasn't a real barrier, just a bunch of static electricity, but still you can feel it! Sadly nowdays no kid will know what I'm speaking about, because flat screens doesn't do something like this any more. Conclusion: But if you want my version, keep the possibilities at a low end - no matter how angry you get or how well you can apply your Chi to objects around you, it won't make you able to lift a car, because your whole body could not generate the energy needed to pull this of in such a short time I think. but grappling the towel from the other side of the bath-room? Here we go. And if you need more practical appliances, just knot the bad guys shoos together. That would be as useful (and funny) as levitating him. EDiT: What about pyrokinesis? Apply your energy at a really small point, and you will just went beyond the inflammation point. [Answer] While many explanations for telekinesis have often been based on magnetics, there is as mentionned no known biological organs for generating such fields (though some organs capable of electromagnetic sensing have been recently identified). Another limitation of that it would make telekinesis only possible on magnetic susceptible materials. However in my opinion ultrasounds offer a much better scientific background for telekinesis: * many living animals have ultrasonic generation capabilities (bats, whales, [moths](http://www.nature.com/news/moth-smashes-ultrasound-hearing-records-1.12941), ...) * science is starting to experiment on `ultrasonic tweezers` which are capable of even lifting small animals ([source](http://science.psu.edu/news-and-events/2012-news/acoustic-tweezers-capture-tiny-creatures-with-ultrasound)) Pyrokinesis can then also be explained through high intensity focused ultrasonic waves ([for details](https://en.wikipedia.org/wiki/High-intensity_focused_ultrasound)). Of course the condition is to have stochiometric mix. Of course, like with any new branch of science you might be faced with a lot of disbelief that it is actually science, so you might be better staying with the long line of magnetic based telekinesis and leaving the `how` to future developments of science. [Answer] Henery Taylor suggested there could be a "watched pot never boils' principle. For example, by ignoring a brick because it won't move if you watch it too carefully and now freed from the 'pressures of observation' it moves. The Zeno effect in quantum mechanics concerns unstable particles and has the "prediction that frequent measurements during this nonexponential period could inhibit decay of the system" which means the decay of a system can be inhibited. There is an opposite effect -- the anti-zeno effect (I thank JDlugosz for drawing my attention to this phenomenon) -- where the decay of unstable particles is enhanced by frequent measurements -- and this might be considered the basis of the 'watched pot never boils' principle. For more information on both the Zeno effect and anti-zeno effect go [here](https://en.wikipedia.org/wiki/Quantum_Zeno_effect). However, the WPNB principle seems to be more due to frequent non-measurements ( or observations) of the system to be influenced such as the brick to be moved telekinetically or wood to be ignited pyrokinetically. This suggests whatever its nature, this mechanism depends on something that is an anti-anti-zeno effect. The enhancement of a change of state (the decay of unstable particles in a system) by the frequency of not taking measurements. Now we are getting into strange territory indeed. Possibly this requires physical effects to be caused by the mental states of the whatever-kinetic. This isn't a concept I feel exactly comfortable with, but we are looking for plausible explanations for different forms of kinesis. Ditto with fire starting. The power of negative thinking at work. Dale Carnegie would be mightily annoyed. This answer was possible because of the contributions of Henry Taylor and JDlugosz. [Answer] I’m surprised that no one has mentioned quantum entanglement, especially the bit that physicists pointedly avoid discussing: (1) in quantum theory, it is the action of your brain, as an observer, which collapses a quantum wave function outside your body into a definite state; and (2) that two quantum particles can also become “entangled,” meaning that a change in one particle’s state is instantly mirrored in the second particle, even if that transmission of information occurs faster than the speed of light. Quantum phenomena can also “transcend” into the macro realm: some 30% of US GDP comes from discoveries in quantum physics. Moving past there, Hannu Rajaniemi has extrapolated this into a wonderful trilogy beginning with The Fractal Prince - which might inspire any number of plausible pathways to your "seemingly" impossible psychic phenomena. One immediate possibility comes to mind: that someone can learn how to control a massive amount of quantum states in his or her mind, and "magically" transpose those quantum states into entanglements with other particles, causing whatever effects you desire. (Also very hypothetically, those quantum states in the brain do not necessarily need to result, e.g., in a fire inside the brain just because the change of state in the entangled particles at a wooden "target" might result in flames.) [Answer] To be honest, I was thinking the exact same thing. I am still trying to figure out a scientific explanation behind telekinesis, but I know that there are many different ways to make chemical fire by adding desired chemicals, some of which are found naturally. If one could somehow mix these chemicals, then the byproduct could be fire. The method of mixing is unknown, but it could possible happen via an organ or gland. Fish's gill passages are used to remove oxygen from water, so I'm sure a possible scientific adaptation could make it so a variation of chemicals could be pulled out of the atmosphere, the soil, etc. If this helps: <https://www.thoughtco.com/make-chemical-fire-607502> Best of luck! [Answer] First I'd like to state that I don't believe that it is actually impossible. The way I see it is that magic is just science we don't understand, and telekinesis/pyrokensis is magic. In same pagan mythology/belief it is said that with enough training and devotion a pagan can gain abilities in divination, telekinesis, and other things thought to be myth. I mean, yes it's highly unlikely, but you can never say it's impossible! Here's my take on telekinesis. Our body has an electromagnetic field surrounding it generated by the fact that our body uses electricity in the firing of neurons. Now if we could control this electromagnetic field and "amp" it up to a much larger level (someone with some mutation that has abnormal bundles of neurons in super high concentrations that aren't cancerous) they theoretically could use their field to interact with out electromagnetic fields. This would allow for telekinesis. Another way this could be done is by using these fields to interact with other electrons/protons and manipulating them to force atom interaction and generate energy, thus propelling an object. My take on pyrokensis would be very similar to my take at telekinesis. With the genetic mutation of abnormal neural bundles in huge quantities. With this you could theoretically interact with protons/electrons and cause them to vibrate/interact with each other. If you can generate enough energy, the energy will turn into heat, and thus something bursts into flame. This could be done with as something as simple as oxygen and thus we have a fire bender! Another thought about these mutations would be the cost on the person. Maintaining that many neural bundles would take a lot of energy to maintain, but I believe it would be a feasable amount. [Answer] 1. Tweak the laws of physics in your universe. Make the energy flows in the world stronger. A person's brain and nervous system now has a stronger EM field. Make the flows only semi-stable so that a properly trained brain can cause "ripples" in the energy flows around it. A properly trained brain might then be able to direct large amounts of force at specific points by generating vibrations that have a peak or trough at the right position (similar to how you can forcibly eject someone from a water bed by building up a set of waves which have frequencies that converge in the right place.) What effects would be possible with this depends on how precisely it can be controlled. 2. Invent a species of non-corporeal life forms who exist as pure energy twisted in on itself into a semi-stable, standing wave. (Substitute hand-wavium of your choice.) Have them live in symbiosis with humans and provide PK and TK abilities in return for some service that they can't perform themselves. (Being in a human body keeps them safe from solar flares maybe? Or they can use excess electrical energy from our nervous systems as a food source? Both? Use your imagination.) 3. There exists some fifth dimension which some portion of the population has gained the ability to perceive (through genetics or training) Once a person can perceive it, they can learn to move through it with varying degrees of success, and it functions as a shortcut through "normal" space. Telekinesis is just reaching out and pushing something that's further away than your arm should reach. (Pyrokinesis is doing the same thing with a lighter or blow-torch in your hand.) Advanced students might well be able to pull off effective teleportation by moving their entire body instead of just an arm. 4. Artificial assistance: The people in this world have learned to build some kind of "psy-amp" that allows amplifying brain-waves with an external power source and directing them with an antenna. Power output is limited by the amp's energy source, but "brainwaves can be modulated quickly and precisely to create the desired effects more efficiently than controlling it by computer." 5. This world is actually a computer simulation which has a daemon process searching for entities which match certain specifications saying "wingardium leviosa" and waving pointy sticks in the proper patterns. [Answer] A rather tongue-in-cheek answer here, at least for pyrokinesis: Probability is your answer. For a spark, and consequently a fire, to spontaneously appear, you would probably need a critical concentration of fuel (oxygen) and heat. There is a very, very, very small but non-zero probability that enough oxygen molecules bumping around a space at any one instant could all come together to form a sphere of concentrated oxygen for one moment. There is a also a non-zero probability that each of those oxygen molecules happens to join the sphere with sufficient energy that the resulting energy of the sphere system is high enough to cause it to spark off. This is probably several orders of magnitude smaller than the initial condition of sphere formation. If both of those conditions are fulfilled, spontaneous combustion could happen! As such, your character would simply have to be EXTREMELY lucky, and here I'm talking about odds of googolplexes upon googolplexes to one. But not impossible, per se. Good luck! [Answer] I don't have a great answer for telekinesis, but if you do crack telekinesis, [Maxwell's Demon](https://en.wikipedia.org/wiki/Maxwell%27s_demon) might give you pyrokinesis. Maxwell's demon is a thought experiment in thermodynamics. Essentially, temperature is a statistical quantity - the average energy of a large group of particles. However, some particles are much more energetic than others. If you knew the energy of each particle and were able to use telekinesis to steer them, you could create hot pockets of gas. Nudge the fast moving air towards the target, the slow moving air away from it, maybe flood it with O2 for good measure, and let it burn. In reality, if this did work it probably wouldn't heat up all that fast. It's really a question of how large a volume of air you're willing to pull from - all the hottest particles in a room still isn't that hot, but in a city... This doesn't happen in real life because we can't work with that fine a precision, and even if we could it would almost certainly take more energy than it's worth. But if you're telekinetic and have some way of applying it intelligently to, like 10^30 particles at once, you can move heat from one place to another more or less for free. [Answer] About the only form of "action at a distance" that exists within modern physics that can operate operates on human scales is electromagnetism. Gravity really only does anything meaningful when masses comparable to planets are involved, and the strong and weak nuclear forces hardly do anything outside of atomic nuclei. Your question has shades of a kind of offbeat telekinesis idea I had a while back: A person that is (via magic) able to control electric fields with their mind. They could throw around copper hoops, then induce string electric currents flowing through them. The currents would create magnetic fields, turning the hoops into powerful electromagnets, which could then be used to attract or repel each other as needed. This doesn't need to be magic. If the hoops were equipped with some electronics and a power source (which may need to be handwaved a bit- these things need a lot of power), it would work just fine. Rather than a brain operating on the hoops directly, a remote control of some kind would keep track of where they are and what they need to be doing, and send them commands wirelessly. Or maybe the hoops communicate with each other directly, more like a hive mind. Also note that with rapidly oscillating magnetic fields, the hoops don't all need to be powered. As [this video](https://www.youtube.com/watch?v=txmKr69jGBk) shows, enough A/C power pumped into a big coil of wire can levitate any random chunk of metal. Taking a hard-science approach to pyrokinesis might be more difficult. Plasma has free-floating positive and negative charges, and thus is an electrical conductor. You wouldn't be able to guide it around very well with electric fields, though, since the electrons would go one way and the positive ions the other. However, both charges will tend to follow magnetic field lines lines, as can be seen in [solar prominence](https://en.wikipedia.org/wiki/Solar_prominence) and [some kinds of fusion reactors](https://en.wikipedia.org/wiki/Fusion_power#Magnetic_confinement), so you might be able to get somewhere that way. Other than electric arcs, lasers, or actual flamethrowers, I dunno. [Answer] This is not a trivial question. Perhaps look at the randomness involved in thermodynamics and propose a rare condition where things suddenly have a correlation, a new form of entanglement that occurs at a larger scale. Maybe some predestination fun where this happens to be the universe where people mostly try things that will end up happening. Another option is something like or involving gravity, an equal "acceleration" on all masses, a new way to distort space time even. I can imagine the kind of rules that would have to follow.... [Answer] Rather than a direct answer, this is a tangential observation that my 7 year old son came up with after watching Avatar the Last Airbender. All bending is energy bending. The bender changes the kinetic or thermal energy of the targeted medium. Based on events depicted in The Legend of Korra, all bending is mediated through a common structure in the brain (a water bender is able to disrupt any benders ability by manipulating the brain). While Nickelodeon didn't care to get scientific about it, and your world isn't theirs, this may stimulate discussion. [Answer] Implants Sound can do some crazy things such as the [sonic tractor beam](https://www.allaboutcircuits.com/technical-articles/how-sonic-tractor-beams-work/) and [ultrasonic welding](https://en.wikipedia.org/wiki/Ultrasonic_welding) which could be pretty close to what you are looking for. It's ok for small objects and starting a small fire but you're not going to lift cars and create walls of flame. Your person could be fitted with an experimental sonic projector that links to the brain. The emitter is embedded in the palms and thought can vary frequency for a variety of effects. On top of telekinesis and pyrokinesis, the person could shatter objects, pick locks, project their voice and even induce vertigo in other using sound. ]
[Question] [ Could a planet have an orbit in the shape of a figure 8 around twin (possibly binary) stars? Mostly curious about the physical possibility of such an orbital arrangement; is it stable over a long time scale? Could both stars be different sizes (masses) and still maintain this 8-like planet orbit? Ideally I'm going for a planet that orbits a red star and a small bluish/white star; it would have effectively three seasons: * Orbit around the red star: the "Red Season" - Hot summer like weather over the entire planet * Crossing between the starts in the center of the figure 8: the "Transition" - the weather is cooler since the orbit is drifting away from the red star, however the planet is almost constantly bathed in light (just not as much heat) * Orbit around the blue/white star: the "Blue (or White) Season" - effectively winter as a small dwarf type star would not have the same out put as the larger red one. Is this at all feasible? [Answer] The question was already asked on the physic stack exchange: <https://physics.stackexchange.com/questions/31201/might-a-planet-perform-figure-8-orbits-around-two-stars> I can add that the difference in mass between the stars is not important as long as the planet moves on the ridge as explained in the example. About red stars: Red is just a color, they can be small: red dwarf or large : red giant. red giant are at the end of their life. This state is only temporary so I would not recommend it. Red dwarfs are stars with a long life expectancy. Some of them are also flare stars that haver large variations in brightness but some are more stable. Blue/white: It's the same about the blue and white stars. They can either be dying stars or normal stars. Keep in mind that stars of that color are usually very hot when they are in their main sequence (adulthood for stars). They are large and massive but have a short life. White dwarfs, These are old dying stars. When small to medium sized stars arrive at the end of their normal life, they become a red giant. Then, it will contract and become a white dwarf. They are very hot at the start but cool down very quickly. The temperature never stabilize but with time it will become almost stable. You can find more about the stellar classification of colors here: <http://en.wikipedia.org/wiki/Stellar_classification> and other informations about star here : [What kind of star should I use for my world?](https://worldbuilding.stackexchange.com/questions/1143/what-kind-of-star-should-i-use-for-my-world) Possible combinations using the Wikipedia table: If you want the planet to develop life, you can't have a really big star. O and B stars are out and A stars are really at the limit. They live for 1 or 2 billion years if I remember correctly. This is a very short period of time for life to evolve but it's possible. Most likely combination: Red dwarf (M star) and white dwarf. Similar mass. This is a stable couple. Not very hot or very bright, the planet will need to orbit relatively close to them to have enough heat. It's hard to tell the influence on the temperature since I don't have the parameters of each star but don't put the planet too far. It is probable for the red star to be the hottest star. The white star is hotter but smaller and this usually mean that it will be a dim star. Possible problem: natural satellites are likely to break the balance of force toward one or the other star when the planet is between the two stars. [Answer] I'm but a hobbist. I believe the reference you need are The press coverage ([Physicists Discover a Whopping 13 New Solutions to Three-Body Problem](http://news.sciencemag.org/physics/2013/03/physicists-discover-whopping-13-new-solutions-three-body-problem)) The paper by Dr. M. Šuvakov and V. Dmitrašinović ([A guide to hunting periodic three-body orbits](http://scitation.aip.org/content/aapt/journal/ajp/82/6/10.1119/1.4867608)) The resource website ([Three-Body Gallery](http://suki.ipb.ac.rs/3body/)) I'm concerned about the 8-figure orbit in that its net angular momentum is 0, which may suggest some very special origin / genesis mechanism / artificiality. [Answer] (I might have to check on meta if this is a valid answer) I think the figure 8 orbit is possible, my only issue is how the two stars interact (orbit each other) and the impacts that might have on a planet trying to go between them. A more physics inclined person should be able to answer that. But the reason I wanted to post an answer, is even if there is gravitational forces at work here, don't neglect the effects 2 magnetic fields will have on a planet. * Recent research appears to be able to link our magnetic interactions between our Sun and Earth influence storms here on earth. * the magnetic interactions of two stars orbitting one another (or even existing close to each other) is something we have little to no knowledge on. Lets assume that the weather to solar magnetism link is there...traversing the area between these two stars where the magnetic interactions are taking place could cause some of the most destructive weather this planet has ever seen. Sorta adds another element of extreme weather phenomenon (maybe some amazing 'northern lights' as well) during that phase. [Answer] If such an orbit was possible on paper, it would not be stable. Having a planet that chaoticly switches stars rather than evey time is better, but still won't last. You would need some waymto contrive it to stay in such an arrangement, such as other bodies sculpting the gravitational gradients (like a Lagrange point but more complicated). [Answer] It appears to me that a planet in a binary star system could have an orbit around one of the stars, perpendicular to the mutual orbit of the stars around each other. The first star would keep the planet in orbit, but it would not be an orbit around the center of the star, because the gravity of the second star would pull it off-center. The first star would rise and set on the planet, but the second star would probably be seen constantly in one hemisphere of the planet, and never seen at all in the other hemisphere. Strange! [Answer] Most probably this can exist, but will be stable for only a very short time. If the planet had really small mass or maybe was just a comet, it could be stable. Here's an animation (I know it's not much - made by eye) showing how this idea would look like - it seems insane to me: [![An animation of the problem](https://i.stack.imgur.com/7iVqn.gif)](https://i.stack.imgur.com/7iVqn.gif) (Planets and stars are not scaled right) This animation is a bit hard to get, so I made another one which shows the same, just without the stars rotating: [![A simplified animation of the problem](https://i.stack.imgur.com/LGAux.gif)](https://i.stack.imgur.com/LGAux.gif) (Planets and stars are not scaled right) So, for me, this is not possible long-term, with a normal-sized planet, and this would be even more unstable, if one of he stars had a much bigger mass. Edit conducted by the flags: this answer adds perspective - shows through an animation how chaotic this concept is. But the animation isn't the main part - The text (answer) part is. The answer is no, this is not possible long-term. ]
[Question] [ Hydrogenic photosynthesis reduces methane and water to build biomass ($\text{CH}\_2\text{O}$) and releases hydrogen: $$\text{CH}\_4 + \text{H}\_2\text{O} + \text{photons} \to \text{CH}\_2\text{O} + 2\text{H}\_2$$ For reference, oxygenic photosynthesis is: $$n \text{ CO}\_2 + n \text{ H}\_2\text{O} + \text{photons} \to (\text{CH}\_2\text{O})n + n \text{O}\_2$$ According to [this excellent paper by Bains et al](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4284464/), the hydrogenic process is some four times as efficient as the oxygenic version, allowing four times the amount of biomass to be constructed for the same quantity of light (see note \1). The linked paper describes how large planets could hold onto a hydrogen atmosphere, but this question is not about that. My question is about strategies for animal evolution, since the flip side of it being 4 times as easy for autotrophs to build mass, is that heterotrophic consumers get 4 times less energy from breaking down one gram of this hydrogenic biomass. Here are the authors words: > > "From a purely human point of view, the evolution of hydrogenic > photosynthesis might be a disappointing discovery on another world, > for reasons implicit in Figure 1. Just as making biomass in an > oxidized environment requires more energy, breaking down biomass in an > oxidized environment releases more energy. In particular, oxidizing > biomass using molecular oxygen releases substantially more energy than > reducing it using molecular hydrogen. A commonly-held explanation for > the rise of complex animals in the late Pre-Cambrian and Cambrian > periods was the rise in atmospheric oxygen that allowed their > energy-intensive lifestyles " > > > My question is; how does the change in 'balance of power' between autotrophs and heterotrophs affect the evolution of both and what is the appropriate animal metabolism to allow animals to display the types of abilities (which rely on storing concentrated energy see note \2) that earth animals display? Please note - any answer that addresses the fourfold animal vs plant imbalance is valid - PhD level biochemistry answers will be much appreciated but I am not expecting to get many of them! End of question: what follows is supporting material from the paper that you can treat as \\TL;DR. Note \1* Here is the passage from the paper that makes the claim about reduced biomass generation requirements. > > "Comparison of Gibbs energies of formation of CO2 (gas ~ −394 kJ/mol, > aq ~−385 kJ/mol) and CH4 (gas ~ −50 kJ/mol, aq ~ −35 kJ/mol) [65] > shows that any reaction involving CO2 as the C-bearing reactant will > almost always have a more positive Gibbs energy of reaction than a > similar reaction with CH4 as the reactant. The quantitative difference > between the reactions will depend on the products of the reaction, as > illustrated in Figure 1. On average, for the set of chemicals in > Figure 1, making the chemical from CH4 takes ~20% the energy needed to > make it from CO2. This suggests that building biomass in a > CH4/H2-dominated environment would require only ~20% of the energy > needed in our CO2-dominated environment." > > > *Note \2 The linked paper mentions that maybe these animals could make use of dimethylsulfonium proprionate (DMSP) to store energy rather than carbohydrate but I don't really understand this process or what its implications are... [Answer] If I've understood your question correctly I'm going to basically ignore the biochemical science and jump straight to what I feel is the meat (actually, veg) of the question: What happens if plants grow 4x faster, but animals get 4x less nutrition from them Please note that above I'm using 'plant' as a synonym for autotroph and 'animal' as a synonym for heterotroph. I'm doing this simply because it feels more natural as a form of address. I'll use the correct terms later as it's important to make the distinction. So: Moving on. The period for which single celled life dominates will become shorter. Your single cells are more likely to be autotrophic, and as such will multiply much more quickly. In this sort of high-energy high population environment any heterotrophs that do emerge will have a glut of food, but won't be as much of an impactor on the autotrophs as they were in our history (as they reproduce at a quarter of the rate). The autotrophs therefore will compete with each other, and the high population density will lead to cellular co-operation faster. When it comes to multicellular plantlife: competition will be fierce. I mean, genuinely fierce. These plants will have 4x the energy, and therefore 4x the capacity to reproduce, grow and generally do what plants do. Tall trees, resource sapping and funky seed dispersal techniques will blossom as all the plants will have more energy to 'waste'. Animals on the other hand will have to move slower by necessity. They still have an advantage in that they don't need the sun, and they still have an advantage in that they're eating a richer energy source, but we won't be seeing purely carnivorous predators anytime soon as the amount of acreage required for a single predator would go up 16 fold (4x for the herbivores, then another 4x for the pure carnivores) Omnivores would likely do the best, but still, slower creatures would do better. As the disparity between the amount of energy that can be gained from the sun vs the amount of energy gained from eating other plants is much smaller lifeforms exhibiting both autotrophic and heterotrophic behaviour would be considerably more prolific. Parasitic and carnivorous plants would be more common, and I'd expect a whole range of adaptations (Jellyfish vines, climbing bananas, Cuckoo-Elm?) and being photoheterotrophic (using sunlight to help fix carbon but not photosynthesising directly) would be a strong evolutionary choice. If you want to see an earthlike system then your animals are going to have to have some serious metabolic mojo. For starters the herbivores will have to eat at least 4x more vegetation, and that's assuming metabolic efficiency works the same way. As previously mentioned any fast carnivores are going to be ravenously hungry, and would also have to evolve some major parenting skills as they won't have the energy to employ a 'fire and forget' strategy and then worry about all the competitors they just spawned. I'm unsure as to whether the same argument about parenting applies to the herbivores. One last, rather intriguing (though contradictory) thought: Underwater the apex predator would probably be Coral... [Answer] Get your oxidizers here! Get them while they're hot!** The fundamental question is where do you get your oxidizer from? All oxygen on this methane+H2 planet is wrapped up in water or something else. Candidate oxidizers might be Fluorine or chlorine but both have their problems. Fluorine is so reactive it never stays free for long. Chlorine is also never found free in the atmosphere. With so much methane and hydrogen floating around, any oxidizer is going to get captured quickly. We only have it on Earth because there's so much life pumping out oxygen. This leave us with two options. First, we develop a reciprocal metabolism that doesn't require an oxidizer and runs on hydrogen. (The world of chemistry is broad. It could probably be done.) I don't know near enough chemistry to even guess at candidate reactions. Or, second, we recycle the oxidizers within the autotroph after consuming them from terrestrial carbonate, perhaps [calcium carbonate](https://en.wikipedia.org/wiki/Calcium_carbonate) which has three oxygen atoms for one calcium atom. I don't know the energy penalty in acquiring an oxidizer this way but it seems convenient. Perhaps a fluorine catalyst of some kind? > > CO2 is also removed from the atmosphere by conversion to carbonate, at a rate that depends on surface chemistry. > > > This atmosphere is the inverse of Earth. On Earth, the oxidizer is freely available and the fuel is in short supply. ]
[Question] [ It is known that armor with accentuated design for breast is a bad choice in an actual confrontation. What can be changed to make "breast armor" more effective? Like materials(fictional or not), design(without changing the "breast room" completely). My character lives in a medieval world, and is a female knight, she is looking for marriage and is trying to look more attractive for potential candidates without losing too much protection. EDIT:Thanks for all the answers, they helped a lot, first let me clarify some things, the objective of the question is not to create a sexist character to appeal for male fantasia, I am trying to avoid it, changing the character to meet the beauty criteria of the time is not a good idea, she is looking for in the world éléments to make herself more appealing, putting breast on armor might not be effective form of male attraction for the time(and probably will not) and will have in world consequences, physically and morally, with which some of the answers here have also helped a lot. [Answer] Most known accounts of women in medieval era war have them wearing armour designed for men. One exception is Joan of Arc who had a suit of plate armour specially built for her. No known images exist from her lifetime, but one depiction (drawn from written accounts) shows the armour as very similar to armour worn by men, albeit slightly smaller and gathered at the waist. The gathering at the waist was very common for men's armour, but probably more exaggerated for Joan's. [![Image of a White Harness via Jeanne d'Arc La Pucelle](https://i.stack.imgur.com/r8uZ4.png)](https://i.stack.imgur.com/r8uZ4.png) In regards to armour that is specifically designed for women's chests, this is a more recent consideration. Some modern body armours are specifically designed for women and while they do not have great drops for cleavage or molded breasts, they do show an actual rise over the chest. [![Female body armour used by some Police forces](https://i.stack.imgur.com/dvAZC.jpg)](https://i.stack.imgur.com/dvAZC.jpg) The armour in the picture above was designed to addresses some complaints of female UK Police Officers, as it apparently holds things in place without applying to much pressure. So while a female knight probably wouldn't have exposed cleavage or molded breasts, it is likely that the bustier of them would have armour that showed a distinct rise over the chest area. [Answer] > > My character lives on a medieval world, and is a female knight, she is looking for marriage and is trying to look more attractive for potential candidates without losing too much protection. > > > I think you need to look at this differently. Marriage, especially among the knighted classes, in medieval times was not primarily about looks (and not even in the West now is it entirely about looks). Social position and property, inheritance prospects and religion or politics had as much, if not more, to do with it. That's not to say that looks were completely irrelevant, but they did take a back seat to many other considerations. Nor did knights, male or female, wander about all day and night in armor. Only an idiot would want to given it adds a lot of weight and has no social purpose that more comfortable and decorative clothing will not do better. Your female knight will wear whatever suitable clothing and personal decoration are appropriate to a woman of social standing high enough to be a knight. Her social grace, wit, charm and elegance are something she can display in appropriate social settings (just as the men could). So there is no reason at all for your female knight to worry about her looks in armor. What she'll worry about is staying alive, with all limbs, still able to bear children and on the winning side. Any armor design that does that is what she wants - mobility and protection and vision are the primary requirements : looks are way down the list. The ability to bear children is absolutely the key role of most women of noble birth in medieval times and frankly for that reason alone it's extremely unlikely her family would allow her to fight at all, certainly prior to her being married and giving birth. This role is of such importance that it brought about the death of more than one queen when they could not fulfill that role satisfactorily, and I do not mean death in childbirth. Without heirs a line may be finished and that would be unthinkable in medieval times. [Answer] Armor is for protection, not sex appeal. A live woman is a far better marriage prospect than a dead woman. The whole sexy armor troupe is about serving the male gaze, not doing anything for the woman who is fighting. Armor is for actual fighting, not walking around. It's heavy and doesn't breathe and you can't move very well in it. A realistic knight has a squire who's in charge of packing all that stuff and having it ready for battle. Certainly a knight in wartime would walk or ride with some level of protective clothing, but it wouldn't be full armor. Most women don't have itsy bitsy bodies with enormous boobs. The stereotype of women with tiny bodies and boobs that made them tip over is, again, created by men for men and is pretty rare in real life. Real life actors or models that look like that are 1) chosen for those characteristics and are a small minority of women and 2) usually surgically enhanced. Larger breasts are more likely to show up on women who are more voluptuous and/or muscular overall. Like a shotputter. Even then, there is a mix of body types. Drawings, anime, and 3D representations (like Barbie) that show tiny women with breasts the size of their heads range from almost to completely unrealistic. Most men and women I know roll their eyes at stuff like that. Real life women with natural breasts that huge suffer from horrible back pain and usually have reduction surgery. Armor is generally custom fitted. There is not one size and shape of armor for men, so there wouldn't be for women either. Men are different heights, have different torso to leg proportions, different chest sizes, etc. If you don't think most women would be tall enough for armor, consider that teenage boys (who were not done growing) often went to war. If you can account for these differences, then it's not hard to also account for differences with female shaped bodies too. Even a very large-breasted woman probably doesn't have a larger chest circumference than many male warriors. A smaller waist to hip proportion should also be easy to deal with. The stereotypical boob armor is not just stupid, it's dangerous. It should be obvious to everyone that leaving gaping holes in armor to show off skin is counterproductive. But even when the woman is covered, shaping it for breasts causes no end of problems. * [It’s Time to Retire “Boob Plate” Armor. Because It Would Kill You](https://www.tor.com/2013/05/06/boob-plate-armor-would-kill-you/) * [Fantasy Armor and Lady Bits](http://madartlab.com/fantasy-armor-and-lady-bits/) Attractiveness is in the eye of the beholder. Fighting well then looking good when she takes off her armor will catch many an eye. Fighting badly (which includes wearing useless or dangerous armor) is a turnoff in all cases. If a potential husband thinks a women shouldn't be a knight, then fighting badly will just reinforce his opinion and make him less inclined to be interested in her. If female knights are normal in that society, or at least if the potential husband is okay with it, then fighting well is an important part of the attraction. Knowing how to choose and use your gear is essential to being a good fighter. Besides, even male knights would have a few gems on the armor, head piece, shield, or sword. They might have coats of arms impressed on the shield. Armor might even be painted. So if you want creative clothing, here's your chance. [Answer] Real breastplates have a lot of space between it and body to soften blows and prevent situations, where dented plate causes problems. Most females will have no problems to wear a standard medieval armor fitted to her, slight extra space won't make a big difference. [![enter image description here](https://i.stack.imgur.com/4mYL6.jpg)](https://i.stack.imgur.com/4mYL6.jpg) You can just make armor in a style and engraved to show your gender. Good move is to show off your slim waist, so less cheat-days and do not forget space for padding under armor. If you want to accentuate your assets or they are impressive. You can make extra bulge around the chest. You would want to make it as small as possible, to preserve acceptable center of gravity and general weight and do not look like a joke. Don't over do your back and shoulder pain. If you want to make separate "mounds" you would need to make it so there still is a good gap between it and your body. Ridge would be a potential weak spot and you would want to make it extra reinforced, same for base of "mounds". I would advise you from using it in battles on horseback, as that is perfect target for a lance or spear. Can't afford spare pieces of harness - go with a fitted good old one, as your life is more important. --- For note, in everyday life you would use minimal amount of armor and for sure it would be rare to go around in full battle armor. [Answer] Taking this in a different tack. During the time you're referring, the most sexually desirable women had big hips, and a lot of fat on them. Being fat meant you're wealthy enough to eat well and you're healthy. [Women’s idealized bodies have changed dramatically over time – but are standards becoming more unattainable?](http://theconversation.com/womens-idealised-bodies-have-changed-dramatically-over-time-but-are-standards-becoming-more-unattainable-64936) Your lady knight is probably more fit than what is desirable for the time, so a man style breast plate is fine, she needs a way to show off her hips instead. Also, as a knight, she will be battered, bruised, have terrible skin, and frankly look about as unappealing as possible, both back then and now. Few men were interested in women that did the work of men. They wanted fair looking women with child bearing hips to produce lots of heirs. So when you really drill down in this, almost none of your original concept works. You would have to first change your world to have female warriors as desirable (vikings maybe?). Simply having sexy armor would just cause potential suitors that are interested in female knights to think she is wrong in the head. -Edit I want to clarify, what was considered beauty was different by place and time. Most nobility values large women but not all. There was a time when women had to tie themselves up in corsets and try to look like boys. This knight lady will need to look beautiful for the time and place she is in. That's why I am suggesting the original concept doesn't work, it needs world building around it to explain why a female knight would be considered attractive. To answer your other question, how to make this armor viable: This is actually simple, modular armor. The breast molds have clasps that allow the wearer to attach another plate the joins and fills the valley, creating a man style plate again. She would only put this on before a fight. It would actually provide better protection than traditional armor because you have an entire extra layer of metal. Probably enough to even stop early guns. Assuming of course there is still the usual layer of leather underneath it. If it has been made fantasy skin tight, then it won't help much at all. [Answer] First, a reframe, then to your problem, then a simple answer, which others have put forth as well. Boobs are not all that important in the time period you seem to be depicting... Breasts were not seen as sexually as they are now during Medieval times. Even in the Elizabethan era, take a look at the actual outfits. The breasts are pushed FLAT in most of the portraiture, for a real flat or uni-boob effect, most of the time. Historically, it's not until a little later that boobs get the emphasis...more towards the 1600s and 1700s. But in an era that's all about armor, not so much. The Renaissance does get boob-a-licious--just, seriously look at Medieval to EARLY Renaissance art. And I am talking art created AT THE TIME, not Reniassance or later art that looks back and reframes historical figures in terms of their day's attractiveness. It's not about the boobs. There's a whole different attractiveness standard. Cinched in waist, Exaggerated hips. Boobs are for babies. Here's what is most important: clear pale skin, flowing hair. Most of the art that people bring up as Medieval is really Renaissance, and the beauty standard completely changed. (The body standard got a lot more voluptuous). But you want boobs because you live in this society and so do your readers, and so neither they nor you can possibly imagine that boobs might not be central to female attractiveness, while still staying true to physics. The answer is not to change the shape of what's worked in armor so that your protagonist can look cute. The answer is in SHADING. This has been used on stage to create boobs where none exist for centuries. And painted armor has been a thing since armor was invented practically. [Answer] ### Not form fitting As any number of people have noted, form fitting armor is stupid and dangerous. Armor is deliberately made with padding between the armor and the wearer. So don't make the armor form fitting. * [This answer](https://worldbuilding.stackexchange.com/a/132973/2113) suggests putting the breast shapes outside the real armor. So normal armor with two breast-shaped pieces added. I would suggest also making it so that the breast shapes are a softer material. That way, they wouldn't deflect the sword into the sternum but instead pad the blow. So they would give a small amount of additional protection while being slightly clumsy. * [This answer](https://worldbuilding.stackexchange.com/a/132969/2113) suggests using paint to give the illusion of shadows to imply different curvature. Note that this might actually make the breast armor better, as it could fool people into striking the armor the wrong way. ### Paint it Instead of painting the armor to give the optical illusion of a different shape, paint the armor to show how the person looks underneath. Paint a face on the helm and cleavage in a dress on the breastplate. Or skip the clothing and paint bare breasts. A lifelike enough painting and gawking attackers might find that they were dead before they realized the lady with breast armor was holding a sword. It's up to you to figure out whether your character would paint a depiction of her own bare breasts on her armor. Perhaps she is more demure than that. But even so, a depiction of her torso in a dress that happens to highlight her breasts would work. [Answer] Check out this armor - the keel-like protrusion over the belly is not the most extreme I have ever seen but it's a good example of allowing space while thinking about deflecting attacks. It is a strong shape against blunt blows and will deflect edged weapons rather than catching them and sliding the point directly into the centre of the chest as more form-fitting armor might. [![enter image description here](https://i.stack.imgur.com/gXSA5.jpg)](https://i.stack.imgur.com/gXSA5.jpg) Now perhaps the wearer of this armor was carrying their extra weight a little lower than on the upper chest but your female warrior could certainly wear a breast plate where the point of the keel is higher allowing for space where it's needed. Unless your warrior is very silly, protection will come before appearance. Your warrior's admirers will just have to admire the finely constructed armor and use their imagination. [Answer] All the answers are trying to get rid of her boobs :( I say a proud, independent she-knight can look as buxom as she wants to. ## 1. Taboo In this world it could be an act of greatest shame—to cut a woman in the chest. Perhaps raising children is hard in this age, with many fatalities, and tradition has grown to treat women's child bearing properties with utmost respect, to the point that even when you're trying to kill a woman, you still avoid the chest and pelvis at all cost. If this is the case, then having round non-flat surfaces on the armor's chest is not a problem. This cultural taboo could also explain why the armor has such an accentuated bosom. ## 2. Intentional bad design The problem with breasts shaped into the armor is that weapons would catch on the chest, instead of deflecting off. So, using this to her advantage, the knight has extra thick armor on her chest, with slightly softer metal too. Swords would bite into the metal and catch halfway, giving our knight the opening she needs to gut her opponent. Maybe she makes the armor-boobs bigger than her own chest, so theres a bit more crash room. Note that this strategy works better against thin swords. If someone is swinging a heavy weapon, you'd much rather deflect than catch. [Answer] Multiple outfits. In just about any society where people wear clothes, people have different outfits for different occasions. The clothes I'd wear on a date aren't the same ones I'd wear to a funeral, a job interview, or to weed the garden. Modern-day soldiers have dress uniforms for looking nice on parade, but that's not what they wear into combat. etc. etc. Metal armour that provides practical protection is heavy and uncomfortable. It requires padding, which soaks up sweat and gets stinky. It's not something you want to wear 24/7 or even nine-to-five. Your female knight might have: * One suit of armour designed for serious combat. * Another suit designed for parades and perhaps for friendly tourneys, which can be as impractical as fashion dictates. * An assortment of nice clothes for social occasions where armour is not required. * Clothes for outdoor, riding, wet weather, etc. Most of her spouse-hunting will be done in the latter. It's not like she's going to be match-making in the heat of battle. Paint. Take one regular suit of non-breast-shaped plate, with the chest designed for protection. Now paint it in any colour you like (other than black) and use shading to create the illusion of curvature. [Answer] Push up armor! She tightly ties her bossom just like she always did and wears the same armor she always did. She just instructs a blacksmith to reinforce and shape the front in a way to resemble attractive, full breasts. Considering the general lack of fatty foods for all but the wealthiest and the kind of physical work and training she does, her breasts would probably be rather small anyway. You see the same phenomenon in modern athletes. [Answer] Pyramids. The curved shape of fantasy breast armor would be tricky to make and would not deflect as well as an angled flat surface. A pointed polygon will typically alter the course of incoming energy, deflecting it down to the base of the pyramid where reinforcements will dissipate the force. Sharp points would also allow a close quarters death hug attack. Regarding attractiveness, that is in the eye of the beholder. Perhaps the pyramids' patterns are attractive. [Answer] The main problem arising from having breasts, especially large ones, is that their mass tends to move the center of mass and thus altering the equilibrium. Not being a bearer myself I cannot speak about the discomfort of having such a free swinging mass. This is particularly visible in female athletes, who never ever worry about showcasing their curves while competing. Only the opposite, the breasts are better held firmly in place. A sound design for a female warrior would then require a linen belt around the breast to hold them as flat and firm as possible, and then a formed thoracic region to allow for lodging the extra volume. But no protruding things. They would be easy targets in close quarters combat, with likely lethal consequences. Moreover, announcing a fighter as a woman with clearly visible breasts can easily suggest weak points or ad hoc tactics to the enemy, and one of the principles of war is to hide as much as possible to the enemy. Consider instead a parade armor, where showcasing and exhibition is the main purpose, that is not a matter of optimization but about mode and trends. [Answer] To make it available we first need to understand why it is not viable in the first place, the reason is simple, it leaves the sternum unprotected while exposing the breasts. Here's a stupid drawing I just made to show a woman wearing boob armor from above. [![enter image description here](https://i.stack.imgur.com/1m7SO.png)](https://i.stack.imgur.com/1m7SO.png) But there is a way to remove all those flaws, something that actually existed in medieval times called [Gambeson](https://en.wikipedia.org/wiki/Gambeson) > > An arming doublet (also called aketon) worn under armour, particularly plate armour of fifteenth- and sixteenth-century Europe, contains arming points for attaching plates. Fifteenth century examples may include goussets sewn into the elbows and armpits to protect the wearer in locations not covered by plate. German gothic armour arming doublets were generally shorter than Italian white armour doublets, which could extend to the upper thigh. In late fifteenth century Italy this also became a civilian fashion. Men who were not knights wore arming doublets, probably because the garment suggested status and chivalry > > > Gambeson alone was good armor but most of time was also paired with mail and plate armor to absorb impact. By wearing a THICK layer of gambeson under the boob plate all the design flaws are removed and now your knight has full protection. [Answer] # Add padding to the outside Rather than reject the premise of the question, let's assume the character herself does think that adding boobs to her armor will make her more attractive, and this matters a lot to her. Given that, she should probably wear normal armor with a cloth shirt over the outside. Then add extra light padding under the shirt to give the appearance of breasts. This would add a bit of extra weight and make her a little bit less versatile, but both effects would be minor. I don't think there's a way to make armor-boobs "better" than traditional armor (since otherwise male knights would have worn them in real life), but you can get the effect while sacrificing a minimal amount of utility. [Answer] Your character can wear body contoured armor if she wants to. She'd probably bind her breasts with a linen or woolen cloth to stay comfortable and [keep everything in place](https://fr.wiktionary.org/wiki/ludus#/media/File:Bikini_mosaic.jpg). Or, she could wear a supportive bodice of supple comfortable leather. Over that, she'd probably wear a quilted gambeson of linen or wool, slightly tailored at the waist, if she wants it that way. [![Gambeson](https://i.stack.imgur.com/IRW6Q.jpg)](https://i.stack.imgur.com/IRW6Q.jpg) Over that, she'd wear her armor. It would help if you mentioned what kind of armor. I'm guessing you mean a suit of plate. She'd wear her breastplate, of course. [![enter image description here](https://i.stack.imgur.com/facoa.jpg)](https://i.stack.imgur.com/facoa.jpg) Consider the breastplate. It has that rounded shape to deflect blows, but if your character considers her appearance more important that optimum protection, she could always wear something like... This [![enter image description here](https://i.stack.imgur.com/ASn6A.jpg)](https://i.stack.imgur.com/ASn6A.jpg) or something similar to this, a modern female fencing chest protector. [![enter image description here](https://i.stack.imgur.com/rPPv2.jpg)](https://i.stack.imgur.com/rPPv2.jpg) Consider how buxom she is. If she's buxom and she's wearing flexible armor, her breasts can move. If she's very buxom and she's wearing a rigid breastplate, that rigid metal shape won't move and it could impede the range of motion of her arms. I don't think a warrior would tolerate that, since it could mean her life. To counter potential trapping, her breastplate or cuirass could have a ridged surface with an reinforcing piece at the center. She'll most likely have a shield as well. If King Henry VIII could have armor bodysculpted for his [prodigious royal belly](https://www.dailymail.co.uk/news/article-1134222/King-size-Henry-VIIIs-armour-reveals-52in-girth--paid-terrible-price.html), it's not unthinkable for a woman warrior to have armor bodysculpted for her figure. Just keep it reasonable and practical, and consider her comfort, range of motion, and the layers of clothing and padding she'll be wearing under the armor. [Answer] Most of the answer focus on how that would be wrong historically, practically, socially, etc., etc., and they're absolutely correct, but, if we go in that direction, the first thing we should admit is that there was no that thing as "female knights", case closed. As I understand, your question is more like "if female knights still somehow exist, how do we make them look distinctly female for a casual modern observer, while not leaving the realm of practicality?" Maybe you should look into [mirror armor](https://en.wikipedia.org/wiki/Mirror_armour) and [plated mail](https://en.wikipedia.org/wiki/Mail_and_plate_armour)? Basically, a chain mail vest with some additional reinforcing metal plates. I mean, not specifically for girls, but for all knights, because the metallurgy isn't ready for plate armor yet, so that's the best they have. Unlike a cuirass, which was usually made with a lot of space between the armor and the body, chain mail follows the body contours out of necessity. Some of those look kinda close to what you may want, e. g., a chain mail with two separate round-ish chest plates, although flat - make them more bowl-shaped, and there you go: both the practical purpose of accommodating the body shape and the aesthetic purpose of making the character look distinctly feminine from our "modern" point of view are there. What's not there, however, is the iconic look of a knight in full plate - knights were not always wearing full plate armor, but, again, that's how they "should be" from our "modern" point of view. And you probably wouldn't want to be jousting in one of those, too. There's also [this](https://commons.wikimedia.org/wiki/File:Varahi_breastplate,_India,_Kerala,_18th-19th_century,_brass,_HAA.JPG), which is a real male armor from 18th century India, but I doubt it had other purposes except decorative and ceremonial: [![enter image description here](https://i.stack.imgur.com/DlUtK.jpg)](https://i.stack.imgur.com/DlUtK.jpg) [Answer] I didn't see it in any other comment when I skimmed through, so I just wanted to throw out that it might not make much sense to have an exceedingly large chested knight to begin with. It's most likely that a female knight would have an "athletic" form. Being an adventurer that is also a fighter would build a lot of muscle and induce a lot of sweating and it's not really conductive to have exceedingly large fat deposits. Additionally, large amounts of fat would probably detract from battle performance in a general sense, making one slower and more sluggish and more likely to die an early death. It makes more sense for battle hardened women to look a lot like the shape of battle hardened men, in which case the chestpiece is probably going to look a fair bit like the male chestpiece just maybe a small slight bit larger. [Answer] What if you you made a breastplate design like this? I'm not seeing any major obvious weaknesses. I could maybe see someone wedging a dagger under the chestplate, but chances are that if you're close enough to her to do that, you're probably already dead. (art belongs to chaosringen) [![enter image description here](https://i.stack.imgur.com/dvyjQ.jpg)](https://i.stack.imgur.com/dvyjQ.jpg) [Answer] Boobplate is fine as long as it is solid plate. Breast form armor can be perfectly practical you just can't go overboard with it. As long as you don't have a hole in the center or an lack of padding under the breasts its no worse than other armor with high relief dimensions. just look a real piece of maximilian armor below for comparison. imagine flipping the top half top to bottom. High relief is fine as long as there is enough room for padding. It should not be form fitting, but you have quite a bit of leeway with the shape. If that narrow waist did not "trap and focus force" enough to worry about then the shape of breasts isn't. [![enter image description here](https://i.stack.imgur.com/4PjLu.jpg)](https://i.stack.imgur.com/4PjLu.jpg) Consider this armor, only a small change gives you something very close to breast form. [![enter image description here](https://i.stack.imgur.com/6iJWh.jpg)](https://i.stack.imgur.com/6iJWh.jpg) Really the sheer absurdity of shapes real armor had gives you a lot of leeway, there are quite a few armors with giant cod pieces, ones that stick out, a simple breast form is completely believable. Compared to some of that something like this fictional armor is reasonably practical. I means the rest of the armor does some strange things but the breastplate is fine even if you are worried about a so called blade trap. [![enter image description here](https://i.stack.imgur.com/Jq2De.jpg)](https://i.stack.imgur.com/Jq2De.jpg) Paint Also remember the wealthy would often painted their armor, meaning you can create all kinds of patterns with no practical effect. You can further accentuate even minor changes in the shape of the armor with color or fluting. The addition of the right embellishments can further hint or accentuate without costing practricallity. If she is wealthy she can afford to have some rather spectacular inlay done to give the impression of all kinds of things. Consider the attire at the time, dress was not form fitting, it was meant to HINT at the what was underneath not put it on display. In fact in many real medieval settings large breasts would be a minor concern compared to a narrow waist and wide hips. Paint on a corset, or use an inlay to create shape that is not there and you can make minor changes in the armor look like major ones. If your armor is really clever they can even use optical illusions to create shape that is not there in enhance minor changes. The below japanese t-shirt is a great example, using simple lines and shading to create false shape. It can be as subtle or as [ostentatious](https://i.stack.imgur.com/vjhif.jpg) as you want. [![enter image description here](https://i.stack.imgur.com/n3qCp.jpg)](https://i.stack.imgur.com/n3qCp.jpg) [Answer] Inflated and spiked chest plates for female warriors who want to show their attributes. [![enter image description here](https://i.stack.imgur.com/ZGJjs.jpg)](https://i.stack.imgur.com/ZGJjs.jpg) [Answer] Less about the aesthetics of the armour, and more just how to make it viable as something a woman might wear. First off, if you’re flat-chested, you needn’t worry about changing the shape of the breastplate. However, if you have larger breasts (which might therefore necessitate changing the shape of the armour), you’re going to have a really nasty time of it as a knight. In order to do any high-impact sports (running, horse-riding, etc.), support is kind of obligatory to avoid shoulder, neck, and back pain - and just mitigate against things moving in the opposite direction from the rest of you. Breast binding could work (wrap a wide length of linen cloth around your torso, tucking your breasts under your armpits to get yourself as flat as possible), but the method I just mentioned also prevents the expansion of the ribcage, which kind of helps for breathing. People do it, but running around on a field bashing people with swords tends to raise one’s breathing rate a bit, and having a very compressed chest makes life difficult. The modern option is to use stretch fabric strapping (similar to that used for sports injuries) - you tape down each breast, again tucking under the armpit, but leave a gap at the sternum and the spine where the strapping doesn’t overlap so you still have some room to breathe. Unfortunately, I can’t really think of a medieval alternative to this. Basically, I’d suggest trying to get your medieval woman to bind as much as she can bear while still having some space to breathe, then stick on some extra boob-shapes lumps to the outside of the armour. Who knows, maybe she could use the space as pockets? [Answer] she is looking for marriage and is trying to look more attractive for potential candidates without losing too much protection Take a normal, good and protective suit of armor ... and add bling. If you go to a museum and look at the armor of high-status individuals, you will find functional, yet excessively decorated armor. What is it, that we find attractive in a potential partner: * Health - she's a knight, and apparently she's an active fighter. Check * Beauty - is in the eye of the beholder. Check * Money - yes, that's a controversial thing to say, but real-life(TM) prooves everyday, that we can't dismiss this. In this department, bling is the established way to go. [![Armor with bling](https://i.stack.imgur.com/RNRdy.jpg)](https://i.stack.imgur.com/RNRdy.jpg) Source: [Wikimedia Commons](https://commons.wikimedia.org/wiki/File:Royal_armoury_Stockholm_1.jpg) [Answer] I question the assumption that breast shaped armor would be necessarily be a death trap. Certainly, if a smith beats a sheet of metal into the shape of an idealized woman's body and some girl wears it without much underneath and goes LARPing, she may be more vulnerable than if she wore a T-shirt. However: * A medieval knight would wear a lot of padding under that armor. This would spread the impact of a blow over her whole torso, so the inevitable hard blows to her sternum would not be felt there. * Due to the padding, even if the wearer is quite busty, her boobs may not occupy the 'boob space' in her armor, so the armor can be made round on the inside for structural integrity. * A master smith would reinforce the sternum area, and could make it virtually impenetrable without adding much weight. * A collar could be placed around the neck area to stop or deflect a spear point from sliding up her armor into her neck. I would model breast armor on Greek/Roman muscle armor. It was mostly restricted to officers, and it also has the same issue of trapping, rather than deflecting, spear thrusts. Yet it was used. I would argue that the lack of a female equivalent is mostly due to the rarity of female officers at times when muscle armor was fashionable. [Answer] Do not use a medieval time period , rather the Hellenistic time period, using the Greek hoplite style armor will allow the use of Boob armor in your setting with believable usage. [Answer] Magic? Example: DnD has a type of armor called "glamored" which retains all it's armor properties while looking like whatever it's wearer chooses and this appearance can be changed at will. With this she's actually running about wearing plate mail (standard variety) but looks like she's wearing a fancy evening gown, freaky demon mail, whatever. That said, assuming this exists in your world has some interesting implications. Depending on level of paranoia, current events, etc... almost every noble would be sporting a set of this. If it's a casual day with no reason to worry it would probably be a light breastplate, if it's during a period of danger or they're just a paranoid git, they would probably be sporting full plate all the time. So, that may make trouble elsewhere in your story. ]
[Question] [ In a RPG scenario, players will look for a MacGuffin Metal (aka MGM.), experiencing the farwest gold fever. ### Short Story: Context : [Farwest](https://en.wikipedia.org/wiki/Deadlands)(~1880), steam punk. 1. First encounter : In a 3-5 minutes time frame, players will have to handle a MGM door. Metal property : Lighter than aluminum, strong as steel, silverish. Inspection method: pick it, move it, throw it, thrust into, punch bite and claw. 2. MGM Discovery : After the "MGM fever", the frenzy and chaos surrounding this quest for a incredible medal, only a bitter taste remains. The MGM is an already known metal! Already discovered decades ago by Dr. MacGuffin, he judges it worthless. And he is right. The veins is there near the Xyz town, the mine already exists but somehow the MGM is worthless. ### Question : How to make a metal with extraordinary property worthless? The MGM has propertied that make it comparable to Titanium. ### In-game restriction : The game cannot accept any kind of Op MGM Armor, or gold like revenue. No full armor or bullet proof vest, light canoe, shield etc. Things it can be used for: horsehoes, knives, things of small value such as spoons and frypans. ### Out side restriction : One of the players is an engineer in a metallurgy company. He knows a lot about metals, and has the knowledge to bring industrial metal into the West if I allow him enough time to do so. He starts his study/career because as a kid he was wondering what it will take to go from the bronze age to the steel age. He is the real reason of my question because I'm afraid he could destroy the plot. ### Possible answer I already have: * It's magic. It's a precious metal revolutionary! ..Changed my mind it's worthless. * You are the engineer, you tell me why it's worthless. * Good question, your char ask that but the answer he got is too complex for him to understand. The answer doesn't need to be hard science, just reasonable enough. You can judge the reasonable based on your own comprehension, Will it fool you? The argument can include magic, curse, haunted. No hard science needed. [Answer] # It turns out to be radioactive. It's light, it's beautiful, it's strong. ... but anyone who carries or wears the metal for more than a very short period of time eventually gets sick. This wasn't known during the initial gold rush and the metal was used to make various things... but eventually the people who handled it most or wore or carried pieces got sick and died leaving behind a town full of the sick families of former prospectors. Short exposure isn't an issue... but don't even think about carrying chunks in your pack for weeks. And anyone foolish enough to try to toy with this metal unprepared? [Answer] Titanium is actually a fascinating example standing by itself, because it's not that hard to find (it was identified as an element before 1800, and is the ninth-most abundant element in Earth's crust) but it's very difficult to work. Titanium can't be shaped simply by heating it and pouring or working it like you might do with iron, steel, brass, or the like. The reason is chemical: pure titanium metal melts at 1668 °C (3034 °F). However, at about 1,200 °C (2,190 °F), it reacts with oxygen to form a variety of oxides. (The most common, titanium dioxide, is a valuable product in its own right; it's a very strong, bright white pigment and has other industrial uses.) If you try working with titanium the same way you would steel, it will literally burn up. So in order to work with titanium, you need to work it under an inert atmosphere. Normally pure nitrogen is the go-to for industrial uses... but titanium will burn in nitrogen, too. You need an atmosphere made up of a noble gas, like argon. In this time period this might just about have been possible in a lab, on a very small scale, but it's still the better part of a century from industrial applications. The one caveat is that most cold shaping methods will still work on titanium once it's purified. If you have an ingot of titanium metal, you can stamp it, roll it, carve it, ream it, etc. and it'll work okay. So it might be hard to justify not allowing your players to cut up your miracle door for body armor or the like, but they'll have a very limited amount to work with, and no way to make more. [Answer] Absurdly strong metal! Well, in the current location/situation - for example, halfway up a snowy mountain. Unfortunately, those properties change greatly with temperature - taking our "strong when cold" example, by 20°C it's soft, malleable, and can barely hold its own weight up. By 35°C it's completely melted. A good door for withstanding the elements in the cold, but no security against animals or hot weather. (For reference: standard "room temperature" is about 18°C-22°C, and the Human Body temperature is typically around the 37°C mark) [Answer] It reacts with certain common substances. As an example look at aluminum and mercury: <https://youtu.be/IrdYueB9pY4> Imagine this kind of thing happening with something more common, like a certain mixture of water, or an abundant chemical that enemies could easily fetch and use. Your armor might be supa-dupa but if it someone throws a chemical at you and your armor/weapon falls apart or worse kills you... You don't want to be using it. Edit: as another example of metals reacting with stuff, think Sodium (natrium). It's a metal, it's got weird properties (in this case bad, like being soft enough to cut with a kitchen knife) and it reacts heavily with water. Throw enough in and it'll even explode. "Hold on guys I have to take off my supa-dupa armor and put it in a water-proof bag, it's about to rain" :D Don't know how to work it yet: Simply put, they don't know how to use it properly. Pure aluminum is light and strong but sheers easily due to its molecular structure. Add copper to the mix to get construction aluminum and the copper molecules prevent the sheering (if properly cooled), even though copper is counter-intuitively weaker than aluminum it strengthens it! The bits and pieces they found and used were natural deposits of good and bad mixtures. And the only way to work it to the knowledge so far is to chip it into shape, severely limiting what you can make depending on the size of natural material you found. A knife could work, but a full armor...? It's hard to work it. As mentioned, Tungsten for example is hard to work. Not only does it form oxides when heating it up, but due to the temperature needed to melt it there's virtually nothing you can heat and contain it in! It's one of the reasons we know much less about Tungsten than other materials. It doesn't need to be that restrictive, but it can be so restrictive that only a handful of top-notch master craftsmen can make something out of it and even then there's a high failure rate. So the limiting factor isn't the material, but the expertise to work it. Who cares if you've got 50 metric tons of the stuff if 10 kilos is enough for a master craftsman to make several attempts and build one armor and practically no one can afford it? This makes it worthless to most people. [Answer] You have answer in your question: > > No full armor or bullet proof vest, light canoe, shield etc. > Thing it can be used for : horse thing, knife, small things with no impact from spoon to frypan > > > The metal is forgeable only in small sizes: * It may be due to heat (very high temperature) it require to be shaped. * it proprieties change with size, the more metal you have the more brittle/unstable it become * Due to it's proprieties it react to much with it's surrounding. A revolver made with this metal don't allow bullets to leave the barrel. A shield reflect bullets but transfer kinetic energy multiplying it by the square size of shield. A canoe/boat/ship is attracted to the nearest large deposit of MGM rather than direction you want the ship to go. And last thing. The "tool wear". In woodworking there are woods of different hardness. The hard ones are, well, the best but they wear the tools used to shape them. The saw are dull, chisel are made blunt. Creating things from MGM destroy your tools. Using hammer and anvil on MGM is like using brass hammer on hard steel. The metal is not scarce, like gold, but creating usable things is not price reasonable. The jewellery made from that metal is costly but ONLY after the dozens of tools are destroyed in the process of making in. So the price comes from waste that was required to create MGM "thing" not from the MGM proprieties. [Answer] # It's weak to copper\* MGM is great. Relatively abundant. Easy to work in its raw state. But after purified and tempered, it is as light as aluminum and stronger than steel or titanium. The problem is it is weak to copper. A copper knife will go through it like a hot knife through warm butter. Heck, a copper coin will go through it as easily as a knife. It might be a great metal, but if one can cut through it wil pocket change, it's not terribly useful. Now from a scientific standpoint it isn't 'weak' to copper. It is highly reactive with copper. If any copper comes in contact with it, it will immediately form Cu2MGM20, a dodecahedron of MGM atoms around two copper atoms. And the new compound won't react with anything else. It just flakes away as dust, leaving it looking like the copper cut through the MGM. And it's a pain in the neck to split the molecules up again. Since it is a 10 to 1 reaction, one pound of copper will destroy 10 pounds of MGM (assuming they have similar atomic mass), or a copper dagger will only lose a thin layer in cutting through a door, armor, or sword. Gold and silver, also being in the precious metals series, may have a similar or reduced reaction with MGM. \You could choose a different metal (metal column) instead of copper. Cobalt, nickel, and zinc might work; they are just less likely to be commonly carried (copper being common for coins) and thus discovered as the weakness. [Answer] A lot of real-world metals are not intrinsically* valuable (like gold is, due to its scarcity), but become valuable in the right context. "Damascus steel" was once priceless, because it made the best swords, and most metalworkers had no idea how to produce it. But it was made from ordinary iron and carbon, so you wouldn't be rich just because you discovered the ore seams it was made from – its special properties came from the unique way it was forged. The same is true of titanium and alumin(i)um, which can only be worked and/or refined with modern technology. Conversely, many metals are scarce, but did not become valuable until people discovered uses for them (neodymium magnets, yttrium lasers, tantalum capacitors etc.). In 1870, an ingot of tantalum would certainly be expensive, but if you showed it to anyone their reaction would be "so what?"; today, the trade in tantalum fuels deadly conflict. A fun idea might be if the MacGuffin metal was some kind of impressive alloy, but it melts at 36°C (perhaps it contains gallium). Getting to and from the town involves two days' travel through Death Valley, and because refrigeration doesn't exist, there's no way to stop the alloy melting on the way. [Answer] The Titanium answer is a good one, but I'd like to offer some other possibilities: radioactively dangerous to be around. A real world example is [Mag-Thor](https://www.orau.org/ptp/collection/consumer%20products/magthor.htm), which is only slightly radioactive but still needs special handling. If the magic metal is fairly "hot" radioactive, it will cause visible injuries, sickness and death fairly quickly. That discourages people from trying to make bulletproof vests out of it. [Answer] *The properties aren't that* much better Sure, it's lighter than aluminium and stronger than steel. But it's only 20% lighter and 20% stronger. The metal has some disadvantages too. It's got, say, poor fatigue properties. Oh, you didn't notice when it was a door, but it you made a sword out of this you'd be replacing it constantly. In the 17th century, the British Royal Navy found that [ships with lead or copper plating would have iron bolts and nails disintegrate quickly](https://en.wikipedia.org/wiki/Galvanic_corrosion#Royal_Navy_and_HMS_Alarm). MGM is similar; if you make armour with an MGM sheet and steel rivets, it's very prone to corrosion. And it's expensive to produce. Aluminium is found in an ore called Bauxite which is very common - but expensive amounts of energy are needed to extract the aluminium from the ore, even with modern techniques. [Back in 1845, before modern extraction techniques were invented, aluminium cost more than gold.](https://en.wikipedia.org/wiki/Aluminium#History) MGM is the same way. You've found the ore and that the refined it has these good properties, but it's going to cost a lot more than steel because of the amount of, say, potassium you need to extract the metal from the ore. Difficult to make it consistent, too For some reason, eight out of ten batches of the metal just don't perform well. And you don't figure that out until right at the end of the manufacturing process, when your armour just isn't as strong as it should be in certain places. Dr MacGuffin thinks the boron used in refining tends to clump together, even though it's the best anyone can make, or possibly that the horse urine was gathered too late in the day. Anyway, the science of the day hasn't been able to solve the problem. Did I mention it's expensive to process?** If you get MGM red hot in a forge, it reacts with air and gets less strong. It ends up less strong than steel, in fact. For it to keep its strength you have to stop the air getting to it, by processing it in a bath of argon. So you can do it, but your world's existing blacksmiths generally can't work with it. They'd need new equipment which is very expensive. Oh, and someone else has patented the only extraction process that works Tycoon Tom has a patent on the only MGM extraction techniques that seem to work well, and he's got big investments in steel mills. He's not really looking to let anyone use his patents. And your setting has very strict intellectual property laws. Plus it's classified The government thinks MGM has such important military applications, it's a state secret. All details about it are [born secret](https://en.wikipedia.org/wiki/Born_secret), even if you discover them without seeing anything secret yourself. The secret applications are mostly in large artillery shell casings, so the properties that make it militarily useful aren't helpful for making swords or anything. All things considered, its advantages aren't big enough to outweigh the cost and problems. [Answer] It never had any value to begin with. It was a product where the marketing got ahead of the development. Some smooth talking salesman found himself in possession of the stuff, silver-tongued his way through a huge sale by promising all sorts of valuable properties to the metal, and it caught on. The material started changing hands, shot up in value as a untested commodity because it's so shiny, it has to be great, right? Large organizations (banks, corporations, government factions) caught wind of the hype and started "Go west, young man" campaigns to get cheap labor in on the ground floor. Promises of wealth and a solid career in the MGM industry brought lots of men and women out to seek their fortune. Soon warehouses all over the map were full of the stuff. Then the metallurgists got a few samples. People were bringing in nuggets, ingots, anything they could get. All were asking for the miracle devices they were promised to be crafted. Weapons, armor, machine parts, the works. It turns out it is only useful as an alloy to other metals, usually metals that are so scarce, large-scale practical uses are too far out of scope for the amount of materials any one person or organization can realistically possess. However, the metallic mix is close to 80% MGM and 20% Unobtainium. Or the process of making the alloy is so time consuming or dangerous to not be worth the effort. Either way, many small trinkets exist, horseshoes, ashtrays. Whispers exist of a family that has an entire cutlery set made from MGM and Unobtainium (Or just plain MGM if that's what you go for, if so, ignore the next paragraph). Because of the scarcity of the Unobtainium, MGM values have plummeted to nil. Sure, some people still run mining ventures because the occasional investor can be duped into thinking that when Unobtainium becomes Scarce-but-still-possible-to-obtainium the future of MGM will blow through the roof. As for now, the abundant surplus of MGM sits uselessly in warehouses, frequently in ghost towns. The value of the material is so low it's not worth paying a few laborers a day's work to move the stock. The door the party encounters is clearly made of either masterfully crafted MGM or the 80/20 mix. [Answer] What if the metal had an inherent, impossible to counteract, and nigh-impossible to slow, decay rate (non-radioactive). When it is in ore form, it is stable and prevented from decay; however, as soon as it is melted down and forged into any form, the decay begins. The larger the item it is forged into, the quicker the onset and severity of the decay, as well as taking a penalty due to the forginig process. *The Decay* This is a base template for the decay. Size differences will change these properties: * Immediately after forgining it is unchanged, and retains its amazing properties * After a few weeks, it has lost both durability and some minor bit of its stregth. As time goes on, it continues the decaying process, which only accelerates with time. * After three months some twenty percent of its initial strength and durability, therein bringing it closer (but still quite superior) to more attainable, and less questionable, materials * By the time six months have passed, it is almost identical to the next-best material; the accelerated decay process has now taken over fifty percent of the properties that originally made it special *The Size Penalty* * For small items, the decay rate is as described above. This would include the aforementioned cutlery, horseshoes, hammer and axe heads, and cooking pots/pans * For medium items, the decay rate is quadrupled (4 times as severe). This would mean that after three months, an item has lost eighty percent of its initial strength and durability due to decay. As well, as soon as the item was completed, it would take a five percent forging penalty. That would put them item at only fifteen percent of its initial state. * For large items, the decay rate is octupled (8 times as severe). This would mean that before even two months, the item would already be destroyed by the decay alone. As soon as the item was completed, however, it would take an immediate twenty-five percent forging penalty. This would effectively mean that the item would last barely one month. This would include armor, shields, or any wearable item. This would also fit into the game rules that exclude such items from being generally made from MGM *The Forging Requirement* * The metal requires very high skill and a massive amount of heat to forge While this is likely not a perfect solution, I think it is a servicible one from a pseudo-chemistry standpoint. This would make it so that only the most powerful and rich people would be wealthy enough to even consider using this material. As well, their use would come at great cost to themselves. Considering the difficulty, expense, and relative short-term use of the metal for any practical application, the metal would be untenable for use. While it is easily attained, and anyone could use it, why would they? The combined difficulty of melting down the metal and forming it, along with the decay and forging penalties, makes it something that would be very hard to find any use for overall. [Answer] The extraordinary property has no practical use (yet). Whatever the property is, it'd have to be immediately recognizable, even as an ore. A visual property seems the most likely. People find a metal with, say, a rainbow-colored sheen to it, even while sitting in the ground. Immediately people would assume they've found something special, and try to figure out how to make money off of it. For a brief period, before any details surface, there's a "gold fever" where people try to grab as much as they can of it. Demand skyrockets, as does the price. Eventually the metal gets into the hands of scientists, who begin to analyze it. and at the end of the day, they discover that it's essentially oddly-colored aluminum. Some impurities in the ground, combined with trace elements in the water, result in the odd coloring. It doesn't make the metal stronger or more ductile, just...prettier. Aside from a small market for costume jewelry, some local tourist trinkets, and people who want to show off, there's no benefit to making anything out of the metal. So it's got a small customer base of rich people who don't know what to do with their money, but otherwise, it's not worth the extra trouble. It may only be available in this one vein, but there's a lot of it. Now, if you want to go long-term, it could be discovered much later that the metal has a higher electrical conductivity, or exhibits odd reactions in a magnetic field, something that makes it useful for certain scientific or industrial implementations many decades later. So suddenly the vein has a use, but people dug quite a bit of it up to make oddly colored horseshoes for the mayor's dressage team, and all of a sudden those items are more valuable for their material than their age as an antique. [Answer] That material should be Wolfraam aka tungsten. Since it can be used for very small stuff, but for large stuff it's hard to use because it's brittle, making it worthless then maybe add the option of making an alloy of say titanium + tungsten if you want to use it for small/bigger stuff :D anyway, maybe just adding the option to make stuff out of alloys in your game would make it better, though it might be hard because making an alloy has like at least 3 parameters, the quantity of each metal you use for the alloy, the metal properties, the reactions some metals have on eachother, which can also depend on many other variables like pressure, heat... and from all that you would need to calculate a bunch of variables for the created alloy. besides that, many alloys haven't really been tested, since there are many alloys possible. Someone should make an api for this if it doesn't exist already :D, would be nice for an application, even though implementing all real life variables would be like mission impossible. Anyway, you could keep the variables limited for your game. [Answer] ## It's not waterproof When it gets wet, it dissolves. This makes it useless for quite a lot of purposes. Armor? Weapons? Hope you never have to fight in the rain... or in the heat where you sweat a lot. Mechanics? Maybe, but only for indoor use. Tableware? Why does my soup taste so metallic and why does my bowl start to leak all of a sudden? Currency? Say goodbye to your wealth when you drop your coin purse into a puddle. Canoe? Maybe you can coat it with waterproof paint, but if the coat gets scratched, you better be a good swimmer. Arts and jewelry? Maybe for an avant-garde artist who wants to make a point about the transience of material possessions and the perishability of beauty. It doesn't even need to dissolve immediately. If it is susceptible to long-term exposure to moisture then this drawback might not be immediately apparent, but still be enough to make it useless for a lot of purposes. If you need a scientific explanation for why a metal would be soluble: It might actually be a salt and not a metal. Or it might react chemically with water, like [sodium](https://en.wikipedia.org/wiki/Sodium) (technically a metal, although it's far too soft for any engineering purpose). If you wonder how it is possible for a soluble mineral to be found naturally in the ground: 1. [rock salt](https://en.wikipedia.org/wiki/Halite) exists 2. It might exist in some form of ore which is waterproof until it gets refined [Answer] The metal includes the souls of demons which gives it its useful properties however while this metal is great for almost every use it has one draw back. If you put enough of it together the power in the metal combines and a demon can come out of your item leaving it as a worthless rusted mess of whatever it was No one wants to form large weapons or armor of this metal as the last thing you need is at an inopportune moment your offense or defense becomes a creature bent on eating your soul. Many once thought that if they only had a shield coated in this metal or a sword that was alloyed with another metal it would be fine, and it was until people found that hitting a partly demon metal shield with a partly demon metal sword pretty reliably destroyed both and summoned an imp Now as this metal is still great for ax head and knives people still use it every day, but no one wants armor made from it as one poke from the wrong knife and your expensive magic armor is now a demon that is craving human souls [Answer] # It got superseded! (Inspired by / adapted from the answer of @Cadence) The metal A was immensely valuable because it has good physical properties and is scarce and hard to extract. The metal T, while abundant, was not considered because nobody knew how to work it. Then people (maybe not everybody!) discovered the trick to work T (cheaply, maybe in nitrogen), and suddenly A is totally worthless because it is much more scarce than T and its physical properties are significantly less interesting. [Answer] Oh hey, you're in luck -- there are a bunch of interesting story options to make the metal useless! As a general theme, a metal is useful if it can be processed into tools and uses where it is more cost-effective (or much more capable, which is really the same thing) than any competing solution. Therefore we are looking to make it very expensive, or have a surprise drawback as a tool (eg. toxicity). ## Flaws in MAKING the Tools We prevent the metal being useful by making it prohibitively expensive or hard to make the tools. One of: * hard to mine the ore The ore could be incredibly durable (thus too hard to get in usable amounts), or the mines unstable, or filled with toxic vapours * hard to refine the ore eg. Aluminium. Bauxite ore is hard to get aluminium out of, requiring electrolysis or tedious chemical processing. This is why Napolean's fanciest cutlery was aluminium, and his medium set was gold. * hard to forge the metal into shapes eg. Diamond jewellery didn't really exist in the Roman empire because they couldn't cut the damn things (emeralds preferred). There are similar, boring examples around titanium alloys in modern metallury, or how the industrial revolution was facilitated by new casting techniques that allowed for bigger iron structures. ## Flaws in USING the Tools You have defined the metal as having some wonderful physical properties, so it is clearly desirable on that basis. However, there is another option that makes the metal a useless tool -- chemical and biological effects. Therefore you could: * Make it chemically unstable The metal rapidly oxidises into a rust that, like iron rust, has a very different crystal structure to the original metal. This means the rust falls off and continually exposes new metal that also rusts (the opposite of aluminium). Thus all tools are prohibitively short-lived * Make it Toxic I: Poisonous Like Mercury or Beryllium, this metal has salts that are toxic and will kill you unpleasantly. Not toxic enough to be immediately obvious, but clear enough that Dr.Macguffin knows and long-term use of the metal is not viable. Bonus points if the metal salt is absorbed through human skin, or causes sterility. * Make it Toxic II: Radioactive Similar to toxicity, there is a wide range of radioactivity that is not immediately obvious, but as users and miners have collapsing immune systems and generally shit themselves to death en-route to systematic organ failure within a few weeks or months, it becomes very clear this metal is BAD NEWS. So in conclusion, pick and choose! There are lots of ways that the metal can be made useless, and lots of ways that you can make a very interesting story with those ways :). [Answer] State change + thermal sensitivity: When originally cast it has the properties you describe. It's internal structure matters, though--when cast it has no crystalline structure. However, as time goes on it develops a crystalline structure. In your dungeon the temperature is constant, this is not a problem. However, when heated/cooled unevenly (which includes anything not done very slowly) the crystals try to shift, inducing huge stresses in the material. It's prone to catastrophic shattering due to this. [Answer] MGM is indeed valuable, but no sane person would ever use it. Why do you ask? (Laughs) Wait, you're serious?! Has no one ever told you? Fine then, I'll enlighten you: MGM is made of ghosts. You see, as time goes on and ghosts get lonely from lack of company, they gather together or go looking for other ghosts. Eventually, the former ghosts lose their former aversion to touch, as it's the only thing that they can really feel and another ghost's touch is apparently really reassuring. As they slouch from despondency and loneliness, gradually collapsing on themselves, they lean into their ghostly friends and eventually compact into something tangible: an MGM deposit. The latter ghosts find ghosts who already deposited and join them or form a deposit later with their new ghost friends. These deposits eventually move to join other deposits, forming veins, or just stay where they are, feeling no need to do anything unless something interesting happens. Besides the social stigma of wielding, wearing, or building something out of ghosts, MGM has a variety of unusual properties: 1. Spiritual Properties-MGM made of aggressive or violent ghosts can only be formed into weapons, MGM made of protective or defensive ghosts can only be formed into shields and armor, MGM made of crafty or artsy people can only form specific "tools of the trade." 2. Spiritual Connections-An MGM item can only link to one person, one wielder. It can only be held (and therefore used) by one person, the last person to touch it. Armor and shields block people's touch, weapons hit enemies, they just can't be held by someone else. However, there is a huge drawback to this. If the wielder dies, their spirit becomes part of the item, adding on to its hardness and sharpness. 3. Spiritual Connections (Continued): When an MGM item contacts the skin, the wielder gains mental and emotional feedback (thoughts and emotions from the ghosts that comprise it). For example, an MGM blade used in combat might exude whispers (heard in one's mind, of course) like Blood! Blood! This would of course keep most people from using it. So, truly desperate or crazy people would use it, but it'd be worthless to everyone else. [Answer] UV light Take a lesson from plastic, maybe MGM reacts with UV (aka sunlight) A door in a cave is fine but one on the outside of a building falls apart after a few day. for armor, coins tools, anything that might get regularly exposed to sunlight its worthless. You might be able to make a sword out of it is you are careful to almost never draw it and keep in the sheath all the time. It makes a great pocket knife just make sure you keep it in the sheath. [Answer] Its so strong, it's not really forgeable, its really heat resistant, so its has no field of use Edited away: OPT2: The market has so much it costs nothing => wothless [Answer] If you're going high-fantasy, the metal is useless outside of the region it's found, due to magic. Of note, this doesn't make it completely useless - just impossible to export. So, your shield, bullet proof vest, etc all work - up to a radius of 20 miles from the veins. This could produce a rather distinctive local culture in time, perhaps a seat of government if the metal is useful enough. Projecting force would be difficult, but it could serve effectively as a defensive deterrent. [Answer] It is believed to be unlucky. It might even be unlucky. The properties of the metal, its strength and lightness make it appear unworldly and it has an unpleasant strangely slippery surface. Although initially interested by the material, people discover that over time they just don't like using it; they just don't like touching it - they don't trust it or things made from it. Despite its useful properties, people just do not like it and do not want it. They are not too sure exactly why, so they simply think of it as unlucky. ]
[Question] [ I have a bit of a problem. My largest dragons have a flight range of over 1000 miles, but I have another continent that is only reachable by ship significantly closer (just over 750 miles). I can't use some excuse about winds, as my ships are mostly sail powered. Further hampering my progress is the fact that my dragons originated on this other continent, as did humans. I need some way my dragons flew off the continent, but can't get back, that also makes it possible for ships to go back and forth. NO MAGIC MAY BE USED.This is because my only magic is the dragons themselves. [Answer] Dragons, Like Birds, Navigate via Magnetic Markers Part of the sea near the far continent has something that causes the magnetic pull of the earth to behave erratically. Or add in some sort of electro-magnetic disruption that messes with their heads in a way that doesn't affect humans (much). It is situated so that it is impossible to go around it without adding at least 500 miles to the voyage. This poses no problem for ships as they can use the stars to navigate well enough until their compasses work again. But the dragons can't function there. They avoid it instinctively. Any dragon who gets close feels so uncomfortable (or even in pain) that they turn around and get the hell out. This problem did not exist when the dragons lived on the far away continent and began after they migrated (or perhaps it spurred the migration). Imagine, for example, an astroid hitting the ocean and continuing to mess with local magnetism. [Answer] The wind isn't such a bad excuse. Say there is a prevailing headwind, which for most of the path is faster than the average speed of the dragon. Dragons can fly one way but not the other. Your ships, however, have a keel and triangular sails. These two inventions together permit a ship to sail upwind, tacking back and forth. This revolutionized the maritime world when we figured it out! As long as we can make sails strong enough to withstand whatever speed wind is sufficient top stop the dragons, we're set! [![How the forces work](https://i.stack.imgur.com/UwUrP.jpg)](https://i.stack.imgur.com/UwUrP.jpg) The only loophole I can think of is a dragon building a ship with a keel and sailing upwind. However, this becomes a different question: how does this fictional plot device you need tell the difference between a human crewed ship and a dragon crewed ship! [Answer] Dragons can't swim. Your dragons can fly 1000 miles but they cannot see 1000 miles. Nothing can. On the ground you can see 10-15 miles. In a plane maybe you can see 150-200 miles. If a dragon sets out over water and it sees only water in front of it, it will turn around before it loses sight of the land behind it. A flying dragon wants to always have some land within view because it knows that if it gets tired and has to come down over water it will drown. Your dragons originally came over because 1: Sea levels were lower and there were islands along the way. 2: It was an ice age and floating icebergs count as land. 3: The dragons of old were not as big of wusses as modern dragons, and were willing to fly over open water without lips quivering in fear. They drowned a lot too but that is part of not being a wuss. [Answer] High altitude jet streams. Your dragons fly at high altitude, and the jet streams are found only there. The jet streams eased their spreading out of the continent, but now travelling against them is too much effort for the dragons, thus they cannot go back. The ships instead, dealing with surface winds, have not such limitations. [Answer] The home continent has been struck by a species of fungus or bacteria that is highly lethal to dragons. It can't survive in the ecology of the other continent, but any dragons that get too close to the home continent, or the waters around it, become struck by the spores of this disease and get sick. [Answer] The dragons have a flight range of 1000 miles--but can they do that in a single hop? There used to be an island between the two that the dragons could stop and rest at. One day the island went Krakatoa. [Answer] It is possible that the dragons have simply been away from the continent for so long that evolution has made it impossible to go back. On earth, many island-dwelling bird species have this same issue, where their ancestors came over to the island from the mainland and adapted to the new climate, but in the process deviated so much from the original species that later generations were no longer compatible with the original environment. This could easily be done in your story by specifying a difference in the climates of the two continents. Considering dragons are reptiles (sort of), your best bet would be with temperature or humidity, both of which mess with a reptile's ability to regulate its body heat. So, with this method, the vast majority of dragons would be unable to go back to their continent of origin, but there would still be individuals that may have a better tolerance for the old environment than the others, which could lead to some interesting plot developments. [Answer] I'd like to expand over [Willk's answer](https://worldbuilding.stackexchange.com/a/132063/58042): At 750 miles away, the continent is beyond the point of no-return for the dragons. If the flying range of dragons is 1000 miles, as they approach the 500-mile mark they either have to head back or risk drowning in the sea. Note that at the said 500-mile mark there's nothing to be seen anywhere. It's just water, water all round for at least 250 miles in every direction. At this point, the dragon already has lost sight of his homeland and is nervous. Near the 500'th mile, the panic starts to be overwhelming, doubts cloud the dragons mind (what if these pesky humans lied and the land is actually farther)? Do not underestimate the overwhelming nature of this primal fear. To overcome this obstacle, a dragon must either: * be very, very fierce and very, very brave, * absentmindedly pass the milestone and come to senses when it's too late to head back, * have nothing to lose (e.g. he was exiled by his brethren) * be just plain suicidal. Any one of these traits would tell very interesting things about the dragon(s) that might have actually crossed the vast sea from the continent in the ancient times. [Answer] Dragons glide, they can't fly on their own power. As long as they can find warm, upwards air currents they can stay up. But on the ocean? Eventually they fall and become kraken food. That, or use a f... Maelstrom of air that ships can go around. Make it natural and non-magical. The way around the permanent storm is longer than a thousand miles. [Answer] ## Continental food isn't good enough It's really about the energy density of the food they are able to carry in their stomachs. On Dragon Homeland Island, there are many rich foodstuffs which can satiate them for a 1000 mile journey. But on the continent, the available foods are full of roughage and fiber that takes space in their stomachs without providing any useful energy. Eating or carrying more just runs them into the rocket problem. They simply cannot fill their stomachs with enough calories to fly more than about 500 miles. And they can't fish. It's similar to how British Airways's most deluxe service can fly nonstop from NYC to convenient London City Airport, but can't depart London City with enough fuel to make it to NYC. [Answer] The magic the Dragons possess creates earthquakes and/or other cataclysmic processes. That's the reason they migrated too, their growing population broke the earth capability to resist their magic flux leaving that continent "hypersensitive to magic" indefinitely. A single dragon coming back can start a chain reaction that would destroy the whole continent. [Answer] Dragons are magic. They fly by magic. They are not the source of magic - they reap it from the air. Eventually, they can deplete an area of magic, to the point where they can no longer fly. This continent is one such. Or the magic died out through some other means, eg <https://tvtropes.org/pmwiki/pmwiki.php/Main/ScienceDestroysMagic>. [Answer] All dragons have sworn never to return, after the Homeland Wars that nearly drove them extinct fighting over the territory, that tore the land asunder in the sites of the worst battles. The survivors called an uneasy truce with one another, and one of the terms was an agreement that they could never again set foot on this place - and they all know that the dragon to break that agreement will singlehandedly end the uneasy, relative peace that exists between dragons - and it may not peaceful per se, but it's not what it was - but will also be personally slaughtered by every other dragon upon its return. The dragons communicate with the smaller beings - or perhaps use magic? - on a regular basis to ensure that no dragons have been seen on this continent. All secretly long for their homeland, but most love it too much to be the one to break that truce. (Plot hooks: "All except one..." or "But the humans who captured Skittish the Dragon have no such sentimentality..." or "But then a long-dormant egg hatched and a dragon who had no knowledge of the truce or the ways of Dragonkind was born there...") If we don't want to rely on fear and sentimentality, the Great Dragon General-Mages may have also cast an eternal ward as the last of the dragons left, preventing the dragons from crossing. ("Until, after millentia, the spell began to weaken...") ]
[Question] [ Phase Metal is a material that is functionally similar to steel but can pass through its user (a single person bound to the metal when it is forged into a new form.) as if it didn't exist. Phase metal interacts with all other things normally. If a person holds a phase weapon that is attuned to them, they must hold it by part of the weapon not made of phase metal. The metal still has weight for its user. The handles of Phase Metal tools and weapons tend to be of wood or other non-phase metal materials so that they can be held by their user at all. A phase weapon can only be distinguished from ordinary steel if it comes in contact with its user and passes through. Phase weapons interact with armor and clothing normally; a phase metal hammer used against its owner would still deal some amount of blunt damage if it struck armor or clothing, but would not deal damage to exposed skin. What melee weapons would uniquely suited for this metal? What stylistic modifications could be made to a phase metal weapon that would enable it to beat someone using its normal steel equivalent? Is there a best possible melee weapon for this type of metal? [Answer] [Chain Whips](https://en.wikipedia.org/wiki/Chain_whip) and [Meteor Hammers](https://en.wikipedia.org/wiki/Meteor_hammer) (and some specially crafted armor) Both weapons have techniques similar to nunchucks but with the added flexibility of length. There are still catches and pivots that involve the weapons, but that's where the specially crafted armor comes in. Instead of the traditional pivot points for these weapons, such as arms and legs for redirecting or acceleration, each piece of a user's armor can be crafted as not only protection, but specific pivot points for unique moves. For example, having a shoulder pauldron but no chest plate could allow a user to sling the whip or hammer over the shoulder, swinging the weapon through the body, and redirecting it to come directly out of the chest of the user. Having a partial shin guard, the user could commit to or feign a pivot around the leg by adjusting slightly directing the chain to either hit the guard and rotate or barely miss it and pass through the leg; the same thing could be done with a gauntlet or bracer. You could even have masters of specific techniques identifiable by what armor pieces they use or how the armor is crafted. [Answer] Outside-in armor. Armor is bulky, which sucks. No-one can tell how hard you have been working out when you have on all your armor. Phase metal can be used to make inside out armor. You can wear your skin tight fightin' leotard that shows your calves and stuff. All the armor plates are on the inside of the leotard which means they are phased thru your body. You can ninja around looking svelte and arrows will not puncture your gut. Arrows probably will still break the skin, so you will bleed some. Which will look tough and the people you are fighting might not figure out you are armored. The physics of getting hit with a hammer are tough for me. I think if you have an internal plate of phase metal armor attached to a leotard and it gets hit by a hammer, the plate will get unattached and fly through your body until it hits the plate on the opposite side. That is good because none of the kinetic energy goes toward rupturing your spleen. But that loose piece of phase armor will might bounce around inside you and then wind up hanging down through your body at some weak spot. That might mess up the lines of your leotard or even rip a hole which would then have a piece of armor hanging out. You would need to tuck it back in with a special tucking stick, since you can't grab it. You might be able to pick out people wearing internal phase metal armor because they would also have a tucking stick on their person, unless they kept it disguised inside the leotard somewhere. [Answer] Shields. The problem with nunchucks and other weapons made out of phase metal is at most techniques in using them actually require the wielder's body to be solid; one often uses (say) the armpit to land the chain, causing the free arm to swing up to grab easily to switch hands mid-combat. Also, if the phase metal passes through the body, you'd never be able to grip the thing in the first place. A shield on the other hand has a grip inside it that can be safely made of another metal and welded into the base of the shield, meaning you can always grip it. But more importantly, a shield that is a large circle (for instance) can be wielded as a weapon, especially with the flat edge, if you're not constantly trying to get your head or the rest of your body out of the way. More importantly, one of the chief limitations on shield size is the fact that it can't be awkward to work around when trying to dodge missiles or instigate your own attacks. Part of that is that the bigger the shield, the less range of angle you have to wield it because it keeps banging either your shins or your head. So, this phase metal means that a larger shield can be brought up on steeper angles by 'ignoring' your head or shins, making it more effective in that regard but also useful as an offensive weapon that can be struck out almost horizontally because your body is no longer in the way. From a tactical perspective, this has another benefit; if you drop the shield in battle and your enemy picks it up, he can't use it to strike you and you can punch him through it every time. In short, a shield made out of phase metal is the best of both worlds; it's a more agile shield and also a pretty good melee weapon. Just one final word of warning though; this kind of shield makes phalanx tactics obsolete, unless the shield is trained to ignore your entire platoon, not just yourself. [Answer] caltrops or some other mine-like weapon that you could spread while ninjaing in, and then just happily run over when ninjaing back out. Not really "melee" but close. [Answer] Frame Challenge: Show/Training Weapons instead of serious weapons. Forge phase metal blades of normal weapons to use for nobles in their duels. They can fight all out and not have to worry about injuring their opponent or losing face. Gladiators fighting without blood spectacle would also be possible and could be scored on a points system for number of time a blade passes through the opponents body. Training can be much more rigorous if you don't have to worry about maiming your soldiers. It will be much more than just going through the motions. [Answer] Dagger pin Make a dagger almost entirely out of phase metal except for a small pin. Conceal the dagger in your body and attach the pin in you hair or to you clothing to hold it in place. You could get through a pat down and no one would know that you are armed. Spear Fight in two lines, the front line is bare chested an fights with spear or sword, and the back line fights with phase metal through the torso of the front line. Now your enemies need to fight 2 weapons and 2 people at once. Surgical tools It could be an amazing medical tool. You could do some types of surgery or scanning with out opening up a person. Does phase metal pass through infected tissue, tumors, foreign objects....? [Answer] Most meele weapons rely on the user's ability to touch any part of it. For classical weapons, make the blade phased but have a spine that can be touched by the user. That way, a double edged sword doesn't feel so double eged anymore but can be pushed at its end to greatly increace force. But we can take this further: Build a staff that is sourrounded by phased blades. The wielder's hands are mostly safe since the blades reach further than them. Normally when fighing against staffs, one tries to (block and) safely grab it and abuse the fact that the attacker holds on to it. But wow your enemies can't do this since they can't safely grab a blade and they can't crush your hands that are safe within the blades (or even a phase metal cylinder around the solid staff but that's going to be quite heavy). For one handed weapons, just forge a spiked (hollow if you want to save weight) sphere around a solid core (or even gauntlet) so that your hands are completely covered by the sphere. Don't connect them to your vambraces though or you might get disarmed eventually. But that's about it. If you add phased blades to pretty much any weapon (including nunchucks) that would likely cut the user if not phased, you would need to fight naked. Imagine a sword that has a medium sized, solid staff to handle it and has double edged blades pointing in all directions. You could "stab yourself" to reach enemys behind you, spin it around to create a deadly sphere and do many other things that are theoretically possible but humanly impossible to coordinate. There are hundreds of possibilities but most of them can't be used since the weapons grow heavier, you can't use them with armor and most of the moves you can imagine can't be coordinated in the heat of a battle. To hide a dagger in your body like suggested by sdrawkcabdear would be handy for assasins but if you can't grab the handle, it would be hard to actually use it. [Edit: So be sure to bring gloves or other fabric that allows you to indirectly handle the dagger. Thanks for pointing that out. Now the only problem is to find a spot and size that allows to transport the dagger without hurting yourself with the weight alone.] [Edit: You might also use this for medicine and/or torture. Make someone forge a long handle and add a solid ball at the end. Insert the ball and perform a haptic gastroscopy/coloscopy - or torture them by forcefully shake the handle or do any number of similar things. I don't want to go into this but the possibilities are only limited by your imaginativeness (and cruelty).] [Answer] ## Finally, those stupid spike-encrusted fantasy weapons make sense! Just cover your ordinary weapon with spiky phase-protrusions. Nasty, razor-sharp blades all around the hilt? Check! Awkward spikes at places you'd want to shimmy your hand up or down to, for leverage, on that polearm? Check! Not only to you have the advantage of those nasty spiky bits slashing and tearing and mangling your foe if you happen to land a blow, you also don't have to worry about anyone wresting the weapon from your hands and using it against you. As far as your hands are concerned, it's just a smooth, elegant spear, or sword, or whatever. As far as your foe is concerned, it's an awkward, unwieldable mess. (Watch out, don't let the spikes catch on your armor!) [Answer] After reading all the answers, and synergizing a few ideas, I think the best use would be with a team of 2 unarmored fighters with a unique fighting style built on trust. Each would wield a sword attuned to the other. Tactics would involve protecting each other and being able to fight without worrying about hurting each other. This would be amplified with weapons with reach. For example, imagine the whirling dervish of twin halberds. Or two guys dual wielding morning star flails. [Answer] A Bo Staff would be amazing. You could add armanents to the ends to make it deadly. Make it extendable so you can shoot it through your body. And make the actual staff have a rough file like texture to rip flesh off your opponents. Now usually a Bo Staff is used in unarmored situations. As a staff, it isn't really made to pierce or cut you. So Bo Staff wielders will likely be able to have less clothing on them and this gives them more opportunities to pass the actual staff through their torso, arms, head or leg to surprise their opponent. Once you put on amour, your phase weapon is basically a normal weapon because you need to cut through your armor to let it pass your body, or expose parts of your body to the enemy (e.g. Helmet, gauntlets, greaves, chest armor ). Now if possible, I would of liked to say the double ended Lightsaber from StarWars as that seems like a great weapon when you can't hurt yourself. But you can imagine that no longer needing to worry about cutting or hitting yourself would be a great relief. A Bo staff basically shares the same moves as the Double Ended Lightsaber but it just won't cut through your opponent like that. Having a phasing ability would open up a whole range of moves as you can now shift and swing the staff through your body. Armor makes the phasing ability mostly redundant. Choose a weapon that doesn't require it and gains a lot of additional flexibility. [Answer] Right. everyone is thinking medieval here. I think that's the wrong way to go about it. My answer is : # Chainsaws Chainsaws are uniquely positioned in that they're super reckless as weapons, so the point where you're likely to even cut yourself if you're not extra careful. We've all seen the horror movies where the bad guy has a chainsaw, and the good guy hits the chainsaw back into the bad guy, resulting in some timely comeuppance. This could never happen with phase weaponry, allowing you to be as reckless as you wish. What is a quickly moving series of chain links to your foe is but a dull butter knife to you. [Answer] Not so much a specific weapon, but this stuff could provide the ultimate hand guard on any weapon. Literally just a big ball of the stuff on the handle so that your hand passes through and holds the actual handle inside and is completely protected. It also means that nobody but you can use the weapon. If you are able to get metal that is attuned to another person then you can make easily disguised assassin weapons that will only work against that one person. For example, you could encase a stiletto made from normal metal inside a block or bar of phase metal attuned to the victim. It is just a block of metal to anybody who touches it, but if you strike the victim then the outer shell passes through them and the blade inside pokes holes in their body. Instead of a plain block or bar it could be some type of small metal statue or something that can be brought past guards as a harmless gift. [Answer] Pretty much any weapon would find a benefit from phase metal. Users could fire phase metal cross-bow bolts through themselves at people behind them without harm. And, they could stab someone through themselves in case they were attacked from behind. But, assuming everyone is moderate to well-armored, then I think any weapons made with flexible links -- morning stars, flail -- would all benefit from being made out of phase-metal. This would significantly change how the weapons were used. In the case of a morning star. The user could twiddle the weapons handle in any direction without worrying about where the spiked ball and chain were moving, in relation to their own body. So they could swing the weapons and maintain a high angular velocity --- deterring anyone from closing on them -- until they saw an opening to attack. Generally speaking, chain-based mass weapons would be used differently. Take the case of nun-chucks. There would be no need to redirect them around the user's body to maintain angular momentum. I am not clear on how phase-metal weapons interact with phase-metal shields when held by the same user. How this plays out might also significantly change the martial skills involved with those weapons. [Answer] Seems mostly useless. If you encase yourself in a metal bunker, you can't attack from within unless you use your hands.. If you use it as a weapon, the only advantage is if it finds some advantage to go through you--I can't imagine a simple weapon where you could make that matter by enough to make a difference. A door in a large wall: Nope, you'd have to get naked to run through. Internal armor with various external mount points is interesting but would be heavy and it would still hurt you a lot to get hit (and you'd tend to bleed) unless it was slightly outside your skin (in which case, how is it better than normal armor?) All the disadvantages of plate (Weight) and more (Skin is still vulnerable if visible). Plus if it took a hit it would distribute the shock to the mount points instead of across the whole side of your body causing do more damage to you because of the concentration than external mail. It wouldn't even make a good solid cube vault, although you could get into it (naked) you couldn't add or remove anything. Sorry, can't come up with a single realistic advantage. Oh, got it! you never said we didn't have new technology: It's not an existing weapon but I'd make a backpack with a motor and a couple large (7' radius?) counter-rotating quad blades that went through my midsection. Not only could nobody get near me without a gun, tilting the blades might let me fly :) Oh and if you hadn't said it had to be melee weapon I'd say bullets would be a good answer. Also, smuggling entire items like guns (as long as nobody x-rays you) [Answer] Imagine a blade attached to a bracelet...it is only long enough to protrude when you bend your wrist otherwise it is hidden in your hand. Could be applied in other ways like this with larger weapons...band just below the knee with blade pointing up...do a standard strike with your knee(think Muy Tai) and a blade is the striker..not the knee. "Beware the person walking with small steps"(small joint movements would keep the blades hidden) [Answer] Any poison tipped weapon. The highest risk is accidental self infliction. Imagine a poison tipped ice pick rapier that can't cut you. Or a set of armor with thousands of tiny spikes so you can give poison hugs. [Answer] Send an innocent looking messenger to your enemy on the eve of battle with a fabulous Enter-name-of-his-favourite-weapon-here and convince him to wield it against you. As he comes in swinging and sure he's got you pinned, beat him to a pulp through the weapon. [Answer] The problem here is that since its a melee weapon you expect to be wearing armor. Only when the skin is bare and unarmored can you use phase metal but that means also exposing your skin to the opposition. The only option for combat purposes would be armor. One of the biggest problems with armor is how bludgeoning weapons can still effectively hurt you and if the metal warps you are in big trouble. But if you can phase supports through your body you can spread the force over a larger area. Now not just the (regular metal) "top" armor protects you but the armor on the other side helps absorb blows! The other option is more is more of a sneaky thing. Say smuggling a weapon into a bar or when trying to assasinate someone. All that would be visible would be a piercing or something similar, you use a handle on it and pull the blade out, then connect the handle to the blade. It could be a knife, spearhead or if you can bear the strain on your skin where its carried a small sword. [Answer] I don't know what your tech-level is so this might be too modern, but I'm thinking giant circular saw, or possibly just a circular saw motor hooked up to a ring of long swords. You hold the motor in front of you with the axis of rotation roughly vertical (so the plane of the blade rotation passes through you), crank that sucker on high speed and you become just a walking circle of spinning death. You can also turn the motor forwards to block incoming projectiles. You'd obviously need to keep some power source available, spare batteries or gasoline, depending on what it runs on. (Or a really long extension cord if you're just protecting a small area.) Down-side is you have to keep your distance from your friends, but if everybody in your army else was similarly equipped, you could just become a wall of spinning blades with a relatively small number of soldiers covering a wide area. (If you're sticking to strictly medieval style weaponry, you could just have something crank- or pedal-driven, I suppose.) [Answer] I can see this being useful for either offense or defense, but not both at the same time. The main problem is kinetics. Defense: There have been plenty of suggestions of internal armor. This is quite clever, but would be difficult to pull off. The armor would need to be anchored to you in some fashion. If hit with a heavy hammer, all of the kinetic energy will end up focused on that anchor. This means that if the armor was anchored at your wrists, ankles, and/or neck, the entire blow would be focused there. Your armor would need to be made to dissipate that energy quickly like kevlar to prevent serious injury. If the armor was "worn" inside a thin jumpsuit, that would help keep it in place as well as spread the secondary jolt out across your entire body. Offense: I'm picturing a screaming naked person running at me with the blade-iest, deadliest looking spinning monstrosity whirring around and through them. Pure offense to a degree that defense is pretty irrelevant. Why naked? If they had anything that the weapon could interact with, it would throw them around like a rag doll. [Answer] Since your world has magic, find an illusionist to fill the battle field with spinning blade towers. After your enemies advance on the blades and find them to be illusional, they will charge forward until the find you in the center of the field, standing in the middle of a spinning blade tower which is identical to all the rest but is made out of phase metal which is attuned to you. Assuming that your unharmed presence among the spinning blades proves that they are just another illusion, your enemy will charge you fearlessly, feeding themselves to your warrior-sized paper shredder in the process. [Answer] Double bladed sword Ever heard of Dark Maul? As a child, I used to wonder how impractical his weapon must be: You can't make a full swipe of one blade without awkwardly bending to avoid the other. It must have taken years of practice to reach a somewhat adequate level of fighting skill (I.e, enough not to kill yourself while swinging your weapon around). See where I'm getting at? Let's assume both your blades are made of phase metal, and the handle of regular, just as you mentionned in the question. Comparatively, it's ridiculously easy to learn to twirl a staff. The fact that you are not concerned by the blades offers a whole world of possibility. You can make a wide swipe and still have a blade ready to parry a counter attack - and you do not compromise your stance to do so. You can wield it way closer to your body without restraining your movements (since you won't be accidentally cutting your leg off). Worst case scenario, you can wield it almost like a normal sword, with just one end sticking through you. If we're talking about one on one, a double bladed sword where the user does not care about injuring himself would be terrifying. And completely cinematic, though not sure how effective it would prove compared to duel-dedicated style, such as fencing. Lucas choose a kendo-ish style mostly because it was way more visually satisfying. (And it's probably worthless for an army. Completly unwieldy in large groups) [Answer] 'Magic' is a tag but if modern weapons are a part of the equation then tag teams with the according bullets would probably benefit the most (with magic I personally think of a medieval setting). Person A has bullets that can pass through person B and vice versa. It's difficult to produce those bullets so having them either in special magazines or weapons would probably be common practice. Think about hostage situations... no worries about friendly fire just hit the target behind. The same goes for non-modern weapons like throwing knives and spears. The best usage for those weapons would be, again, in teams of two or more (with fitting fighting techniques), really long swords or spears that you can thrash around without worrying of hitting your own people. In general, very few weapons used by the person attuned to it would get an in combat benefit from those properties. Concealing weapons would be way easier, concealed armour for fast-moving objects, slow ones would push the clothes that the phase-metal is attached through the body of the wearer, completely negating the purpose of armour (the phase metal parts would simply pass through the body, it would be like hitting an empty set of armour). To digress a little bit: for utility tools, you could probably come up with quite some nice things. Like having a non-phase-metal hook on you and the chain attached to it is simply filling up space where your leg goes. ]
[Question] [ Many times in sci fi, the concept of full body armor has come up again and again. Most famously in Star Wars where we see Stormtroopers wear white armor covering their entire body. [![enter image description here](https://i.stack.imgur.com/nZLGA.jpg)](https://i.stack.imgur.com/nZLGA.jpg) What I'm wondering is why? Modern soldiers wear armor that only protects a small region of the upper torso and head to save on weight and have better mobility. Why would a future military have standard issue armor that covers the entirety of the body? Some assumptions: * The material the armor is made of is light and strong enough that it does not burden the solider much, or at most requires assistance in either a passive/very minor assistive exoskeleton to operate with. * Guns and projectile weapons over all are still a thing. * Covers at least 75% of the body if not fully. Nothing is stopping use from going the way of the peasant soldier i.e. focusing on head, torso, arms and hands protection. Maybe leg armor too, if you're lucky. * The soldiers wearing this armor are in a terrestrial environment. [![enter image description here](https://i.stack.imgur.com/uPoE0.jpg)](https://i.stack.imgur.com/uPoE0.jpg) [Answer] Environmental dangers Space is a dangerous place. You may find that you're more at risk of dying from radiation or lack of oxygen or heat than by being shot by the enemy. Sure you might get instantly obliterated if one of their ship artillery hits wherever you are on the ship but should you survive you want to be protected from dangers such as depressurization and lack of on-ship life support systems. You will need to be protected from head-to-toe in order to be protected from most if not all environmental dangers, especially in space, which is what I'm assuming is the general environment of your setting by your use of storm troopers as example. [Answer] Body armor is designed to protect mostly against the type of bullets we use. These bullets produce localized damage. They don't fly that fast. Some body parts are more vital than others. Armor is heavy and cumbersome. The enemy will aim for the center of the chest because it's a lot easier to hit than the head. So it makes sense to only put armor on the most vulnerable parts. To justify full body armor, you'd have to change one of these parameters. Remove the current rules of engagement and allow for poisoned bullets that kill you even if they hit you in the pinky finger... or white phosphorous, or explosive bullets... then damage is no longer localized, and most body parts become vital. In that case, you would need full body armor. Change the enemies, for example give them acid for blood that sprays everywhere when shot. Make flamethrowers legal! Everyone get an asbestos suit! Fight in vacuum: any hole in the suit means a very bad day, so it has to be bulletproof everywhere. Make aiming more accurate, for example robotic auto-aiming space pew-pew lasers that travel at the speed of light, or homing bullets that can reliably hit any non-armored part on a moving target. Then you need to armor everything. Use the Space Shotgun instead of the space rifle. I mean, if you're shooting people inside a sci-fi spaceship you probably don't want to use .50 cal or armor piercing bullets that will go all the way through the ship and puncture the reactor confinement or just blow the air out. So you'd use space buckshot instead, which works better in close quarters anyway. If the enemy uses space shotguns that aren't armor piercing, you don't want a heavy thick chest plate because the spread of the shot means you'll get hit somewhere that isn't covered anyway. It would be better to have lighter protection and more coverage. [Answer] There exist already today full body armors: hazmat suits [![enter image description here](https://i.stack.imgur.com/NTpRJ.jpg)](https://i.stack.imgur.com/NTpRJ.jpg) In a scenario where the enemy can use biological, chemical or nuclear weapons, you want to avoid that those substances enter in contact with the body of the soldiers. The only solution is therefore to fully cover the body and leave 0 exposed surface. [Answer] # One New Thing (Name Your Problem): All you need to justify head-to-toe armor is ONE new attack form that requires armor to protect from it. It doesn't matter WHAT that is, as long as the logical defense is armor. It doesn't even have to be an attack currently in use - even knowing the enemy WILL use it if you don't defend against it will require everyone to be armored. And a suit isn't enough, because the slightest breach of the suit will kill you. * SONIC WEAPONS: Sound weapons are developed so lethal or debilitating sound waves cripple the nervous system. Only adding vibration-cancelling protection to all parts of the body keeps out the sonic attack. If armor can be made to absorb shockwaves, this can even apply to reducing ubiquitous blast effects. * NBC: Nuclear, biological, and chemical weapons mean chemicals, radiation and disease are able to penetrate to a man not covered everywhere. Chemicals can include things as humble as irritants. Only constant isolation protects you. Anthrax can be everywhere and new strains made to overcome the best immunity. * INCOMPATIBLE ENVIRONMENTS: Alien worlds, ice-cold arctic winters, deep ocean, hydrochloric acid atmospheres, space, the list goes on and on. * KILLER MICRODRONES: Tiny robots are everywhere, and out for human flesh. The armor needs to be strong everywhere to keep these evil things from finding a vulnerable spot. And perhaps you need to periodically douse in acid or flaming gasoline to kill off the things as they accumulate on your gear. That list could go on all day. But in addition, there are other reasons to completely protect your troops. * YOUR COST PER MAN IS INSANELY HIGH ALREADY: Each trooper requires vastly costly training and equipping to make him effective, or the men who can fight are wildly rare. Maybe 1 in 100 men is immune to mind control, or 1 in 1000 is psychic. Maybe you need a PhD to operate the linear accelerator cannons in all the possible situations. Or the effort to deliver one soldier to the battlefield costs a billion dollars (teleporters, interstellar travel). No cost compared to that is too high to assure each man is able to fight to peak efficiency. * EVERYBODY USES POWERED EXOSUITS ANYWAY: Every man needs to operate completely independent of the supply chain or the equipment (weapons, life support) they use is too heavy to move in without an exo-suit. If you can haul 10 tons of gear, what's half a ton of ablative projectile & heat resistant plating amongst friends? * PROJECTILE-RESISTANT OPPONENTS: If the enemy (zombies, super-armored guys, shock-resistant aliens, robots) is resistant to small penetrating projectiles and the tissue shock that goes with it, they might close to melee range without being substantially slowed. Against that alien's fire breath, acid spit, claws and swords you're going to want to have a full-body suit of armor just like the ancient knights did as you incinerate the still-moving chunks of your opponent. * INDEFINITE SURVIVAL: Your battlefield can't guarantee your soldier supplies. Your suit recycles CO2 into sugars, amino acids and oxygen. It's your food, clothing and shelter. Every bit of you is covered because every bit of anything that comes out of you is recovered. It's like a Fremen stilsuit and space suit hazmat suit and body armor all in one. * SHRAPNEL: If your battlefield is full of high-explosive weapons blowing everything everywhere to tiny flying bits of shrapnel, the primary threat becomes either vaporizing (not much you can do about that) or getting hit with tiny projectiles that can cripple your soldiers. Without head-to-toe armor, no soldier will last more than a few minutes before they have so many minor wounds that they can no longer function. VR goggles tied to sensors let you see through the smoke, VR hearing means you aren't deafened by the blasts, respirators mean you can breathe when the air is full burning gasses. You can walk through the burning buildings, absorb some of the shockwaves from explosions, and so on. * MEDICAL: Your suit is a walking medic. It detects injury anywhere on the body instantly, administering stabilizing chemicals and immobilizing crippled limbs. It tourniquets at the sight of bleeding, inactivates pain locally to allow a soldier to withdraw or keep fighting. * ZOMBIE SOLDIERS: In the event your soldier dies or is crippled, the suit can activate the exo-suit and continue to operate. It will move the soldier to a medical facility or fire on opponents without the appropriate transponders. Dead soldiers can be 'ordered' into suicide attacks to draw enemy fire or carry bombs to destroy enemy positions. How terrifying is that? * YOUR ARMY CONSISTS OF WEALTHY FOOLS: If your army is a group of poorly trained volunteers but supported by a nation of great wealth, then the sons and daughters of the elite are walking into a gunfight without the skills they need to live. Maybe your advanced society has forgotten how to fight wars as wars disappeared. Maybe it's a bushido thing where the elites lord it over the commoners but have an expectation that they be willing to fight and die for the nation. The solution? Those ridiculously expensive suits of armor that protect the fools from the consequences of their own actions. Once they figure out how to fight again, they're used to the $2.5 million dollar gear and don't know how to fight without it. [Answer] Homogeneity. Who are the officers? Who is telling people what to do? Who are the high value targets? If soldiers have their entire bodies concealed it is harder for an enemy to figure out which soldiers warrant more attention. Additionally, if you are a soldier, uniforms of this sort will conceal the fact that some of your fellow soldiers are aliens, or robots, or resurrected zomby soldiers. [Answer] ## You've already answered your question > > The material the armor is made of is light and strong enough that it does not burden the solider much, or at most requires assistance in either a passive/very minor assistive exoskeleton to operate with > > > If the material is so light and unencumbering, then there would be little need to leave out armour pieces for weight or mobility. And so, given that an armoured bodypart is more resilient than an unarmoured part, it would be a no-brainer to cover up the entire body [Answer] Armor must be effective against the primary threat. Platemail went away because it as guns become sufficiently advanced, they cease to offer sufficient benefit frequent enough for its cost and burden. That doesn't mean armor went away entirely, they just might not be in the form depicted in Star Wars. Kevlar vests, ballistic armor, etc. do exist and are frequently worn. 1) Material science advance sufficiently that body armor can sufficiently protect against the most common threat. There can be multiple methods armor mitigates damage, and depending on your world the most common source of damage need not be kinetic in nature. * Direct (As conventionally known) * Ablative (Reduces or Eliminates the material from the incoming attack) * Absorptive (The armor takes away the incoming attack from the weaerer, perhaps absorbing an electrical charge, or perhaps taking all the impact force in the wearer's stead) * Dispersive (Maybe in your world bullets became obsolete and energy weapons became dominent, the armor disperses the energy harmlessly across its surface) * Insular (Is the primary source of damage through biological/chemical warefare, or even electrical or heat?) 2) The environment or operational conditions warrants it. Maybe your characters live on a hazardous planet. Maybe rockslides are common, toxic gas, heat waves, etc. Maybe they live under the sea. Armor isn't limited to combat use. Real-life Exoskeltons will probably see heavy duty use in the form of mining etc. before combat use, that doens't mean your soldiers cannot equip such an armor for non-combat purposes while on active duty. Once it is established that operational conditions warrants such an exosuit, they might start adapting it for combat utility based on field experience, but such a suit's priamry function will be to fulfill operation conditions. [Answer] ## Psychology + Uniform Even light plastic armor with some kevlar under it goes a way to protect from discontent civilians. At least if the solders are in compact group. Also it improves their morale, as they see brave friendly solders around, even if they are scared inside. It protects from inconvenient scratches, or in case of falling from speeding motorcycle. Even if soldier is wounded, enemy cannot say how much or even wheter - so until really disabled every unit looks like fully functional. Full body armor looks intimidating, may have demon-like face and does not show, if it contains scared newbie or hardened special unit veteran (but suggest the later). As such units are usually used against civilian "rebels" in big number, this looks make half their work done - week civilians take cover, run away scene and only "hardened criminals" are left to oppose such power demonstration. Also having the same armor makes good uniform, to recognize your man from opposition fast. And small and cryptic distinctions make easy to be spotted by trained eye and recognize to fast evaluation of who is from which unit, which specialisation or which level of authority. Plus it is easy to mass-produce such armors and have soon big army where only few are really trained, while it looks, like all are top specialist. Good for evel overlords as well for film studia :) [Answer] ## Armor Simply Needs to Become Lighter Full body armor is always better than partial armor as long as it can meet the following two criteria: * It must stop all common threats when hit. * It must not be so cumbersome as to make one combat ineffective. If you make your armor too thin trying to get full body coverage, it will not stop any common attacks; so, it is just waisted weight, but if you make it too thick or too heavy, then you can not move in it which also makes it useless. The only reason we do not still use full body armor is that modern armor is not good enough to cover the whole body and stop a common riffle round without also being too heavy. To fully cover a solider today with riffle armor would mean loading him down with over 100kg of body armor; so, to compromise, we use armor that weighs just as much as a suit of medieval plate armor did, but we focus that armor only on the most critical and likely places to be shot. If you were to improve armor enough that you could stop most common riffle rounds with a full suit of armor that still weighs 25kg or less, then full body armor would very quickly come back into common usage. Alternatively, if you were to improve a soldier's carry capacity to over 100kg using cybernetic or biological augmentation, then you might also see an increase in full body armor, but... this may be less likely since a higher carry capacity also means you can carry a bigger gun; so, higher caliber weapons may also become the norm simultaneously eliminating the advantages of more armor. So if you were to try to solve this problem with super strength instead of lighter armor, you need to make sure that the main threat will still be normal soldiers packing things in the 5.56-7.62mm range. So super solders have to be the exception, not the rule, for this solution to work. Lastly, the problem we see a lot in sci-fi (and a lot of fantasy actually) is that common attacks go right through full body armor. When you look at something like a storm trooper, full body armor makes no since because every common hand gun seems able to go right through the armor and kill them, even when hit in the chest which should be the most armored part. However, if you instead envision something like the [Kull from Stargate](https://stargate.fandom.com/wiki/Kull), you then have something that makes a lot of since to see full body armor on. Since their armor is actually effective at stopping most common weapons, they can walk right out into a hail of bullets taking shots to the arms, the legs, the face, the chest, and everywhere else. This means they can focus their whole effort on shooting the enemy and not have to waste any effort on not getting shot. [Answer] Secret police or collaborators from an occupied country. Occupying another country is hard. Doing it with just my troops from home? Now that's tough. So I need some locals to help out, but the local population isn't on-board yet with my leadership and I don't want my people hassled when they're off the clock. What better way to protect them than to conceal who they are with full body armour and face coverings? [Answer] ## Laser weapons Their armour looks shiny.. Modern armour material can be reflective, that is why it may return. In Star Wars, the stormtroopers have a light weight, reflective white armour. Edit: In real life, strong laser beams will damage mirrors, same would happen to armor. A shiny armor would be most effective compared to clothes, when the angle of the laser light is not perpendicular to the surface. In any case, the comments below are justified.. body armor against laser should be thick and (very) heat resistant as well ! [Answer] The armor incorporates a powered exoskeleton. It allows the soldier to carry the armor, and its power supply, without increasing their burden. It will also allow the soldier to carry additional ammunition and supplies and even heavier weaponry. It could also include environmental protections (possibly including heating or cooling) that would not be practical for a soldier without such a suit to carry. [Answer] I'd say that the previous answers have covered most of the reasons why armor could return. Effectiveness against commonly-used weapons To add to the above, if the materials from which armor is made prove to be sufficiently effective against "short range" weapons (i.e., machine guns, pistols, shotguns, grenades) they would normally encounter during combat, then you'd have an argument for them to make a return. Intuitively, as no sufficiently-light AND comfortable armor can protect from a hit to the face or hands, there is no reason to inconvenience soldiers with it, but if technology allowed for a face cover or "armor glove" that would save you from it, and be comfortable enough as stated in other answers, then military forces would definitely incorporate it. Effectiveness against new weapon types If the materials, alloys or fibres from which armor are made are better suited to stop or deflect new types of weapons (i.e., beam weapons), such as Star Wars' armor, which is supposedly "designed to disperse the energy of a blaster bolt and insulate the wearer, lessening injury", then full body armor would make sense. This ties to the previous: if, for example, beam technology became cheaper, safer, more economically efficient or better overall, then militaries will switch to beam weapons and full body armor might be the most reasonable counter. [Answer] It's already returning. E.g. this is the Sotnik infantry armor that Russia is developing, planned to be done 2025(picked it as an example, because it looks the most sci-fi ish, there are plenty of others): [![enter image description here](https://i.stack.imgur.com/XGLkt.jpg)](https://i.stack.imgur.com/XGLkt.jpg) <https://taskandpurpose.com/military-tech/russia-sotnik-combat-armor-development/> You must remember, that body armor didn't go away due to ineffectiveness as such, e.g. 17th century plate was quite effective at stopping muskets from all but point blank range and would have been for a couple centuries more, until muskets went away, the word bullet-proof comes from the literal proof that it would stop a bullet that the purchaser required the armorer to provide in front of him: [![enter image description here](https://i.stack.imgur.com/elcl1.jpg)](https://i.stack.imgur.com/elcl1.jpg) However, due to the large quantities of high quality, tempered steel required to do it, it was too expensive to mass-equip the new armies of the modern age and due to the fact that no armor would do squat against cannon anyways, the cost-benefit equation worked out to: heaps of cheap unarmored troops > a small number of armored troops. The tech for at least somewhat effective 3/4 armor has arguably existed since the 80s, but it was too expensive for the mass armies of the time. Now, all militaries, including the Russian one are moving in the direction of a relatively small number of well-trained(hence valuable) troops, so the cost-benefit equation has shifted back to armor. [Answer] As you stated: the main reason that soldiers today only wear light partial armor is due to weight. The encumbrance of full-body armor outweighs the benefit of full protection. To get back into full armor, one or both of that must change: either full body protection must become a definite benefit, or the weight of the suit must be reduced (or both). One way to do this is with some variation of power armor. Things like exoskeletons that do exactly that are already in development. Such a suit will at least support its own weight, making encumbrance a net-0, and if it increases carrying capacity or walking speed, it gets to be a complete benefit. This can be combined with benefits that other posters mentioned; like protection from environmental hazards (poison, or the vacuum of space) [Answer] ## The balance of Offence vs Defence swings the other way Right now, the problem is that an armor that can stop a bullet in its tracks is expensive, heavy, inflexible and generally only good for one or two hits with low-calibre weapons. Weapons technology has vastly outstripped personal body-armor to the point where we no longer defend against direct attack. Instead, we defend against secondary effects. Shrapnel, debris, glancing hits. Things that would cripple but usually not instantly kill. This, incidentally is the ideal-case for a Storm-trooper's plasteel armor-plate. Remember the prison-block in A New Hope? Remember how fast the fire-fight turned it into a storm of debris, shrapnel, smoke and alarms? Those storm-troopers might die in a single direct-hit, but they shrugged off the shrapnel caused by blaster-fire hitting walls and blowing up nearby hardware like it was nothing. And they started shooting before the smoke from breaching the doors had cleared. Those helmets have all kinds of respirators, filters and optics to let them fight in hostile environments where a lesser-equipped person would be blind, choking and probably dead. We also never see a clear over-penetration of the stormtrooper armor. Plenty of burn-marks and troopers falling over, but plenty of times a trooper was clearly still alive after being hit. For example one trooper fell off a catwalk when directly-hit and was clearly screaming as he fell. One imagines that the storm-trooper armor is actually excellent as a defense against lighter blasters (such as their own E-11 carbines and hand-blasters) and most of the storm-troopers we see shot are actually alive, just knocked on their asses by the impact and burns they just received. So back to the offence/defence tradeoff. Stormtrooper armor is very light-weight. The clue is in the name "Plasteel", a lightweight polymer with properties reminiscent of steel. If it weighs anything like say.. ABS, or a thermally resistant resin, it could be very lightweight indeed. An armor that defends against most non-military small-arms well enough to prevent the trooper being killed in many/most cases, and can turn a military-grade glancing hit into something survivable, provides NBC protection, can see through smoke and gases, shrugs off shrapnel and acts as highly functional riot-gear? Sounds great. Now imagine what that would look like in real-world modern terms. A suit of body-armor that can stop pistol-caliber hits entirely (even if the wearer gets knocked off their feet), and can turn a killing blow from larger caliber weapons up to .50 cal into something survivable. We don't have the technology for that right now, but if we did, we might see the return of the suit of full body armor. [Answer] Your military strategy emphasizes sheer numbers and brute force over everything else. Remember that the Stormtrooper example is based on what is essentially a limitless clone army. Not all of them will require this level of full-body protection, but some will, and the full body armor is standard issue to all. It's the mass production of troops, without any exceptions or differences whatsoever, right down to every element of gear. Each branch of the U.S. military has its own standard working uniform, and each MOS has a relatively standard issue of gear all its own; for instance, a Bosun's Mate must be equipped with knife, lighter, and marlinspike at all times. This is just the same, except there's only one MOS throughout the entire force. [Answer] I recently read Seven Eves by Neal Stephenson. Potential spoiler: Combat in that universe takes place mostly in space habitats. Conventional weapons are not ideal in that environment. So they developed a kind of weapon that shoots tiny robots that avoid penetrating habitat structures. When landed on humans they would crawl around to find an opening in the suits and wreak havoc. Full body armor could definitely be useful in this scenario to prevent or slow these small robots from entering their suits and bodies. [Answer] Armor doesn't have to stop incoming projectiles from infantry rifles (or bigger) Up until very recently, there were no helmets that were rated to stop rifle rounds. They were meant to stop shrapnel and fragmentation. That's not to say that a rifle round wouldn't bounce off a steel helmet at the right angle. The same with early flack jackets. The amount of material required to make something bulletproof also made it impractical for infantry to run around with. After all, they are called $Flak$ jackets because they were issued to bomber crews to protect them from German Flak. It took another 20 years for infantry to be issued body armor. Infantry kit is becoming heavier and heavier. According to [this](http://www.45thdivision.org/Pictures/General_Knowlege/combatload.htm) the fighting load of an infantryman in 1944 was about 75 pounds. The last time I went to the field, my load was 112 pounds. Eventually, the amount of kit an infantryman is required to carry will dictate that he needs some mechanical assistance. An exoskeleton will react A LOT poorer to a piece of shrapnel than the squishy thing wearing it. Think of the scene in Iron Man 2 with the prototype Iron Man suits from the other countries failing. In short, the suit of armor would likely be designed to protect soldiers fully in the upper chest and head, with lesser protection to prevent unessasary mechanical injury everywhere else. [Answer] Let's make two changes: First, a weapon already under development: Grenade launchers with rangefinders and spin-fused rounds. You take the range to whatever the enemy is hiding behind, you take the range to whatever's behind the enemy and set the grenade in between. The grenade launcher sets the fuse to a certain number of spins and you fire just to the side of whatever the enemy is behind. The grenade goes past and explodes beside your target. Second, improved armor. Lightweight material that can repel grenade fragments. Now, any soldier that doesn't have such armor is very vulnerable to such side-attack grenades. Note that you won't see many such grenades used because the armor stops them--so long as they are available it makes the enemy wear the armor. ]
[Question] [ Humans have achieved FTL and have colonized several planets in our greater stellar neighborhood. While we have discovered several planets that harbor life as we know it, we have not yet discovered other intelligent life. However, this isn't because we haven't yet encountered it; within the same stellar neighborhoods we've come to inhabit, there exist one or more intelligent and technologically advanced civilizations, none of which have yet become aware of each other or us. It may even be the case that a single star system plays host to all of them simultaneously, and they still haven't found each other. How do you keep FTL-capable, intelligent, advanced civilizations from noticing or even bothering each other? EDIT: Constraints: The creatures themselves must be similar enough to humans that they could be easily recognized as intelligent if encountered in-person. Individuals should be roughly similar in size to humans (they could be as large as whales or as small as bugs, but not, for example, microscopic or telescopic in scale.) [Answer] # Easy ## Space is big. > > Space is big. Really big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist, but that's just peanuts to space. > > > Douglas Adams "The Hitchhikers Guide to the Galaxy" > > > We like to think that radio waves we send out can be picked up by another civilisation, but this is just a huge comforting lie. Distance to Alpha Centauri system is about 4.37 light years. Radio signals lose power as a square of distance. For comparison, as of last year, Voyager 1 is 137 AU away from Earth (1 ly is about 63000 AU). According to [this answer](https://space.stackexchange.com/questions/9824/how-much-rf-transmit-power-does-dsn-need-to-send-commands-to-voyager) power of about 20 kW is needed to communicate with Voyager probes. Knowing that, we can estimate that since Alpha Centauri is about 2000 times further away, communicating with it would require 4000000 more power, for a total requirement of about 81 GW (Giga-Watts). And that's using large focused antennae. Radio and TV transmissions dissipate into noise much sooner, I doubt they are detectable beyond Pluto's orbit. Basically, detecting random radio transmissions is a pipe dream. You can have interstellar radio communications only if you use massive antennae, pumping terawatts directly at other systems. Unless you actually know there is someone to talk to, it's rather pointless, even without considering light-speed communication lag. Because of that, you can have two civilisations inhabit neighbouring stars without ever finding out about each other. Only real chance is if their probes, scout or colony ships happen to run into each other in some system. If you want to eliminate this risk, you simply need to make them completely different in terms of biology. Through observation of other stars, including planetary transition effects, we have a pretty good idea where to find rocky planets like Earth, located in local goldilocks zone. There is little reason to visit systems lacking such planets, because those are the ones which could possibly be seeded with Earth-like biosphere and as such, are the most interesting for us. Simply give aliens vastly different requirements, and they will not bother visiting systems targeted by humans. This can go on for a very long time, with both civilisations being entirely spatially intertwined without ever learning of the others. Until they happen upon system having planets preferred by both... [Answer] Haste makes waste! You have your brand new shiny FTL drive, and the bureaucrats are demanding progress. You have to catalogue 50 new planets this week. Never mind that you can barely check the boxes on your planetary assays with that schedule. The bureaucrats demand progress, and this is the metric they chose! That cliff with 30 foot tall giant golden squiggles certainly looks interesting. Maybe it's the product of intelligence. No time for that, though. The paperwork required to properly name every one of the 70 oceans on this particular planet is going to be a killer! You gaze at the pile of forms to be filled out if you find intelligent life. You'll never get a promotion if you fall behind on the catalogue. Time to jet off to the next planet! Maybe future adventurers will come back and figure out what the squiggles are [Answer] Make them inhabit vastly different environments inhospitable for the other species. Example: Jovian gas giant dwellers with a different perspective of time (living longer with slower metabolism etc.) might not bother talking to those pesky fast humans on their little rock worlds, or the humans might have been moved in for a few decades before even being noticed. [Answer] ## Plot twist: the star system IS the intelligent civilization. The starship captain finally made it! After years of training, her first FTL flight had been a success. The approach was perfect, landing textbook and her disembarkment catchphrase worthy of Neil Armstrong himself. The last thing to do was to use the hydraulic ram to ensure the Comms Pole / Earth Flag wouldn't get dislodged after they left. She primed the Pole into the guide tube, powered on the ram and flicked the switch- Kranthos-5, youngest of the planet people jolted as a sudden itch broke out on its surface. Young and rash at 200 million years old, Kranthos volcanoed out a jet of lava to remove the offending sensation. "Strange, it didn't feel like an asteroid." ... [Differences in scale make communication difficult](https://worldbuilding.stackexchange.com/questions/75471/how-can-an-unimaginably-huge-life-form-reliably-communicate-with-mortals). When was the last time you had a meaningful conversation with a cold virus? Edit: Oh you changed the scope of the question while I was writing this :( [Answer] Bigotry. Make one race like tigers and the other like deer, and they won't recognize each other as "human". * For example, as every tiger knows, the defining characteristic of intelligence is "undaunted ferocity" and these timid herds of all-look-the-same grass-eaters obviously have none of that. * Similarly deer-people know that the symptoms of intelligence are social harmony ("consensus") and ecological harmony ("wisdom"). Tigers (whose landers leave scorch-marks on the alpine meadows) clearly have less than none of that: and are less inteligent than rabbits, even. According to our own history books, not very long ago, there were humans who didn't even recognize each other as intelligent. [Answer] You need to make their anatomies, societies, means of communication, nature of technology, and other seemingly small details so radically different from each other, that even when they see each other, they fail to recognize it. I can see a small parallel with the Real World (TM) humans, chimpanzees, ants, and dolphins. All four species live in cooperative social groups, often with hierarchies. All four use language in some form. All four have what could be argued as tool use. All four exhibit signs of intelligence (although ant intelligence is on a collective level.) Humans arose last of all, but we have co-existed on this Earth for a million-ish years. Yet only recently has one of us begun to realize the potential of the other three. To this day, ants see humans only as large, dangerous things that might step on them or dig up their homes. Chimps see ants as food. Dolphins probably don't even know what an ant is. Humans debate whether a bubble net is actually a tool. As another precedent, just a few hundred years ago, some humans looked at other humans and labeled them savage animals, just because their definitions of society differed. Expand this to an interplanetary level, and one particularly anthropocentric (or whatever it is called for their species) creature could easily overlook another, dismissing it as just another puny insignificant life form. [Answer] Well, I am afraid you really will have to rely on space is large. There are two requirements for that to work: Neither is civilization is noisy and will not be detected unless you actively look. No radio or other broadcast communications. No routine use of nuclear explosives. FTL does not cause Nova-like lightshows on arrival. No routine large scale terraforming. Neither civilization is actively looking. Basically both civilizations assume that they are alone in the neighbourhood, so they are not actively looking. Presumably because they have never found any sign of anyone. Which is because they have not really looked. They'd basically see astronomical objects when on a system and then sends scouts to physically look at interesting planets. They would discover each other when scouts stumbled on something. Presumably this would be a permanent settlement. So you'd manage the odds of detection by limiting the extent of permanent settlement. I think something like densely populated cores distant from each other and then overlapping sparsely populated fringes where settlements are small and rare enough to avoid random detection. I see no reasons why the empires could not claim the same system or even have mining or science stations in the same system. Or even the same planet. If you do not actively look even few hundred kilometers hides things pretty well. The needed distance and thus density possible will probably hinge on whatever engines used for lifting off or coming down on the planet. Something like a rocket lift off or shuttle re-entry would be visible for far way. Coming down or going down on anti-grav might be hard to notice even for people right below the vessel. So you'll want anti-grav and some sort of reactionless space drives to match your FTL. [Answer] If both civilizations are mutually recognizable then the only way the them to be unaware of each other is for them to not be in the same space. Perhaps they have vastly different definitions of what habitable and interesting are when selecting where to travel to. The odds are pretty high that they would become aware of each other as soon as their radio signals are picked up by the other. This is unless one race or the other has never communicated by radio, which is unlikely. To see how far our own signals have propigated check out [this](https://xkcd.com/1212/). [Answer] Advanced civilization #1 is human. Advanced civilization #2 evolved on a gas giant and can only live under extreme pressure--they can't build spaceships because the only way to get the pressure they need to survive is gravity, there is nothing strong enough to contain the pressure. This does not mean they can't build probes that can leave their planets, though. They are extremely difficult to construct due to the changes that will take place as it rises from the depths, not to mention the rare materials that must go into making them. Hence their space program is tiny and the craft suborbital (so the materials can be recovered)--until they finally discovered how to open a wormhole. The energies must balance, a wormhole can only be opened to another location at the same pressure. Hence the hop from world to world without visiting the space in between. Humans get around by the same wormholes but the same pressure rules apply--we can no more jump into their realms than they can into ours. There could even be more than one such race with different temperature requirements. The Jovians and the Neptunians never want the same world so they don't find each other. Advanced race #4 lives in space and at an extremely slow rate. (Handwave--while I believe such a race is possible none can exist as their slow life process means slow evolution--there hasn't been enough time for them to evolve to civilization.) They aren't common, none of our scientists have noticed that some rocks in space aren't rocks. Our life processes are too fast to have come to their attention yet. [Answer] By definition, neither they nor us could be a Kardashev Level >1 civilization since utilization of most or all of stellar output would definitely be notable. Given our utilization of energy, it seems that what you'd need is these other civilizations exist at either much faster or much slower rates, so that any heat or emr signals from them would be indistinguishable from noise. An alternative would be that they exist somewhere which we have not adequately explored. Obvious candidates include the interior of planets, or in the Oort Cloud. I suppose there is no requirement for an "advanced" civilization to be curious, so if they developed a million years before we did (our species is estimated to be roughly 200,000 years old, although it seems that significant changes occurred about 50,000 to 100,000 years ago). And if they "kept their heads down" during our electromagnetic "noisy" period (still on-going), then if they were few in number - a "civilization" existing in a Matrix type machine might only occupy a very very small space maybe only a few hundred or thousand kilometers². [Answer] FTL means time travel. So let's assume there's some magic that allows for much faster than light travel, but nothing between that and conventional travel. So to get from here to a neighboring star, you either have to go way back in time, or wait thousands of years (for a direct trip.) Thus these civilizations could co-exist on 'nearby' stars, but not notice each other because the FTL travel path takes them too far back in time in the process. Traditional radio-emissions might still take decades to reach the other star system in present time, and would only do so at a very weak and possibly undetectable level. [Answer] As has already been posted: space is VERY big and radio signals tend to get lost even within a single solar system. It is absolutely possible for multiple advanced FTL civilizations to be in the same system without finding one another for an extended period of time. Here's a point that wasn't brought up previously: Why are we in the system? What are we looking for? We are assuming that humans are there to look for Earth like planets, right? We further assume that these aliens would be similar enough to humans to be instantly recognizable, and that does imply enough similarity that they might be interested in the same kind of planet, right? What if one party's FTL technology was so limiting that it demanded the primary objective in going to a new system be servicing the FTL drive and NOT looking for new, colonizable planets? For example: let's say that the FTL drive (which also serves as a communication unit, since FTL travel without FTL comms is problematic) uses mass to energy conversion that demands a very specific and rare type of material to be stable. The very first thing a brand new colony in a brand new system has to do is camp out next to a deposit of this stuff and mine enough of it to have a ride home (or even a phone call home to let others know they are ok). Unfortunately for them, this stuff is rare and usually only found in Oort belts way out on the outskirts of a solar system (or maybe in the molten cores of hot planets very close to the sun). So, for the first few years of colonization, this species is living in very uncomfortable pressurized domes in a location that is NOT optimal for them. Species #2 on the other hand has a very different type of FTL technology. Their drives work in a different way. They aren't as worried about making a phone call back, so they head directly to the planet that BOTH species find most optimal for colonization in the "goldilocks zone". Now, unless they were specifically looking for one another, it could take a long time for either side to realize that they aren't alone. Random radio chatter wouldn't do it either, since there is SO much noise out there and signals get so weak so fast. This would be particularly true if one of the two was camped out very close to the star. [Answer] It would be easy to fail to notice an intelligent species if they did not make significant alterations to their environment, if those significant alterations were structured in such a way that they did not appear "artificial". I did initially also consider an underground civilisation, but we're already in a position where our probes routinely scan for gravitational anomalies, so this would not go unnoticed. At the very least this would be a trigger for investigation due to never-before-seen geological structures, and first contact would then be inevitable. All previous answers seem to assume an "FTL drive". If instead you assume "FTL portals" allowing rapid transit to another place (via wormholes or whatever other handwavey pseudo-science) then you could very easily avoid significant changes to the environment. Most of our infrastructure comes from transport requirements; if you remove this then you immediately remove all roads, large buildings, need for lighting (if you want light to work by, you can simply portal to a place with daylight), and so on. If you want food, you can simply portal to a field and pick stuff; and telling a field (without walls or fences, naturally) from a naturally-occuring area of plant-covered land would be very hard. Examples in fiction would be the Foxen from [Grass](https://en.wikipedia.org/wiki/Grass_(novel)) (and other advanced races from the Tepperverse), or the way farcasters allow travel in the [Hyperion Cantos](https://en.wikipedia.org/wiki/Hyperion_Cantos). [Answer] They live in a multiverse, and FTL actually involves going to other sheafs of the multiverse. Targetting is a problem; most of the multiverse is chaotic noise. Nothing interesting there. To find an appropriate target, we have figured out how to use massive body location patterns (stars and planets) to produce a fingerprint, then target our FTL based on those coordinates. The multiverse isn't infinite, so if we input random patterns we'll end up nowhere and lost. So we very carefully survey nearby solar systems and target a local pattern of the planets and stars that actually exist. We do not, however, actually arrive in our universe. We arrive in a nearby one. If we want to get back to Earth, our location in the multiverse is also anchored into a hyperplane defined by Earth itself. In effect, there is one alpha centauri we can reach (or a small limited set). It isn't in our universe; if you FTL there, and fly back to Earth, there are no humans there. To keep colonies from being lost, FTL beacons are set up, and we FTL from one beacon to another. Possibly the FTL is actually planet-to-planet, and we don't go into space for our FTL travel. Conventional space travel remains expensive and mostly pointless. The other civilizations exist within our space, but possibly in other sheafs. Our beacons are incompatible, and we haven't noticed each other yet. [Answer] So, if I understand this right, humans have found several species who are able to go FTL and travel but they have not chosen to yet. They come in contact with humans, who have the ability already to and you want to know how humans can basically police them? Before I get started, it would probably be worth noting that, as soon as a technology is shown, others will try to achieve it. Humans showing up on planets with species with technology capable of FTL are going to inspire them to build it too so they can explore. Preventing them from exploring will be pretty impossible unless you find some way to control them through culture or religious means. If they have FTL technology... I have a feeling though that religion may not play a factor.. but who knows they could be like the covenant in Halo XD Okay, for one... Humans need to establish credibility. If we don't establish any reputation and credibility, no one will listen to us. If species A meets species B and you try to walk in between them and say stop fighting, if they have no respect for you, they will just push you away and keep fighting. They may even team up against the humans to get us away so that they can do as they please. As I said above... it won't be about how to prevent them from seeing each other, but rather, how to keep them to being friendly neighbors. Again that falls into how the humans interact. If you can set a good example and show them how to explore and be friendly, they in turn will be inspired to do the same and you will have a quadrant of species exploring and being good neighbors. Of course not everyone will be friendly. Some people are aggressive by nature no matter what you do. [Answer] The FTL is not detectable, or not easily detectable. Maybe they all use different types of FTL so they aren’t looking for each other. FTL is possible from the surface of one planet to the surface of another (Star Gate). So everyone travels directly from their home planet to another planet of ideal habitability. Species could share the same planet if one preferred to live under the ocean, and another preferred to live in the magma core. [Answer] We don't even know what 'intelligent life' means. Whales have far more complex, and far larger, brains than ours - do they count as 'intelligent'? (I'm not suggesting that they are FTL capable, though Star Trek suggests they have FTL relatives). Putting that to one side, the answer is simple: What makes us 'noticeable' is the use of radio, which sucks as a communications medium since we have FTL. Let's assume that we have ansible comms, and that ansible communications is a directional closed signal, so you can only notice it if you are the receiving end of the device (some sort of fictional 'quantum entanglement' magic - which doesn't allow ansible communications in the real world), then it's very easy for many very similar species to co-habit our region of space. Space is huge, and so are planets. If you aren't looking out for another entry vehicle, you won't notice someone else's. You could even have a relatively stable population on a planet before other alien colonies on that planet were discovered. [Answer] The Universe is expanding at an increasing rate. Even now there are galaxies in the visible universe which are moving away from us faster than the speed of light. What this would signify is that any light from the galaxy would never reach us ever, let alone reaching the galaxy we can never see it again. So even a civilisation capable of doing FLT would not be able to see galaxies moving away at a speed greater than light. Long time from now ( billions of years ), we would only be able to nearby galaxies. In such a situation even galaxies which we consider neighbourhood would just freeze and fade away from us. Even if FTL is cheap to do, it is extremely unlikely that a civilisation would decide to venture into nowhere without any reason. ( Because they can travel FTL hence they can definitely reach galaxies which are not visible to them ) Finally place the other civilisations in galaxies moving away at faster than speed of light. Impossible to see them / communicate with them despite them being exactly human. [Answer] if the different technological civilizations inhabit totally different biospheres on totally different types of planets they might never notice their colonies in the same solar system. If type A aliens only visit the surfaces of Earth like planets and type B aliens only visit the subsurface oceans of ice moons like Europa, they might never meet. Unless they have space radar for interplanetary traffic control in their solar systems and they detect a lot of space ships that aren't theirs going to places they would never go to. Detecting the spaceships or other advanced technology of the other race would reveal their existence. [Answer] Several thoughts: 1. If the two/three/ten races use point-to-point communications, laser would be the obvious option, then they won't see each others' communications except by accident. 2. If they live in different environments like David Brin's Oxygen/Hydrogen divide in the [Uplift](https://en.wikipedia.org/wiki/Uplift_(science_fiction)) books then entire civilisations could co-habitat a section of space without bumping into each other. 3. Time and movement are big factors, most estimates make the odds of multiple intelligent species actually overlapping in time exceedingly small but assuming they did then a migrating species and a sedentary group would have little opportunity to encounter each other. Imagine if Sol had been visited by a migratory harvester race that skimmed some atmosphere from Jupiter and a few Oort and Kuiper bodies on the way through in the 1200s on a 10000 year migration route we'd never know about it. A number of migratory species could knock around a given volume of space nearly forever without much noticing each other unless one, or more, of them was sloppy and left equipment lying around. 4. Early life stages, if a creature with a long life cycle left eggs or pupae to mature unsupervised then other species probably wouldn't realise they were sharing living space until mum and dad came to check on the kids. ]
[Question] [ Let's say a carnivorous species loses all available food sources, and they begin to eat one another to survive. Let us also say that prion diseases are not an issue for this particular predator. Assuming there were enough of these creatures when this practice began that they could survive through a few breeding cycles and adapt to this way of life, could such a system actually be sustainable? Or is it pure fantasy? If possible, what kind of special physical traits, population density, behavior, etc. would the creatures need to have in order to prevent their own extinction? [Answer] I'm going to say this would be impossible. If all the species eats is other members of the same species, where does it get its energy to reproduce from? Your species would have to have a huge number of offspring to provide food for itself but you would have no way to give the parents the energy to produce those children. You're basically asking for the biological equivalent of a perpetual motion machine. [Answer] What if this is a creature that doesn't become 100% carnivorous until it reaches adulthood? This means that the younger of the population can sustain themselves by other means but once they mature they shift to a meat-based diet. The adults could breed, allow the young to fatten themselves up and then go in for the kill, allowing only a small percentage of the younger generation to mature. [Answer] > > could such a system actually be sustainable? > > > As laid out in the original post, not for any reasonable length of time. One of them would need to eat lots of its fellows during its lifetime in order to grow and survive, which means that each generation would be, say, one hundredth the size of the previous one. In a very short time, they would dwindle to nothing. It is necessary to continuously supply energy to the cycle; otherwise, each generation only contains a fixed quantity of nutrients and energy (locked in their meat, expressed as calories), and dissipation will inevitably drive it to zero. One could do this with @plasticroyal's workaround, having the young subsist on something else (obligate herbivores if at all possible) and most of them serving as food for the adults. This is the lifecycle of Leo Frankowski's [Mitchegai](https://www.goodreads.com/book/show/245809.Kren_of_the_Mitchegai): > > ...a species whose biology has made them inherently evil. The > carnivorous adults lay and abandon vast numbers of eggs, some of which > grow into vegetarian juveniles, which are the adults' only food > supply. > > > The above would be certainly sustainable, as long as there were enough juveniles, and the adults would then eat "only their own" (nothing prevents them from also eating each other, as long as it's not their only source of sustenance). For the same reasons, an organism cannot subsist on [something it grows from itself](https://worldbuilding.stackexchange.com/questions/100982/can-humans-survive-just-by-eating-hairs-and-nails). [Answer] Pure fantasy or not, Niven, Pournelle, and Barnes' [The Legacy of Heorot](https://en.wikipedia.org/wiki/The_Legacy_of_Heorot) uses the same biological structure: > > However, the colonists make a disturbing discovery: the grendels and the aquatic samlon are actually the same species. Their life cycle is similar to that of terrestrial frogs – the herbivorous samlon are in fact the juvenile form of the carnivorous grendels. Like certain species of frogs, they change gender over the course of their lifetimes. The juvenile samlon are male. The adult grendels are female. Interaction is unnecessary as the grendels continually lay their unfertilized eggs in the water for the samlon to fertilize. And like many species of frogs, they are cannibalistic – if no other prey is present, they will eat their own young. > > > If I recall correctly, the juveniles ate algae or other plant matter, and the adults ate (some of) the juveniles. The concept was based on some terrestrial frog species, but I'm having trouble finding good references for the specifics. [Answer] There are such species of desert frogs. Some of the tadpoles are carnivores, [feeding on the rest of their siblings](https://www.newscientist.com/article/dn25387-zoologger-cannibal-tadpoles-eat-the-competition/) who are herbivores. They are in a hurry to grow and mate before the water dries up. Herbivores are able to feed on whatever organic matter is in the puddle, carnivores can grow faster, and the species as a whole can survive until the next rain. Sometimes nature is stranger than our wildest imagination. [Answer] Reptiles can be flexible as regards body size. You can make your scheme happen for a while by having the carnivores gradually shrink with the generations. I have laid out a schematic. Imagine dragons. They are huge. But some cataclysm happens and their prey is gone. They sleep, ready to wake if the scent of prey comes, but it never comes. Every generation they mate, and after mating the female eats the male. Each female has two eggs. Once they are able, they eat their mother. Then they go back to sleep. I have made an excel file. The dragons start at weight 1000. Each time a dragon is eaten there is a loss of 100 with the rest of the weight going into the next generation; each time eggs are laid there is a loss of 100 and the weight of the eggs (100 each); these are sacrifices to the hot god of Entropy who prevents perpetual motion machines. [![spreadsheet](https://i.stack.imgur.com/pdTDv.jpg)](https://i.stack.imgur.com/pdTDv.jpg) The adult dragons get smaller and smaller with time although the young are always the same:100. By generation 6 the females are still only the weight of new offspring after eating their mates. In generation 7 there is one female who has eaten the 4 others. She can lay two eggs and all three remaining dragons are the same size. The daughter eats her mother, mates with her brother and eats him but still weighs only 100. She is generation 8, the end of the line. The larger the dragons are to start with the longer this can go on because there is more accumulated caloric treasure to spread over the generations. My loss of 100 with each exchange (eating a male, laying eggs, young eating the mother) is arbitrary - you can make the losses to entropy as large or as small as you want. You could make losses to entropy be a percentage rather than a flat 100 which would be reasonable and this cycle could go on substantially longer. [![pygmy crocodile](https://i.stack.imgur.com/4xlvU.jpg)](https://i.stack.imgur.com/4xlvU.jpg) <http://www.abc.net.au/news/2013-07-03/dwarf-pygmy-crocodile/4796176> > > Dwarf crocodiles are small because their growth is stunted by a lack > of food. > > > [Answer] Continuing where plasticroyal and LSerni left off... The juveniles must not only have a separate food source, they must be protected from the adults while growing. I think the best model would be [the amphibians](https://en.wikipedia.org/wiki/Amphibian). An amphibian terrestrial carnivore would have the right properties for this kind of life cycle. I think such beasts used to exist before reptiles, birds, and mammals evolved. First, amphibians are [ectothermic](https://en.wikipedia.org/wiki/Ectotherm). This means your predator will use much less energy while it is waiting for food to appear. This is a very good thing for your scenario. Second, most dry land amphibians must lay their eggs in a body of water. The eggs cannot survive on dry land. And the first stage of their life cycle is aquatic and typically eats different food in a different environment than the adults do. A predator evolved to hunt on dry land might be starving while watching a lake filled with life edible by the larvae. This separation is enforced by the tadpoles having gills and the adults having lungs. Eyes might also differ. So once the tadpoles fatten up eating aquatic life, they will undergo a metamorphosis to adults with legs and lungs, rise to dry land. They will probably eat others of same gender while looking for mates. You could evolve this to harem style social grouping if you wish. Although unless it is a pack predator pair bonding seems more likely. After finding a mate, the female will lay eggs in a suitable body of water and the cycle will repeat. [Answer] It's trivially possible by arguing semantics. Digesting food can at best convert 100% of energy. Even if that was possible (it isn't) the total amount of energy available to a species would shrink anytime a member moved, until there's no energy left and the entire species is dead. Related: a random page on the internet claims a dog needs to be fed 15-20% of their body weight a week, so a dog would have to eat 10 other dogs a year. This problem can be solved if the species has ways to acquire energy (and mass) that are not called "food". The cheesy way out is if they acquire most of their energy by "drink" instead of "food". An alternative approach is to make them capable of harvesting completely different energy sources, e.g. by means of photosynthesis. In all cases you can let the "non-food" energy be insufficient, so some cannibalism is still required. [Answer] There's theoretical biology papers that work on exactly these type of questions, so best use Google Scholar. There's enough papers on the evolution of cannibalism, and most examples are from fishes. I'm working below from 15y old knowledge; consume with pinch of salt. A Google Scholar search on ["cannibalism fish theoretical model"](https://scholar.google.co.uk/scholar?hl=en&as_sdt=0%2C5&q=cannibalism%20fish%20theoretical%20model&btnG=) produces heaps of accessible papers from 2002--2006. What I remember from these things is that there's no problem being cannibalistic, but there is a problem preferentially eating your own kids over others'. So if you have a tendency of eating babies close to where you left yours, you'll statistically eat more of your own than of others, and your genes won't spread [meaning: your exclusively cannibalist species cannot evolve; only by creation it might exist]. But if your species' babies and juveniles have another (abundant) food source, then there may be enough of them to feed your adults AND let them lay abundant (small!) eggs; so this system can both evolve and sustain itself (hunt for juveniles on their feeding ground; you'll mostly eat others' babies). Generally there's a 10x biomass decrease per trophic layer (think "100kg of grass can sustain 10kg of rabbits which sustains 1kg of fox"). So the numbers must be right, to get 10kg of snack-sized juveniles allows 1kg of adult of which 100---200gr becomes babies/eggs. See [Wikipedia](https://en.wikipedia.org/wiki/Trophic_level#Biomass_transfer_efficiency) (for "trophic level") and that link scrolls to the "10% rule, which is exactly the factor 10. Notice (see the "dragons with 2 babies" model in another answer) these things only work with "many small offspring" species, not "few large offspring". Any intense parenting requirement fails this! Summary: (a) it's possible to make a stable population dynamic model with purely cannibalistic adults (b) that it must have many small children exploiting another source (maybe algae, else other creatures) that's too fiddly for adults (or unreachable: think of a net/gauze only the little ones can pass). The exact efficiency (8%? 10%? 12?) per trophic layer, you can look up if relevant. [Answer] This strikes me as a possible scenario where the carnivorous species lives in symbiosis with another species and the carnivore is a host. For example, the microflora may evolve rapidly to supply additional inputs, such as proteins, by direct synthesis. EDIT to add: remember most of our energy and nutrients is currently provided via our enzymes and gut microflora already. [Answer] Though it may not be the focus of your story and I apologize for failing the in depth details needed but the question is reminiscent of the movie Soylent Green. In the movie, the premise is that humanity has ravaged the ecosystem to the point where the majority of humanity subsists of a semi-mysterious source of food known as Soylent Green rationed out to the populace. The entire movie revolves around the world's dependence on this food source and a quest to discover it's true origins. It is a 39 year old movie and if you aren't aware of the meme "SOYLENT GREEN IS PEOPLE!" Sorry if I spoiled it for you. How does this pertain to your civilization, you may ask? Well, if they are a cannibalistic culture, measures would need to be put in place to: * Increase supply * control demand Increasing supply could be through any means. As the movie attempts, persuasion for euthanasia will increase supply. It may also help to introduce a blood sport such as gladiatorial battles or the promotion of small scale conflicts for entertainment, think football with swords and shields. Another idea, to take from a different movie "Logan's Run" is to set an age in which people are carted off under some other motive to be turned into food. controlling demand has many ways of achieving this goal. Most are rationing, either in how many a source can dispense to how many a source receives to dispense. Perhaps limit the number of population by capping off at a certain age. Again, I apologize for any leaps being made but I suppose this answer only pertains to if your species has advanced to such a level as to have a society. [Answer] There are species of frogs that eat their young. There are crocodiles that eat their young. Of course that's not ALL they eat, and there would have to be at least some other forms of food for them (other creatures?). In your fantastic setting you could look at some of these critters that exist IRL and extrapolate. Larry Niven, Jerry Pournelle, and Steven Barnes wrote Legacy of Heorot about just such a scenario. Good book too. Edit: Maybe this is a solution(?), though it is most unpalatable (lol). Neanderthals and Homo Sapiens were different enough DNA-wise that one could argue it wasn't necessarily cannibalism if one ate the other. Maybe your creature splits into sub-species so they're not actually eating "each other"? [Answer] Long term survival of the species by means of cannibalism is simply not possible. Without any other mechanism to put energy in the system it is simply not sustainable. The stronger will eat the weaker and then the last remaining will starve to death. Although a vast population spread over a large area could take quite a while before complete extinction. Consider that even on Earth, with its countless species of life, there is no such thing as a self-sustainable ecosystem. For the vast majority of ecosystems on the planet, save for deep sea creatures, 90% of the energy actually comes from the outside - namely that is solar radiation, a.k.a sunlight. A simplified foodchain energy pyramid puts every step of the pyramid at an order of magnitude less energy content. Meaning that plant matter constitutes only 10% of all incoming solar radiation energy, primary consumers only 10% of plant matter, and so on. [![enter image description here](https://i.stack.imgur.com/JRJ2W.jpg)](https://i.stack.imgur.com/JRJ2W.jpg) Now, eliminate every other food source save for cannibalism. It will probably be worse than 10x decrease, for the sake of simplicity assume that a predator reaches maturity in 2 years, and all predators are cannibalized at that age, it would take on average consuming 1 member of the species monthly for 2 years, or 24 in total for the system to produce another "ready to eat" adult animal. Now, if you have a 24 fold decrease for every iteration, it is quite obvious that sustainability is entirely out of question, and you have an example population size, it is trivial to calculate how many generations it will take until extinction. Let's assume a rather numerous population of 1 million: ``` gen 0 - 1 000 000 gen 1 - 41 666 gen 2 - 1 736 gen 3 - 72 gen 4 - 3 ``` In just 4 generations, or 8 short years that population will be reduced to only 3 individuals, which will have quite the dilemma - breed or eat, presuming you still have members of both genders, and of with the prospect of no more food whatsoever. In reality it will be even worse, much, much worse than the theoretical worse, because younglings will have a really hard time taking down adults, and parents will have higher energy expenditures and less chance overwhelming another adult to feed themselves and their offspring until it is large enough to hunt. It will be far more likely that adults consume the young, because of the energy disadvantage their parents are put into. There will be a lot less additions to the population than the theoretical number and extremely slim chance than any newborn reaches maturity. In practice, it will be nothing short of a miracle if the population is not completely extinct in 5 years or less. --- If a plausible scenario is desired, then there must be another food source, one that is of very low efficiency, requiring a lot of effort to obtain food with very low nutritional value. This also offers additional plot directions, as the population will gradually diverge into a cannibal group that seeks the high stakes, risking their lives to obtain high protein meat, and a group that is more like herbivores, although they can go for insects or microorganisms or some symbiotic relation with other species of life that can still provide nourishment. Depending on the environment setting, both groups could develop either collective or individualistic behavior and grow more and more distinct. The divergence can be either a conscious choice or a product of evolution. A subset of the species might not be able to extract nutritional value from a source other than meat. --- Another possibility is that younger individuals, being smaller and more nimble and agile, might be able to catch food that older, larger and slower individuals might not. But that's not very sustainable IMO. It could also be the reverse, as individuals age, they might acquire traits and skills to obtain food from alternative sources. For example growing external physical features with the properties of a net that can trap large enough quantities of insects or microorganisms (like a whale does with plankton) to be a viable source of food for a long term survival. The older an individual grows, the more calories it can obtain, allowing it to grow in size significantly, to the point of becoming a high value target for a pack of younger individuals that will be required to take it down. With age individuals might also develop glands that produce chemicals that attract more of their foodstuff. That sounds fairly sustainable, the young will initially be breast-fed up to a point, after which they will be forced to prey on one another, as they wouldn't really pack enough force to take down an adult, in a process of natural selection that will allow only the strongest to reach physical size large enough, so that they can take down adults by forming packs. And only the most successful members of each pack would be able to reach adulthood when they can attain self-reliance by developing capabilities to access another food source, and over time become prey to the subsequent generations. [Answer] Back around 1970, Professor Pat Doyle wrote a paper for the in-house journal of the Mathematics Department at Michigan State University. I assume it is difficult to find, but the main idea in the paper is that if you set the prey variables to be the same as the predator variables in a standard model of predation, the resulting system had a stable solution. In other words, yes, it is theoretically possible, under those assumptions, and the population will stabilize at some level. If I remember, the title of the paper was something like An in-eating cannibalistic society could be stable. [Answer] I think this question might have different answers based on whether you consider the species as a single unit, or as a collection of groups. Does the loss of food affect everyone equally, or some more and some less? Is this a small, closed ecology they are in, or is there diversity? And is social dominance a part of this equation? Based on those questions, here's a suggestion that relies on tribalism or grouping, plus ideas of social dominance. Imagine the species organized by tribes, units, families, or some kind of grouping. And their normal primary food source is based on subsistence agriculture, where they focus on growing enough food to feed themselves and their entire families. The output is mostly for local requirements with little or no surplus trade. Now imagine some kind of change or event has happened causing a partial to full collapse of food sources. Group A has a complete collapse of their farming ecology, creating famine for them. Group B has had partial collapse, but has just enough food to get by. Group A attacks Group B, eating Group B's meager food supply, and then shifts to eating Group B when the food is gone. Strengthened by this big influx of food energy, Group A starts to think perhaps this cannibalism thing is a lot easier than farming. And they continue doing it to other weak groups by becoming the dominant, cannibalistic driven group. This cycle could be kept up for a while, but eventually it might falter. Group A perhaps has to travel farther and farther perhaps, or other groups flee or move, or crop conditions improve and other groups become strong again. Perhaps Group A purposely keeps other groups in a weak position of barely subsiding on what they create for themselves, thus making them easy to "harvest" for food. [Answer] There are a number of variables in this splendidly oxymoronic and gastronomic evolutionary construct, most of which have been investigated in the well-observed comments above. The difficulty with cannibalism is that it leads, eventually, to degenerative brain diseases such as the spongifom encephalitis strains. A pandemic would, thus, lead to pandemonium; et ergo extinction. [Answer] Good News While a species that fulfills nutritional needs solely through cannibalism might be slightly far-fetched sounding, it might not be as crazy as it sounds. For example, there's a species of squid known as the Humboldt Squid that regularly with attack and eat other members of its shoal when food is running low. This can be due to the victim having an injury or many other things, but it still happens. Furthermore, these are a large species of squid, nearly 5 feet long on average, perhaps even bigger. Bad News However, it saddens me to say that this species doesn't exist using cannibalism alone. They generally eat other things like fish or krill. So the idea of only existing on cannibalism is not very likely. *Maybe News?* Humboldt Squid go too deep to track very well during the day. At night, they come to the surface to feed. This means that there's a large portion of their time that we don't have much data on, so perhaps there's more to this cannibalism than we know? ]
[Question] [ An alternate world is populated by mainly intelligent trees and other plants. These plants are almost exactly the same, biologically, as Earth's plants. The world's climate and geology are very similar to how Earth would be if intelligent life (other than the plants) had never evolved. Without causing any major changes, would it be theoretically possible for these plants to communicate? And how would it work? [Answer] ## Sound They would produce sounds in one of two ways (probably both) * By shifting their branches and leaves in just such a way that when the wind blows it makes the sounds they desire. Much like our vocal cords. The drawback is we produce our own wind whereas they would need to rely on air passing through their foliage. * By creaking. They shift their entire bodies to extremes causing them to make sounds. The added advantage of this is that the young who have "poor language skills" or "developing language skills" are mostly struggling with the fact that they are extremely flexible and don't make a lot of noise as such. All of these sounds can be detected as vibrations they pick up in their bark or their foliage (or both.) ## Earthly Vibrations Or perhaps they have the ability to cause vibrations in the ground by wiggling their roots. The other trees can also sense the vibrations through their roots. This would like make it hard to make out more than one "speaker" at a time. ## Chemical Signals Similar to the way ants communicate. However this would have to be transferred in some way. Perhaps pollen? Then it is more like they write messages in their pollen and wait for the bees to deliver the messages for them. [Answer] Plants already communicate, we simply ignore or are just now starting to discover most of the mechanisms they use. An African tree has been found capable of communicating with its neighbors to warn them about excessive consumption from antelopes, so that they can secrete more tannine. (paper cited below) Tomatoes communicate using roots: plants growing close to an infected one started producing antibodies against the pathogen. (paper cited below) Some pines have been found exchanging electric signal, even though they lack neurons. (paper cited below) Here is a set of scientific papers where you can find more info: * Baldwin IT, Schultz JC. Rapid changes in tree leaf chemistry induced by damage: evidence for communication between plants. Science 1983;221:277-9. * Dudley SA, File AL. Kin recognition in an annual plant. Biol Lett 2007;3:435–8. * Mousavi SA, Chauvin A, Pascaud F, Kellenberger S, Farmer EE. Glutamate receptor-like genes mediate leaf-to-leaf wound signalling. Nature 2013;500(7463):422-6. * Ramakrishna A, Giridhar P, Ravishankar GA. Phytoserotonin, a review. Plant Signal Behav 2011;6:800–9. * Robbins CT. Role of tannins in defending plants against ruminants: reduction in dry matter digestion? Ecology 1987;68:1606-15. * Roshchina VV. Evolutionary considerations of neurotransmitters in microbial, plant, and animal cells. In Microbial endocrinology. Lyte M et al. (Eds), p. 17-52, Springer 2010. * Simard SW, Beiler KJ, Bingham MA, Deslippe JR, Philip LJ, Teste FP. Mycorrhizal networks: mechanisms, ecology and modeling. Fungal Biol Rev 2012;26:39–60. * Song YY, Zeng RS, Xu JF, Li J, Shen X, Yihdego WG. Interplant communication of tomato plants through underground common mycorrhizal networks. PLoS One 2010; 5: e13324. * Van Hoven W. Mortalities in Kudu (Tragelaphus strepsiceros) populations related to chemical defence of trees. Rev Zool Afric 1991;105:141-5. * Van Hoven W. The tree’s secret weapon. South African panorama 1985;30:34-7 [Answer] You don't have to speculate very far at all; it's a widely accepted notion, since Prof. Suzanne W. Simard's 1997 research paper, "Reciprocal transfer of carbon isotopes between ectomycorrhizal Betula papyrifera and Pseudotsuga menziesii" that plants communicate using chemical secretions, primarily through their root systems. Her team proved this by injecting the root systems with radioactive "tracer" isotopes, the passage of which could be tracked through to the root systems of neighbouring plants. It's become known colloquially within the Plant Sciences domain as the "Fungal Internet". <https://interestingengineering.com/study-reveals-plants-communicate-through-root-secretions> <https://e360.yale.edu/features/exploring_how_and_why_trees_talk_to_each_other> <http://centaur.reading.ac.uk/48102/1/Gorzelak%20et%20al%202015%20Inter-plant%20communication%20mediated%20by%20mycorrhizal%20fungi.pdf> Original paper (requires login for full paper): <https://www.cambridge.org/core/journals/new-phytologist/article/reciprocal-transfer-of-carbon-isotopes-between-ectomycorrhizal-betula-papyrifera-and-pseudotsuga-menziesii/05B4F05708AA2EF3EFA87965EADFE307> [Answer] When elephants eat the acacia tree, they start down wind because the attacked plant produces toxin as well as pheremones to alert nearby trees so they can start producing toxins. By starting down wind the elephants can work they way up wind without the trees alerting the other trees See [Alarm Scents](https://spectregroup.wordpress.com/2010/01/08/acacia-self-defense/) [Answer] If you want to take it slowly: ``` Leaves are the mouths Roots are the ears ``` So a conversation would involve the tree creating a chemical composition in the leaves to communicate some 'message'. These leaves fall and decompose, with the resultant message being transported through the soil and taken into the roots of another tree. Naturally, with the dependence on leaf scatter patterns, prevailing winds and distances between trees, such exchanges in conversations take an extremely long time. Hence rather than each leaf containing a single message such as "It's a nice autumn we're having", leaves contain partial messages with a high level of redundancy across the leaves so that a cascade of falling leaves communicates an entire concept or state, in a very similar way as the logograms in the book Story of Your Life (film: Arrival). As the entire knowledge of one tree can be transmitted in this way, it leads to an accumulation of understanding in large dense forests. Some of which have evolved in ways that would not be expected of 'normal' plant life. [Answer] Since both the communications of plants to warn of pathogenes, predators and to exchange nutriant has been mentionned in previous answers, let's just add that Darwin had speculated about the roots being to plants what the brain is to animals [source](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2819436/) > > “It is hardly an exaggeration to say that the tip of the radicle thus endowed [with sensitivity] and having the power of directing the movements of the adjoining parts, acts like the brain of one of the lower animals; the brain being seated within the anterior end of the body, receiving impressions from the sense-organs, and directing the several movements.” > > > If we have intelligence then you might want to have settlements, which with network effect multiplies communication. Huge root networks like [Pando, the largest organism on Earth](https://en.wikipedia.org/wiki/Pando_(tree)) would enable very fast communication. Also, since you mention `populated by mainly intelligent trees and other plants`, we could assume some form of animals might be present and could have been domesticated for communication when roots or chemicals cannot do it. Based on Earth insects would most likely be domesticated and used for communication, but possibly bigger animals since they are already used on Earth for for seed dispersion on long distances(extract below, [source](http://advances.sciencemag.org/content/1/4/e1400103.full), they could be used on your planet for long distances physical artefacts deliveries. > > "large herbivores are irreplaceable as seed dispersers because, relative to smaller frugivores, they are able to consume larger seeds and deliver many more seeds per defecation event over longer distances." > > > [Answer] You could do a lot worse than read [The Companions](https://www.kirkusreviews.com/book-reviews/sheri-s-tepper/the-companions/) by Sheri S Tepper. Too many themes to even start to summarise, but one of the main characters is a sentient plant on a planet of variously-sentient plants. The book puts forward some simple concepts of grammar for a language of emotion-triggering pheromonal scents, and describes that character's perceptions based on its sensory abilities. The next question after that, of course, is that if plants can communicate with each other, what would they say? Therein lies some of the plot of Tepper's book, and presumably your story will also need to cover that too. [Answer] would to communicate in the first place trees have to evolve a brain or equivalent to use that communication, but to communicate i would expect trees to produce a "scent", as Graham said, from flowers if they had them, to stimulate meanings, similar to that of animals marking their territories might produce. Along with transmitting as much information as possible. Then again communication evolved out of necessity so what do trees need that asks for communication? ]
[Question] [ This question is inspired by several similar questions on this site. The scenario: at one moment, all people above the age X disappear without a trace. How low this X can be that human civilization survives? Obviously, 1 year old is too young, and 18 is arguably too old. I set the following criteria of success: * Language is kept (which may change with time, it's Ok); * Tech level above stone age is maintained (at least in some communities). Scavenging is Ok for as long as people are able to scavenge; no mining or smelting is needed up until that point; * Sufficient artifacts and knowledge from our current civilization survives, so, eventually, younger civilization can utilize it for a "reboot". Children don't have to maintain world in order after the event. Any level of chaos, regression and massive dying is acceptable if the rules above are satisfied. P.S. Extra bit of information - there are apparently more than a few children under the age of 18 (likely thousands, if not tens of thousands) who are familiar with [Survivalism](https://en.wikipedia.org/wiki/Survivalism). A proper "failure" scenario should mention how all of those children will be eliminated, or isolated for the rest of their lives. [Answer] I'm not convinced that 18 is too old at all; in point of fact, if ALL the 'adults' left at once, society would be ruined in many different ways. What we call civilisation is really a very delicate balance in this world. Let's start with something as simple as food distribution. Without people who know how to drive trucks, most of humanity will starve because it lives in cities and its food is produced on farms. Even if an 18YO knows how to drive a truck, they're not experts in logistics, planning, economics, etc. That's even assuming there's enough fuel to power the trucks, now that all the workers who actually know how to operate oil rigs and refineries are gone. Let's assume that this mass extinction is really a mass disappearance, and there aren't a truckload (no pun intended) of bodies to dispose of before they generate disease. The real problem here is that civilisation, society, and all the other words we use to describe the framework of human social and cooperative interaction is NOT based on knowledge alone; it's also based on experience. You've just lost all the experience that would under normal circumstances mentor the younger generation through the awkward transition of knowing something theoretically to actually understanding how to do it. Any mechanic will tell you that knowing how to fix a car isn't as simple as reading a book on how engines work. The value an older mechanic brings to the table is all that experience of knowing what that knocking sound on the left side of VWs really means, and what to do to fix it. Similar scenario with doctors, and other critical professions. Engineering is another example; knowing the math is one thing. Knowing how to design a building by knowing how people think, how they work, how they use the various elements of the building, what they care about - that's decades of experience. We often make fun of the older / younger generation (cross out that which does not apply to you) and we talk about how the old world thinking is no longer relevant, and how these new whippersnappers come in with their fresh ideas and no understanding of how the world really works, and we're both right. At the same time, we're both terribly wrong. The young in society are able to surpass the old precisely because the old are sharing the knowledge and experience they've accumulated with the young. That gives the young a 'leg up' on things, allows them to devote more of their time to refining and improving on what's already known rather than learning it all over again. What you're doing is effectively disrupting that cycle. Assuming all the young folk don't die off in the short term from starvation or disease, the society that would remain would go back to a tribal nature, at least for a time. Cars and other tech may not last through extended periods without this young generation taking up the mantle across a very wide range of industrial fields, and if even one of those fails, it's possible society collapses, at least for a few generations. Bottom line is that there are very few industrial and technical pursuits in our society that are extraneous, or even easy to learn without experience of others being passed on through the generations. Your society not only has to keep all that going without the experience, but then has to learn to pass that on in their own turn without the benefit of having received it themselves. Your child society is in more trouble than I think you suspect. [Answer] Children in more traditional, agriculture based societies have much better chances of survival. Especially in areas where families still live almost self-sufficiently on farms and children are involved in the farm work. For example, among the [Amish](https://en.wikipedia.org/wiki/Amish): "Until the children turn 16, they have vocational training under the tutelage of their parents, community, and the school teacher." And [child labour is still common in Africa](https://en.wikipedia.org/wiki/Child_labour_in_Africa#Contemporary_child_labour): "Agriculture alone employs more than 30% of all African children aged 10–14." Based on this, I'd estimate that the limit would be somewhere between 10 and 16 years of age. Of course living on a self-sufficient farm is demanding, and children would have hard time surviving on their own. But there is enough of such families that even if some don't make it, some will. It helps that there are usually many siblings, so they don't get isolated when adults disappear. [Answer] # About 35 And even then it would be traumatic. Civilisation is the accumulated knowledge of our need to work cooperatively to survive. It's a set of skills and knowledge accumulated over centuries, passed down from one generation to the next by a combination of education and in-work training. To be able to maintain your technological level you need the infrastructure, that requires an active workforce who have the skills and knowledge to operate it. At around age 35 a graduate has 10-15 years of practical knowledge and some seniority. You've killed off the government, much of the bureaucracy and any senior management outside the tech industry. You've also killed off much of the legal profession, large swathes of your food suppliers and a few other industries that you probably haven't thought of that define civilisation, like art historians for example. What's more interesting is you've still killed off many of the people who have the skills needed to allow you to maintain any technological level without the major infrastructure of the power stations and power distribution networks. People like blacksmiths and farriers who know how to work metal by hand. [Answer] if these are the criteria: > > I set the following criteria of success: > > > * Language is kept (which may change with time, it's Ok); > * Tech level above stone age is maintained (at least in some communities); > * Sufficient artifacts and knowledge from our current civilization survives, so, eventually, younger civilization can utilize it for a "reboot". > > > Then I somewhat arbitrarily assert based off of [cognitive development of children](https://www.cincinnatichildrens.org/health/c/cognitive) that the minimum age needed to achieve the above falls roughly between 12-13 years of age. Society will collapse horrifically from the event with lots of children dying, however, 12 year olds generally have obtained enough skills in literacy and mathematics to re-learn lost knowledge from leftover books. Moreover, key cognitive changes occur at that age range allowing them to adapt to cognitively adapt to those changes. Children younger than that would probably adapt more primitively with a higher chance of loss of knowledge........ This isn't perfect because a lot of it is individual and situational driven. Theoretically, if a child as young as 2 managed to learn literacy and survive the apocalypse they could reboot society. Not to mention overcoming the literal "Lord of the Flies" scenario incurred by the loss of authority, however that will happen even if the age cap is 18. [Answer] # Responsibility The other answers here concentrate on technical know-how so much that they completely miss another factor: Responsibility and self-control. Now that makes me sound old, hu? However, if you think about it, even grownups without responsibility and self-control can easily fail their jobs. I would say childhood is by definition not there yet, it's about achieving those traits. It comes from within, but it also comes from parents teaching their values. # Scavenging I think we all agree that there will first be a period of scavenging. Mixxiphoid commented\* on your question > > If you remove everybody older than 18 from Japan you removed about 80% of the population. In most of South-America it is the other way around. > > > That makes a huge difference for scavenging. With children being 1/5 of the population, in the supermarkets etc. there will be non-perishable food corresponding five persons available to one kid. If this is literally the other way around, that's only non-perishable food for a bit more than one person per kid. For long term survival, farming is important, but the non-perishables determine how much time the kids have before they need their first harvest. Also note that there's quite the trade-off here: If your age X is high, you will have more know-how, skills and responsibility, but also less food per person, so you will need to start to farm earlier. \*I've got comments here that those numbers are not correct, so don't take them that way. However, they don't need to be correct to illustrate the concept of the kid-to-food ratio. # Farming Farming is important for long term survival, but it's also a long-term process. The problem I see here is that if you're running out of food, it's too late to start agriculture and there's not much of a second chance. It probably averages around half a year of planning, from seeding somewhere in spring to harvesting somewhere in autumn. We all remember how back in the days, the next Christmas was just "very far away". You need to not only understand the concept of a calendar or at least the 4 seasons, but also a way to determine where you currently are on that timeline. You also need the (let's call it) discipline to not forget things that have to be done less than daily. However, I think "the concept of seasons" is the easier one. What will be more difficult will be to get through a work day. If you get "Are we theeeeere yeeeetttt" after an hour long car ride, I doubt that we get a decent workday of boring, repetitive farm work out of that kid. Especially purely internal, without the impulse control that grownups are. Again, there's enough examples of such behaviour from adults, even with the emotional support of other adults. # Japan - the Mekka of saving society with children Given these musings, Japan actually seems like a prime candidate here. They have big cities that will have a lot of non-perishables stored and they have a really good "age multiplicator" on that value. They have arable land - and with rice also an efficient locally growing food crop. Seeing how children clean their classrooms at the end of the day etc., it also seems like they have a leg up on what we called "discipline" before. Some farmer's children are already helping out on their farms, so they have the know-how and will be able to go on farming. However, apart from know-how and discipline, they also need the idea of continuing to farm. While there's still a lot of non-perishables, they need to understand that the situation is dire and they need to farm. User anon provided this [information about cognitive development](https://www.cincinnatichildrens.org/health/c/cognitive) in their answer, which lists "Begins to think long term" under the header "Middle Adolescence", which would be around age 15. That being said, "dramatic events" could have dramatic effects. For example, if many kids die early on from something else than hunger, the leftover non-perishable food would be able to sustain the survivors longer, pushing the number down. However, they will need to be at least of reading age so that they can study the old texts. If nobody can read anymore, it will probably be too difficult to decipher a for all reasons foreign script, especially when daily life is about fighting for survival. [Answer] It jumps off the page that the death of (say) 99% of the population would not mean that any of your three criteria had failed. I think criteria 1 and 3 would be met if 6-year-olds were to survive. Some of them, especially from subsistence cultures, would have some idea about farming. Even if they couldn't do it, at first, some of them would find enough food stocks to to survive until they were old enough to figure out how to farm. Most would not, but it only takes a few. Some 6-year-olds can also read and know about dictionaries. Libraries would survive and would still be there for people to use to re-learn. Criterion 2 is tougher. I am assuming that a temporary loss of technology, followed by re-learning even within a few years, does not qualify as "maintained". I also think you need significant age to maintain knowledge of manufacturing. I'm guessing you'd need age 15 or so for above-stone-age tech to be maintained in "at least a few communities". The electric grid would fail, but there are a lot of above-stone-age technologies that don't depend on it, i.e. metalworking, paper, non-electricity-based printing, sailing, mechanical watchmaking, and college-level physics, chemistry, biology, and math, all of which would be would understood by a few bright children. With 15-year-olds, I'd assume that tech would initially drop to the level of 1600 or so -- more in some areas and less in others. That is still above-stone-age. [Answer] ## About 15 I once met a young man who was 15 years old in a country with a poor economy (Guatemala). He was working really hard at a variety of things, so I stopped to chat with him. He was building a factory for casting aluminum pots. He had already build one set of molds, and he built his fires from biofuels his little brother gathered in the area. He was taking care of his little brother and sister without any adult supervision. He had figured out how to make these pots on his own, developed a marketing plan, and was expanding his line. There was a few other street urchin boys who were hanging around, trying to get a job. And in poor countries, a 15 year old adult, or even younger is not that uncommon. Even more, in rich countries, children in neglected and abusive homes start functioning as adults earlier than age 10. For example, I knew how to drive, avoid the police, cook, grocery shop, balance a check book, and repair a furnace by age 11. I surely could have figured out how to make pottery and stone tools; much easier than many tasks that I already knew. However, 11 is too young to have the social maturity to interact with a community the way the 15 year old Guatemalan (as I mentioned above). Edit: If you want to learn more about high-functioning youths, check out the movie [Turtles Can Fly](https://en.wikipedia.org/wiki/Turtles_Can_Fly). In my opinion, a very realistic film. The more I think about it, I have known many 15 year olds who survived without adult help very adverse situations - rape, homelessness, addiction, etc. The idea that 15 year olds lack the ability to have emotional maturity, as other answers say, is wrong. [Answer] The age cutoff would need to vary depending on the child's experience, proximity to resources, and the nearby population of other survivors. Here is a plausible scenario that could work. Everyone will need to be fed. Farm children are often given chores, starting at around age 8-10, with increasing responsibility as they get older. A large enough family should have an eldest child who knows enough about the operation of the farm to keep it reasonably self-sustaining for the near term. Although a few 12 year-olds might be able to take on this role, a more reasonable age would be 14 or 16. [This answer](https://worldbuilding.stackexchange.com/a/7180/52704) to a related question makes a great point about military campuses as a means of preserving civilization. The cut-off age for this group would be at least 20, although 22 or 25 would be better. Among their advantages: * They have an existing structure to make and follow orders. * They have better access to technologies for self-sufficiency (e.g. weapons, diesel vehicles) than your average city-dweller. * Although they are not experts in medicine, engineering, logistics, or law, many cadets have basic training and an interest in these fields, providing a good starting point for preserving or rebuilding technology. * Some of them will have the foresight to plan beyond survival, and work toward the retention of existing technology and the long-term re-development of civilization. These two populations could mutually assist each other in a concept I call "the citidel". * Farms would grow crops needed for food and raw materials. * The military would develop and produce bio-diesel fuel, needed for farm equipment and military vehicles/generators. * Simple goods such as clothing could be made on farms. More advanced goods such as machinery parts would be handled by the military, both by scavenging and by manufacturing. * The two populations would trade goods with each other. * The military would provide transportation of goods and people. * The military would provide law and order, much like a county sheriff. * The military would provide other specialized services such as medical care, equipment repair, and dispute resolution. * The youngest children would be raised on the farms. They would receive an elementary education there. * During the farming off-season, persons above a given age could be conscripted into projects such as road repair. * When farm children get old enough, they would have the option of leaving the farm, joining the military, and receiving higher education. It should be noted that West Point is within marching distance of productive farmland. Furthermore, the survival of these two particular groups could be related to the cause of the disappearance of adults. For example, if adults were being abducted by aliens, these two groups would have a better chance to resist (access and training with weapons) than your typical city dweller. [Answer] It's way harder than you think. Maybe impossible. I'm going to tackle this from a different direction. What is the minimum age to meet each of the three requirements? > > Language is kept > > > This is an easy one. Language is extremely useful, and children acquire it early. Probably any group of children above five years or so of age will keep some sort of language. > > Tech level above stone age is maintained > > > This is where things get a bit tricky. What exactly is tech level above stone age? Do they have to actually be able to make their own tools, or can they simply re-purpose existing scrap. It's way easier to fashion an extra shovel into a passable pitchfork, or an extra pitchfork into a passable shovel, than to make either one from scratch. So if your goal is to have them be able to salvage portions of existing objects for their own purposes, I doubt you need to increase the minimum age very much. Certainly by the time children are 7 or 8, they'll be familiar with the basic premises and purposes of basic implements like the hammer, the plow, the saw, the anvil, etc. Human ingenuity is a pretty powerful thing, so they should be able to survive for generations without ever even needing to know that metal ultimately comes from the ground. If you want them to be able to produce new goods "from scratch", that's a lot trickier. Knowledge of smelting, for instance is almost certainly lost. Not only do very few children (or adults, for that matter) know how to recognize the proper ores and build sufficiently hot fires, but the bigger issue is, none of them will actually care. If any significant portion of the population disappears, there will be so much scrap lying around that for probably at least a generation or two it will be far easier to scrounge what you need than to make it yourself. Minimum age for scrounging: 7-8 Minimum age for producing: 30-40 (The issue isn't that you need to be 30 in order to know how to smelt, it's that if you lose more than about half your population, it's going to be way easier to scrounge than to produce. There's plenty of extra lying around.) > > Sufficient artifacts and knowledge from our current civilization survives, so, eventually, younger civilization can utilize it for a "reboot" > > > This depends wildly on what you mean by "reboot". Given enough time (say 10,000 years or so), any group of people will "reboot" society. We did it once, we can do it again. But I assume you want something faster. So let's say 100 years. What can our society do after 100 years? Not much, it turns out. At the most optimistic, we're back into the Industrial Revolution -- maybe 1770's tech. More realistically, though, we don't even get that far. Again, this is much less a function of age than of the sheer number of people left -- the more people, the better. Existing knowledge is almost immaterial, in some ways. First of all, what is this society not going to be able to do? You can kiss computers goodbye, for instance. Now maybe you're about to object we built computers in less than 100 years, so surely this society, with its current knowledge, should be able to do it faster. But this is wrong. Yes, we were able to create computers in less than a century. But we had a bunch of existing knowledge to draw on. Early computers, for instance, utilized vacuum tubes. Probably no one alive today of any age knows how to make them; almost certainly no single person knows how to mass-produce them; and even if someone did know how to mass-produce them, they wouldn't have the resources to build, run, or maintain the factory necessary to do so. So computers are out. So are cell phones. So are regular phones, probably. How many people know how to build an old rotary phone? Even if someone did, your new society doesn't have the manpower to maintain and staff the switchboard network. When people are worried about getting enough food and water to survive the year, calling New York just doesn't seem like much of a priority. Automobiles are similar. We discussed the issue of actually producing new goods above, but even if we ignore those difficulties, by the time people could reproduce the Model T there wouldn't be much call for a Model T. To begin with, cars run on gasoline, and your society surely doesn't have the ability to produce it. Not to mention that without any maintenance for several decades, much of your road system isn't in great shape. Basically, if you're kicking your society back to before the Industrial Revolution, don't expect them to get back to where we are now in less than two or three centuries minimum. My guess is it will actually take them longer, because so much of the knowledge and security that people had during the Industrial Revolution is now gone. No one is working on reinventing the cotton gin when they're worried where their next meal is coming from. No one's even planting cotton. If we lost more than half the working-age people, the resulting impact to society would be devastating. Starvation would be widespread. Society as a whole wouldn't recover for centuries, even with adults still around. With only children? Good luck with that. Depending on how many millions they lose over the first year or two, it might take them centuries just to breed their way back up to Industrial Revolution population levels. Minimum age required to fully rebuild within 100 years: 40-50 (approximately 2/3 of the working population) tl; dr: If you're writing Young Adult fiction, I'd say that 17-18 is your minimum age. Not because I think it would actually work, but the genre does encourage age-related suspension of belief. There have certainly been other similarly absurd scenarios that have gone on to widespread acceptance (cough Hunger Games cough). On the other hand, if you're trying to make a serious, well-considered construction of what society would be like if all the adults suddenly disappeared...understand that probably involves massive casualty rates, especially during the first few years (but also increases in other types of mortality thereafter; expect infant mortality rates to skyrocket, for instance); a return to subsistence farming; and abandoning any technology much more complicated than the plow for anywhere from a few to several centuries. Keeping language and basic societal structure is easy. Keeping advanced technology is nearly impossible. [Answer] I'd say around 8 to 10 years old. First off, any city kids will die. However, in rural area's, especially in poor countries, there's plenty kids working on their parent's farm who know enough about crop rotation and the like to run it, if they keep working. Why the poor countries ? Because in rich countries the farmers are a lot more dependent on technologies, and in poor countries they're more self-sufficient. This'll be enough to get self-sufficient. You aren't quite back to stone age - they'll know basics of both agriculture and husbandry, which will be enough. Reboots will take ages as all many of the wealthy countries, where knowledge is concentrated, will be wiped out completely. The groups of boy scouts might take a bit longer to die. Any reboot is probably dependent on low-population-density countries that are still rich and well-educated. For example, kids in certain parts of norway learn basic survival out in the wilds, while also being taught normally in schools. These could be a focus of a reboot, if enough knowledge is preserved in books they can access. Note that every digital dependent storage will most likely be wiped out completely. You'll probably also have traumatized every single one of them. But humanity is tough, and children can be better at adaptation than you'd think. After a year or five, it's just the way life is (and they'll start marrying again). They'll almost have forgotten the world used to be different. Most likely, older siblings will try and take care of their younger siblings, so those probably won't all die, but the lower you get in age the higher the mortality goes. Right away, civilization will fall down close to stone age levels. Groups will either go agricultural, hunter-gatherer or animal-herding. Or some combination of those. They'll lose global communication as soon as automatic systems start failing. Electricity will fall out, and that's that. From that moment on, every group is on itself. Oh, yeah. They'll form groups, or tribes, before the week is over. Most of the ones fated to die as well. In a year of five, the survivors will have a more or less stable life. This means they might start attempting to harvest technology. Expect the first new children to be born around this time - about 12 is a pretty normal age to be fertile, and they'll start it right away. Perhaps there are exceptions before, but as a rule humans are conditioned to start families by choice when they feel more or less stable and capable of feeding the offspring. This goes for most animals. 5 Years after the collapse sounds good to feel stable again. At this moment, basically everyone will have only distant memories of the previous world, or none at all. Note that there will be all weird kinds of religion or random beliefs popping up left, right and center. Humans look for structure in the world. Also, there are a lot of books kids could read, but at this time, the current world might be a dream for all most know. They won't be able to tell the difference anymore between a lot of science or science fiction - someone who finds a star trek book might consider it historical, and therefore conclude that they are are plenty other worlds containing humans out there. Or people read harry potter and attempt magic. At this point, high school educational material should be easy to find, and this may help them. After about 20 years, you're probably in medieval level society again, at least the more developed parts of the world. From there up, it depends on how smart the ones are that try and harvest knowledge left behind, and how accessible that is. College level educational books will still be common around this period, and most science up to about 50 years before collapse will probably be preserved in one form or another inside those. [Answer] IMO the answer is "older than you might think". The glue that holds civilization together is communication. A functioning wide-area network using modern electronic communications is soon going to break down, as key devices fail and don't get fixed. So, who in your post-disaster world actually knows how to run a society where most of the comminucation network consists of telephones connected by physical wires, or the physical delivery of messages written with pen and ink on paper? Arguably, only people who were alive when that was the only thing available to them - and that probably means "people over 50", at the youngest. [Answer] A bare minimum scenario: * There are a few isolated islands or valleys, * Each of which has some children of ages four - six who know how to read. * These islands or valleys happen to have very hospitable ecosystems. * That produce year-round food supplies that do not need cooking. * The islands or valleys are not subject to fatal heat waves or cold spells. * A large fraction of the books available teach practical skills for rebuilding civilization. For best results, the young children do not have to care for any babies, toddlers, or other children younger than themselves. In this scenario, the entire world does revert to the Stone Age. Most of the world's D-Day+1 population dies within a year. But starting about ten years after the disaster, the literate children in the surviving pockets become strong enough to build new homes, start signal fires, make new boats, and find each other. Lord of the Flies and Orson Scott Card's Ender's Shadow present sadly plausible scenarios for the social dysfunctions such societies might have. Jane Auel's Clan of the Cave Bear novels and Scott O'Dell's Island of the Blue Dolphins have more hopeful scenarios. [Answer] At any age less than ~40 collapse is certain, modern civilization just relies on too much specialized labor, you can't remove a large part of of population and not have collapse. The older the cut off is the less persistent technology will be lost, but no matter what you are looking a a reset to preindustrial/WW1 tech levels depending on what specific tech you are talking about. Oddly the less developed countries will be the ones that are the best off since said children will have actual work experience and will have apprentice like understanding of more advanced skills and will have a large number of farmers. Below teenage a small percentage will survive but you are talking about a reset to stone age or close too it. Some children will possess some specialized skills but they will be few and too far separated to really take advantage of it, and there will be a huge die off afterwards caused by mass starvation. There will be no rebooting such a collapse they will have to progress normally as if modern civilization never existed. The real questions is what technologies do you want to loose and which do you want to keep. For instance keeping some of modern medicine will require something in mid to late 30's. It's not enough that a few some people with skill X survive it is you need many many people with the skill to survive the initial die off becasue only some of them will survive all the subsequent die offs collapse will trigger. the more severe the collapse the more tech will be lost not becasue no one has the knowledge but because people are too busy trying to survive to preserve the knowledge. [Answer] For a given culture, the cutoff would be the age that kids generally accept responsibility for others. As you lower the age, the death rate increases. As the current tech level increases, the death rate increases. So urban north american city with it's narcissistic youth you would get massive die offs even with twenty somethings. That tech is hard to maintain without the people who ran it, and too much isn't written in books. Small town rural north america with numbers of farm kids, and some old simple equipment (a 40 year old diesel tractor is a simple machine) probably would do better than the city even with a cutoff of 15. Far east rice paddy culture? Big enough to harness and control the water buffalo. [Answer] The way things are going, higher than whatever it is right now... > > How low this X can be that human civilization survives? > > > Given you mean human civilization above stone age, and not necessarily this one, nor any particular civilization. * language surprisingly, humans seem to spontaneously develop language, without any help at all, as the [Nicaraguan sign language](https://wikipedia.org/wiki/Nicaraguan_Sign_Language) suggests. This fits with Noam Chomsky and the "language instinct" of Pinker and others. It might not be English or related to any present language... but assuming text (advertising, signs, books, perhaps computers etc), it's gonna be influenced by existing languages. * tech (asuming machines still exist, and are in working order) just using much of todays technology is not that hard. Consider also that not everyone has to be able to do, but just that there are some who can work it out. Of course, they won't use well (first anyway),. and there'll be mistakes, some serious, some catastrophic (locally). Even most repairs could be it will be managed more or less. The problems will come from serious repairs, and chains of dependency. e.g. iron foundaries, power stations, tool making tools, silicon lithography. And then, being able to improve on them, which requires theory and excellent prototyping skills and tools. * knowledge arguably, the renaissance was a reboot after the dark ages (at least in europe), using classical knowledge which was preserved. That took a while. I do think today's texbooks and online resources (assuming they kept working for a while) would be enough for some children to re-educate themselves. Though, there are oral traditions and attitudes even within fields as "pure" as maths, which wouldn't be properly passed on, and would have to be rediscovered or redeveloped (perhaps somewhat differently). Given all this, I think the age could be extremely young, such as 5 years old or even 2 or 3... perhaps 6 months The barrier is whether the children could survive without carers - perhaps even younger, provided some survive. Arguably, the human infant is born prematurely, and continues gestation ex-uterus. Birds are similar, with constructed nests. But this is an immediate, short-term consideration, and not what you're interested in. The next problem is having enough food and shelter etc for all this learning to occur. But if we assume a stocks of food (NB: fewer people makes stock last longer, and the mechanisms of production still exist, this is not too hard. # but... However, I think the big problem is the survival of a culture that avoids war and conflict enough for all this to occur. People - including children - naturally form groups (gangs). In the world right now, there are several places that would not be able to do this. Historically, war and conflict is common, and regions and times with stabliity sufficient for development is rare. Related to this is the institutions that make it easier to avoid conflict than escallate, from councils, police, up to disputes between immensely powerful corporations and even governments that meekly accept judicial decisions, and a judiciary that, by obsession on technical correctness, is more-or-less not corrupt. So, getting along is the problem... But I guess that's what you mean by "civilization". I'm not sure what age would enable this to survive... I'm not even sure we can do it today, with whatever it is right now. ]
[Question] [ I was looking through a bunch of different ways we can shape a map of the Earth and it got me thinking. We map out planet as a stretched rectangle with NSEW as Up Down Right Left, with the Equator right in the middle. But what would cause a species to prefer a different way of mapping? Tidal Locking may cause a species to develop a map for each hemisphere. Maybe they would focus more on the positions of extreme weather conditions. What would cause other unique ways of mapping a planet? Edit: I’m specifically looking for 2D maps not 3D maps like globes. [Answer] It's very much a matter of what information they want to display in their primary 3d to 2d projection. The [Mercator projection](https://en.wikipedia.org/wiki/Mercator_projection) that everyone is so familiar with is simply designed so that lines of latitude are straight horizontal and any simple compass bearing is a straight line. This makes ocean navigation easier as the important factor was knowing how many degrees north or south you needed to be. > > The Mercator projection (/mərˈkeɪtər/) is a cylindrical map projection presented by the Flemish geographer and cartographer Gerardus Mercator in 1569. It became the standard map projection for navigation because of its unique property of representing any course of constant bearing as a straight segment. > > > Any minor details like distances or areas of countries can be neglected, that's not what this particular map projection is for. The reason north is at the top and the prime meridian goes through Britain is because the British cartographers made the best maps and they chose such a layout. There's also McArthur's corrective Mercator projection that puts Australia top centre and it looks really strange to the rest of us. If you go far enough back in history, you'll find maps with Jerusalem at the centre, but they're not particularly useful. What you have to do is define what it is that your map is supposed to show accurately and what can be sacrificed in turn. Say that the primary empire of the early industrial period was landlocked, now ocean navigation isn't a defining factor but rather land distances from the capital. Now you have a map that has the imperial capital in the centre and uses something like [Azimuthal equidistant projection](https://en.wikipedia.org/wiki/Azimuthal_equidistant_projection) which preserves the distances from the centre. > > The azimuthal equidistant projection is an azimuthal map projection. It has the useful properties that all points on the map are at proportionally correct distances from the center point, and that all points on the map are at the correct azimuth (direction) from the center point. A useful application for this type of projection is a polar projection which shows all meridians (lines of longitude) as straight, with distances from the pole represented correctly. > > > This map isn't great for travelling to or from anywhere other than the centre point, but as they say, all roads lead away from Ankh-Morpork\. Perhaps regional cities would have their own local map with the city in the centre allowing local navigation. --- \Sometimes people go along them the wrong way. p.s. Somehow we overlooked the [mandatory xkcd](https://xkcd.com/977/) [Answer] ## Bizarre real maps In our real world of the planet Earth, some traditional cultures created maps that for most people would look absolutely like alien objects and will not be recognized as being actually maps, still the are maps, and they are of practical use. ### Inuit wooden maps [![enter image description here](https://i.stack.imgur.com/QF6jj.jpg)](https://i.stack.imgur.com/QF6jj.jpg) The Inuit people of Greenland [used carved pieces of floatwood](https://decolonialatlas.wordpress.com/2016/04/12/inuit-cartography/) to depict the coastlines (Inuits live along coastlines). The maps are compact, buoyant, and can be read in the dark. Here is a couple of examples. ### Micronesian stick chart [![enter image description here](https://i.stack.imgur.com/dbUlP.jpg)](https://i.stack.imgur.com/dbUlP.jpg) > > Micronesian stick charts show wave patterns and currents. The shells represent atolls and islands. Using stick charts (also called rebbelibs, medos, and mattangs) ancient mariners successfully navigated thousands of miles of the South Pacific Ocean without compasses, astrolabes, or other mechanical devices. > > > [The charts](https://www.nationalgeographic.org/media/micronesian-stick-chart/) aren't made of sticks. Most stick charts are made of coconut fiber and shells. Placement of the fibers and shells indicate the location of islands, waves, and currents. [Answer] Maps don't have to be geographical, they can also be diagrammatical, like the London Tube map. For instance, ancient Roman maps, the [itinerarium](https://en.wikipedia.org/wiki/Itinerarium), were graphs showing points of interest along a road rather than geographical relations. A branch in the road was a branch in the graph line. Another approach is symbolic maps, like the medieval [T-O maps](https://en.wikipedia.org/wiki/T-O_map) and [mappa mundis](https://en.wikipedia.org/wiki/Mappa_mundi). The simplest of such are extremely abstract, but at the other extreme, you could have more detailed ones as well, like the one at [Hereford Cathedral](https://en.wikipedia.org/wiki/Hereford_Mappa_Mundi). These maps are constructed the way they are to fit the prevailing religious worldview of the time. [Answer] ### The aliens did not evolve on the surface These aliens evolved from ant/bug/worm-creatures, possibly moles if you want a more mammal origin. They never cared about how the surface looked, and only cared about 3D connectivity and branching. It's likely that they couldn't even see. In the beginning their maps were made out of knotted straws, where knots indicates a larger hollow or other points of interest, and branching was made by tying another straw. This would be superficially similar to our [quipu](https://en.wikipedia.org/wiki/Quipu) used for bookkeeping. If the map had to be more accurate it had to be made out of something stiffer, like twigs or roots, so that directions such as up/west/east could be recorded. Surface points would be marked in a way to show the type of environment around it: field, rocky, woods, close to water, etc. The version made out of straw would be portable because you can just fold it down to a small ball, and keep the relevant sections unfolded. This would of course require training and maybe special equipment to keep it from tangling. ### Move to the surface When this race started caring about the surface of the whole planet, the maps would still be made in the same way as had been previously done: folded straw/twig sections, the more advanced the society got, the more advanced materials could be used, and portable maps would be intricate jointed constructions automatically folded by small machinery. However, they had never needed anything flat to write on and it would never occur to them to ever make a 2D projection of something that was not 2D from the beginning - especially since they don't rely on vision. ### Forced 2D projection Even though you want a classical 2D projection, this would be unnatural for these guys and would probably only be constructed for trading purposes with other species. This map would only contain points-of-entry to the rest of the 3D network, and they would have no real concept of "projection", so the map would very likely be divided into sections sized so that the curvature would not cause too much of a distortion, and then these sections would be printed out next to each other. Think of hexagons or square tiles. The closest system I could find today is the "[interrupted Goode homolosine projection](https://en.wikipedia.org/wiki/Goode_homolosine_projection)": ![Goode homolosine projection](https://upload.wikimedia.org/wikipedia/commons/thumb/f/f2/Goode_homolosine_projection_SW.jpg/640px-Goode_homolosine_projection_SW.jpg) It would probably not have any borders at all, just point clusters - the different nations would just be separate sections, with textual descriptions on how the pieces should fit together. [Answer] If you're dealing with cartological evolution, the answer is "pretty much nothing." I suspect all species would develop maps in the following way: 1. They sit down with a stick and some rocks, draw the local river, put some rocks in to mark the villages, then in their own language intone the words, "grog, you take bugga and clobber dis place. Me take Wherk and pound over der." 2. A little while later, something akin to paper/vellum/papyrus is invented, and the conversation goes something like, "Hermicules, thou taketh thy holy troops and stand atop the Hilltop of Crahakia the Elder and then shalt thou count to three, no more, no less. Three shall be the number thou shalt count, and the number of the counting shall be three. Four shalt thou not count, nor either count thou two, excepting that thou then proceed to three. Five is right out! Once the number three, being the third number, be reached, then thou shalt assault the city in the name of Daiphus and bring salvation to the wicked!"1 3. A little later, someone discovers a rock, or a pin, or something on a leaf, that happens to point in a useful direction in a predictable way. Such a person might suggest that direction to be "Gorp!" Thereafter, the "top" of the page upon which the ~~battle plan~~ holy consecration is thus inscribed is known as "Gorp!"2 4. And sometime after that subways are invented and some genius figures out that actually knowing the geography involved with cartography isn't actually relevant or practical when it comes to dropping down to the corner to buy a box of smokes. My point is, cartography inevitably starts with a 2-D rendering of the local geography and becomes more complex as more data needs to be represented, but there are only so many ways simple geography (the local river, hill, and village) can be represented unless your aliens don't have eyes. An advanced species may have a reason for not using what Humans use today, but how they came to the threshold of that decision is, IMHO, highly unlikely to be any different than Humanity experienced. Remember, knowledge is a pyramid, ever growing in size, and your aliens are at any given moment standing atop their pyramid. However, in the beginning, that pyramid is very small, and that means very little variation compared to any other sapient species. IMHO. --- 1 My undying thanks to Monty Python for one of the most enduring and funniest moments of dialog in history. 2 It's worth noting that step #3 might come before step #2. It's a bit wishy-washy in the middle. [Answer] Population distribution and travel means As others ponted out, math says that a perfect map is impossible. The aliens have to pick what they really care about. We chose that projection because nobody lives at the poles. If your world is, say, not inhabitable except at the poles maps will be different. Maybe all known maps cover just part of it because the other half is all but impossible to explore. Technology is also a factor. In the age of exploration, on Earth, traveling by sea was way better (cheaper, faster) than over land. This made sailing crucial, so maps that had a bad representation of the oceans were impractical. If the alien civilization had different areas of interest and different ways to move around (and tell where they are) things might be different. Note: There are polar bases now and also in the past there have been populations living in places like Siberia or northern Canada. The fact is that when our map projections consolidated in the past centuries those regions were considered of little interest. [Answer] The math of projecting the surface of a 3D sphere to a 2D piece of paper is well studied, and the main solutions together with their strengths and shortcomings have been discussed. So let's go with something different. > > What if for this culture altitude information is more important than either E/W or N/S direction? > > > Imagine an avian species living on a steep hillside following a ridge. For the purposes of their surroundings the two relevant dimensions would be the distance to a point of reference along the ridge, and elevation above the bottom/sea level/whatever. Sure, the laws of planetary physics/geography make it unlike that the hillside would be a totally vertical cliff, but if the incline is steep enough, there would be relatively little variation in the distance from the ridge. Much like relative flatlanders such as yours truly don't really pay much attention to the elevation above the sea level of their whereabouts. For example, assume the ridge is running N/S. Such a community would surely have more use for a map where locations are marked using N/S distance to a reference point (gubernatorial center) and elevation. > > Highly evolved razorbills or puffins on a scaled up [Látrabjarg](https://en.wikipedia.org/wiki/L%C3%A1trabjarg). > > > [Answer] The aliens know some mathematics that we don't. In the question, there is mention of a particular rectangular projection, best known as the Mercator projection. However, there are many other ways we Earth people have figured out for projecting a sphere onto something flat, including conic, conformal, gnomonic. There is a decent article at [Wikipedia](https://en.wikipedia.org/wiki/Map_projection). Each of these projection techniques requires an understanding of some type of geometry, trigonometry, or related areas of mathematics, and there could easily be other possible projections we have yet to discover, but the aliens have known for a long time. Their maps won't be radically different as a result, but perhaps just different enough to handwave it into your story. [Answer] We project our world on a bi-dimensional surface because we learned to make flat surfaces well before making spheres. And don't forget that you can easily cut a flat surface in smaller pieces, while cutting down a sphere is more difficult. In other words, if you don't need the whole world but just the 1000 km around the Republic of San Marino, it is more easy to do it on a flat surface than on a sphere. Moreover, flat surfaces can be more easily carried around and stored. A map can be rolled up, a ball will stay a ball. Change those factors above and you will have a different outcome with respect to map making. [Answer] The geography of the alien planet can be very different from ours. Imagine a water world with just a single continent centered on one of the poles, like our Antarctica, with no other continents, not even islands. In this case, they wouldn't just need to map the other water-only hemisphere, and their maps will be of round shape with the pole in the center. Or the planet can have the shape not near-spheric like the Earth's, but of irregular shape, for example it had a heavy collision with another object that deformed it. In this case, the projection of the planet's shape on a flat surface can take rather weird shapes, the ones that cannot fit effectively into a rectangle, or the planet can have even not two, but three or more "hemispheres", so where we have the map of two round hemispheres, their map will have four triangular ones. We can go on imagining different geographies and different planet shapes with their respective maps. I'd love to see a map of a planet which has tunnels going through the core as wide as to allow the aliens to live not on the outer surface of the planet, but on the inner surfaces of the tunnels, too. [Answer] Some pre-Columbian and near-post-Columbian North American maps, such as the Nahuatl (Mexico) map below, showed winding rivers and winding trails as straight lines. The features between the rivers and trails had distorted positions to line them up with the straight rivers and trails. [![enter image description here](https://i.stack.imgur.com/kuSHT.jpg)](https://i.stack.imgur.com/kuSHT.jpg) This was very practical because one could not venture far off the trail. Therefore, the actual curves of the trail or river were unimportant, what was important was easily knowing what one would find up- or down-stream. There are more maps and explanations on [the NPR site](https://www.npr.org/2019/08/23/753114640/440-years-old-and-filled-with-footprints-these-arent-your-everyday-maps). [Answer] ## Religion Beings who have the astronomical ability to navigate by are going to notice that the stars in the night sky rotate around a point, and if they develop the mathematics and surveying technology necessary to make accurate maps, they're bound to work out the same map projections as humans did on Earth. But there's no reason for them to develop the "north at top" convention we use for the most part. For centuries during the Middle Ages, maps were oriented with east at the top. That's why we have the verb "to orient". The best examples of these maps were "[T and O](https://en.m.wikipedia.org/wiki/T_and_O_map)" maps, with Jerusalem, the desination of Christian pilgrimage, in the center: ![Hereford Mappa Mundi](https://upload.wikimedia.org/wikipedia/commons/thumb/4/48/Hereford-Karte.jpg/413px-Hereford-Karte.jpg) (The [Hereford Mappa Mundi](https://en.m.wikipedia.org/wiki/Hereford_Mappa_Mundi), ca. 1300, source UNESCO, via Wikimedia Commons) T and O maps developed because of a limited knowledge of the world by medieval Europeans. Your alien mapmakers may have a convention that starts during such a time, with a map oriented towards an important cultural/religious location. However, there's no reason that has to change as that worldview expands. [Answer] # Just enough intelligence to draw Or maybe they lack a neural region in their brain linked to basic match. If so, they might be unable to reason much beyond their senses, and they will think that the planet they live on is flat. This leads to some bizarre maps, with real weird justifications for a lot of things. [![Flat Earth](https://i.stack.imgur.com/TDos7.png)](https://i.stack.imgur.com/TDos7.png) [Answer] Vernor Vinge's The Witling is set on a planet whose native humanoids can teleport. Teleporting preserves velocity: for example, if you jump to a higher latitude you're moving eastward relative to the destination; upward if you jump east. Their maps show an orthographic view of the northern or southern hemisphere. From such a map you can read the local velocity directly. If you make jumps of equal length (map-length, that is) along a straight line on the map, you get the same kick each time; this is the easiest way. [Answer] As others pointed out, there are some well-explored ways to project a sphere onto a map sheet, including ones to preserve angles (e.g. Mercator) or to perserve areas (e.g. Gall-Peters). Each has advantages and drawbacks for various purposes, and there is mathematical proof that there is no projection to perserve angles, distances, and areas at the same time. * Have your aliens use an [azimuthal equidistant projection](https://en.wikipedia.org/wiki/Azimuthal_equidistant_projection) centered on a holy city or capital. Then have some adventure set on the opposite end of the world, near the point which becomes the outer rim of the map. (The usual maps have two such points, but they are at the poles where few people live.) * Have them use a [Peirce projection](https://en.wikipedia.org/wiki/Peirce_quincuncial_projection). But in both cases you would have a flat map and one would have to know the continents to recognize how they are distorted. [Answer] Edit: I understand the OP is asking for 2D maps, but I decided to offer this as an alternative for anyone else who may happen by. :-) What about a 1-D map? The concept in a nutshell... Consider this, your alien species have no sight. Perhaps they live at the bottom of an ocean. They may or may not possess some mental model of 2-D or 3-D, but for the purpose of composing and transferring information without sight, the only option I can think of is modulation of a serial stream of data. We have ways of doing this, the way I'm communicating with words right now is an example. Sound is another example. So if your alien is blind, they may have some peculiar system of sounds or some nearly optimal system of conveying landmarks and instructions for navigation. Take a sentence of normal speech, this one for example. It conveys a concept, "example", an object "sentence", it has a context "navigation grammar", and meta-data "objective self-reference". One could, in this regard, imagine a kind of grammar not used for conveying common ideas, but specifically ordered for the use of conveying spatial information, directions, or instructions for navigating, perhaps with some error correction. Note that language and grammar already have all of these qualities which have developed from hundreds of thousands of years of trial and error. Conversely, a species which has no sight, but can communicate and still needs to convey spatial information, could have as a part of the common language such mechanisms developed seamlessly into their own language. This kind of usage may also influence the language as a whole. I won't go into detail about language studies, but there is a lot of information on the web about how the use of language shapes it's structure and grammar. There are good reasons why language is the way it is and it all boils down to the energy required to conceptualize things and communicate them. Life is an experiment in optimizing the use of energy and language is only one example. Speculations about the structure of such a "map"... So this kind of "map", if you would choose to call it that, is more like a set of directions than a 2-D map. And rightly so, as it is very inefficient to convey higher dimensional information in a lower dimensional format. Conversely it's much simpler and more efficient to convey lower dimensional information in a higher dimensional format. So we could think of it as a set of landmarks strung together with directions for how to proceed at each landmark. Pretty straight forward. But the interesting part is how one conveys the information. As a series of sounds, vibrations, perhaps these aliens have a mechanism for producing vibrations over the surface of their bodies, like shivers. To be more specific, sound is three dimensional, but we perceive it as a temporal series. And words are two dimensional, but we interpret them in the same way, as a temporal stream of meanings. So to expand on the complex, temporal ( 1D ) ordered "map", think of bats. They use echo location to derive a sense of their surroundings, all from a temporal stream of sound, that which reaches their ears, and their brains parse the modulation of that sound and determine a sort of 3-D depth map where the level of detail increases as they get closer to things. For our "map" it could work the same way, but rather than being an echo, it could be encoded into the sounds. Furthermore, if these aliens have the ability to produce vibrations from most of the surface of their bodies ( consider autonomic contractions of the skin or shivers, but rather under conscious and directed control ). By controlling a series of shivers over the surface of the body, when the body is oriented in a given way, the output vibrations could be, in a way projected to produce a higher amplitude of vibration in some region of space ( or water ) near to and outside the body, or more specifically, close to the surface of the alien receiving the message. So rather than saying "there's a rocky outcrop 100 meters ahead on your left", the alien might just say "big rock" while at the same time projecting some haptic feedback to the left side of the one listening where the haptic signal encodes information about size and distance to the rock from the current location or context on the "map". So 10 words in this way is reduced to 2 with some haptic feedback. In this way very long maps would be easier and faster to convey, they would contain a lot of information, the information would be very rich and, at least the human mind, would seem to have a easier time remembering them due to the richness of the information and the high level of abstraction. [Answer] # Time Travelers A time traveling race would want maps that portray the same area during multiple periods of time simultaneously. Perhaps, multiple two-dimensional layers in a block? [Answer] I'll toss my hat in the ring, and focus on the idea of reasons why an alien would map the curved surface of a 3d object onto a flat 2d surface differently than we do on earth. So, one way of looking at all the different projection schemes is: do you favor area or do you favor angles? Well, there's another, simpler way to look at it: what parts of the map do you care less about? I mean, a polar map sucks at conveying information at the equator. Standard projections suck at conveying the poles. 'Sliced' style maps suck at conveying continuity at locations along the edges of the slices. One way or another, any 2D projection of a globe's surface will have segments of the globe that are conveyed badly. Now, for us on earth, we're generally concerned with 45-to-45 latitudes (aka, stuff around the equator). That might not sound like a lot, but it covers all of Africa, almost all of South America, China, India, Australia, US/Mexico, and the southern half of Europe. Sure, there are people living closer to the poles, but that's not where the majority of earth activity happens. Because of that, it's no coincidence that pretty much every projection scheme is awesome at conveying information along the equator, and its weaknesses are all in some aspect of the land by the poles. Once you look at the problem this way, the solution is obvious: make the aliens care about different sectors of the planet than we do. A great example: a planet where the only easily habitable areas are the north and south pole. Imagine a polar graph of the upper latitudes, with a second graph a bit beneath it that's a polar graph of the lower latitudes. Connect the longitudinal lines in a way that almost makes it look like a magnetic field diagram. [![enter image description here](https://i.stack.imgur.com/TRhwB.png)](https://i.stack.imgur.com/TRhwB.png) Sure, the information around the equator sucks... but the aliens reading that map wouldn't care - they just want the information on the parts they live at to be as accurate as possible. [Answer] Your aliens are water-breathing and never leave the water. Thus they map only the underwater parts and don't care about the dry part. If they inhabit the entire range of depth, right down to the bottom, they need 3-D maps. They could carve them of coral or some such substance, or construct them of wires or sticks, and mark places of interest with stones or shells. Where the dry parts interrupt their world they can leave a space "terra incognita". The oceans are not still, there are currents all over, and need to be shown too. A map of currents could be made of ribbons or strings attached to the 3-D map. I can imagine there would be signposts set up at important junctions. ]
[Question] [ I have a huge planet with two continents separated by a wide ocean. Inhabitants think that their continent is the whole world because the other side is too far and they never visited it. What if people try to travel the ocean without turning back just for the sake of knowing what lies beyond? Remember they don't know how long they have to travel (even until death) so they might want to make the ship of their lifetimes, possibly the best possible ship they can make. Please don't mind the gravity, or super-earths being gas giants, or other physical laws that might make life impossible. I'll probably make something up. Something magical. Something that can make gravity feel the same as our earth. The circumference of the planet is around 120,000 km. The two continents are 50,000 km apart (opposite to each other on the planet). Also, I want to make the trip very hard. No one has ever reached the other side. So maybe no islands to replenish supplies. Possibly many shipwrecks beached. Each more advanced than the other. --- EDIT: Thank you all so much for these good answers and questions. Here are my thoughts about them: * Challenges about the ocean's vastness, like the size of the waves, the storms they will encounter, etc., are hard for me to answer right now, since I have not planned that in detail yet. However, it is a fantasy world so there will always be a way to cross. Your ideas about what the ocean might look like is really helping me shape the travel. * I do already have a plan for what they will see on the other side. For those who are curious, the plants and animals will be significantly different. Yes there will be humans there, but they will also be... different. How they got there will be a secret. The story will show perspectives of humans from both continents. * I do have ideas for their motivations for the big voyage. They are important, but for now they remain flexible. * It's actually important that they reach the other side without the knowledge of what is in there. Yes, satellite/orbital technology might strongly affect how this goes. But keep in mind I have not revealed the cultures and capabilities of humans in this super-earth. I just wanted to have a good reference of what humans on our earth can do with their knowledge level in different eras, then steal ideas from them. You guys have been helping me form good arguments to justify how different tech can fail/succeed. I know specifying more can help you answer more clearly but please bear with me. Many aspects of this world aren't actually fixed yet, so it's hard for me to add those details. I really enjoyed reading all your answers and comments. They have really helped me evolve my ideas and decide more about what the world should be. Thank you so much for your help so far! [Answer] Since you ask specifically for a technology level, I will answer only considering this aspect. At a cruising speed of 22 knots (roughly 40 km/h), a ship needs 52 days to sail 50 000 km, so a current era cruiser ship can do it without any problems. Probably any ship built in the second half of the 1900's, if designed with that goal in mind, can do it. Now the problem is that they don't know how long the trip is, which has the effect to make the calculation hard on how much food and water you need to take with you. Luckily some of the food is in the water and it is not too difficult to have a desalination plant on board to produce water to drink and for the hydroponic cultures (vegetables). This way you can stay in water for longer than 52 days (maybe up to 100 days if the ship is really slow). While this trip probably is not doable with an 1800's technology level ship, a relatively modern ship can be built with this goal in mind and be doable with current era technology without too many problems. Update for clarification I am thinking about a nuclear powered ship, so the range is not a problem, but probably a custom designed ship (something like a light tanker) can embark all the necessary fuel. [Answer] Stone Age Tech The pacific Islanders were able to colonize the most remote islands without any technology you might consider 'advanced'. In fact, their sailing technology has been quite sophisticated for a very long time. They can effectively live at sea indefinitely. There's a good argument that the Ancient Egyptians sailed to the Americas, too: <https://www.ancient-code.com/3-discoveries-that-suggest-ancient-egyptians-traveled-to-america-thousands-of-years-ago/> The limiting factors in crossing a large ocean are not technological. Wind Conditions: Are there prevailing winds that allow for travel in both directions? The more consistent the wind, the easier the trip. Sea State: How rough is the trip? Rough winds and waves can make a trip much, much harder. For example, for a long time, it was more difficult to round the Cape of Good Hope in S. Africa than it was to cross the Atlantic. How frequent and how strong are storms? Is there a hurricane season? If storms are infrequent, it will be relatively safe, but the more frequent the storms, the more dangerous the trip. How cold could it get? Again, the colder it might get, the more dangerous the trip. The Vikings could cross to Greenland in the summer, but had a hard time getting to England in the winter. How abundant are fish? Pacific islanders can feed themselves on the go by catching fish. There is (was) a lot of life in earth's oceans. How frequent is rainfall? Stores of fresh water can be harder. With frequent rainfall, they won't have to worry about fresh water. It's also possible to collect water from condensation every morning, but this takes up a fair amount of space, so its hard to do on a ship. Most importantly: Does anybody feel like making the trip? People need reasons to make such a journey, especially when there might not be a destination. The Chinese could have discovered & colonized N. America whenever they felt like it, but they didn't for cultural and economic reasons. [Answer] ## Doable: Space age tech: USA / USSR 1970's tech. ## Lucky: 1840's tech. Let's take a look at some ships, 1 knot = 1.852 km/h, 50,000 km distance, one way trip, best case, no detours. * [Frigate](https://en.wikipedia.org/wiki/USS_Constitution), 12 knots -> 93 days * [Clipper](https://en.wikipedia.org/wiki/Clipper), 16 knots -> 70 days * [Container ship](https://en.wikipedia.org/wiki/Container_ship), 24 knots -> 47 days * [Carrier](https://en.wikipedia.org/wiki/HMS_Invincible_(R05)), 28 knots -> 40 days To know where you are going, you will need satellites and imaging of foreign shores. Also weather forecasts are very useful. Yes, you can plot your way due East or West, but no guarantee to get to a place where you can land. But you might get lucky And, you will want to get back to your home. And spend some time at the other side. So let's go with 5 times a one way trip. Say an even 10 months to go there, meet and greet, and come back. Doable, but a very large project. Akin our moon landings. Option 1: single nuclear carrier: Rebuild / custom build a ship for this mission. Make it large with nuclear power so no refilling and fresh water. And pile in the food. Lots of it. No, pack in more I tell you! Option 2: the grand fleet: So go and find your other continent with a (large) fleet of ships. Container ships and Carriers. Supply ships, fishing ships, repair ships, scouting ships, hospital ships... what ever you think you need. Big nuclear ships to reduce the need for fuel and fresh water. And much of it build just for this mission. Option 3: the mad navigator (Columbus): Pile in as much food as you can and get lucky you don't starve before you hit landfall. Columbus took 5 weeks (35 days) in his first trip. [Answer] The Franklin expedition, launched in 1845, was provisioned for 3 years. That would be adequate for a 50,000km voyage under sail. Fishing might provide additional food. One of Franklin's ships, the HMS Terror, was built in 1813. Magellan 3-year voyage circumnavigating the earth covered 69,800 kilometers, and that was from 1519-1522. His journey might be a source of inspiration for you, as only 18 members of the 270-person expedition survived! That's about as difficult a voyage as it is possible to imagine. Of course, Magellan made many stops along the way. Looking at the greatest fictional sea voyage, Homer's Odyssey, again one finds he made landfall repeatedly in his decade-long journey. I would respectfully suggest some islands along the way would be a good idea. Regardless of how heroically difficult it would be, months or years of sailing across featureless open water sounds pretty boring. [Answer] ## Circa 1800 - Age of Sail The (fictional) Horatio Hornblower made a voyage of roughly this magnitude of distance, with orders to stay out of sight of land until arrival, in a typical Royal Navy frigate (with a full crew), in the very early 19th century. The journey was from a West of England naval port to the western coast of Central America, via Cape Horn, and made a precisely accurate landfall. Though fictional, C. S. Forester's novels are well-regarded concerning historical plausibility. In your scenario, I assume both continents have been sending out expeditions to each other and would have evidence of this, in the form of wreckage washed up on shore. This would constitute sufficient evidence (together with astronomical observations and the successful introduction of celestial navigation) that such a voyage was possible, even if nobody had yet succeeded, and probably also indicate the correct latitudes to pick up favourable trade winds. NB: celestial navigation requires good knowledge of mathematics, an accurate observation instrument (eg. sextant), and an accurate timepiece (marine chronometer) if longitude is required as well as latitude. These were all available and in regular naval use by 1800. Possibly even evidence of the length of voyage required could be obtained from the wrecks. If some of them failed only due to shortage of supplies, the ships might reach land intact but with nobody alive at the helm. Medical knowledge would be sufficient by then to approximately determine the time of death of the last survivors, and correlate this with the size of the crew and the quantity of supplies they set out with. The ship's logs and charts would also be very valuable to future expeditions. A civilian expedition would probably take a much smaller crew than a naval frigate, which would help to extend their supplies. Not carrying a large gun armament and not requiring a manoeuvrability edge in combat substantially reduces crew requirements. Adopting a schooner (or topsail schooner) rig also helps, though it may reduce sailing speed in tradewinds. Since the winds and waves are likely to reach similar magnitudes as in the Roaring Forties on Earth, a schooner rig is almost certainly adequate. Storing large quantities of preserved food on board is not a problem - salt pork and hardtack was the standard of the day, and would keep almost indefinitely. In roughly this period, pemmican was also introduced to expeditionary rations. Catching fish en route is a possibility, but probably should be regarded as relieving the monotony of diet rather than a primary source. Avoiding scurvy requires carrying a source of Vitamin C, probably derived from citrus fruits; concentrated lime juice became standard in the Royal Navy, and is not especially difficult to make. The major problem is likely to be fresh drinking water, which is difficult to keep drinkable over a period of months, even if a sufficient quantity is taken on board. Depending on your planet's climate patterns, it may be possible to collect enough rainwater to sustain a small crew. The key technological advance that makes the expedition successful might be a relatively efficient solar-evaporative distiller, which could be made with a glass lid. Carrying spare lids would be advisable. [Answer] ## You need the Industrialisation To put a definite upper bound, I would say mid-19th century. Take Brunel's [SS Great Eastern](https://en.wikipedia.org/wiki/SS_Great_Eastern), launched in 1858, originally designed to ferry 4000 passengers from Britain to Australia without refueling. That is already about half the distance you require. If you replace the passengers, their supplies and their amenities as well as the cargo with more fuel (and supplies for your crew) instead, a range of 50000km or more should not be a problem. To put a lower bound, there are two technological advances made in the late 18th/early 19th century that allowed for this ship to exist and in my opinion are necessary to attempt such a trip. The first is related to size. It is easy to see that a larger ship is preferable, especially a long ship. Roughly speaking, the capacity to carry supplies increases with volume, that is cross-section times length, while the resistance to traveling through water only increases with the area of the cross section.¹ Larger ships also tend to need less crew per tonnage. Now the thing about wooden ships is that they are kind of limited in size. The iron-hulled Great Eastern, mentioned in the beginning had a length of 211m. Wooden ships of half that length already had big structural problems. So what you need is a ship with a metal hull. And while metal working was done since ancient times, the large scale precision engineering needed to build them just arrived at this time. The second is related to propulsion. The reason people were able to routinely cross large distances in the age of sail is that they knew how the trade winds generally were blowing. And even then there always was a lot of luck involved as there might be no wind for weeks or a storm which is to strong to effectively sail. In transatlantic distances, this is already dangerous. At the distance you are thinking about, these uncertainties are simply deadly. So in short, you will need an alternative to sails, the first feasible of which were steam engines.² While there were some experiments earlier on, the first practical seagoing steamships were built around the early 19th century. ¹ Yes, I know the reality is more complicated, yet the general idea still stands. ² There are oars as an alternative to sails, however they are not really feasible for long distance voyages. [Answer] Sailing As everyone has stated, sailing takes you a long way. Sailing allows fast circumnavigation of planets because winds and currents form specific patterns due to [atmospheric circulation](https://en.wikipedia.org/wiki/Atmospheric_circulation). A major challenge to circumnavigation in 1500 was that land kept getting in the way, and sailors had to cross through alternating ocean and wind currents as they sought paths around continents. If there isn't a land mass in your way, you can sail on a raft or canoe for as long as your food supplies last, as evidenced by ancient Polynesian travel patterns. Larger planets have more belts in their circulation; [Jupiter](https://en.wikipedia.org/wiki/Atmosphere_of_Jupiter) has 7 belts per hemisphere while Earth has 3. Yours is 3x earth, but still 1/3 Jupiter, so you might have 3-5 belts of atmospheric circulation. Preventing Sailing So, assuming a rotating planet with Coriolis effect and a star that creates equatorial heating and circulation of ocean and atmosphere, there need to be other specific barriers to finding the other continent. Polar Continents Both continents could be polar, with several bands of winds and currents, plus equatorial doldrums to cross. Equatorial oceans would have doldrums, air is heating and rising, so no wind currents. Hot oceans If your continents are polar, the world could be 20-30C warmer, so the poles are temperate, but the equator is a hot ocean, 40-50 C, which is hypoxic, so no sea life. A hot, dead, stormy belt that is uncrossable without (pick your tech and bravery level). Storms The planet, especially with continuous equatorial oceans, could (with a little stretching) form large, semi-permanent storms, like the eye of Jupiter, which create a dangerous band of storms combined with doldrums. Storms could be so powerful that modern airplanes can't cross, or an intrepid explorer in a small craft could thread the storms and make it through. Space travel would definitely make it over any obstruction, but increased gravity could make it harder to build orbital launch systems. Dangerous shoals Some crazy plate tectonics could be in place that create a ring of shoals and uninhabitable volcanic islands that make seafaring dangerous. Clouds of sulfur gas, boiling seas, rocky islands that rise from and sink into the ocean, etc, etc. These could be akin to the [mid-Atlantic ridge](https://en.wikipedia.org/wiki/Mid-Atlantic_Ridge), only way shallower and more active. Continentality affecting winds and currents Without being strictly polar continents, large continents shape ocean and wind currents by changing thermal patterns. The right shape could create currents in which the world is circumnavigable, but you won't reach the other continent. There would obviously be a blank spot on maps, maybe explainable by some cultural phenomenon. Explorers sail, ride the waves and wind, and end up back on the other side of where they started. All of these have different tech requirements. Sea impediments could stop ancient rafts and canoes, sailing ships, or even modern ships and submarines. Atmospheric impediments would stop aircraft and dirigibles. You'd have to have extreme gravity or some crazy radiation and magnetic field issues to stop orbital technology. Or there could be a cultural explanation why the maps all end at a certain point and no one tries to go further. Shipwrecks Shipwrecks could be common in the doldrums or mid-areas, where explorers from each side find strange and unusual wreckage. You could even have two cultures at different tech levels finding eachothers' wrecks. Hot oceans or poisonous volcanic gases could also kill crews but allow ships to drift, so shipwrecks occur on each continent, but no survivors tell the tale of the other land. [Answer] Change some of the assumptions. The biggest single issue is water - so make the ocean freshwater. Next, forget the talk of steam power - that is daft, steam or oil power requires fuel. Go for sail. If you want a truly long-lasting voyage, choose a propulsion method that doesn't need fuel. Choose sail. A sea-going people can fish as they go. The real limitations are therefore water supply and withstanding storms. Relatively small vessels, well built, can withstand major storms as well as large storms. Some of the whaling ships of the previous century would spend a year or more at sea. [Answer] > > So maybe no islands to replenish supplies. > > > That's a big maybe, and the whole question hangs on that. # If there are islands every few 1000 km... 9th Century Polynesians. Then [@James is correct that the Polynesians could do it](https://worldbuilding.stackexchange.com/a/111250/760), but incorrect about how, and I wouldn't call it "stone age tech". [Polynesian navigation](https://en.wikipedia.org/wiki/Polynesian_navigation) was extremely advanced. Over the course of about 1000 years, starting roughly at 900 BC on Fiji, [Lapita](https://en.wikipedia.org/wiki/Lapita_culture) and later [Polynesian](https://en.wikipedia.org/wiki/Polynesians) culture, crossed all the South Pacific islands finally reaching the very isolated Hawaii and Easter Island in 900 AD. The longest crossings were to Hawaii and Easter Island. From their likely jumping off point of [the Marquesas Islands](https://en.wikipedia.org/wiki/Marquesas_Islands) these are both journeys of nearly 4000 km. [![enter image description here](https://i.stack.imgur.com/li497.png)](https://i.stack.imgur.com/li497.png) So over a few thousand years you could have an ocean spanning island culture using Polynesian technology. # If there are no islands... 16th Century European + 9th Century Polynesians. While the Polynesians were very good navigators and could cross thousands of km of open ocean, they had their limits. Their crafts were not self-sufficient. [They had to carry water and food with them](http://archive.hokulea.com/ike/canoe_living/holmes_provisioning.html). While they were very frugal and could supplement their stores with fishing and rain water, this was unreliable and eventually they'd run out of food and water. We know they could go about 4,000 km, but not 50,000 km. We need a self-sufficient voyage that can navigate 50,000 km of open water and survive on open ocean. Let's take that in parts. ## Navigation. There's two problems of open ocean navigation: latitude and longitude. There's a number of ways to handle navigation, star charts or sun sightings, and that's been known since antiquity. No problem. [Longitude is a problem](https://en.wikipedia.org/wiki/History_of_longitude#Problem_of_longitude) and wasn't really solved until the 18th century. But plenty of explorers were navigating the Earth's oceans well before then, so maybe we don't need longitude. And if you have magnetic compasses you can get a rough idea of your position from [magnetic declination](https://en.wikipedia.org/wiki/Voyages_of_Christopher_Columbus#Magnetic_declination). Latitude is enough to at least keep you on a straight line. ## Stores (and Speed). How much food, water, spare parts (and maybe fuel) you need to carry depends on how fast you can cross. The [Kon-Tiki expedition](https://en.wikipedia.org/wiki/Kon-Tiki_expedition) recreating a possible Polynesian voyage from the South Pacific to South America took 100 days to cross 7000 km at a rate of just 70 km per day. At that rate they'd need about 700 days to cross your 50,000 km ocean. Christopher Columbus made his first voyage of about 5500 km from the Canary Islands to San Salvador Island in about 30 days making about 200 km per day. At that rate you'd need to carry 250 days worth of food, water, and spare parts. What if we combined the two? I've been to [the Kon-Tiki museum](https://www.kon-tiki.no/), the Kon-Tiki was basically a big, but deceptively sophisticated, raft. What if we combined the navigation skills and frugality of the Polynesians with 15th century speed and technology? The Kon-Tiki was able to sustain 6 people in one ship for 100 days. Columbus was able to sustain 90 people in three ships for 30 days, 5 times more efficient than Kon-Tiki. If Columbus had just 6 people he could have sustained them for 500 days. And if he could sustain 15th century speeds of 180 km per day he could have crossed 50,000 in just 280 days. But a 15th century European sailing ship can't operate with 2 people per ship, they require a much larger crew to operate than a Polynesian sailing raft. Perhaps there is a happy medium. I can imagine a combination of improved 16th century sailing and provisioning technology with 9th century Polynesian navigation and frugality to produce a ship that can sail at 180 km per day with a crew of 10 to cross 50,000 km in 300 days needing 3000 person-days of stores. [Answer] I"m firmly convinced that the kind of storms and "rogue waves" (google it) that an ocean of that size will generate are the cause of every lost ship. You'd need either a fantastically large, stable ship, or preferably one that can go submarine during storm events, to survive. Ninja'd by Azrantha. [Answer] I have some logistical concerns about this endeavor. * If they don't actually know that there is a continent at a specific location and specific distance, then they need to be prepared to keep sailing and keep sailing until they have effectively circumnavigated the globe. So they can't plan to sail for a 50,000km distance, they have to plan to sail a 120,000 km distance (or at least 120,000km less the width of their native continent). * The precise technological development to allow this voyage isn't a precise answer as much as it is "in this era, it will take X years, but in that era, it will take Y months." But that begs the question of... if it is considered highly unlikely that the continent is there, then are they willing to make an X-year journey as opposed to a Y-month journey? It may be that if the journey is believed to be fruitless and suicidal, then they would wait until technological development makes the journey easy, rather than just possible. * At some point in technological development, around 20th century, you're going to get aviation and satellite technology that will render the nautical voyage moot. They will be able to launch some sort of airplane or balloon that can confirm the continent's location. * Suppose, hypothetically, that there is not just one huge continent 50,000 km away, but many smaller, scattered continents that are a similar distance away. For all this society knows, that could indeed be the case. That means that if you do set sail on a particular circumnavigating course, you are not guaranteed to hit one big continent, but could instead sail right through the middle of two smaller continents and not see either one. Imagine a ship sailing from Antarctica to Alaska on a particularly unlucky course that does not bump into mainland North America or Hawaii on its way. This possibility means that a single voyage as described in the original post could both fail to confirm and fail to refute the theory that there are other continents out there. How many voyages of this type must you go on before you are reasonably sure that you are right? In a smaller planet with more land mass, you won't have to go on too many. But on a humongous planet that is mostly ocean, you might actually have to go on hundreds of such voyages just to rule out that there are any very large continents (and even that would not be enough to rule out the existence of smaller land masses). My point is, if this society could go on a single 10-month journey to confirm or refute their theory, then they might undertake it. But if they have to go on hundreds of such journeys, and each individual journey is likely to be a waste of time and akin to throwing your life away, then they might delay exploration attempts until they reach a 20th century level of development. [Answer] Early Space Race Era I agree it can be doable (with a lot of luck) at steam power era but will need a massive effort akin to put the man on moon, maybe even requiring a international task force. Below I will list some challenges were are not pointed in previous answers. Why not in the age of sail? Because we never got an age of sail for start. At sec XV we unified some kingdoms and they started a tech race akin to the space race to finally develop oceanic navigation. At sec XVI we founded colonies in the new world and it pushed the navigation development and with the growth of the colonies culminated in the "Age of Sail". Without those elements OP super earth most likely skiped it entirely. A Fearsome Sea The size of this Ocean will bring a lot of weather and climate challenges. You can expect winds, tides and currents to be way bigger. Also expects typhoons to be cataclysmic. The tides per se will be a good challenge for the building of ports. The tsunami size weaves can make even fishing impossible in large coastal areas. The sea conditions will be nasty, even in good weather and impossible in bad weather. Navigation will be a really dangerous business. Also the sea conditions will make coastal erosion a thing. I ever wonder if most of coastal will be of massive cliffs. All those factos summed make me wonder coastal cities will be almost entrenched in big natural harbours and important sea trade routes will be exclusively between cities in bays (the only place where is possible to build a big port anyway) and where the route travels along a, most time, very peacefull chunk of the ocean. Lots of Trains & Planes but no Fleet The size of the continet this points out railroads will be in demand early ans planes too but navigation will be very limited in all aspects, speacially in tech. This leads to a strange scenario where we will hit industrial age and even space age skipping sail age. The Dark Side The Moon is a great target for mankind aspiration, from dawn of time we can see it but we cannot reach it. We dreamed to land here a million times. But what if for millenia we do know Super-Terra has a dark side out of reach? Once scientist proves we can launch a object in orbit and retrieve it the first thing to be flung out will be a camera to take pictures of the uncharted lands. Once the first pictures are retrieved be sure it will trigger a space/exploration/colonization race. Age of New World The reason the new continent will spring a sort of space race is to gather data from the land, not only a coastal line but weather a major biomes, moutains ranges, rivers. Everything necessary for future settlers. Also a new tech race on navigation will sprung. Visionaries will dream of under-water-boats, starting the project of the (probably first) submarine. Long-range-any-weather-transocenic ships will gain the status today we grant to a mission to Mars. It will bring a new age. What if there already people here? They are probably in another phase in tech development, even using a different "tech tree" but fact we reached them first. Also yes its unlikey but possible small grups can end strained here but OP can wave a complex geologial/ice age to explain it. Maybe thermals isles of heat making a sort of ring of fire connecting boths continents in immemorial times. What in that case the answer instead can be Ice Age [Answer] Check out : [generation ship](https://en.m.wikipedia.org/wiki/Generation_ship). You're suggesting a ship that can sustain any amount of travel time so it should be assumed they could even sustain death (via reproduction aboard the ship). If previous attempts have been tried and have failed, the next venture would have to assume any possible distance, and proceed accordingly. Alternatively, if they are confident their Earth is round and they can advance scientifically/technologically without definitive proof of its roundness (eg circumnavigation), they could eventually launch satellites that orbit their Earth that could inform them of the vastness of their ocean, any potential land bridges or straits, the general layout of this other continent (like if it appears inhabited, etc) and even potentially provide a means of communication with the other continent without making the trip. [Answer] Christopher Columbus found the Americas in the 1400s, realistically what you are asking would FIRST be capable in very late 1700s or early 1800s, i know this will probably annoy some people but bear with me Columbus set out expecting to find land, however he stopped at several islands and had enough water for the comparatively short trip, Food really isn't the problem for this trip, water is, clean drinking water is expensive, it is widely believed that in 1791 Thomas Jefferson invented the first stages of desalinization, once a ship could be built to house a desalinization plant, then in theory water no longer becomes a problem,then its a matter of building ships, humans have been good at this for hundreds of years, and many much larger than the Santa Maria, the flagship Columbus took, along with two smaller ships, but the journey would be perilous and have little chance to being easily repeatable until the 1900s [Answer] Circumference of Earth is approx 40k, continents in question is apart 50k. Hence i can safely assume till 19th century, it was never possible with the sailing technology at the time. Now, later ships got the capability, but still such voyages are not possible to make as people are not certain on the distance to cover. You cant plan the things without estimating the distance. Though, Many explorers attempted before, only lucky return to tell the tale of emptiness or missed out in the sea. So First step is the distance gauge, such a long voyage can only be possible after knowing the distance to cover. WW1 era ships with expert sailors can do the job, [Answer] Biology of intelligent species is very important too, if they can survive long time with no water source, food, hibernate, swim in water long distance, can reduce resource they need for travel and lower technology. If very robust life form, they can use ocean current and get there by accident. They probably travel for explore their planet, and challenge, like travel to north and South Pole. First they explore near areas and then farther areas while mapping where they travel, building maps of their world. They travel for finish their map. Species need strong curiosity. Evidence for other continent: volcanic ash/dust when no known volcano erupt (or ash have different composition), unknown species dead trees in sea, flying life forms leave and return after months, years (flying life form also show way to other land). Very small probability have two intelligent species evolve at same time. Continents separate at least 10s or 100s million years, evolution very different in each place. ]
[Question] [ Closed. This question is [opinion-based](/help/closed-questions). It is not currently accepting answers. --- Want to improve this question? Update the question so it can be answered with facts and citations by [editing this post](/posts/60203/edit). Closed 1 year ago. [Improve this question](/posts/60203/edit) I'm not asking about communism. The society I am thinking has no sense of value or wealth at all. To them there is no sense of ownership either. It's not that everyone shares, it's that ownership is a completely foreign concept to them. How could such a society develop and could it exist as a modern country with technological advancements? [Answer] The difficulty I see here is the need to develop intelligence in an environment in which ownership and value are unimportant. Value is a thing because items have value. Your spear has value, it allows you to stay alive when the lions come. It also allows you to hunt. To take away the value of the spear you need to either remove the sense that life has value or the feeding/survival requirement. They don't need to hunt because there's plenty of food. They don't need to fear lions because they're too big, already have defenses (horns/claws or otherwise) or move in large groups able to defend themselves otherwise. Your clothes have value, they keep you warm when it's cold and stop you dying when it's very cold. Either the planet must be a balmy temperature or your species has a layer of hair or fur all over to keep it warm. Your home has value, it gives warmth, comfort and protection, somewhere to eat and sleep. Again, hair/fur and herd mentality can take this value. Your food store has value, it keeps you alive when times are hard. Only a natural fat store or food that is plentiful regardless of season can take away that value. Without the challenge of needing to find food, without problems to solve, why would they be intelligent? The tools they develop have no value, because they have no purpose, so they don't develop them. Even chimps have [favourite tools](http://www.cam.ac.uk/research/news/chimpanzees-have-favourite-tool-set-for-hunting-staple-food-of-army-ants) for certain tasks. # Your society, such as it could be, more closely resembles a herd of cows than a tribe of sapients. Plenty of food, no need for weapons, no need to make tools so no requirement to value anything. Then along comes some jumped up monkey with a spear... [Answer] Such a society could exist if one did not have a concept of self. For example, societies of rocks have no sense of value or wealth. However, once you have a concept of "self," the idea of "I own myself" is pretty hard to suppress, and once you can own yourself, you can consider the idea of owning other things. A related concept that can cause issues is the sense of agency. If you have the ability to act with freewill, it becomes difficult to not have a concept of "ownership" of the objects upon which you may act with agency. You may be able to get a close approximation of the society you describe by having a society which has a concept of a greater being which has complete ownership of everything. You could also get such a society as a subset of a greater society which oppresses those who have no sense of value and convinces them that they do not need to feel oppressed. In general, such societies would be so completely unlike anything we can think of that it is highly unlikely you would choose to call it a "modern country with technological advancements." We do see some examples in fiction. Such societies are typically associated with "ascension" from this realm. A great example would be the ancients from Stargate SG-1 [Answer] The concept of ownership probably has [competitive advantages](https://en.wikipedia.org/wiki/Competitive_advantage) in environments with scarcity of resources. Practically speaking, you will want to own land because there's only a finite amount of it and it's a useful thing to have. ie. * to live on, * grow things in, or * dig things out of. Wealth is a good thing to keep possession of because it allows you to do things. In the case of monetary wealth - you trade in for scarce goods and services. I imagine you don't have strong feelings towards owning air because it's a super common resource (also because you can't see it). Scarce resources are valuable. Common ones are less so. My point here is, people from a [post-scarcity](https://en.wikipedia.org/wiki/Post-scarcity_economy) society are much less likely to have a strong sense of ownership. The wrinkle here is that experiences are still going to be a scarce resource. People will still harbour sentimental feelings towards objects that elicit feelings and memories - a childhood journal will have a lot of value to its author, even though journals themselves may be commonplace. [Answer] It can't, even in post-scarcity world there are things that are finite such as land and time. Species that do not at least instinctively understand ownership can't exist. If you don't have sense of ownership of your head what stops somebody from cutting it and using it as football. [Answer] I think the concept of ownership is too simple for there to be intelligent individuals in this universe which don't have it as a concept. If you can use some kind of tool - even if you are post scarcity and there are millions of these tools available, there will be one tool in your hand. If you climb on a tower and want to use the tool there, you will carry it there. If someone takes the tool away from you you cannot use it any more. This will be a problem for you, because you cannot do what you wanted to do. So if a being can use tools and can have an agenda (an idea and the motivation/will to act on the idea) you will have the concept of "I need this tool at this place and time" - and if someone else wants to use the same tool, there will be a conflict of interests, as both cannot follow their agenda. And thus will naturally occur the notion of "I need this tool now, so no one else can use it now" - and if I need the tool multiple times you are already at ownership "I will need this tool today, so no one else can have it for this day". ## I think the only possible options are: 1. The individuals of you society don't use any tools/objects at all. Maybe they are in "spirit form" and don't interact with solid individual things at all. If you interact only with ideas, there is no sense of individual objects - and without things to own, there is no ownership. 2. Your society are digital programs living in a cyberspace with virtually unlimited virtual space. And each resource can be copied and accessed by everybody. So an insert-only file system, where you can never block or change any resource, only create new variations and save them under a new name. 3. The individuals of your society don't have an individual agenda. There is some kind of hive-mind or universal telepathic link. So everything belongs to the swarm. This is of course a kind of ownership, but if they recognize only the swarm as the single entity in the universe which by definition owns everything (including all other species) - there is no concept of someone owning something, because everything that exists belongs to the swarm, so it is the same as existence. [Answer] First, let's examine WHY we have concept of ownership in the first place, since I see in the comments that you are wanting an answer in which the people NEVER developed the concept of ownership and can't even understand it. The roots of a sense of ownership aren't merely societal--they are evolutionary in nature. In the wild, the concept of "this is mine" can be seen in ANIMALS. Not people. Animals. It starts, of course, with food and resources. Who survives? The animals with the best/most resources. Therefore, the animals who defend those resources from others have a higher likelihood of survival, and thus, a higher likelihood of passing on genetics. Staking a claim on territory--guess what, that's ownership, that's "this is my turf, and not yours." Big cats do that. Eating food and not allowing another to take it because it's yours? Ownership. Animals who exhibit what looks a heck of a lot like ownership are winners in the Darwinian lottery. There are very few animals who do not guard a piece of food by instinct. The only way a sense of ownership doesn't happen is if there is NEVER any lack of resources. In this case, all resources would be easy to get, and nothing needed would be rare. Since everything needed is provided for and easy, there really would be no need to develop things like tools, language, or being smarter than other animals. Animals develop a bigger brain, flight, a taller neck and other things, in response to scarcity. There's really no need to ever go beyond what you are currently, if food is always there and you have everything you need all the time. So, in short, I think that a people can eventually develop a society that doesn't have ownership, but that for it to NEVER have had a concept of ownership is not possible, if you want them to be intelligent. Now, if there are two groups of your proto humans, and one group does have a sense of ownership, and the other doesn't--there would have to be some advantage to the group that doesn't. Why does the Non-ownership tribe survive? Especially since, without a sense of ownership, they'd be happy to give all their food and stuff to the Ownership tribe. I will say that any hardship whatsoever would likely "switch on" the sense of ownership. A hive mind, as others have suggested, is actually the best way around this. [Answer] Firstly, I agree with the comment/answer regarding a post-scarcity society. In a context where no resources were scarce and all goods were essentially fungible, I could imagine people operating without concepts of value or ownership. If you need something, grab it from the nearest replicator; when you don't need it anymore, throw it in the nearest universal recycler. Likewise, when you need a place to sleep, just find the nearest empty bed/apartment. Another context where I could see this way of thinking maybe proliferating would be in an extremely "primitive" culture, especially a nomadic one as mentioned in another answer. If you're living off the land, and everything you need can be made from things found readily in the environment, with skills possessed by every member of the society, then there may be no need for concepts of value or ownership. Need a spear? Grab a stick and a sharp/abrasive stone to carve a point. Don't need it anymore? Throw it away, it's just a stick. Time to sleep? Build a lean-to or humpy out of whatever is nearby, but don't bother hauling it with you when you leave. I feel I have read accounts that suggest Indigenous Australians lived much like this ‚Äî they mainly worked with wood and grass. They did however also have art/craft, and so I assume some objects would have had more significance than others (e.g a well made and decorated didgeridoo would likely have been valued and owned, but a piece of bark used as a plate would not be) [Answer] How come nobody has mentioned the Kender race from the Dragonlance series yet? They are popular in LARP, and there's a lot of material available for them. This fantasy race has no concept of personal property or ownership. If they need something, they take it. If they don't need it anymore, they leave it for the next person. They have no concept of money or value and will gladly exchange valuable but boring things for worthless but interesting (read: colourful) things. In LARP, well-played Kenders are incredible fun to play with, and a proof that such a society just might work. The core to the concept is that "use" or "usefulness" replaces "ownership" in Kender thinking. A Kender will make gifts, trade or borrow (even without asking), but he will never steal something. Stealing, to them, means taking something away that you need. As long as you are using something, it is yours. When you are not using it, the Kender will "borrow" it for himself if he needs it, but put it back before he thinks that you will need it again. The idea is that everyone should always have what they need. If I need it more than you, I have a right to take it. As soon as I don't need it anymore, you have a right to have it back. This view requires a highly social thinking. There is no reason why such a culture could not advance technologically. There would certainly be no equivalent of corporations or stock markets, and at the same time there could not possibly be a communist or central planning organisation, either (Kender are notoriously freedom loving people). There may be less incentive to make inventions for personal gain, but then again if you look at the history of inventions, few of them were made for that reason. From the printing press to the first computers, "I want to be rich" does not seem to be a driving force of the history of inventions. I strongly suggest doing some research into both fantasy and real cultures that have no or different concepts of ownership or money. [Answer] The alternative to a post-scarcity society is one where resources are so scarce that the overhead of an individualized economy is too great. If you have private ownership, then individuals need to continually negotiate for resources. With plenty to go around, this can be streamlined somewhat, by setting up market places, but there will still be individuals who spend significant effort on facilitating trades, and do not produce goods in that time, so you need a certain production surplus for that. If everyone is just barely scraping by, then trading will happen mostly between people that already know each other (to minimize risk) and know that they have complementary interests (so the trade will be mutually beneficial). This is a major impediment for societal progress, and a group that successfully organizes collectively can outperform a group of individuals competing with each other. Let this run for a few centuries, and you get a group that knows that they have always fared well with collective ownership, and any attempt at privatizing certain resources will be seen as detrimental to the group. [Answer] I really like this question as it goes completely against what our society is based on really. Concepts like 'effort->reward', 'privacy' and 'justice' become hard to imagine. I feel like this exists to some extent, but it's a non-human example: I recently saw part of a documentary on ants. They act as one big hivemind really, they are very facinating. Ants do not have individual property, while there is still hierarchy (but I don't know if you can really talk about a society). If I had to translate this to humans, there would probably be a need for very good communication (you could go as far as having implants that are connected to the brain that form a giant neural network of sorts, if you like to go sci-fi). I'd also argue that it would be ok for people to be unable to function as individuals. If any object/space is non-personal, everything is 'owned' by the society rather than individuals. You sort of adress this in your question by mentioning this society living in a 'country', implying they 'own' the land. If this country would somehow have an overabundence of rescources there would be a strong need for military forces since neighbouring countries would be very interested. I will probably keep thinking on this EDIT: as you can see from the comments below, there is a lot to learn about ants (and other hive species). I am not an ant-expert or whatever so take my information with a grain of salt. I mainly wanted to provide a different view on where to get inspiration, where to look. (I leave most of the actual research up to you so this is by no means a great answer) [Answer] It's an animal behaviour question. Ants and bees and to some extent cows do this. Can humans have no territorial, sexual, racial, criminal, adventurous instincts, and no fear of death in service of it's community? Primates typically don't. It's the same as news reports about racist and sexist issues, they bypass the human rational system because they act on primate self defence instincts that act in the periphery of your concious vision and make you react emotinally faster than you have actually visually identified the subject, through a primitive fast neural pathway. It means that you have to re-program the brain significantly to make the individuals less carnivorous and tribal and more like ungulates like cows. Cows don't have tribal wars and they are settle their ownership disputes once a year and are relatively peaceful, the female cows are not very agressive. Indian Sadhus are supposed to live selflessly, but they have to defend themselves because most of the population still acts with ownership. Legal structures to turn primate instincts into a benign society are very complex in our own society. You have an idealist argument of a utopic nature which sidelines the human behavioural aspect. Everything in the human sphere today is about crowd control and primate emotions, personal thirst for blood, racism, sex, socialising, playing, thrills, and territory. The communist doctrine was written at a time with very low workers rights and worker pay in factories and was relatively good, except that it didn't give a mechanism of action, Ghandi did, and if communism and Ghandhism had some kind of combination of fervor and method, perhaps communism could have survived a bit long in spite of it's flaws. [Answer] Many people have discussed examples from science fiction or hypotheticals, but I'd like to attempt to ground this in history. I don't think you could have a society completely without a sense of self, but that doesn't mean you can't attempt to guide it along those principles. I would point to examples of human cultures driven by the attempt to value selflessness. For example, Protestant Christianity, and Buddhism. ... I've used "I" a lot in a discussion of lacking a sense of self. Anyway, Protestantism, as it originated, was a rejection of the culture of the Catholic church, which had become, to say the least, ostentatious and materialist. The church attempted to expand its power by demonstrating its wealth, and dealt with a mass of illiterate peasants by hiring artists to create works which would visualise key aspects of Christianity. But this backfired with the arrival of the printing press, and protestants rejected all of this in favour of plain literacy. They took offence to the Church's straying from Jesus' anti-materialist teachings, and their becoming too much of a political institution, rather than a spiritual one. It's worth noting that this seems to be where the separation of church and state, as an idea unique to western civilisation, originated. The scale of iconoclasm was profound, with stained glass windows, statutes, and painting, all destroyed in favour of empty churches which allowed them to focus only on the word of God. Protestantism also developed a fierce egalitarianism, and often religious collectives were established as much to share resources as to divorce the individual from their need and desire for material things. This culture persisted for centuries, and remains something of a historical exception. Protestants, even though they accumulated wealth, felt that showing off and indulging was a sin. They were proud of their plainness, which opposes how things go in almost every other human culture, where the wealthy and powerful feel the need to evidence status by showing it off. Buddhism however may be a closer fit, since the aim is to abolish the sense of self. Attachment to the material world is considered a flaw which spawns cycles of suffering, and one must attempt to cleanse themselves of this, ending the cycle, by ending their belief that they exist. Foundational to Buddhism is the belief that you, the individual, do not exist. And this realisation is required for achieving enlightenment. It's not so much anti-materialist, as anti-individualist. Maybe thus early protestant and especially Buddhist cultures are worth researching to give an idea of how these beliefs may manifest socially. [Answer] Natural selection makes it impossible for the behaviors you seek to arise naturally and if induced artificially, they would not be stable and would not persist. Material abundance will not help because a 3rd of humanity already lives will such material abundance it's choking us to death with cream. For a person from the medieval ages, 1792 or for that matter many of 3rd world poor still, we have no unfulfilled wants or needs. If you can't be happy being a 1st world middle-class, you never will be. The major driver of destructive acquisition and unhappiness today, is that natural selection has primed us to value social status over all things and to use materialistic objects to broadcast our status. Freeing one's self from the atavistic urge to "keep up the Jones" is the greatest key to happiness. The society you postulate would prove almost instantly self-destructing. A society with no since of value for anything, even if they shared all things in common, could not prioritize work. How could they tell whether they should plant food, build a house or stop someone from bleeding to death? Although self-rightous, moral elitist have denigrated ownership since the dawn of civilization, it is undeniable that the stronger the property rights are in civilization, the greater ALL the positive social factors. About the only drawback is that the surplus wealth produced cause a parasitic class of self-rightous, moral elitist to evolve and propagate. What the pseudo-intellectuals, priest class etc ignore in condemning ownership if that the flip side of ownership is responsibility for whatever is owned. If no body owns anything, no one is responsible for anything either. If something breaks or becomes dangerous, who takes care of it? I could see some utopia using genetic engineering or brain implants to produce an inability to assign value. Injury to forebrain will often cause this by severing the predictive cognition in the forebrain from the emotional centers that assign value to people and things. Such individuals can often give highly detailed breakdowns of the pro and cons of any action (and thus the value of whatever state or object the action produces) but even with all the right facts logically arraigned have no ability to prefer on outcome over another. They are utterly paralyzed when making predictions and they do act as if all things and people are of equal value to the extent that some simply wander away from their families and loved ones. And even if you could erase somehow the concept of ownership, but such a group of altered people who likely simply stand around passively as they starved and the environment killed them. They could take productive action because they would have no sense of which action would produce the most value. Without ownership, they would have no means of assigning responsibility for any productive or protective work even if they just chose their actions at random. Of course, such a population would make near perfect slaves, albeit ones requiring constant supervision. [Answer] I realise that this is a bit out there as an answer, but it's the only scenario where I could envisage the human race adopting a different value system. At present the human population of the planet is estimated to be 7.5 Billion. The crude death rate is estimated at 7.89 per 1000, the average life expectancy at birth is 71.0 years and the median age for the population is 29.9 years. Consider a situation where the human race was rendered sterile tomorrow. Life as we know it would be fundamentally changed - within 40 years (2056), the human population will have halved and in the 40 years after that (2096) the human race will be on the brink of extinction. In this scenario the concept of ownership and wealth become obsolete - it would dawn on people that you can't take anything with you when you die and any would be heirs will be joining you relatively soon. Assuming that we don't collectively go for the Armageddon option and start blowing the place to pieces, it would be in the best interests of the human race to focus on solving two problems: 1. Increase the life expectancy of the existing population. 2. Make the human population fertile. There's no doubt that some people would opt out of society, while others would dedicate themselves to trying to fix the problems. It could potentially take decades but supposing #1 proved to be impossible and it took 50 years to restore fertility to humans. In that time, the human population would be devastated. By 2066, the human population is approximately 3.25 Billion people, of which 1.95 Billion are aged 50-65. There would be a limited handover period (15-35 years) between the survivors and the new generation. It's unlikely that the new generation would have much of a childhood, the passing on of knowledge would be the utmost importance. Would the concepts of ownership/wealth fit into the new society? It's not likely that they would given that there wouldn't be time for luxuries. A new value system is likely to be forged with a new vision of the human being and recognising that we are part of a whole bigger thing. [Answer] You can't have time without the concept of having or not having. How do you differentiate the past from the present, or the present from the future? You had things in the past. You have things in the present. You will have things in the future. Or, you did not have things in the past. You do not have things in the present. You will not have things in the future. Think about it, very very carefully. There is no difference between yesterday and today other than differences in what you have and have not. --- You could have a society without the concept of deeds or titles for ownership. But that's not what you're asking. --- These ideas are not original to me. [Answer] Why you don't create a hive-like species? Individuals beings won't value possessions for themselves, nor themselves - something is only useful, only has value if it can help the colony or the "queen". If you think about it, bees, ants and termites are already pretty societies without the concept of ownership - at least inside their huge families. Heck, even their lives aren't something they own - their lives are tools for the colony. You may check out the borg from the Star Trek Universe. They are already pretty much what you want! [Answer] It seems like you are talking about a Group mind. Star Trek's Borg drones have no sense of individualism, so nobody owns anything (not even their own live). However, the Bork hive pursue others biological and technological distinctiveness to add that to their own. To answer your question: This society could develop if there is a (fictional) greater goal, which benefits the individuals more than if they would pursue their own goals. I agree that in an uncivilized environment the ownership seeking individual will more likely reproduce, but a civilized culture is more efficient than an uncivilized culture. [Answer] Curiosity may be the "prime mover" instead of value or ownership. To move the next question (or the answer) they need to collaborate at some point. [Answer] The concept of a world without ownership was handled very well by Ursula K. LeGuin in her novel [The Dispossessed](https://en.wikipedia.org/wiki/The_Dispossessed). It won the Nebula award in 1974 and both the Hugo and the Locus in 1975. And it's a great novel well worth reading. [Answer] Such community will exist and prosper without a doubt even if the abundance of resources isn't certain. We can classify the species which exist based on the level of ego . For example the predators higher in the food chain have an ego which gives them a sense of ownership which dominates any other activity which benefits their specie as a whole. They are very hostile towards anyone who crosses their territory even if the individual belongs to their own specie. They refrain from sharing their resources (Food mostly) . In a broader sense they have a high sense of individualism and thriving. On the other hand the ants have been successfully able to eliminate ego or individualism , thus most of their actions are directed towards benefiting the species as a whole. Communicating with the colony when one senses the availability of any resource can help such a community to thrive. The profits in such a society cannot be materialistic . Prosperity of the species the objective which the species should realize to build such a world. [Answer] Note: I debated making this an answer or making it a comment - but I wasn't sure which answer to make it a comment on... Several answers here talk about a post-scarcity society; I think this is the right path to go down. Rather than take a species that starts off with no concept of ownership and try to figure out how to evolve a society, start with a species that no longer needs a concept of ownership, and see how their society would evolve. @KarstenGutjahr talks about hive minds like the Borg; @slobodan.blazeski talks about post-scarcity societies still needing land. ... but what if we take someone so technologically advanced (or magically advanced) that there is literally no need at all? Someone like the [Q Continuum](https://en.wikipedia.org/wiki/Q_(Star_Trek)) from Star Trek: The Next Generation? The Q have such power that they can transcend space and time, create things out of whole cloth, etc. Note that you don't need to go to the extreme. I'm hungry and need food, I simply create it out of magic/replicator tech. I see a beautiful painting you have and want one of my own, I simply duplicate it magically or technologically. I want some land with a view, I simply create a small pocket dimension with the right aesthetics and pop right in. Once anyone can simply snap their fingers (or close enough to) and obtain any needed/desired item, ownership ceases to be "necessary." [Answer] Technically such a society is possible, but it would not develop very much. First, because a person feels a sense of ownership of one's body, they feel a sense of ownership about that which is acquired with one's body and mind. What makes such a society still possible is that a society can be created in which transfer of ownership is not allowed. That is all trade is forbidden. Because even the most basic specialization requires exchange of useless for useful objects, that would not allow for any kind of specialization of skills. Which would not allow for any development. [Answer] Firstly, I disagree with the seeming consensus that it's not possible, or not possible for an advanced civilization. One way to make a world like this would be to have everything wiped out at very fast intervals. I'll invent one semi-contrived example: all the things in the world are made from a material that constantly rains from the clouds but disappears after a few minutes. Once it lands on the ground, you only have a few minutes to mold it and shape it and do whatever with it until it disappears. In that world, since ownership wouldn't matter, nobody would have a sense of ownership. Or, imagine a group of sentient clouds in deep space. These types of civilizations could still be advanced, and have histories ("in the year that the moon turned blue, there was a great eclipse...") and have rich knowledge of mathematics, literature, art, poetry, music, etc. passed down by oral tradition. [Answer] "people in general thought of as living together in organized communities with shared laws, traditions, and values" Guessed yet what this is? Yup. The definition of "society" from Meriam-Webster. So, how can a thing exist without the attributes that make it the thing? It's like a thin but very long square. It just cannot be. By definition. Maybe try another word instead of "society". Somehow "cattle" comes to mind. [Answer] The closest society that I'm aware of that actually exists isn't herd mentality as other have mentioned, but swarm mentality. The concept that individuals aren't as important as the survival of the swarm, as is the case with wasps and bees. In this situation you have very clear collective ability to develop tools as life isn't easy and food may be scarce, there may be predators or threats to the society, but the recognition that the society itself is more important than the individual. In the case of swarms (I believe) this is achieved due to genetic similarities between all the individuals - there is no difference on an evolutionary scale which individuals reproduce (or some individuals can't reproduce). In this case there would be a clear sense of Value and Ownership, but only to the collective rather than the individual. But in general the definition of a society is a collective that has the same set of values - therefore the existence of society and value are indivisible. And should a collective exist that had no concept of the value of anything then they would almost certainty be doomed to self destruct as they would destroy the things that survival depended upon. eg Easter Island - the environment itself had no value (or not enough anyway) and was destroyed until the island became uninhabitable. (I may be wrong about this) [Answer] I believe a society that creates abundance trough robotization could first of all eliminate a lot of problems caused by scarcity like; Hunger, starvation, ill health, depressions caused by individual monetary struggles of the poor, illegal activities caused by individuals who can't fill legal niches in the market to provide for themselves and loved ones -Pooching endangered species (ivory, butterflies, beaks, etc.), a lot of drug abuse caused by hopeless monetary situations -and the dealing of the demand for it, human trafficking, child labour, etc. etc. etc., the list is very long... For the rest: A world not based on money would have a lot of room for creativity and would not be bound by the limitations of budgets to produce good nor limited by the long lasting patterns owned by people that broke human development even further. Even the richest people living now would have better goods to their exposal (no limited budgets for creating high quality goods). We could still make decisions of ownership. I believe we would share a lot more and create a lot of general usable spare parts for most goods (interchangeable) creating a lot less waste and have much cleaner ways of production and a high efficient way of recycling the things that eventually would still wear out (also a lot less then today's goods).. About competition: I believe there would even be more competition when it comes to individual ambitions. A lot of people today are only dreaming about the possibilities they would have when they would have more possibilities. Unfortunately most of these dreams die with age because a lot of these people in today's world have 1 not the monetary incentives to do so. Or 2 will not be discovered by someone who is willing to help overcome these problems. A lot of Jobs that are boring, dangerous, repetitive, exhausting/hard would hopefully soon be replaced by Robots (because in a world without money people would not be willing to do these jobs in the first place). The Jobs that will be left are jobs that are creative and nice as a hobby in today's society, but unfortunately became to expensive to pay for and a people could not do them anymore to make a living (local products; chees making, shepherds, handworkers making and restoring historical buildings, loaming, weaving, - old traditional styles of handwork). Or jobs that require budgets in today's world and the budget's don't last to pay all the people who would like to take part (development of rockets for space, building designing aircrafts and infrastructural projects etc.). Don't forget that if the majority of today's jobs will be taken over by machines these other jobs (which are nice jobs) will have a lot more people available taking part in them -so the amount of hours we have to work will become a lot less.. We share the leftovers doing so creating more free time for all of us, making the enjoyment of work even higher. The people who are not smart enough to become rocket scientist, would maybe want to take pat in restoration of old historical buildings for cultural purposes (how many ruins we have in today's society?!). Or they would take part in endeavors like reprint park benches, clearing the paths in the woods of weeds that grow over them etc. You-they may do so. But you don't need to feel obligated to do so (a robot could also be programmed to do some of these things on schedule). And what about the people who do not want to work? Just let them stay home! They obstruct the workflow today already any way; pretending to work, getting jealous at people who have to motivation to work harder then they do (making them look bad).. Sooner or later they will get bored and would be healthy and fit enough to find themselves a nice creative enjoyable occupation in one or other direction... By taking away all the limiting factors of money and patterns, we would have much more progress in the world; becoming a interstellar race sooner. Having no more recessions and likely no more wars (maybe still wars between individuals we could deal with much easier, but probably not to the extends we have seen trough history).. I hope I have given you some things to think about? Because I can Talk for day's on this topic. The way today's societies are structured are just so mind-blowing constrictive and insufficient. it's like watching a dystopy in action -I'm very sorry to say... [Answer] ## Ownership is needed to advance beyond the level of hunter/gatherers Ownership is not a feeling that you have about stuff, it is a concept that exists within groups to avoid physical conflict. You own something if group members acknowledge that you own it and will still protect your claim while you're away. Animals have no concept of ownership, only competition. They want/need something and if they can take it without getting killed, they will. They will also guard it and fight others to keep it if they can, or hide it for later use. No animal has an expectation that other animals will leave their food alone when they leave the scene. This goes for food, but also things like a den or nest that take significant investment to build. Animals do proactively fight and kill competitors. Not out of a sense of ownership, but exactly because there's no other way to protect what they want/need. For social animals, this is still mostly the same: the group leader takes anything he wants and the others take what they can without being hurt or killed by higher ranking members. The moment the leader is away anything is fair game (including his harem). Despite this, the competition within the group is more formalized and killing other members is rare. Even the leader risks a backlash if he's too violent. The group is also stronger than individuals because they unite against outside competition. This works well as long as there is nothing that requires longterm investment of time and effort. If one group member spends a week making a sharp axe from flint and somebody takes it away when he sleeps, that's a much bigger loss than (part of) an animal kill or fruits. Risking conflict to get it back is worth it now. Taken to an extreme, if someone spends a season farming crops and all of them get taken by others, fighting and killing them to take it back is the only way to survive. This level of conflict is unsustainable for a group/tribe, so guarding what you need/invested time in becomes ritualized. To avoid conflict, members will not take what they saw someone else build/farm/hunt. The group assigns that member ownership of the resource. The group members will also assist in returning owned stuff from the taker (now known as thief) to the owner and apply punishment if needed. This promotes group cohesion and further reinforces the concept of ownership. For a society to develop beyond basic hunter/gatherer level, it needs this concept of ownership to reduce conflict and safeguard investments made by its members that go beyond daily needs. It allows specialization because it allows trade. (I trade some grain I own for a pair of shoes you made and own). You ask about development of a civilization (not hive-mind) without a concept of ownership. I see 3 scenarios: 1. It stays at hunter/gatherer level 2. It would be extremely violent with the strong coercing the rest, and while it might make some progress, it could just as easily backslide. 3. It would be extremely altruistic, then die out. The altruistic would of course collapse if they ever met the violent or some society that exploits their altruism. But even if they were the only society in the world, they would deal very badly with scarcity. During a famine, they would likely still share the little available food until all are too weak and die, rather than having the strong take what they need, survive and rebuild. ]
[Question] [ First, let me introduce the setting. It's happening in post-apocalyptic SE Europe (Balkans specifically), about 100 years from now. Strange genetic disease wiped out large portion of humanity in a matter of a few years. The rest of humanity killed and pillaged each other until our numbers were indeed few. The surviving humans have a genetic disorder which makes pregnancy harder. Nature is, for an unknown reason to people, thriving, mutating, being more hostile to people. Wild plants are growing slightly faster, predators are bigger, stronger, smarter and more dangerous. Beside that there are the "wild ones", feral humans that live like animals. All this has made trade and traveling quite hard, but not impossible. Cities are overgrown, forests are bigger. People are living in smaller independent settlements (100-300 people), scattered, fortified. Bandits and roamers are common. Settlements are somewhat self sustaining, but still need to trade between each other - for example some are agricultural, having extra veggies but lacking meat and tools, others are hunting or fishing based, and there is one specific settlement, based around the old University, which harbors and preserves "old" technology and knowledge, and uses that knowledge as a commodity. There is no unified government or force, and all attempts do do such have failed. Technology is somewhat preserved, but only partially. For example, people know what solar panels are, or that somehow electricity can be produced from a windmill, but only a very few people actually know how it works and the science behind it. Now, finally, to the QUESTION. I am looking for a form of currency that people can use in trade or for paying for services. I don't need a fiat currency as modern money, or backed up currency like bottlecaps from Fallout series (they are backed by water). I need something that has actual practical use and value to people. I've researched that various things have been used as currency before, like animal pelts, cattle, shells. But, I can't really picture post apocalyptic random traveler hauling bunch of pelts with him or dragging 3 cows and 2 pigs just to have a way to pay anything anywhere. Or how do you pay for shelter in a settlement or pay your bodyguard for a week of protection? Give him two chickens and he's on his way? People will also say why don't they just barter, but, in a bartering system you can't really pay for someone's services (protecting, fixing, and so on). I think in this setting, also, precious metals like gold and silver are practically useless for surviving, except they are rare and look pretty. So, I welcome ideas for currency that fits in this: * Has actual practical use and value to people in this environment * Should be rare, hard to find, but not impossible. * Hard to counterfeit or cheat with * Size matters - should be easily transportable (like precious metal coins or lumps, only, as stated above, they don't really fit the bill, that you can carry it easily) * Durability, can't be fragile * Take in consideration described technological level and society, and that a hundred years have passed since "the end" and most things are gone and decayed I've been trying to come up with a realistic solution to this problem but having hard time. Any help or ideas would be most welcome. [Answer] > > /I think in this setting, also, precious metals like gold and silver > are practically useless for surviving, except they are rare and look > pretty./ > > > That has always been true of gold and silver. Also, they are durable and not easy to fake. If there are people, there will be people who want to let others know they are rich, and gold can accomplish that. Gold ornaments display your wealth and at the same time look pretty. Beautiful, durable things can be made of gold. Many ancient economies were predicated on the trade of luxury goods and gifts between powerful people - gold is always acceptable in this role. There is gold now, and the gold now will be around in 100 years. Your people will have access to gold artifacts collected from the ruins even if they cannot mine it. [Answer] ### SALT! As per your request it: * Has actual practical use and value to people. Think of the need to preserve food and bodily need for sodium. * Is hard to counterfeit or cheat with. What can you add to salt to increase it's volume that could be created cheaply in a society like you described? Can't think of none. * Is easily transportable and not fragile * Is a a natural resource, so no need for advanced technology to extract it (Romans already extracted and used it a lot) The single aspect that it does not pass is rarity, since oceans are full of it, but depending on how common are human gatherings (cities) near oceans, it should be somewhat rare. The outstanding aspect of salt is that it is a low-tech mean to preserve food and everyone needs food during the whole year and not only when the food is available. That has value on its own and should make salt a really sought after product in your post-apocalyptic scenario, just like it was in history where [salt was used as a currency](https://en.wikipedia.org/wiki/History_of_salt). [Answer] > > All this has made trade and traveling quite hard, but not impossible. > > > Then People are living in smaller independent settlements (100-300 people), scattered, fortified. Bandits and roamers are common. Settlements are somewhat self sustaining, but still need to trade between each other - for example some are agricultural, having extra veggies but lacking meat and tools, others are hunting or fishing based, > > > You're set against precious metals, so barter is all that's left. > > Yes, but, gold, silver, they, as an exotic goods, a currency, are always connected with organized societies, be it bronze age society, antiquity or modern age... This is not the case anymore. > > > Society was organized, and there was gold and silver. Lots of it. Have them go scavenge it. > > and there is one specific settlement, based around the old University, which harbors and preserves "old" technology and knowledge, and uses that knowledge as a commodity. > > > Knowledge is not a commodity, though what it can produce is. [Answer] The most useful direction to take is to look at proto-currency. Something portable enough to carry around, yet useful enough that a community can use it without necessarily having a trader come by for a long time. Lumps of metal would be most useful for this. Little bits of workable iron or tin, weighed and shaped into ad-hoc coinage and valuable to any community for a wide variety of uses. Iron is useful because you can shape it into nails, tools, weapons, anything you need. Tin similarly because it can be mixed with copper to make similarly useful bronze, or used to patch holes in cookware, make utensils, and so on. Both are broadly useful for different reasons and a traveller could be fairly sure that they could get a meal and a bunk in exchange for a few lumps of tin or iron. Someone can always find a use for a little extra tin or iron at hand, after all. If electricity is available to your societies, copper will itself become a potentially useful currency - the stuff is expensive to use even today: one of the advantages of fibre is even that it doesn't need so much copper! And they're going to need a relatively steady stream of the stuff to replace old, worn out cables and extend the network and build generators and all kinds of things so there's never going to be enough. In future someone may begin minting coins of guaranteed weight this way and continue progress along the historic development of currency, but for your world proto-currency seems more than sufficient. --- Outside of workable common metals (which have value over scrap because they're already refined) there's also one precious metal in particular that meets both your rarity and post-apocalyptic value criteria: Platinum. Platinum is rare. Very rare. The world mining throughput of platinum is about 200 tonnes per annum. (Contrast, Gold sits around 2500 tonnes p.a.) It's also very durable: Scratching platinum only displaces the metal, rather than scraping it off. It's more durable than gold. Platinum recycling is big business, it's so valuable. It's also valuable. Very valuable. Besides consumer uses like the catalytic converters in cars, platinum is important for a wide variety of applications, such as electronics manufacture, fuel production, medicine, and the very highest temperature applications. Nevermind that not all of these applications would be possible 100 years after the collapse, if nothing else the University would understand how important it is to all kinds of old-world tech they're trying to hold on to and maintain. This makes platinum a bad currency. It's rare enough as it is, and in the post apocalypse, the University would probably try to have people killed to get hold of it. It's too valuable. But, there's a way out. Platinum isn't just incredibly valuable - it's incredibly difficult and expensive to refine. Or recycle, for that matter. Most of the actual platinum (from, say, salvaged cars or other platinum-containing scrap) won't be usable, or at least not contain enough to justify the post-apocalyptic cost of making them usable. In divided communities of less than a thousand the infrastructure necessary to do platinum recycling would be near-impossible; University might have a small scale operation but even that would only be able to handle so much at a time. Which leads to the currency - Platinum Scrap. Platinum-containing scrap is assessed (through a combination of tools and plain old knowhow) for how much platinum might be salvageable from it, and the density of it. More platinum-dense scrap is worth more than the same amount in a lower-grade collection of scrap, because it's closer to being usable (even if still impractical to actually recycle). Sufficiently high-grade (ie. platinum-dense) scrap would be especially valuable as currency, because high-tech groups like University will happily trade valuable knowledge and equipment for it. Lower grade scrap would be less valuable, but savvy dealers would have an interest in trying to process low grade scrap into higher grade scrap to improve their value. Or, for that matter, selling to people trying to get into the 'rebuilding technology' game for themselves. Surrounding this particular standard is the possibility of adding Rare-Earth elements keyed to the platinum-scrap standard, all of which have valuable high-tech applications but are useless to most factions due to the lack of viable infrastructure to effectively extract and utilise them. As with other precious metals, though, platinum-containing scrap isn't directly useful for survival. If it's being utilised at all in your setting it's likely only for research purposes and maintaining whatever technology survivors have been lucky enough to discover and hold on to for 100 years. Most of its value here comes from the demand from those few factions in a position to actually make use of it [Answer] The problem here is that you are looking for one currency. And that you are looking for currency. With the society you describe, there is little pressure towards it. There is almost no trade beyond the community level, and the existing trade will be mostly local. At community level you actually don't need much currency; rural communities in "developed" countries like England and France in the 16th, 16th and 18th centuries would seldom use money except for "imported goods" and taxes (and a part of taxes would be in locally produced goods). You remember who took three cabbages from you yesterday, so you go today to his house and ask for half a chicken. Playing the system (failing to pay debts, for example, or claiming debts that don't exist) is very hard in small, closed communities. Additionally, such small communities won't have much to trade. Survival will take most of their efforts, and whatever surplus they can get is probably not very different from town to town. Historically currency1 developed because: * A way of certifying the quality of the bullion in the currency. * A show of sovereignty; the first thing new kings (and claimants to the throne) would do was to mint money with their name/likeness. Lacking a strong authority able to back it2, there are many hurdles to any proposal. In some areas your proposal may be so abundant as to be meaningless, in others too scarce. If there are big differences between areas (as your example of a tribe settling in Fort Knox) the people in worse off areas may refuse it (why give the effort of a year of work for what, to someone else, is just getting into the vault and getting an ingot?3). With that said, an unified currency is not a necessity. You may have different currencies in different areas, with some interchange rates that are variable depending of the situation. A significant alternative for local trade could be credit based in an honor system; if a trader went to town 1 to sell A but there was nothing interesting to him there, a person of authority there could buy A in exchange of a letter (or simply a verbal agreement!) so the trader could go to town 2 and get B from another local authority (who could then ask payment in whatever town 1 could offer). And, last but not least, the need of survival would make a currency based system very dangerous. So you have a good harvest and get your boxes filled to the rim with (let's say) floppy disks. Good, you are the top dog of your village. But next year there is a drought and everybody harvests are poor. Since floppy disks are not edible, nobody gives you a single carrot for all of your savings. Since there is no honor/community system protecting, you are left to starve. Now, in the town next door, they do not use currency but they store the food surplus. When the surplus is extra (you have your stores full with last year harvest, and this year harvest is near and will be plentiful) you may exchange some of it for other goods. If the harvest is bad, you just eat your savings. --- 1 Please be aware that I am talking about currency and not about bullion (e.g. raw slumps of gold and silver). 2 And that needs currency in order to manage their taxes and budgets, because it is the only significant group of people working to grow their own food. 3 And now you are thinking "But the people in Fort Knox may keep it a secret". Well, no, because they will begin using their gold instead of farming/producing goods and people around will know that there is something fishy, even if nobody talks about the vault. [Answer] In some respects, this problem has already been solved in an environment that simulates your post-apocalyptic environment; [Prison](https://www.wsj.com/articles/SB122290720439096481). The problem that you face is that your 'currency' has to be durable. Everything you own will be useful in this kind of environment as you can't afford to keep things around that don't have some practical value. It's the durability part that is more of a problem. In prisons all over the world, things like tinned fish have been used as currency for a very long time. It bypasses the actual cash limits imposed upon prisoners, is relatively light-weight and easy to transfer, can be controlled in terms of the amount that enters the system, and most importantly of all, lasts long enough that it can be traded many times before consumed. Let's assume for a moment that your settlements have some way of preserving their food goods. Let us further assume that there is a food type that is more or less ubiquitous, preservable, and preferably not so tasty; say a food of last resort. For the purposes of this example, let's call it Dried Brussel Sprouts (DBS). These could easily become a centralised currency. If they're everywhere and can be grown at a consistent level of effort by all settlements (say 2 man days of effort per DBS) then it becomes a useful measuring stick of all production. Sure they're edible, but people prefer other foods to DBSs so they only get consumed if you absolutely have to. That means people are willing to trade them and the consistent production effort means that they have a consistent value across settlements. In the tinned fish example, durability is similar to coins meaning that the currency is easily controlled but in this case, your DBS may only have a trading life of (say) 2 months. After that, it has to be eaten or thrown away. But, you have new DBSs being produced constantly to replace them. Controlled introduction and disposal will be a problem, and as such your DBS based currency is going to be subject to more volatile inflationary and deflationary pressures than a conventional metal-based commodity currency and certainly more than a fiat one, but you're in a post-apocalyptic world; currency fluctuations are seriously the least of your problems. This would however solve your social welfare initiative issues. In this environment, you could literally throw money at the problem (the starving poor) and know that the help has gone where it's needed. [Answer] It has been said a couple times I think, but I think considering your restrictions, ammunition may be your best option. It matches all your prerequisites: 1. Obviously ammunition is exactly that, ammunition. Usefulness should be self explanitory. 2. If society has really been reduced such a dwindling population and understanding of technology then it stands to reason that much of the ammunition will have been spent between the plague (for lack of a better word) and the violent days that followed. This already gives you an obvious basis for its value. 3. Faking ammunition is relatively difficult if you actually get to hold it in your hand, much like really money. 4. Bullets and shells are relatively small and transportation is easy as filling up a box or a bag or even your pockets. They are already comparable to coins in that sense despite being a bit larger. 5. It is decently durable for transport and trade so long as the primer isn't hit by anything or they don't get too hot. 6. As mentioned above, ammunition should still be around and the function and scarcity of certain types of ammunition even give you a basis for multiple trading values depending on the type of ammunition. I imagine by that point that real bullets would be much more rare. The necessary precision to produce them just wouldn't be available unless you had a fully function factory that could make them en masse as much of that is automated today. That said, refilling shotgun shells is actually pretty easy as long as you have the appropriate propellant. Furthermore, I see no reason why they wouldn't start using muskets or black powder rifles. Many of those were made by individual gunsmiths by hand, and the ammunition is simple as filling a ball mold with lead. Taking another step down the line, anyone lacking ammunition would revert to melee weapons or more ancient projectiles like arrows and slings. Arrows are simple to make if you know how, and a sling uses any rock on the ground. In the end you could have an ammunition currency system where each type holds a value comparable to today's cash bills (not necessarily proportional to value, just an example): * Arrows = 1 dollar * Musket ball = 5 dollars * Shotgun shell = 10 dollars * Low caliber bullet = 20 dollars * High caliber bullet = 50 dollars Obviously this means that the ability to produce your own ammunition/currency is still available, but the difficulty should be reflected in the value of each ammo type. [Answer] ### Barter > > People will also say why don't they just barter, but, in a bartering system you can't really pay for someone's services (protecting, fixing, and so on). > > > Protection was traditionally purchased with goods. The local lord's men would come by and remind you how they protected you. When they left, they would take a bunch of your goods. They would call this taxation. Similarly, one would pay a doctor or even a lawyer with food (see Harper Lee's [To Kill a Mockingbird](https://en.wikipedia.org/wiki/To_Kill_a_Mockingbird) for a relatively modern example). Food (and for a traveler, a place to stay) would be a common payment for labor. Until they can industrialize, food production will consume most of the time for everyone. It will be relatively scarce. That's why our grandparents were often smaller than us. They weren't fed as well as children. Paying in jewelry is also an option. It won't work in the first few years after the apocalypse, but a century later? It will be common for jewelry to be traded. Really advanced economies might coin money (stamped precious metal discs) or even use paper money. Respected money will be used outside its natural environment. ### Prison I don't know that prison would be a good model here. Part of the problem in prisons is that they don't let the prisoners have actual money. Instead the commissary manages balances. Pretty much the only things they can trade are things that can be bought in the commissary. This includes cigarettes traditionally, as well as canned food. The better something stores, the better money it makes. But it also needs to be desirable and a little scarce. Canned tuna makes sense in a prison where it may be consumed frequently to add to one's diet and where one can store it. Post apocalypse, they can't can things and even if they could, it would weigh too much. The traveler would eat it rather than use it as currency. Food works better as a currency paid to a traveler. It would be paid from a farmer. A goat, cow, or sheep would be better, but I can't see them as commonly traded by travelers. A traveler might trade excess wheat paid by a farmer for an animal from a herder. ### Services A traveler might pay with mail. Stop in at the local general store or inn. Perhaps they have some mail that needs taken to the traveler's next destination. The recipient would be expected to pay for the mail. Sender-paid mail wouldn't work because then travelers could just throw the mail away. But recipient paid mail gives an incentive for the traveler to make the delivery. Similarly, travelers might pay with deliveries. But then the traveler would probably be expected to pay the manufacturer part of the cost of the item. The recipient would pay the the full price. Travelers might commonly use a wagon so that they could carry a bit of freight. They might keep trade goods on hand. So a few knives or pans might be scratching around in the back along with a barrel of beer, some spices, and a few pieces of mail. The beer and mail are deliveries. The spices, knives, and pans are on speculation. [Answer] The main problem, I think, with most of the suggestions made by other folks is the items they suggest have an inherent usability that might tempt or require you to use them for their original purpose as opposed to a trading medium. If a bottle of decongestant will get you five pounds of meat, but you have a real stuffy nose, you may choose to destroy the "currency" by taking it. A better common medium would be something relatively useless for any other purpose, hard to duplicate, and easy to carry. In honesty, bottle caps would make a pretty damned good one, but it's been taken. So I'm going to suggest car keys. Cars are presumably no longer a thing, and the ability to make more keys is gone. Most car keys are made of aluminum or other non-rusting metal, so they'd still be around. They're relatively rare, and save for someone finding a lost auto dealership, there won't be some massive glut driving down the market. And they're certainly easy to carry. [Answer] Aluminum Mining new aluminum is difficult, and processing ore would be really hard in your setting so you are limited in supply to what you can find lying around. Melting it down is certainly possible, but not totally trivial. It is certainly useful. It can be melted into tools, devices, weapons, what have you. Again, not totally trivial, but it is doable for someone with access to a furnace. It melts at a lower point than iron, so that helps. It's lighter than iron, and fair amounts can be carried easily. And unlike iron, it doesn't oxidize readily. Smiths with the ability to reduce scrap aluminum into bars or ingots would become the new bankers. They would be able to take scrap by weight, melt it down, and return it to the person who brought it, deducting a healthy commission, of course. Rendered bar stock or coins could be traded in your settlements, and even be taken and traded to others. Your people would be able to scrounge for "raw" aluminum, like cans, car parts, old airplanes, etc., but this would, obviously, less immediately negotiable until it got processed. The immediate area of the town would get scrounged clean pretty fast, so those who want to go find more would take their risks like gold prospectors of old. [Answer] Not one currency, but many... Reloaded-Amumunition, black-powder, primers, antibiotics, painkillers, batteries, light bulbs, seasonings, salt, sugar, nuts, hard-tack, water purification pills, matches, toilet paper, moonshine, canned-vegetables, knife sharpening stones, nails, fasteners (nuts & bolts), copper-wire, rope and dried-meat. In the future, currency must have real value and that value will fluctuate with the seller's need. Best to carry a little of everything. [Answer] I'm going to have to start by saying that you are rather confused. As others have commented, commodity currency has to be useless. So the two requirements, > > Has actual practical use and value to people in this environment > > > Durability, can't be fragile > > > are at some level incompatible. The problem is that once you start using something, you can't use it as currency, since that requires that you give the thing to somebody else. No matter how durable the object or material may be, if it is usable (and used) as a commodity, it has been destroyed as a currency. There are a few examples of usable "currencies", such as cigarettes in Europe immediately after WWII, but these also show why the idea doesn't work. If a cigarette costs a dollar, and you give someone a dollar for a cigarette and then smoke the cigarette, the dollar remains as a value marker for another trade. If you give someone a loaf of bread for a cigarette, and he eats the bread and you smoke the cigarette, there is nothing left. This is not good for exchange, when the medium of exchange evaporates. There are other problems with your scenario, and while you (as author) can write whatever you want, you don't seem to have thought things through. 100 years after the Big Dying, you want villages not to be self-sufficient in food. Veggies for meat, for instance. Let's say imported food amounts to 4 ounces per meal per person, 2 meals per day. Have you done the arithmetic? That's 50,000 pounds per 300-person village per year. Over degraded roads/paths in the face of widespread bandit activity. Well, it's easy to see how the bandits are surviving, but not how the villages manage. Other answers have trotted out the idea of using ammunition as currency. Given 100 years since the Apocalypse, this fails on so many different levels. Ignore the whole currency/commodity issue. With the population dispersed into small villages, where is the industry going to come from? Smokeless powder requires large quantities of both nitric and sulphuric acid, and those aren't exactly craft products. Where does the cotton come from? (In principle, you could use wood chips, but they have to be ground exceeding fine to allow complete nitration, and that's not easy.) How do you expect to handle the plasticization of the nitrocellulose and the subsequent extrusion? If you don't do that stuff precisely, you'll get overpressure on firing. Even worse, where are you going to get primers? They need the same sort of chemistry as smokeless powder, PLUS precision metallurgy to fabricate and install the cups. Plus, there's the whole issue of counterfeitting. Gold coins, for instance, can be checked for purity in a number of useful ways. If very pure, the classic bite test combined with weight gives an excellent quick test, while for lesser purities touchstones did quite well. Importantly, both tests are essentially non-destructive. How do you check a rifle cartridge for authenticity without firing it, which reduces its value to something near zero? Oh yes, and there's a problem with gold, too. There's just too much of it lying around. All those cities which were depopulated had jewelry shops just waiting to be grabbed. While you could simply assert that such looting did occur during the Bad Times, and the resulting hoards were lost when the looters were killed, you'd need to specifically state it. I suspect that you've confused the idea of a universal value token with currency. It's one thing to denominate value in terms of some reference commodity (in early days, it apparently started with cows), but having done so immediately produced trade in symbolic cows, not real ones. Equally important, currency doesn't become terribly useful until trade is widespread and complex. Trading a ton of wheat for 200 pounds of meat from the neighboring village doesn't require currency, but a 3-sided trade of wheat for meat for cloth spread out over several hundred miles and several weeks (due to slow transport times) gets really inconvenient when attempted by barter. Basically, you seem to have described a setup which makes currency irrelevant, and want advice on what currency to use. [Answer] Since you mentioned that that solar cells etc still exist, I'm almost surprised noone mentioned this yet: Batteries or any other kind of Power-Cell It fulfills your needs and in addition has a few additional perks that might allow for interesting ways to deal with money: * Empty power cells are only almost worthless - people with the technology to recharge them, will be quite eager to get them, so there is still some market value * Not everyone might be able to tell the difference between recharable and non-rechargeable cells * The Equipment to actually recharge cells practically becomes a gold-mine As for your other criteria * Obvious practical use, in that you can power all kinds of 'ancient tech' with it. * After 100years most old cells will be in bad shape - but some should survive * Charged cells are impossible to counterfeit, any light-bulb (or similar) can tell whether something gives of power or not. (This makes trading with uncharged cells even more risky & suspicious) * Relatively small & not too heavy * Durability might be the 'biggest issue', they wont fall apart but you shouldn't get them wet etc. [Answer] Seeds Settlements of any size will need to grow food in order to survive. The ability to plant crops of edible food is imperative, as humans cannot live on the nutrients from meat alone. Hunting is time consuming and can yield in quantities that might not be sufficient to survive on. Even a primitive society can reliably plant and tend crops of fruits and vegetables. A more advanced society can increase that output, as well as grow food year round. Seeds of edible crops are small and easy to transport. Depending on the seed, they can survive unplanted for a long time. Some seeds, like beans, peas, tomatoes and carrots, can stay viable as long as four years. Seeds like cucumber or lettuce can stay viable up to six years. The rarity of a particular seed could make it far more valuable than another. Berries, which grow natively in the wild, would likely have a low value. However, tomato seeds, which are not native to Europe, would be much more highly coveted, and therefore more valuable. [Answer] What does something need to work as a medium of exchange? 1. It needs to be durable. Money that decomposes over the winter, or shatters if handled roughly, or can be eaten by termites isn't much good. 2. It needs to be scarce. Sand may be durable, but it still doesn't make a good currency, because anyone can go out and pick up a handful. 3. It needs to be resistant to counterfeiting. If it's easy for the average person to make copies of it, the above-mentioned "scarcity" requirement fails. 4. It needs to be fungible, ie. it's easy to judge the value of one unit of the currency against the value of another. This is where the commonly-suggested "information as a currency" falls down: it's virtually impossible to judge the worth of a piece of information. Gold would make a pretty good currency here, but you've decided that you don't want it. One interesting possibility, though, would be for the University settlement to issue "work credits": tokens that can be exchanged for a certain amount of research effort by the scholars there. Theoretically, any of the settlements could do this, but the University is best-positioned to make tokens that are hard to duplicate. Durable? Stamp them into steel, or print them on parchment, or otherwise make them out of something that will survive normal wear. Scarce? The University controls how many tokens are in circulation. Counterfeit-resistant? The University probably has some tech that nobody else does. Fungible? An hour of research is an hour of research. [Answer] How about jewelry? Gold wedding bands for example have to be something you can find all over the western world, they're portable, wearable, you can thread them on a chain or keep them in a bag, they'd make great trade-goods even if you don't recognise them as de-facto currency. They come in a fixed size and their value can continue to be estimated on the old Caret standard. The metal is already worked and shaped and has a strong association with value from the get-go, If you need it to have practical utility, most of the various "jewelry" metals like Gold and silver are excellent electrical conductors and easily shaped. So they'd be potentially very valuable for maintaining any electrical hardware. Attached to that, you can play with the idea. These rich little kingpin characters of their own fiefdoms entirely covered in old-world bling and chains. Wearing their wealth literally on their sleeve. Echoing the Gangstas of the pre-apocalypse in a kind of twist on the spikey post-apocalyptic punks we normally get fed with Mad Max and Road-warrior. [Answer] Why not use the American colonies' first common currency: whiskey? Back when states were issuing their own currency, many people found it easier to conduct business using whiskey than go through the hassle of trying to change coins or banknotes from another region into something accepted locally. Whiskey is durable, useful and easy to subdivide into whatever amounts you might want (anything from a keg to a shot). It's easy to transport and difficult to counterfit. It's also tricky enough to make that you don't run much of a risk of someone producing so much that they devalue the market. [Answer] I have a suggestion? Iron. It has utility, a set value (need x amount for y product), and it can be broken down to easily portable bits. Example, it takes about 2 lbs of iron to craft a decent surival style knife (iron not steel) and if i have a pound of iron i can trade that as currency for about half of what i could get for bartering that knife... Give or take a bit for variance in the barter system that would be predominant locally in a setting like that. True Aluminum. Not alloys. Real aluminum is "pretty", useful for creating basic steels, and incredibly light for its strength. Pound for pound its stronger than steel, and rarer (assuming you could find aluminum foil in this world, now you have to make it into useable ingots.) If you doubt the use of aluminum, wiki it... You'll be surprised. [Answer] Items of practical value which would be of use are not currency. They are barter items. Barter items can ACT like currency but if they are of use there's a tendency to USE them, and their value disappears. The hides that you speak of were mainly used as currency out west in the United States because there wasn't ready money out there, and they were to be converted to cash back east where there was a use for them (shoes and other leather goods). When hides were used with a fixed value in rural communities, they were as much a barter item as they were considered money. The best suggestion I have seen on here is keys from @VBartilucci. Everyone, upvote @VBartilucci because I can't take credit for this idea! I'm going to just use that as a jumping off point. Old keys could work, and even if you made new ones, you'd have to have aluminum to that, which would mean something like old soda cans and other things would instantly have value. There may be rare places and machines that can machine keys, but they would need the raw materials to do that. Aluminum IS useful...Keys are also useful, so if you did have a lock made for something, and a key to fit it, that would be your last key. I can see that seeping in culturally. "Man's down to his last key, if he trades that away, he can't even unlock what he bought before." (Might just be symbolic, might not even unlock anything, could be passed from their father or mom). The last key might be a simple one, like keys from several hundreds of years ago when lock mechanisms were simpler or even a tiny key to a music box, or a faux golden key jewelry--mostly anything that doesn't look like the standard machined key from our era. It may or may not actually unlock something. They may be less valued than the obviously machined ones from the time before, because they are easier to make. But I would view anyone who has a lot of these types of keys with suspicion as I think that it would be something that a person would not give up except in death. These might be made of any material because they wouldn't be something you would want to trade away. Were I the University, I would be machining keys with the sigil of the university. Keys might be used commonly in the larger area, but I can see a currency exchange program--you bring in common keys, and you get University keys of equal value (perhaps a little less owing to exchange rate). And University keys are the only accepted currency within the township. Counterfeit Test is a simple magnet. Try it at home with your own keys. Aluminum doesn't attract a magnet. Iron, nickel, cobalt, gadolinium, neodymium and samarium are magnetic. There's going to be a lot of old iron laying around but things like gold, copper, silver--none of those attract a magnet. Those three are relatively rare compared to the other metals, so even if they are used to make keys, it's still a way to trace value. As for keys being "faked" the level of tech you're talking about is low, and the skills and equipment needed are specialized, so anyone making machined keys will be making a limited amount. Ammunition would be much, much rarer than keys, and harder to make. While it can be faked, it's also very useful (if you have a gun). But this means that ammunition isn't money. It's a barter item that could be used to trade for currency (like keys) or other items. How much use is ammunition if there aren't that many guns? And if you have a gun that takes rare ammunition how much use if that gun? As others have pointed out, checking for authenticity of bullets uses the bullets... Batteries look like a good idea, but after 100 years, well... [Answer] Certain books. The kind that teach how to build stuff. How to make concrete. How to build a forge and make tools. How to make gunpowder and a alcohol still. How to fix a car and how to make a electricity generator. Even today, these books make a very small percentage of the total amount of books. Libraries are full of self help books about building a positive image for yourself and how to deal with depression. Not so much with books about tanning a hide from hunted animal, or making electricity from a river. Add 100 years of decay and ruin, and paper books of this kind will be near impossible to find and treasured as a important resource. One that is lighter than metal, so its easy to transport. Has lots of value and everybody wants it, so its easy to exchange. The Old University can trade in tech because it can produce books, copies in fact, adapted to the new reality, short, practical versions of the originals. The "secret" tech of the Univerity is paper making and a human powered, Gutenberg like, printing press. The University is realeasing a very limited amount of books because keeping the supply low makes books more valuable and The University relevant. [Answer] You are looking for something exotic, light, possibly useful. As a currency, you need something that cannot easily be faked or duplicated, but is available in large enough quantities. I offer pre-apocalypse ammunition. Bullets require metalworking that will not be available anymore, they are light, plentiful but in limited supply, and since at least some firearms certainly survived as well, in a life-or-death situation you are faced with the interesting choice of using your bullets or keeping them so you can later buy things.(\) There are even different types of ammunition that can have different values, so you can circumvent the usual "bottle caps" or "gold coins" problem (ever had a D&D character hauling around 50,000 gold coins? --- (\) a hundred years is a stretch, but ammo kept in good storage conditions can last decades. Under optimal conditions, a century is possible, though misfires and duds would be common. [Answer] What about cigarettes? They're portable, have a practical use for those who like to smoke; and you can use cigars as a more valuable "bill". They're not too durable but they're durable enough if you keep them in a bag. More can always be produced and i'm sure theres still some cig packs around from the old world. [Answer] [Pachinko](https://en.wikipedia.org/wiki/Pachinko) balls. Small, durable, hard to manufacture. Useful as ammunition in slingshots, with added benefit of being reusable if you dig them out of the target. Can be used as ball bearings, etc. Only downside is that these are only abundant in Japan. Set your post-apocalypse in Tokyo and you're set. [Answer] Medicine More specifically, general use antibiotics, especially in tablet form. * Small and light to carry. Easy to count the tablets, or trade by whole bottles. * Remain usable for a long time. Even though they will gradually become less effective, [many types will last more than 10 years](https://articles.mercola.com/sites/articles/archive/2000/04/02/drug-expiration-part-one.aspx). * Are very valuable: bacterial infections will be quite common in a world with general lack of hygiene and healthcare. A dozen antibiotics tablets can save your life. * You'd generally want to keep some with you even if you don't currently have an infection. Thus, most people would be able to pay if desperate enough, and would be happy to get some more tablets as a payment. [Answer] ### Days or hours Everyone can do something. Time is not something easily broken or stolen, some people have more valuable skills and would get more out of their time obviously, but that plays well to the nature of currency exchange. People would trade days or hours of their own proficiency and skill. Some would trade chits for the days of others and become wealthy making good exchanges. The chits could vary from place to place easily without diminishing the value. A simple and visible penalty like a scar on the arm could easily be given to one who 'stole' by not providing service, not unlike cutting the hand off a thief, but a clear sign that... this person with five on their arm may not be trusted to be honest. There's room for abuse and theft, which is part of a rounded system while still having broad use. Different villages could easily have community boards, they might have entries like "five days of cow milking and one day of manual labor work in exchange for a winter blanket, see the local chitmaster to claim" or "woolen undergarments for the winter, prices vary from three hours housework (socks) to many available days work needed for more extensive wardrobe additions, speak to Bob at the Inn of Shepherds or his wife Jill to claim" [Answer] Ground Spices Especially medicinal ones like Sage, Thyme, Oregano. Useful for flavoring food and for antioxidants and antifungal/bacterial properties etc. [Answer] What about pages from books? Wouldn’t have much tactical value but they would be hard to come by and people would desire them, plus if they were from a technical book or something they would be even more valuable, and you bring one book with you and you can pay for a lot. [Answer] Assumption: Barbaric Overgrowths With the natural setting of your world, I bet a lot of plants and animals became a lot more savage. This means animal domestication and plant eugenics would be pretty hard to accomplish for the first few generations. This results in food itself becoming such a rare commodity, considering that many canned goods would have spoiled already after a century. Assuming your people remains the same meek humans of today, we'd be better off living like ants, scavenging the scraps of our angrier fellows. But that wouldn't be sustainable. We'd turn into filthy wretches if we don't become savages ourselves. Idea: Scarcity = Profitability So there. We're about to run out of food sources because creatures that used to taste good are becoming more and more lethal everyday while the stocks of mass-produced goods from the better days are becoming inaccessible due to wilderness if not outright expired. Backstory: Genetic Mutation Origin Fortunately, the Svalbard Vault, the tartarus where the genetic anomaly originated, also spreaded heavenly blessings. The melting of the polar ice caps unleashed ancient microbial horrors more potent than any plague we've ever faced. And with a nicely prepared catalogue of "what's new in biology", those horrors had the perfect library to learn the ways of the world as we knew it back then. And upon learning the strengths and weaknesses of the very foundation of our food pyramids, they gained on us, infecting every living creature that relied on autotrophs one way or another. Justification: Seed Vault The seed vault we so preciously guarded became the breeding grounds of death. But even so, life finds a way. All is not lost. Some seed vials are completely unaffected, but they were scattered across the world. The rising sea level carried the lucky seedvials after the seed vault got breached, drowned, and exploded. These seedvials can now be found everywhere a human settlement can be found. Somehow, the immunity and the luck of the plants grown out of those seeds can pass on to whoever eats them, giving humanity another chance at life. The people who found these washed up seedvials are most probably the only ones that survived the plague. Actual Answer: Seed Vials As the plague forced nature to evolve very fast, humanity was left out. Our very immune systems failed to save us, and now the very things we need to live are dwindling - most specifically, food. They say there are fruits grown somewhere in some rainforest, or crops farmed in some island, and some wheat and vegetable just right beyond the beach. There's even rosewater being sold in some tavern. I bet those are all plants bred out of those seed vials. I also unearthed seed vials of my own, but can't seem to grow anything out of them, and my vial is running out of seeds. I wish I can trade my remaining seeds at least for some food to last the week. Hopefully, I can also save some of the seeds of some of the food I could buy, so I could trade them for more. Maybe I can ask people to collect seeds for me if I can grow enough plants for them to also eat. Just maybe. But for now, three seedvials containing fruits, crops, and wheat can buy me some rosewater. TL:DR: Plant seeds from before the 22nd century became a form of currency because they contain an ingestable "immunity" to the genetic mutation. Plus, the plants that grow out of those seeds are the only edible things in this world. Farmers are practically billionaires. [Answer] Well, settlements ne ed to grow edible plants and breed edible animals. So corn, potatoes, tomatoes, cucumbers, chicken, cows, pigs, horses. Sometimes deer, boar etc... For hunting and fighting people would use something that cannot be depleted or can be easily refilled. Say goodbye to guns. People would use Fiskar tools sport bows and crossbows made from aluminium titanium or carbonized alloys from prefall era. Also improvised handcrafted weapons. Any other goods can be subject of trade. Luxury goods, craft goods like baskets, plates, cups. Hard to get herbs for healing. Seasonings, salt. Maybe dried meat. Products of farming :dried mushrooms, corn, wheat, rice. Jewelery. Some prefall era nondecaying things like plastic bottles canisters. Scavenged medicines, basically anything that would make your life better. But in a society this small you cant afford to rely on someone else. The things necessary for one settlement to survive must come from that settlement. Otherwise people would just pack up and move their asses somewhere greener. One currency isnt a good idea a) it attracts unwanted attention 2) is just added weight with no real purpose. But if a hunting party comes to town with lets say 50 pelts, i can imagine people will be grateful their asses Dont get all icy during winter and would happily share some food surplus in exchange. You need to choose whether your society thrives to better future or declines to oblivion as common currency is usually a thing in a thriving culture. Also human work will be on demand. It was usually a thing to get paid in food or bed for your work. Grandma needs new roof? Great you've got yourself a meal and bed for a few nights . Sorry for my english, its not my native language plus Im lazy to go all Oxford on my smartphone :-D [Answer] Rare Earth Magnets Useful in generating electricity. Impossible to make post-apocalypse (materials and manufactory capability). Easy to test (have iron?). Not divisible, however. Last a decently long time. Ceramic, so shatterable, but not rusting out. May be too rare. ]
[Question] [ [Medieval bestiaries](https://en.wikipedia.org/wiki/Gold-digging_ant) describe a creature, a type of desert-dwelling ant that digs for gold. It was also said to be the size of a fox, but I'll ignore that in this question. Why would ants unearth pieces of gold? What evolutionary purpose would this behavior serve? [Answer] > > Why would ants unearth pieces of gold? What evolutionary purpose would > this behavior serve? > > > # It makes their chimneys work better. The workers gather the gold and bring it to the colony. The soldiers use their large powerfull mandibles to shape the soft gold into roughly flat flakes which they distribute around the nest site. The gold's reflection of the sun's light and heat in an upwards direction has two effects: * It heats the chimneys, encouraging convection and allowing air circulation around the ant's farmed food source - the fungus below. [![enter image description here](https://i.stack.imgur.com/FlpNF.jpg)](https://i.stack.imgur.com/FlpNF.jpg) Attribution BBC 2019 * It reflects the heat off the surrounding ground, allowing it to be cool - enabling the underground tunnels used for farming the food fungus to expand and grow and thus the colony to be bigger and more succesfull. [![enter image description here](https://i.stack.imgur.com/dMzRQ.jpg)](https://i.stack.imgur.com/dMzRQ.jpg) Attribution: Darwin's Toolkit by UW–Madison CALS 2019 [Answer] They don't value the Gold - They expel it from their burrows What use is a shiny metal to an ant? They don't make artefacts or have currency. They don't have an aesthetic sense apart from food. The ants line their burrows with a sticky substance they produce from their rear ends. Obviously a lump of gold is an obstruction to the building of their underground kingdoms. They discard these annoying lumps of useless metal by bringing them to the surface and abandoning them there. If humans remove this refuse then so much the better. [Answer] ### Electrical conduction Gold is a good conductor. Perhaps these ants use electrical pulses (rather than pheromones) to communicate in their nests. So they move the gold so that there are paths wherever they need them. They might also evolve special "router" ants that serve as junctions between paths. So the central pheromone unit (CPU) can send pulses that only reach specific sets of ants. Each ant could be identified by an instead of pheromone (IP) number. [Answer] The ants are giant packrats! The gold digging ants are not typical ants, <http://blogs.getty.edu/iris/the-monstrous-ant-of-the-medieval-bestiary/> > > There are also ants that, according to some bestiaries, live in > Ethiopia or India, are the size of dogs, and dig up gold from sand, > guard it, and pursue anything that tries to steal it, especially > greedy humans. Artists depicted these ants not as larger versions of > the familiar-looking insects, but more like actual dogs. > > > [![enter image description here](https://i.stack.imgur.com/lzBzY.jpg)](https://i.stack.imgur.com/lzBzY.jpg) <http://www.terrierman.com/goldenant.htm> > > The mountain ant > > > In ancient Persian the word for marmot was "mountain ant". And the > mountain ants do indeed dig up gold on occasion. > > > <https://www.nytimes.com/1996/11/25/world/himalayas-offer-clue-to-legend-of-gold-digging-ants.html> > > Now a team of explorers says it has solved the puzzle. The explorers > believe they have pinpointed the land of the legendary gold-digging > ants and the people who profited in one of the most inaccessible > regions of the Himalayas along the upper Indus River. > > > They say the outsize furry ''ants,'' first described by Herodotus in > the fifth century B.C., are in fact big marmots. These creatures -- > Herodotus calls them ''bigger than a fox, though not so big as a dog'' > -- are still throwing up gold-bearing soil from deep underground as they dig their burrows. Most important, the explorers say they have > found indigenous people on the same high plateau who say that for > generations they have collected gold dust from the marmots' work. > > > Here is a colony of these big marmots. [![marmots](https://i.stack.imgur.com/5hYKl.jpg)](https://i.stack.imgur.com/5hYKl.jpg) <https://www.kathmanduandbeyond.com/feeding-himalayan-marmots-ladakh-india/> But these marmots don't care about the gold. They just bring it up. Why would a rodent care about shiny gold nuggets enough to hoard them and even fight for them? There is one rodent that does. Packrats! <https://nuggetshooter.blog/2018/01/31/pack-rat-gold/> > > That morning as the horse and mule were loaded Tucker noticed a hole > in his saddlebag with gold dust spilling from it and cussing that rat > for chewing into the bag he began unpacking to save his precious gold, > but it was gone…Only the fine gold that hadn’t spilled from the pouch > into the saddlebag after being chewed apart by the packrat remained. > All of the nuggets were gone as well as his pocket watch, and other > objects small enough for the critter to haul off. > > > So: your "ants" are colony dwelling, burrowing rodents with a packrat-like habit of hoarding neat things, especially shiny things. In the above linked article, the prospector who lost his gold to the rat spent several days digging into burrows trying to find the one where his gold was, without luck. The article concludes by speculating that in an area naturally rich in gold nuggets, resident packrats might accumulate nuggets over time, giving rise to nugget troves in ancient rodent dens. I am not sure a marmot would charge a guy with a sword like the ones above are doing but I would not want to test them. They are pretty big one at a time, marmots. --- @chasly from UK pointed out that this answer does not cover the evolutionary angle; true. And a downvote for this lack - horrors! I was unable to find any thing written about why packrats might favor shiny things for their nests. I have taken this speculation on myself. 1. Packrats like to incorporate shiny things into their nests - this is well known. 2. Packrats like to use old nests if they can find them. It makes sense - if a nest has long been inhabited that means it is a good place for packrats. Plus older nests are more substantial, in part because of... 3. Amberrat. <https://www.flickr.com/photos/centralaustralia/8419933870> [![amberrat](https://i.stack.imgur.com/yeAxs.jpg)](https://i.stack.imgur.com/yeAxs.jpg) Rats and especially packrats urinate onto their nests. Over time the accumulated urine can crystallize, cementing the nest material together into shiny masses called amberrat. These cemented nests are durable and of use to paleontologists, as the preserved materials record eras past. Thus we have selective advantage for rats that like old nests, and old rat nests tend to be shiny. This could mean a selective advantage for rats who like shiny nests. Such rats will make their nests shiny if given materials to do so because they like shiny nests. Gold nuggets are definitely shiny. Thus - selective advantage for "ants" that seek out gold and incorporate it into their nest. [Answer] I cant find a good source, but gold found in streams are supposed to be created by bacteria that are allergic to gold. They use mechanisms to make the water stop retaining the gold so it drops to the floor of the riverbed. Your ants have larvae that are allergic to gold. They might not die from it, but its not good for them. The ants have evolved to actively dig up the gold and drag it to specific area's where larvae will not be living, and the ants who do the digging and dragging will avoid contact with larvae and ants that care for them. Edit: found source. <https://www.businessinsider.com/bacteria-creates-microscopic-gold-nuggets-2013-2?international=true&r=US&IR=T> [Answer] They live on a planet close to an X-ray star. A layer of heavy metals in their integument gives them some resistance to radiation. They were engineered this way by a race that lusts for gold. The ants actually eat it, dissolve it in an internal equivalent of Aqua Regia, and plate it out on their integument. The original species was much less discriminating and would use lead, cadmium, platinum, osmium -- almost any heavy nucleus. Periodically the engineers land and release a pheromone that brings the ants to collection jars where they are flash burned, and the metal taken for further processing. [Answer] Sex First, I'll assume that, as per other answers, we're not actually talking about ants, but rather large(ish) mammals. Rather than take the packrat route, let's go with bowerbirds. The males build elaborate courtship structures, and decorate them with colorful objects. The satin bowerbird, for instance, is partial to blue. So, if a species of "ants" has females which are partial to shiny, males will collect and display shiny objects - such as gold nuggets. Furthermore, deep digging which brings up pieces of gold will also be selected for. It's amazing the number of behaviors which can ultimately be explained by sex. [Answer] # Gold helps with their Farming They don't bring gold to the surface and "throw it outside", but they could bring it into their fungus farms, where it could either: * Repel harmful bacteria or organisms that would otherwise harm their farms. * Attract & grow beneficial bacteria or organisms. Some metals in our world exhibit an [oligodynamic effect](https://en.wikipedia.org/wiki/Oligodynamic_effect) ("a chemical substance or microorganism intended to destroy, deter, render harmless, or exert a controlling effect on any harmful organism by chemical or biological means" [[1]](https://en.wikipedia.org/wiki/Biocide)), including gold. > > [Apparently stainless steel is terrible at inhibiting bacteria, while brass would be much safer, in a hospital for example](https://archive.is/w95SW). > > > Some ants in our world have been [farming fungus](https://www.youtube.com/watch?v=5an0djjJz_g) for millions of years, and apparently some people are wondering how they manage to avoid devastation by disease or parasites (like what happened to the [Big Mike bananas](https://en.wikipedia.org/wiki/Gros_Michel_banana)). And so in this other world there could be ants that farm a particular type of crop that either thrives on or around gold, or the gold repels a particularly nasty organism that would otherwise devastate their crops. [The gold might not even affect their crop directly, but could be a link in a chain, like preventing a bacteria that would feed another fungus, that would feed another organism or predator, that would destroy the ants' crop or the ants themselves. Imagine a truffle-hunting pig (or elephant) that destroys everything in it's search.] [Answer] It's a result of Darwinian evolution. Ant colonies that expelled gold to the surface, for whatever reasons, naturally attracted humans to them. Humans have a proclivity for carrying food and water with them when they journey through the desert. Gold-laden dirt would be relatively heavy, so humans intending to collect the dirt and return it to civilization for refining would tend to leave an equivalent amount of mass behind. This jetsam would frequently contain consumables such as food and water that would no longer be needed due to the interrupted travel plans of the fortunate discoverer. Those ant colonies would be more likely to successfully spread deeper into areas of desert that would otherwise be too inhospitable for them. [Answer] ### Dummy gold war They are exceptionally clever ants. When they find gold, they plant it on the anthill of they enemy and wait for a human to see it and destroy their enemy. Very effective. [Answer] > > Medieval bestiaries describe a creature, a type of desert-dwelling ant that digs for gold. It was also said to be the size of a fox, but I'll ignore that in this question. > > > Their large size is the key. These very large ants will only dig their mounds out of the sides of mountains, hills and cliffs. The geographical area contains a large deposits of quartz over several square miles, and there is less chance of a tunnel collapse inside a quartz mountain. Gold is found in quartz deposits, and the ants can dig out the gold far easier than quartz because it's a soft metal. So where there are ants, there is gold by the entrance to their quartz caves. [Answer] Ants (of any size) communicate largely through pheromones - everything from mating to directions. As it happens, these ants also communicate through pheromones, but something about properties unique to gold either scrambles or removes the pheromone signals. Instinctively realizing that gold, therefore, is quite dangerous, the ants would thus attempt to remove the gold from their burrows, and depending on the strength of the effect, they may even hunt for gold and collect it to keep from being influenced. Normal ants often have "garbage rooms" where they store their dead, as well as other garbage produced by the hill and its occupants, which would make a fine place to store excavated gold. They may even try to protect this gold, as their instincts have taught them that other creatures can use the gold to disorganize them. [Answer] It is possible to train ants. For example, these articles mention doing this incidentally to their main line of research: [Desert ants do not acquire and use a three-dimensional global vector](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1868725/) [Ants on stilts](https://www.sciencenewsforstudents.org/article/ants-stilts) Training them to collect things is admittedly a bit of a further stretch, but it isn’t totally outlandish. By the way, the legend stretches way back into antiquity, long before the middle ages, to at least AD 79, in Pliny’s [Natural History Book XI](https://en.m.wikisource.org/wiki/Natural_History_(Rackham,_Jones,_%26_Eichholz)/Book_11), section XXXVI: > > The horns of an Indian ant fixed up in the Temple of Hercules were one of the sights of Erythrae. These ants carry gold out of caves in the earth in the region of the Northern Indians called the Dardae. The creatures are of the colour of cats and the size of Egyptian wolves. The gold that they dig up in winter time the Indians steal in the hot weather of summer, when the heat makes the ants hide in burrows; but nevertheless they are attracted by their scent and fly out and sting them repeatedly although retreating on very fast camels: such speed and such ferocity do these creatures combine with their love of gold. > > > ]
[Question] [ I know its questionable whether such an entity could exist, but if there were entities big enough to be mistaken for a planet, how could it reproduce? Would two collide and recombine into three or would it be in a nebula? [Answer] If the creatures can be mistaken for planets, then by [duck typing](https://en.wikipedia.org/wiki/Duck_test), they must have [the following properties](https://en.wikipedia.org/wiki/IAU_definition_of_planet): * They orbit stars, * They have sufficient mass to assume hydrostatic equilibrium (a nearly round shape) * They have "cleared the neighborhood" around their respective orbits. This means that they cannot copulate by physical contact. The different orbits would necessitate prohibitive Δv's, and if they did come close they would collapse into a new, larger body. Therefore, the only way for them to reproduce is to send gametes or spores into space. The absurd size of space would make gametes unfeasible. Check [this video of Dr. Becky explaining why when galaxies collide, no star collisions take place!](https://www.youtube.com/watch?v=_dZUNAZI2eg) The probability of two gametes meeting within the lifetime of a galaxy would be practically zero. So the only feasible option is spores. The planet would shoot out a spore with enough speed that it would exceed its star's escape velocity. That spore will travel the galaxy until it finds a nebula or proto-sun being formed. In the case of a nebula, its passage may precipitate star system formation. Once in these places, the spore will grow into a planet [through the usual process of accretion](https://en.wikipedia.org/wiki/Accretion_(astrophysics)). [Answer] A different take on Daron's answer: They play god--guided evolution. All that junk in our DNA? Some of it is actually the genetic material of the planet-beings. The sentient star travelers are the gametes. [Answer] Hitch a ride on Spaceships. Renan mentioneed these creatures cannot possibly make physical contact and live to tell the tale. The answer suggests spores, meaning much smaller particles that get shot off the surface to find other spores in the depths of space. Problem: > > Space. Is big.[[citation needed](http://en.wikipedia.org/wiki/Wikipedia:Citation_needed)] > > > Solution: The reproduction strategy relies upon sentient life evolving on the planet, then inventing space travel to find other sentient life. The spores piggyback on the spaceships. Of course this might take a very long time. But the creatures live a VERY long time. [Answer] Homing sperm shuttles Planetids have a mating cycle. For ten thousand years they listen on the radio waves for mating songs, and send out enormous rocket-propelled winged gametes in the direction of whichever nearby star has the planetid who sings the most beautifully. Then they stop, and sing their own song for ten thousand years, while another planetid's love dart follows their voice across the void, through the solar system, into their atmosphere and glides right into the most intimate organ hidden delicately under their radio antennae. A mere dozen years later, a hundred rocket-eggs are launched into the void towards any nearby stars that have no song, each the size of a large building. A few of the larvae that hatch from these eggs ten thousand years later may be lucky enough to find enough light and tasty tasty asteroids to grow into planetids themselves. By that time, their mother has already started making love darts again. [Answer] ## Division. Some bacteria and other microbes reproduce in this fashion when they don't require a mate. There are many forms of Asexal reproduction that would work. Self-cloning through pathogenesis, cellular division. When there's no chance of a mate or finding one, using its own genetic material to reproduce would be the next logical evolutionary trait. ## Mating "grounds". Now, this would be a simple area of space where the Spheres would come and deliver their genetic material into space, covering several hundred AUs if they have a reasonable population and go on their way every few thousand years. Male and females would do this and sooner or later, the genetics would combine. the newly forming planets would no doubt go rogue at that got bigger, sending them on their new path. [Answer] # Intelligent Design Perhaps these sentient planets are intelligent enough to design their own descendants. They don't need others of their kind to reproduce. Imagine that they can, through some sort of delicate telekinesis (or other way) design their own children at the molecular level. Once the child (or children) is developed enough to live on their own, they are released into space. This could be done via shooting them into space, extending a tentacle into space, telekinesis, teleportation, or simply by the original mass exploding and releasing the children. There might also be a way of a sort of sexual form of reproduction: perhaps two or more of these gigantic creatures consult with one another about the various possibilities. They don't need to exchange matter, just information. I don't think you'd want a grouping of more than three, because who wants their children designed by a committee? :) [Answer] First I'll write a hand waving answer, then the most probable answer which others have also discussed. The hand waving way. The planet has some kind of internal clock, and some very advanced knowledge of quantum gravity. The reproduction process means writing some information that tells the children planets how to grow and how to reproduce themselves. The information is written in the form of global symmetries or topology of some "seeds", lumps of matter, of size and composition determined by the needs of the story. Suppose that growing of the planet is done by shooting wormholes into space and accreting mass from stars, gaseous planets or just asteroids. For that, one needs energy which is obtained by all the means that are available to us, humans, plus some. When the planet reaches a certain size, the clock tells it it's time to reproduce. In its case, that process has a few stages: * Shoot a wormhole to bring hot plasma from a star. * Bring the plasma to some fusion chamber inside the planet core. * Use the energy to create a few small black holes and keep funneling matter from the star to keep them gaining mass until they are big enough to not evaporate immediately * Write the genetic information on the black holes by just sending the data (the seed) beyond their event horizon. The information needs to be symmetry, or topology protected so that it's not radiated back by the black holes. * Shoot a new set of worm holes and connect each black hole to its own worm hole. * Use the energy left to push the black holes through their worm holes, effectively turning them inside out. Such process should normally generate just Hawking radiation, but, you can hand wave some Higgs wormholes, which do not allow for that to happen, and would allow for a percentage of the black hole mass to turn into massive particles. * The particle cloud contains the genetic information encoded in some global symmetry properties that the original black hole had. Over a few million years it condenses to some planet, and this is where it turns out it was a good idea to let it be captured by some star. * The new planet just grows to become a similar life for as the previous planet, provided no disaster (asteroid or supernova) happens before that. * The old planet is a husk now, which looks just like some cosmic dust cloud, but it still contains its genetic code. Provided enough dust floats its way, it may condense again in a live planet, which is why these life forms are so dangerous. Closer to the science we know. A planet size could simply send something akin to a spaceship to the nearest useful planet and write its genetic code, or whatever its equivalent is on that other planet. The ship would be some kind of Von Neumann machine which would contain all the genetic information from the old planet as modules. Each module would consume matter from the host to create more units according to the information. Once enough modules have been created, you could have them merge into one entity. The whole process will probably take billions of years, but, at the end, you would have a new grown planet similar to the old one, but different because of different materials that were on the original planet. This is more or less how we want to duplicate Earth using other planets. We call that process terraforming. Terraforming may take a lot of time, if our modules are just some bacteria surviving the crash of our colony ships. [Answer] What is life? If life is “reaching a certain complexity level” + “being able to reproduce” then once machines reach certain complexity level, and can reproduce in any way. They can be considered life. We are made of thing found in the same universe after all, and must use those things to survive and reproduce. Other answer suggested a very interesting possibility. We, humans, have a fixed reproductory mechanic, dictated by evolution of known life. If you can make the concession of accept a planet size machine as something complex enough to be, in a practical sense, a life form, then you gain some fancy possibilities. As the other answer suggested, this life form doesn’t have to passively accept a fixed reproductory mechanic, it can use its "intelligence" to design an improved version of itself, and that improved version will in time design and improved version of itself, and the loop goes on until universe ends. If you want your entities to look biological, there is no problem. A complex enough entity, no matter its ancient history, will probably be indistinguishably from biological beings. Elements like carbon are very abundant in the universe. Any "intelligence" will notice this sooner or later, and may choose to design their children to be made of these easy to mine elements. They may prefer a good compromise of repairability plus resistance versus a higher resistance. Examples of from electronics to biology in fiction: we have Battlestar Galactica (the second series, not the older one) that can be watched on Amazon Video. The worldbuilding has many holes, and the process of transcending to biology isn’t explained, obviously. My point is that the idea isn’t new. Is ADN the first and definitive space colonizing entity? Also suggested in another two answers. A real hypothesis, maybe theory, that you can find in the internet. While some bet to the primordial soup (Miller Experiment), others bet on panspermia. But, how panspermia actually happens? The simpler life forms are the ones that have the higher chances of surviving a space odyssey. Consider extremophiles. They don’t even require to be radiation resistant (but that would be welcome too). They may use structures present in some asteroids to guard themselves. They can continue metabolizing using things found in the asteroid, gases and other bacteria. The loop would be like this: * Life evolves in an Earth clone planet. * Asteroid or anything else destroys that planet. * Some fragments carry life out of that solar system. * That life survives long enough to colonize other planet. * 0,00005% chance of evolving to reach civilization. * 0,000000000005% of civilization reach required level to not leave it to chance anymore, then they develop a super bacteria that will improve previous step, on next loop iteration, in a 200% or 400% (and accumulates on previous iterations, it doesn't start at original value). * Repeat. And my favorite fantasy: after millions of iterations, a civilization finally found a way to preserve not only life, but to ensure that life will reach civilization. And finally, a future civilization finds a way to preserve knowledge, or ensure the knowledge that matters will quickly be rediscovered. While you may argue that "knowledge that matters" implies bias, and that may be better to not reach that point. My answer is not about if it is good or not that those people will do that, but that there is a high chance that they will do that. Let's hope it's a good bias, if such thing exists. [Answer] Via explosion. The planet-sized being has a structure that allows reactions which result in a two or more component explosive. It could also be nuclear fission or fusion. The components are accumulated until the being is ripe for reproduction. Before reproduction, i.e. explosion, the internals arrange such that children get everything needed and that children are shot onto orbits favorable for growth. Children grow through collisions, which keep its constituent "cells" unharmed. The energy for some processes can come from a central star, but the planet beings could also form a system without an overly massive central member. [Answer] I think that the answer is dependent on how the planet sized creature grows. If the creature began its life cycle as a clonal colony like Pando, and matured as it encompassed the entire biosphere of its host world, it could be considered to be a planet sized organism. If the organism's seeds or spores were sufficiently able to hibernate and were sufficiently impact and radiation resistant, they could migrate across solar systems via panspermia. Throw in a bit of the trees from Avatar's Pandora, or the chemical networks in The Uplift War, along with the ability to observe nearby asteroids and you have a plant based intelligence that could gather reproductive material in regions likely to experience a meteorite. [Answer] Certain plants can live for years, flower once, then die. Yucca and Hens & Chicks are two examples. Certain fungi have far more than two sexes. Not all are required to form a new organism. Lots of bacteria reproduce by fission but also will take in dna from other bacteria. Lots of fungi and insects have radically different appearances at different stages. Some will alternate diploid and haploid generations. Suppose your planet-critter reproduces once. Scenario: It shatters into a multitude of comet cores that are scattered at faster than the local star's escape velocity. The comets move into the Oort cloud. Stage two reproduction occurs there, using natural comets as food and reaction mass. The comet critter sets course to another star, eventually colliding with a suitable planet there, and converting it to a planet critter. 30 km/s is .0001c So a 10 light year journey is 100,000 years. ]
[Question] [ Consider a futuristic world where space travel and colonisation of the solar system's planets is an everyday reality. In space vessels, the airlocks are used quite often to execute people. It's fairly easy: shove a person in, push a button and they're gone. They call it "spacing". How would you make airlocks safer? How would you reduce their usefulness for murder? [Answer] A couple ideas: * If there's vacuum on the outside of the airlock, then the outer door can only be activated from within the airlock itself. There's also an override within the airlock to prevent the door from being opened. * The airlock security system identifies when people are in the airlock and requires that everyone have on a functional spacesuit before unlocking the outer door. [Answer] Space Navy Code D.E.E.P/6 para 4 I think you're possibly looking at this from the wrong direction. You're proposing a scenario where the death penalty is a legitimate punishment. You say the air lock is used "quite often" as a method of execution. In such a situation I don't understand why you would want the method to become less effective in doing its job. This would be like injecting a homeopathic dose of KCl into a death row inmate. If you simply want to change the practice of execution to a different method, you amend the above naval code to read "...the airlock shall not under any circumstances be used as a means of carrying out the penalty of death." You simply make a regulation that specifies what methods of execution will be allowable. Naval officers in general are honourable men and women: they often come from military families and are decent, patriotic folks. They are also trained from academy days to take the rules and regs seriously. If you make it a rule that the air lock can't be used to execute someone, then it won't be used for that purpose. Officially. Same goes for any non-naval vessel. You just make it illegal (generally) or against corporation regs to use the airlock as an execution device, assuming corporations have been granted the juridical right to execute a person in the first place. Anything you do to the airlock itself that would prevent its use as an execution device is also going to prevent its more legitimate functions. [Answer] # Not much, really. Space is a dangerous environment and keeping people alive requires a lot of things to go right. You can put safety measures and backups in place to reduce the number of accidents, but they will do little to stop premeditated murder and even less to stop executions. (Here I define an execution as a premediated killing by the local authorities, e.g. a ship's command staff.) * Any safety measure to prevent the opening of the outer door in less-than-ordinary conditions could also keep rescue teams out when the ship is damaged. So it wouldn't be there, or there would be a rescue override. * If there is a button or whatever to prevent the airlock from cycling, any mechanic could jam it or glue it open. * Any safety measure reliant on complicated computer systems is subject to someone with the root password. * If there are emergency space suits in the airlock, the executioners can remove them or handcuff their victims. For that matter, the executioners could always gum up the air vents in a storage room and send their victims there. That takes longer and leaves more of a mess, but it would circumvent any airlock safeguards. [Answer] * Remove the executioner-just-outside-the-airlock button entirely. Like a [Death Ray](https://en.wikipedia.org/wiki/Professor_Frink), it has only evil applications in the script. * Require the use of multiple buttons simultaneously --one on the bridge and one inside the airlock-- to cycle down to vacuum. But only one button is needed to cycle up to pressure. * Have the outer door open conveniently inward so the corpse cannot be freely ejected to space. You gonna kill somebody, you gonna stick around and clean it up. [Answer] Decompressing airlocks by opening of the outer doors is undesirable as you will lose some of your precious oxygen to the vast emptiness of space. Besides, pressure equalization by opening the hatches may be explosive in nature, as the rate at which the pressure equalizes is uncontrollable. Explosive decompression might cause damage to equipment as well as severe injury or even death. The airlocks hatches shall therefore either open inward (similar to what you'll see on submarines or decompression chambers) or have a pure mechanical interlock which prevents opening the hatches unless the airlock pressure has already been equalized. During normal operation, the airlocks will be equalized by using an equalization compressor which will evacuate the air from the airlock and store it on a tank. The equalization compressor shall be equipped with emergency push buttons both on the inside and the outside of the airlock, which will stop the compressor and open a valve to bleed the air back into the airlock from the air tank. There will be mechanical valves for emergency equalization of pressure between space and inside the airlock, as well as from within the airlock and to the interior of the spacecraft. The mechanical valves will require specialized tools for operation. The valves for equalizing between space and within the airlock can only be operated from the outside or from within the airlock. Similarly, the valves for equalizing between the airlock and the spacecraft interior may only be operated from within the airlock or the spacecraft itself. Obviously someone from the outside will have the theoretical possibility of bleeding out the airlock against the will of the crew of the space craft, but this is mostly a hypothetical situation which does not warrant any particular countermeasures unless it first proves to become a issue. The requirements for safe design and operation of airlocks will be a part of the SOLIS-code (Safety Of Life In Space) sanctioned by the International Space Organization (similar to International Maritime Organization) which is an organization consisting of the different governmental space agencies of nations with vested interest in space operations. The codes will require periodic inspection of the safety functions of the space craft. The national space agencies will have the authority to inspect and to place any space craft that does not meet the SOLIS-codes under arrest until the spacecraft is up to standard. The governmental agencies can also blacklist space crafts and impose sanctions on the space craft owners in case they attempt to bypass the inspections by never docking in a regulated space port. [Answer] Multiple locks. [![locks](https://i.stack.imgur.com/ugcNL.jpg)](https://i.stack.imgur.com/ugcNL.jpg) Mass can be valuable in space. A series of airlocks would facilitate reclaiming air by having a series of small rooms that together constitute the lock. Let us call them ship, A, B, C and space. On closing the wall between ship and A, atmosphere from A is pumped back into B. As the pressure difference increases, the pump must work harder. A then opens to B. After the wall between A and B closes, B is pumped into A, probably with the same pump. Then B to C and then when C opens to space there is very little remaining atmosphere to lose. You could push someone into room A, and pump down the pressure in room A and make their ears pop but they would not be obliged to leave room A when you opened the partition to room B. The condemned would just stay in A, glaring at you through the window, breathing steamy breath on it, drawing pictures in the steam, labelling the pictures with an arrow and "YOU". The pictures are unflattering. Side benefit of locks like this is that they can be used as a decompression chamber. Just as a diver ascending to fast can get the bends, if persons accustomed to a higher atmospheric pressure came onto a ship with a lower pressure, those people could get the bends - decompression sickness. A stepwise lowering of pressure allows gradual outgassing of gasses dissolved in the blood, and avoiding the bends. [Answer] That’s kind of like asking how do you prevent the plugs, switches and other electrical equipment in your house from being used in an electric chair or any guns you may own from being used for a firing squad. Presumably an advanced, spacefaring culture would make use of a standard airlocks with redundant safety features ie multiple interlocks, restricting unauthorized use, etc. If said culture also had capital punishment on the law books with ‘spacing’ as an authorized method of execution, they would probably have a specific location and equipment specially designed for the purposes of carrying out the executions, similar to what modern death houses at prisons today do. That’s not to say that someone might misuse an airlock to commit crimes, or make use of one to commit suicide, etc. [Answer] For safety reasons the airlock will be designed so that the controls for each door will be adjacent to that door, so that the outer door cannot be opened by someone who is within the inner door, and vice-versa. The airlock is used only when personnel are entering or leaving the ship, and during normal operations this must be authorized by the officer in command of the ship. Consequently the door controls are inoperative unless activated from the bridge. Furthermore, no door can be opened unless the atmospheric composition is the same on both sides. This is to prevent mixing atmospheres of different compositions (so that properly-suited personnel can be transferred to a ship with a different atmospheric composition), as well as to prevent the venting of atmosphere to space. The danger of fire is addressed by prevention: The ship is constructed from materials that do not combust under normal conditions. If spacing becomes a lawful punishment, it will take place by putting the condemned into the airlock, closing the inner hatch, pumping out the atmosphere therein, and then opening the outer hatch, with perhaps a mechanism to push the condemned out. The reliability of the systems, and their vulnerability to sabotage, will always be an issue. [Answer] As multiple answers have demonstrated, electronic, mechanical or computer "fail safes" have the potential to create issues and problems of their own, up to disabling the ship itself. You certainly don't want to do this with such a critical piece of equipment, and indeed if this was installed in the factory or shipyard, hackers would soon be looking to defeat these measures to protect themselves and the ship. If the issue is judicial executions, such as the death penalty from a "Captain's mast" or the crew quelling a mutiny, then there are either legal safeguards built into the process, or common sense limitations. Spacing a person ejects valuable oxygen from the ship, as well as the person themselves. A body might be more profitably sent to the recycling staton where it is reduced to component atoms and fed into the hydroponic gardens or something similar. space is a high energy environment, and ships using nuclear fission or fusion for propulsion will have lots of on board energy. In a pinch, the ship's engineering division could create a large parabolic mirror to capture the available sunlight to do the job (if the ship is in free fall, the mirror can be arbitrarily large and made of a sheet of aluminum or similar material a few molecules thick). So judicial executions would be done in such a manner as to preserve the ship's stores of life support, and even replenish them by conserving and recycling the bodies. Depending on the circumstances, non judicial murders may be done with the same reasoning in mind. Captain Bligh isn't going to be cast adrift with the loyal crew, they are all going into the recycler, one way or another. Indeed, the extra time, effort and energy needed to drag a victim to the airlock and set up a cycle to space a person might be enough to deter most criminals, and crimes of passion are going to take place "on the spot" where the aggrieved party gets their hands on some sort of killing implement or uses their bare hands. So the reason to not use the airlock to "space" a person revolves around maintaining the integrity of the life support system, and the extra difficulties that using the airlock would cause most criminals who are contemplating committing murder. The exception, of course, is when HAL 9000 is the one planning to kill you using an airlock.... [![enter image description here](https://i.stack.imgur.com/f7V7T.jpg)](https://i.stack.imgur.com/f7V7T.jpg) "Dave, I need you to get something for me...over there by the airlock..." [Answer] Trying to make an airlock that can't be used to kill anyone is like trying to make a knife that can't cut someone's throat. It's not impossible, but doing so will compromise its effectiveness. Instead, have a logging device that shows exactly what is in the airlock and who is activating it. Automatically transmit all recordings home. That way, if someone uses it for murder they will get caught. [Answer] It's just not a good way to execute someone. It's slow, gross, ineffective at getting rid of them, inefficient, and undramatic. How it goes in the movies: Bad Guy tricks Hero into the airlock, then slams the door, trapping the hero inside. Bad guy outside the airlock pulls the big red lever with the black and yellow danger-chevrons around it, and the far door quickly opens to space, sucking the hero out to their certain doom, where they freeze and/or explode. This is dramatic! Audiences love this stuff. How it would go in reality: Bad Guy tricks Hero into the airlock, then slams the door, trapping the hero inside. Hero seems to have some kind of plan, and starts to don an EVA suit. Bad guy looks around for a way to open the far door, and sees nothing. He reopens the door, overcomes the Hero, and pulls them out of the EVA suit to tie them up. By chance, he sees the procedure manual for operating the airlock, grabs it, and reads it, cursing, realizing he needs to be inside the airlock to start depressurization. Following the manual, he begins the pre-breathe protocol, ten minutes of exercise elsewhere in the station, while breathing pure oxygen. After a further 40 minutes of breathing O2, during which he watches an episode of his favorite TV series, he climbs into the tiny airlock with the Hero, and initiates depressurization which sounds an alert throughout the station, but nobody comes running because reasons. Over a period of 30 minutes and another episode, the pressure drops from 14.7 PSI (1 atm) to 10 PSI (~2/3 atm), at which point an alarm sounds telling him to suit up. This is equivalent to moving from sea level to an altitude of 10,000 ft in half an hour. The Hero will start to find it difficult to breathe, and may suffer signs of altitude sickness at this point, such as pulmonary edema (fluid in the lungs), cerebral edema (swelling in the brain), and general hypoxemia and hypoxia. He is likely to pass out during this period unless the Bad Guy gives him oxygen too. Bad Guy, still breathing oxygen, puts on the EVA suit, glad that the hero is well trussed up in these tight confines or he'd be in big trouble. He clips his safety harness to the ring by the airlock, and waits the final 60 minutes for the airlock to completely evacuate, binge-watching two more episodes with subtitles because he can't hear through the suit, let alone through the vacuum that's forming as he watches the pressure slowly drop. Even with a breathing mask, Hero definitely passes out and dies at some point, his skin blackens with bruising, he swells up and maybe starts bleeding and/or prolapsing from some orifices. Other bodily fluids start exploding out and floating around the airlock, and Bad Guy is glad he's in the suit. They fluids boil, spattering globules as they bubble, and as the fluids boil and gas off, what's left drops in temperature until it freezes in little ice-gobbets, sparkling shards of gore. Eventually the pressure has dropped all the way. Bad Guy waits expectantly, but the hatch doesn't open, so he walks over and pushes on the hatch. It still doesn't budge. He fiddles with the latches, which seem to work fine, but it won't push open. He checks the manual and finds that airlock doors ALWAYS open inwards, so that: locking failures cannot cause the doors to pop open under air pressure; and it's impossible to open the door when pressurized, since it would require literal tons of force to open. Sci-fi always gets this wrong, because it's non-dramatic, and because they feel that hatches should open outwards like on tanks. He pulls, it opens, but there's only a barely perceptible puff of the last remnants of the air going out. Hero's bloated and messy corpse just drifts where it was, up against Bad Guy's facemask in the cramped quarters, both of them surrounded by a halo of gross boiling globules. Bad guy flails at it and shoves it toward the hatch, but it bounces off and has to be kinda weightlessly wrestled out, all the various bodily fluids going freaking everywhere. Eventually it's out, and he recloses and latches the door, and begins the repressurization process. This time, he waits the whole time in the suit because he knows it's going to stink out there. Partway through the next episode of his show, he hears a splatting thud and looks through the airlock viewport to see that the corpse has flown in a slow, graceful loop and splatted back against the closed airlock, losing more fluids which boil and freeze almost instantly. It's drifting away again, though this time in a much smaller circle, having lost in the impact most of the energy with which he threw it out of the airlock. This is because they're orbiting every 15 minutes, and the body is in only a very slightly different orbit, just slightly more elliptical. Bad Guy is now faced with two unpleasant options. He can either shed the suit here and try to touch as few floating particles of corpse-slime as possible as he escapes from the airlock back into the station, or he can wear the suit out of the airlock and remove it there... but the suit's covered in the stuff too. Either way, the air in the station is now contaminated with the stuff and when he goes through the door, particles will be following him. The scrubbers are good, but they aren't amazing: there'll be droplets of this stuff dried all over the place forever, and the air will from now on always stink of dead Hero dude. Damnitt, next person he kills will be going into a suit before spacing them, and he'll just cut the air pipes. In fact, screw spacing them, he'll kill them and put them in the trash bags with all the rest of the trash. In fact, thinking about it, the next person is going to be whoever comes with the resupply vessel, and that might try to come in through that airlock with the hero-corpse floating outside of it... he probably needs to go drag it back inside and stuff it in a trashbag, so's not to tip them off. Crap. This is... not dramatic. Audiences will not love this stuff. --- There're a few cases that designers need to consider when creating an airlock in a spacecraft or space station... or in a novel. 1. One person accidentally or deliberately cycling the airlock while a second person is in there for cleaning, equipment check, just returned from EVA, etc. Addressed by having the controls inside the airlock; a very slow cycle time measured in minutes or hours; and no doors that lock on only one side. [Edit: this is how it is in real-life craft] 2. A single person triggering the airlock on their own while in it (suicide, unauthorized EVA, etc). Audible and visible alerts when depressurization starts: "Alert: Port-forward airlock depressurizing. No scheduled EVA at this time." Allow depressurization to be canceled from the rest of the station. [Edit: this case is not covered in real-life craft: depressurization is done from the airlock, venting the air into space until pressures equalize] 3. One or more people (including rescue personnel) outside the station needing to get into the station when someone has accidentally or deliberately locked the door, overridden the airlock controls, etc; and where all crew inside the station may or may not be incapacitated. Allowing depressurization to be started from outside the ship should address this. [Edit: this case is not covered in real-life craft: the inner door is kept open except during EVA,so you can't "come in from outside".] 4. A single person needing to get out through the airlock when nobody else in the crew is capable of functioning. Controls in the airlock resolves this case. [Edit: this is how it is in real-life craft] 5. One or more people needing to operate the airlock from inside the craft, while nobody is in the airlock, is low, and MIGHT NOT be worth factoring into spacecraft design. They can just suit up and go into the airlock to operate it. [Edit: not possible in real-life craft] 6. One or more people getting spaced by multiple others coordinating together (murderous mutiny or execution). Probably not worth considering, could never be made foolproof anyway. [Edit: not covered in real-life craft, because you can't space someone who's not incapacitated already.] 7. Hostile boarders: probably not worth considering. Even if space pirates are really a thing in your universe, not even locks and door keys are needed. Space pirates will just magnetically clamp onto a ship and cut through the hull, rather than waste time waiting for some slow-ass airlock. If the victims are lucky, they might pressurize the area around the hole they cut, so people don't immediately die. [Edit: in real life craft, the inner airlock door is always open.] Everything needs to follow some basic design tenets: * Minimize complexity. Keep everything as simple as possible, with minimum moving parts, minimum electrical systems, etc. * Maximize redundancy. At least one fully redundant system for everything. Not just two airlocks, but each airlock having two air pumps, etc. * Everything should fail safe. [Ref for some of the numbers: <https://spaceflight.nasa.gov/station/eva/outside.html]> [Answer] Advanced AI In an era of advanced every-day space travel, ships would have advanced AI to do any number of ship operations including: * Navigation (contrary to popular belief, navigating in space is really hard and cannot be done by hand) * Power allocation, generation and supporting systems, such as airlocks in question * Life support systems, food, lighting and air (such as in airlocks) * Repairs and manufacturing (in case of tampering, or simply damage) It is likely that any ship in this era would have almost all systems, if not ALL systems, automated and controlled by advanced computer or software. Just like airlines of today there are systems that were handled by Flight Engineers, now a redundant position, and which now are handled by computer - in space mathematical calculations, issues and problems are much more complex than humans can handle and thus computers and AI would be in place, accompanied by appropriate robotics if necessary. This AI would ensure the safe passage of its occupants to the destination - and simply would prevent the use of airlocks if it endangers the crew or passengers. Multiple redundant safety systems would be in place, making it impossible for abusing any onboard ship system. [Answer] Implement the following logic: * A pressurized airlock stays closed. * Depressurization happens manually from the inside of the airlock. * Depressurization can not happen if inner door is open. * Depressurization can happen only after the airlock is closed for a few minutes and no rise in CO2 is detected Ok this still leaves the possibility that somebody climbs in a spacesuit, together with the person to be killed (which is already tied up), puts him/her in a spacesuit and opens the door there. * Chip every human aboard with an NFC transponder. Don't open if NFC transponder for human is inside the lock, and not with a space suit, and require verbal authorization from every human in the lock [Answer] Put a cancel button inside the airlock The airlock can't be opened if the cancel button gets pressed. Make sure there's a 15-30 second (minimum) delay so that anyone inside can have a chance to press it. After that, the cancel has to be manually reset from inside the airlock before the airlock can be depressurized. Could the victim be tied up and put in the airlock? Sure. But if they are tied up, they can also be strangled, so you're not really preventing anything in that scenario. [Answer] Maybe a O2 sensor for checking if there is sufficient air? This could allow the airlock to open if there is a sufficient amount of O2.[FLAW 1] Precaution 2: Button is inside [FLAW 2] 3: Heat sensor inside and out of the airlock. [FLAW 3] 4: Suit sensor [FLAW 4] 5: Access code required [FLAW 5] 6: AI [WARN 1] 7: Automatic atmospheric generation [FLAW 6] Flaws and warnings: WARN 1: AI can backfire and do it themselves FLAW 1: Can be faked. (See precaution 7) FLAW 2: Signal can be sent externally (TIP 1) FlAW 3: Can be faked. (TIP 2) FLAW 4: Hat made out of suit. FLAW 5: Access code can be added (Can be faked, TIP 3) FLAW 6: Can be terminated, Can trap. Would pop eventually anyways [Answer] Air lock doors, like the canal lock doors they are based on, only open towards the side with higher pressure. When the lock is pressurized, a door 2 square meters in size would take 20 tonnes of force pulling it open to break the seal, and there is no need to install actuators that will do that for standard operation. To execute someone by throwing them out the airlock, the condemned would be carried into the lock by two suited guards, the lock would be depressurized by pumping the air into the ship, so as to not waste it, a tether would be attached to the now unconscious prisoner, the outer door opened, the body thrown out. And then reeled back in, doors close, the lock repressurized, and the corpse taken to the organic waste recycling center like the rest of the dead. You don't want to waste that either. It's bad enough that you wasted some water in that spacing execution. [Answer] As many here point out, all reasonable fail-safes can be overcome. If they can't they are likely to dangerous. I think the what is needed is not technical but cultural, religious or ritual practices around the use of the airlock that are socially and psychologically significant. The original meaning of the work 'sacred' didn't imply 'valued', just that it was outside of the realm on everyday, or 'profane'. So in the ancient Greek world, prisoners needed to be made sacred before they could be executed, because normally killing a person would be murder. Airlocks and their use needs to be embedded in culture as significant ritual practice, so that stepping outside of this is a psychologically difficult transgression against norms. I think there's hint of this in different cultures ideas about guns. Guns are actually plentiful in australia and switzerland, but for most people, they are culturally considered 'sacred' objects, to carry a gun in everyday life, except for a specific activity (eg, hunting, professional, sporting) is culturally shocking. Australians aren't cooler headed that Americans, it's the cultural, not legal barriers to possessing and holding weapons that is responsible for the low numbers of gun deaths. The famous Australian 'gun buy back' that has reduced gun deaths, may actually be more about the cultural message it sent that the reduction in gun ownership, which seems to have been temporary: <https://www.gunpolicy.org/firearms/compareyears/10/number_of_privately_owned_firearms> [Answer] Have the airlock on the outside mechanically unable to open without a keyed dock physically connected to it. If you want to do maintenance - a pod like vehicle, akin to the starfury forklift from babylon 5 makes more sense than an EVA suit on its own in a larger deep space habitat. Basically make it impossible to open these airlocks into space. [Answer] # Child-safe airlock. If people try to live in space any length of time, there will be hanky panky, and before long, rug rats. Well, baby's first airlock should be designed by somebody who has thought about it a minute. * Airlock checks for human flesh. If it sees human skin or smells human presence (CO2, pheromones, etc.) then obviously that is a huge red flag to biohazard sensors that are designed to spot a single Andromeda Strain monomer. Under those conditions it's not opening without a full manual override, including all the usual frenetic safety klaxons and alerts and automated head counts by station sensors that implies. * Airlock does not go along with silly requests easily. If you want both doors open at the same time, cue the klaxons and head counts. * Airlock is meant to work with suited astronauts and suitable packages. If it spots anything that is likely to be a mess in vacuum conditions - like a half-eaten container of strawberry jam - it's going to check with Mommy. * Airlock likes to have a notion of what's going on. It may not know where the kid is going, but it wants to have basic indications from suit telemetry that he didn't forget his galoshes or the extra oxygen bottle. There's a plan for most things, and it responds to variations in the plan by inquiring with the right people. ]
[Question] [ I'm designing an alien civilization that has achieved wormhole travel. Their devices are used by every member of their society and are usually located on their wrist. They type the coordinates of their destination, then shoot a small projectile in the air before opening a wormhole. The wormhole can be any size, and can get someone anywhere in the universe in an instant. However, in their society they still have other means of transportation like hyperloops, spaceships, space elevators and even sea ships. Now my question is, why would a civilization that has such means of instant transportation still use other means of transportation? [Answer] Entertainment There are days when absolutely nothing will make you happy other than the sound of a Harley Davidson motorcycle polluting the atmosphere in style. To Impress People One of my favorite scenes from the book [The Stars My Destination](https://en.wikipedia.org/wiki/The_Stars_My_Destination) is when the protagonist, hiding in plain sight via enormous wealth (and in a world with mental teleportation, not unlike your story!), arrives at a social function in a railroad engine. People stood and stared as workers laid track to the door of the mansion so the train could drive up and drop its passengers. Think about it. Dang. Because the Line's Busy Do you remember the good old days when the smallest emergency guaranteed you could't get through on your cell phone... or your land line...? It's nice to think your population of (I'm suggesting) 9.2 billion can open 9.2 billion simultaneous wormholes — but the reality is they can't (and shouldn't). Too many wormholes in too close a proximity causes bad things to happen. (And probably would in real life. That, or the current existence of one wormhole guarantees through the magic of physics that no other wormholes within a specified distance can be opened.) So, whadaya do when everybody's using the line? You get on your Harley, of course.... Because the Destination is Popular Even if your world allows any arbitrary number of wormholes to open in close proximity... that doesn't mean there's enough landing space for everyone! The 100th Marvel Movie ([The Runaways](http://whatculture.com/comics/10-little-known-superheroes-that-would-make-marvel-millions?page=11) save the world!) is opening at the Odeon and you absolutely must see it on opening night! The problem is, so do a number of people representing at least 700% of the actual number of seats in the theater. The result? Thousands of people trying to arrive in the same 500 square foot space — all at the same time. Gratefully, your tech simply won't allow the wormhole to form if there's not enough physical space to deposit you. So, you jump on your bicycle and hope like crazy you can beat at least 1,000 of those people to the theater! (BTW, if you think about it, this would be a very common problem at any goods distribution facility. It doesn't matter how big or small you can make the wormhole... there simply is only so much wormhole transit space to go around. Everybody else gets to use trucks.) Your Wonder Woman Wormhole Bracers... Broke There ain't no such thing as perfection. It's pretty rare that the wrist controls for the wormholes break, but when your little brother swung the tree branch at you... well... Dad's not gonna be happy paying another \$1,000 for a new ~~cell phone~~ set of Wonder Woman Wormhole Bracers. Bzzz, thank you for playing. Your consolation prize is you get to walk. (You can add to this one taking away your allowance, privileges, grounding you literally, or any other means of imposing reality on the unappreciative teen mind.) There's Too Many People Near You You know what the basic problem with a rave is? They're packed! And in this city, raves are packed for miles. Oh, yeah! We're talking Zaphod Beeblebrox on tour! Woot! And you can't just open a wormhole in the middle of all that. You'd cut a dozen people in half as the event horizon formed. At least a dozen. OK, to be honest, congestion (which at least three of these are talking about) will be a major reason why people don't use them. You Can't Afford the Tech I don't own a \$1,000 cell phone, do you? Some people do, others take the bus. That's the circle of life. Because Security Disabled the Destination And last of all — The folks over at [Fort Knox](https://en.wikipedia.org/wiki/Fort_Knox) takes a dim view of people trying to open wormholes into their vaults. I suspect there are all kinds of government, military, corporate, institutional, judicial, and who knows what else locations that absolutely, positively do not want your wormhole to open anywhere other than where they permit. Which can easily be believed to be "nowhere on this site." Prisons come to mind. There will always be the need for transport into and out of locations where security is a big deal. --- *Edit* I forgot one (or more)... It Takes Longer to Teleport Do you remember that fabulous opening scene from the movie [The Gods Must Be Crazy!](https://en.wikipedia.org/wiki/The_Gods_Must_Be_Crazy) (That really dates me!) where the woman gets in her car to drive 100 feet down the road to post a letter or some such? Yeah. Humans can be stupid. But she did it because it was faster than walking and cost her nothing to get in the car and fire it up. But, what if your wormhole has a minimum allowed distance? Or the time to form the wormhole is substantially (aka, minutes, remember the movie) longer than hopping on your bicycle? Then again, humans are creatures of habit! Maybe this isn't a good enough reason after all.... [Answer] * Energy expensive. Make a wormhole is a very energy hungry operation. * Expensive. Maybe it doesn't consume much energy, but the technology or the item itself is very expensive, not everybody can afford it. * Disbelief, Insecurity. Did you know that planes are statistically speaking the safest transport? They are in order of magnitudes safer than cars, but still, people have fear of planes, like your people have fear of wormholes. Maybe the first wormhole devices were quite dangerous and two or three great catastrophes occur with them. Now they are safe but some people got traumatized by the events and still not trust in them. * Luxury. Wormhole travel is instantaneous, but what if the user wants to rest while travelling? It's like cruisers trips, people go there also to rest, relax and get fun, in addition to travel from A to B. Some people love driving cars... [Answer] Because wormhole travel involves destruction of the physical body, or deformation sufficiently traumatic that it raises the problem of the [Teleportation Paradox](https://en.wikipedia.org/wiki/Teletransportation_paradox). If wormhole travel deforms or even destroys the brain (or analogous organ that produces consciousness in these aliens) then, there is a school of thought that this this process thereby kills the traveler. What emerges at the other end, then, is a copy, clone, or facsimile of the traveler, but not - in a very meaningful way (which you will have to articulate) - the same traveler who actually opened the wormhole. So, as with Captain Kirk and the Enterprise transporter, the traveler actually is killed with every single usage, even though they do not realize it. In your world, this was actually confirmed through a catastrophic experimental failure that occurred in the beta testing of the wormhole technology. This was hushed up for obvious reasons. Therefore, politicians, diplomats, aristocrats, intellectuals, high-ranking clergy, and similar persons do not actually engage in wormhole travel, even though they display the devices on their wrists. They take taxis and hyperloops and so on. That other people use these ordinary physical modes of travel is basically a coincidence (for reasons given in other answers), or perhaps, they've actually come to understand the way the technology works; or, they just intuitively distrust it for philosophical or religious reasons. Said high-rankers might keep the devices on their wrists for ornamental reasons, or they might actually use them in an emergency e.g. the wearer has information known to nobody else that they are willing to die in order to transport elsewhere. [Answer] ## Transporter phobia Some people may just be really afraid of using transporters. The idea of your atoms being ripped into pieces and put back together, with no margin of error, is certainly going to be scary for some people, even if it is both the fastest, most efficient, and safest method of travel. From Star Trek: TNG, there was an episode, [Realm of Fear](http://www.chakoteya.net/NextGen/228.htm), in which the hypochondriac Lieutenant Barclay was terrified of getting transporter psychosis, a rare disease that only affected those using very old transport technology. Despite constant reassurances, he remained terrified of transporting: > > BARCLAY: You know, maybe ignorance really is bliss. > > > O'BRIEN: Sir? > > > BARCLAY: Well, if I didn't know so much about these things, maybe they wouldn't scare me so much. I can still remember the day in Doctor Olafson's Transporter Theory class when he was talking about the body being converted into billions of kiloquads of data, zipping through subspace, and I realised there's no margin for error. One atom out of place and poof! You never come back. It's amazing people aren't lost all the time. > > > O'BRIEN: With all due respect, sir, I've been doing this for twenty two years and I haven't lost anybody yet. > > > BARCLAY: Yes, but you realise if these imaging scanners are off even a thousandth of a percent. > > > O'BRIEN: That's why each pad has four redundant scanners. If any one scanner fails, the other three take over. > > > LAFORGE: Reg, how many transporter accidents have there been in the last ten years? Two? Three? There are millions of people who transport safely every day without a problem. > > > BARCLAY: I've heard of problems. What about transporter psychosis? > > > O'BRIEN: Transporter Psychosis? There hasn't been a case of that in over fifty years. Not since they perfected the multiplex pattern buffers. > > > LAFORGE: Reg, transporting really is the safest way to travel. > > > [Answer] Disclaimer: I'm a public transportation advocate. I am heavily biased towards public transportation. --- If everyone in a society has the ability to instantly go anywhere they wish, there will inevitably be conflicts. If two people want to travel to the same destination, they would need to queue up, or there would need to be some form of other restriction to prevent overloading the destination/having multiple wormholes end up at the same location/etc. For a more concrete example, take a major event (sporting/etc) where members of society will want to be physically present. Controlling access to the locale when people will travel via personal wormhole would be a mess for both safety concerns (what happens if two people exit a wormhole at the same time and injure one another?) and would be a logistical nightmare as well (how do you organize burst loads of people traveling at the same time to the same location when they arrive at any time and at potentially any location?). The best solution would be to have people gather in multiple locations elsewhere and then travel to the locale in a high capacity mode of transportation. This is logistically simpler since the number of vehicles moving in the vicinity of the locale would be drastically lower than the number of people that would be trying to access the locale directly. This is independent of the other concerns that have been raised with wormhole transportation in other answers. [Answer] Cost: The use of this tech is prohibitive for specific journeys. The teleportation in my story works better for living beings than it does on inanimate objects. You're better off shipping commercial goods using traditional means, unless delivery is time sensitive and the object is very expensive. People, on the other hand, usually use teleportation. Ask yourself where it is economical to use other methods vs. using teleportation. Range and location: Another facet of my teleportation system is that it is limited by range. Someone traveling around the world would need to make a large number of jumps, and the placing of teleportation systems is limited and specific. Most often, the affluent teleport to a location close to their destination, and then use conventional means to complete the journey. In addition, everything but large cities lack the natural features needed to send and receive teleported material. In short, teleportation acts like an airport. It gets you most of the way there, it's expensive, uncomfortable, and small towns don't have the needed infrastructure. Fuel: Last but not least, teleportation in my settings gets exponentially more resource intensive outside of local energy fields. The range limitation is in effect on planet. At interplanetary distances, jumps are no longer subject to the range restriction, but become exponentially more costly. Teleporting to other planets is far, far, more costly than teleporting to other cities, even controlling for distance. Interference: There may be specific disruptive phenomena that make teleportation unreliable. Unreliable meaning that it only works at certain times, requires more energy, or is downright dangerous. Bandwidth: Depending on your concept, maybe only a certain number of people can teleport at a given time. This could be a technological limitation, a legal one, or a social one. Side effects: There may be side effects associated with teleportation. Either for the person being teleported, or the entity doing the teleporting. Maybe one can only teleport a certain distance within a certain period of time, or risk certain adverse effects. [Answer] Any technology has multiple cons, which mean we don't over-use them. Here's a few ideas, based on real-life transportation that we have today: Wormhole-nausia It sometimes causes temporary but embarrassing side-effects. Some people are more susceptible than others, and some trips are more likely to trigger it than others (for plot reasons, could be short trips, long trips, or could be when there's too many others transporting nearby... Multiple hops in a short period increase the risk...) But for some people, the risk of vomiting (or perhaps worse!) to save half an hour isn't worth it, particularly if you're going out for a date... Environmental concerns Environmentalists have been complaining for years, but now scientists are admitting, the effects of opening thousands of wormholes per person per year is probably not good for the environment. This could be small wormholes left behind ("studies show that most devices do not meet the standards, and over 20% of wormholes do not close completely within the regulation 10s after transport. In some cases, wormholes as large as 1mm persisted for over a day after use."), microbes transferring through wormholes affecting the local biosphere, or just 'normal' issues like pollution from the devices or their manufacture... They'll almost certainly require heavy metals etc in manufacture, and perhaps they leak something nasty during use, like cars. Wear and tear on devices / servicing Much like a car, your device needs a service every 12 months or 150 hops, whichever is earlier. Only an idiot would skip this, given the risks should it malfunction! Insurance Of course you need insurance on them! The risks of doing something stupid are high... Even if it's just an accident, if you teleport to an inappropriate location, you risk high fines or jail time. So there's insurance. And the insurance is priced on the number of hops you do a month. [Answer] Time experience is warped. Although you appear instantly on the other side, to you it feels like it takes hours/days/years/millenniums. Meanwhile all you see is darkness. This goes from mildly inconvenient to downright maddening, i.e. people are coming out completely insane if they’re not sound asleep while entering. It’s not always practical to be asleep when entering so people only use this feature when the travel distance is truly great. Idea partially based on Stephen King's short story ["The Jaunt"](https://en.wikipedia.org/wiki/The_Jaunt). Time is warped. Although you appear instantly on the other side, your body actually ages quite a bit. This could be anything from ‘don’t do this every day if you want a long life’ to just aging a year every time you use it. This option can be in combination with the first point, or just standalone. [Answer] To me, this questions echos "Why take the stairs when you could take the elevator?" Two valid reasons for the stairs in the modern day and age are giving preference to the exercise over convenience and safety of arrival. In the case of teleportation, it's about perception, not reality: people may have the perception that there are health benefits to other means of transportation over wormhole teleportation. With respect to safety upon arrival, there are risks to blindly appearing at a location. In the event of a fire, part of the reason they don't want you to use elevators is because you could unknowingly be placed at the location of the fire and become trapped. With teleportation, who knows what could be a hazard upon arrival. Just because you can teleport anywhere, doesn't mean it is safe nor desirable to do so. The Luddite Argument: For centuries, people have been opposed to technologies of every kind just because it is new and they do not understand it, or it seems like it poses a threat to their exiting lifestyle. Transit operators and the elderly are prime examples to demographics who may hold preferences to other means of transportation over teleportation. Planes, Trains, and Automobiles A Rest Factor: teleportation is probably faster in most cases, but it may come at the cost that another means of transportation affords people the opportunity to rest when they are not scheduled so tightly they must teleport. Cost Factor: just because everyone has teleporters and uses them regularly doesn't mean they are free or cheap. Assuming they are a capitalist society, teleportation is probably overseen by a company that charges for their use in some way. Since its convenient, it's pretty easy to see them setting the price point for teleportation close to other means of transportation, including above the cost. Traceability Wormholes may be really easy to track, so someone on the run from a tracker may find they need to stay hidden by using other methods to travel. [Answer] It could simply be an unplesant experience, so people might prefer alternatives when possible. How could it be unpleasant? Well, let me quote from The Hitch Hiker's Guide to The Galaxy on how in Douglas Adams' Universe jumping through hyperspace is quite an unpleasant experience: > > The jump through hyperspace is a lot like being drunk. > > > You might ask, what's so bad with being drunk? > > > You go ask a glass of water. > > > (I just quoted this from memory, so the quote might be slightly inaccurate) [Answer] Some ideas that I don't think quite overlap with [the current top-ranked answer](https://worldbuilding.stackexchange.com/a/135305/10048): To Keep Control of My Personal Information: As mentioned before, when you teleport you probably have to file the equivalent of a flight plan, show the equivalent of a passport, and so on. So someone on the run from the law would have a reason not to teleport. But never mind the politics — did you know that every time you teleport, the teleporter company actually reads the quantum state of your brain and transmits it to your destination? I don't want [Ma Bell](https://en.wikipedia.org/wiki/John_Stewart_Bell) reading my brain, thank you! Sure they [say](https://en.wikipedia.org/wiki/No-cloning_theorem) they're not keeping a copy of your personal consciousness in their database, but corporations have lied before. Because Alexa Told Me To: This is almost a duplicate of Because the Destination is Popular and/or It Takes Longer to Teleport, but allowing for interaction with other futuristic technologies. You're asking why someone would decide to do x instead of y — well, most likely it's because they plugged their destination into Google Maps and just did whatever the machine told them. Why did the machine tell me not to take the teleporter today? Maybe it knows that teleporter use organically increases when it rains (Because the Destination is Popular), and rain is predicted for today in my location, so it's telling all its users to take the tube instead. ("Nobody goes there anymore; it's too crowded!") Maybe it's trying to be more [ecologically conscious](https://www.citylab.com/transportation/2011/12/coming-soon-your-gps-green-routing/733/) (Environmental concerns) by weighting teleporter travel differently than, say, rideshare. Or maybe — if the [zaibatsu](https://en.wikipedia.org/wiki/Zaibatsu#List_of_zaibatsu) that controls the most popular recommendation engine is different from the zaibatsu that controls the most popular teleportation provider — maybe they're [leveraging corporate synergy](https://en.wikipedia.org/wiki/Conflict_of_interest) to subtly direct customers away from teleportation and toward some more lucrative alternative. Because the Mom Group Told Me To: I heard teleportation causes autism. [Answer] There was an Isaac Asimov story -- I think it's called "The Door" -- about a little boy who started walking home from school instead of using the teleporter like everyone else. His worried parents had him talk to a child psychologist. The boy takes the doctor on the walk with him, and the doctor learns the boy just likes the outdoors. In fact the doctor starts taking walks himself. [Answer] Orientation If you instantly travel to a destination, then relative to what do you travel? The roleplaying game Traveller has this as a restriction on teleportation: You arrive with the same orientation and speed as you left. There's a lot in simple physics that restricts teleportation ranges. If you teleport too much up or down, the instant pressure difference you experience will be quite unhealthy. If you teleport to the other side of the planet, you will arrive upside down. Also, the ground under you will be spinning the wrong way relative to your movement, depending on your latitude possibly quite fast - speed at the equator is 1650 km/h. If you teleport to the other side of the Earth from and to the equator, you are upside down and moving sideways at Mach 2.6 If your teleportation does not account for orientation and relative speed and pressure differences and all the other nasty details of physics, then by those simple laws teleportation is limited to short distances where the difference are manageable. [Answer] Your pets. You might be able to overcome the fear of going though a wormhole but your dog runs away at the first sight of a wormhole. So if you want to travel with your pets you have to go the old fashioned way. [Answer] Nostalgia. Many people will drive big muscle cars from the 1960's- 1990's. Not because it's cheap. Not because it's easy (maintenance is very difficult), but because it's their hobby/something they seek enjoyment out of. One can imagine that a hyperloop and all other forms of transportation were created before teleportation, as technology advanced slowly. You can reference nostalgic feelings to justify this: * The acceleration of starting in a hyperloop * The gentle rocking of a sea-ship * The weightlessness of a spaceship * The cool, gritty feel of the ceramic heat shields as you wipe the flame-retardant polish on the belly of your entry shuttle before taking off. [Answer] Because the cost is per kilogram of matter. Teleportation is fine for individuals, but freight is sometimes transported other ways for cost reasons. [Answer] It damages space-time Like in [forest's answer,](https://worldbuilding.stackexchange.com/a/135327/49819) I'm going to pull from TNG. In the TNG episode [Force of Nature,](https://memory-alpha.wikia.com/wiki/Speed_limit) the Federation discovered that high speed warp travel was actually causing subspace emissions (pseudo-science, roll with it) that damaged the structure of local space-time wherever there had been high warp traffic. This was demonstrated when the scientist Serova overloaded her ship's warp core, causing it to effectively tear a hole in space-time. Though she died, her actions had the intended effect of pushing warp-capable civilizations to limit the maximum warp-speed allowed except in the most dire of need. Now, one way to interpret a wormhole is that you are tearing a hole in two separate points in space-time. Taking inspiration from the plot described above, it's not unreasonable to think this might cause long-term and cumulative damage. If your wormholes do in fact cause that kind of damage, then it seems like a very good reason to use these only in the greatest of need. [Answer] You probably want to take a peek at [What if a portal is opened from the Mariana trench to the Sahara desert?](https://worldbuilding.stackexchange.com/questions/79797/what-if-a-portal-is-opened-from-the-mariana-trench-to-the-sahara-desert) Essentially, one of these wrist-mounted devices could destroy the planet. What happens if you open a wormhole between two places with significantly different air pressures? Highest air pressure is 1084.8 hPa, lowest is 870 hPa, assume a round portal 70inches across, so 665,174 standard cubic feet/minute from <https://www.tlv.com/global/US/calculator/air-flow-rate-through-orifice.html>. That works out to 24,894 feet/minute, or 282mph winds. This is as fast as the strongest tornadoes eer measured, and plenty fast enough to demolish buildings, and turn anyone passing through it, or nearby and sucked through it, into a puff of red air and bone-shard shrapnel in the first few seconds. So even without water, just moving from atmosphere to atmosphere, portals may simply kill people. Unless they can somehow withstand pressure, yet not withstand the pressure of a person walking through them, they are a deadly tool. Unless you're willing to handwave away air pressure, and the possibility of terrorists dropping one into the ocean, they would need very strong and non-overridable security constraints. Then there's the obvious violation of the first and second laws of thermodynamics, in that you could get infinite energy from gravity. One possibility is to have the portal require energy equal to the change in potential (some variation of gravitational, electrical, magnetic, kinetic, etc) between the two points in order to pass through. Then the air molecules on either side would be held at bay, as they would lack the energy. This would also mean that if you were to portal from one side of the equator to the other, you wouldn't suddenly be moving at 2,000mph counter-spinwards. Instead, you'd need to do it in a series of hops, and the work required from the walker overall would be the same as the kinetic energy required to change their velocity by 2,000mph over that time. This - preservation of potential - would be plenty to make people prefer other methods of travel if they can. Though there's still the problem of what happens if two portals are opened to the same target coordinates at the same time, and two people step through into the same spot. ]
[Question] [ The world is identical to earth except for the above, which only started happening about 40 years ago. In addition to the miracles there are also a group of humans who have started developing telekinesis and mind reading. The miracles and spirits' strength are not limited to one particularly religion. There is also a dramatic rise in ghost sightings. The types of miracles: Healing, bringing the dead back to life, calling on divine judgment. Basically the same type of miracles that people claim to have happened to them today, so commonly that veracity cannot be denied. Visiting spirits: They come and visit us every few years, sometimes they talk, usually they just look around and then leave. But sometimes particularly the benevolent or malevolent ones will either hurt or help The mortals they come across. They have over the past 40 years appeared in some very public places, been recorded on camera countless times, and been seen publicly to do some very impressive supernatural feats. About a year or so back reporter finally managed to get an interview with One particularly malevolent Spirit visiting Earth before a group of priests banished it. It claimed to be a demon Sent From Hell. [Answer] As a Christian I'd say, How is this all the different from the real world that we live in? There is ample proof of the existence of God -- historical, scientific, philosophical, etc. -- and yet some people still refuse to believe. Ok, I'm sure any atheists here are immediately raising their hackles at that paragraph. But surely any rational rebuttal would have to be on the order of, "The evidence is not convincing at all". So what constitutes convincing evidence? What is convincing to you may not be convincing to me. For example, people who believe in ghosts can point to thousands of eye-witness reports, photographs, readings on their ghost detecting instruments, and so forth. Personally, I remain unconvinced. But why? If someone claimed to have discovered a new species of tree frog, and had many eye witness reports, photographs, etc, I doubt I'd question it for a minute. There are lots of controversial questions in the real world. In many, many cases people on one side or the other insist that the evidence is overwhelming, and that those who disagree are just denying reality. In some cases people on both sides say this about each other. Do I need to give examples? I'm sure you can think of many. If people are committed to an idea for philosophical reasons, or because they have something to gain by affirming it, it takes a lot more evidence to change their minds than if they have no particular stake. And in real life, it's often not that hard to explain away evidence. To get back specifically to the supernatural and atheism: I've often heard atheists say things like, "If there really is a God, I dare him to strike me with lightning right now!" Suppose that someone said that, and at that very moment a bolt of lightning tore through the roof and knocked him senseless. Would news of this event instantly lead all atheists in the world to believe in God? Surely not. I'm sure 99% of atheists would say, "Wow, what a bizarre coincidence that was." If the man wasn't badly hurt they'd be laughing about it. I'm sure plenty of atheists would say that it "probably never happened, just a story Christians made up". Even if there was video posted on You Tube, atheists would claim that it was a hoax. They'd quickly have all sorts of proof that the video was doctored. Etc. And I can't fault atheists for this. Suppose you saw a story on the news tomorrow that said that something that you are quite certain about, say the existence of gravity, was in fact a big mistake or a hoax. Suppose you saw a headline, "NASA scientists prove that gravity is a hoax: rocks don't really fall when you drop them." Would you immediately abandon your belief in gravity? I really doubt it. My first response would be to wonder if this was some sort of joke. If convinced it was serious, I'd ask if what they really meant was that there was some special or extreme case where gravity doesn't work like we've long thought it did. Etc. So I'm sure atheists would come up with plenty of alternative explanations for the observed events. Ranging from "that never really happened, it's all a hoax" to "here is a more plausible alternative theory". [Answer] Atheism would certainly be a different thing, but I can already see a few reasons to be an atheist yourself in that world. First of all. If all religions are equal with respect to those miracles, then none of them is right about god or how to serve him. Miracles would be like the rest of the world: a proof that it is more complex than we think it is. Second, from what you say, spirits are enough to explain those miracles, so there is no real need for a god (or multiple ones) to justify miracles. What do spirits say about gods ? They seem to be the ones in charge. The fact that priests banished a spirit may be seen as a conspiracy to avoid the spirit addressing the issue. Lastly, from what you say, religion seems to have taken a pretty hardcore turn. I mean, priests from all religions are fighting demons. Chances are, they'll probably fight priests from other cults. That has happened before, and as miracle will be claimed by churches to be proof of their belief, we may end up with a lot of [Elijah style contests](https://en.wikipedia.org/wiki/Elijah#Challenge_to_Baal) (they don't end well). Someone with peaceful intentions may want to declare himself as agnostic or atheist as a simple way to say "I'm not trying to kill you". UPDATE (after precisions from the asker) Now, some (or all) spirits may well be revered as gods, as they seem to be in charge. Most likely religious people, politicians and scientists would try to talk with them about their origin, intentions, purpose and nature. As they seem pretty uninterested in answering though, worshipping of them would unlikely thrive in the western christian society (not that it is only society, it's the one I know best). Religions don't like new competitors, and telepathic telekinetic inquisitors from already in-place religions would probably make sure people stay in the "true faith". Now, I'm assuming we keep the Christianity in charge of things. Why would people not follow? As the definition of atheism as been discussed in pretty much all answers, I'll try to cover most of them. * Some people would refuse to accept the existence of that. There are always people who can't accept the facts and there always will be. * Some people would refuse to acknowledge the divine/supernatural element (I probably would be in that category). Except for a malevolent non-trustable one, no spirit seems to have claimed a particular myth. Why jump to conclusions when we obviously know nothing? * Some people would consider the apocalypse is now in and they have been forsaken by god. The poor lads may renounce their faith (traumatic events can have that impact AFAIK). * Some people would accept the divine thing, and refuse to be part of any cult of non-benevolent beings. You don't pray just because of power, or a spirit/mage caused harm to you. * Some people would just not care. Probably more than you think. I mean, in a sense, technology as given us powers and most of us don't care how. 20 years later, teenagers seeing people impressed by spirits would go "dude, this is year 2036, chill up a bit" or whatever kids will say those days. Now, let's address a bit the actual divinity of spirits. First of, I ripped most of my ideas about the nature of divinity from reading [The Chronicles of Amber](https://en.wikipedia.org/wiki/The_Chronicles_of_Amber). A series of books anyone should read. In those books, people with god-like powers (immortality, world creation, time bending, being superior at anything) are shown as human, sometimes even childish. It does a great deal about showing that divinity is mostly a matter of point of view. They are god to us the way we are gods to our pets (or to insects, if you prefer). The second part of the series even deals with omniscience and omnipotence, then again showing how those powers are not what makes the "essence" of a god. So, to sum it up. "What is a god?" is to me a semantics question. We'll decide to adapt the definition to whatever we want to worship. Are spirits gods or not? Your call as a worldbuilder. They may or may not be as you wish. Will they be seen as gods by humans? Some probably will. (I tried googling "weird religions", I won't do that again). Some won't. That probably will depend on the spirits behavior and you haven't developed that yet (if you do, I'll have to add titles and subtitles to this post). [Answer] Since nobody has said it yet: ## Sufficiently advanced technology is indistinguishable from magic Generic statement about sufficiently advanced aliens, but that's not the point I'm trying to make here. For those who prefer the Hitchhiker's Guide to Clarke, this is more my point: > > Now it is such a bizarrely improbable coincidence that anything so mind-bogglingly useful could have evolved purely by chance that some thinkers have chosen to see it as the final and clinching proof of the non-existence of God. > > The argument goes something like this: "I refuse to prove that I exist,'" says God, "for proof denies faith, and without faith I am nothing." > > "But," says Man, "The Babel fish is a dead giveaway, isn't it? It could not have evolved by chance. It proves you exist, and so therefore, by your own arguments, you don't. QED." > > "Oh dear," says God, "I hadn't thought of that," and promptly vanishes in a puff of logic. > > "Oh, that was easy," says Man, and for an encore goes on to prove that black is white and gets himself killed on the next zebra crossing. > > > It's much easier to believe in something that is vaguely out there, that way you can get some real believing done. If something is here and now and in your face, it's hard to believe in it. I don't believe in the postman, I know he is there, I don't pray to him to bring a parcel, I know what I've ordered is coming. Actual proof takes gods to the level of the postman, once you know they exist, you don't believe any more. "God" becomes just another job description rather than a special thing. We don't kneel down and give thanks to our doctors morning, noon and night for all the times they may have saved our lives in ways we don't truly understand. Nor would we kneel down and pray to these "gods" with abilities we don't understand once they become a regular part of our lives. Atheism becomes not a denial that they exist, but a denial that they're anything special. [Answer] A world where religious miracles are real is a world where gods are real too. Otherwise they would not be religious miracles, only mystical events falsely believed to be religious. Then, in this world where gods actually exist, being an atheist would have a very different meaning than it does in our world. In this world being an atheist would mean that you reject reality and deny what you have seen and experienced. You would have to make up alternative explanations for why miracles happen if they are not granted by god. And if you are in the habit of denying reality and making up your own explanation it seems a given that you will not be very scientifically or logically minded. So you could explain it by strong sectarian leaders in radical groups who are fighting to gain more power and spewing this nonsense to their followers. Or you could explain it by madness. Neither is entirely implausible. And it might be a lot of fun to write. [Answer] Atheism is rooted in the idea that one should only believe facts that can be tested and observed. In the universe described those creatures that some are calling angels and demons and the people that have those psionic powers are something that can now be observed and tested. Now they know that there are new, previously undiscovered laws of physics that are dictating how these creatures are operating. Atheists in this world would believe something similar to what [notovny](https://worldbuilding.stackexchange.com/a/44378/21639) said about the spirits. Their existence doesn't presuppose a God or gods, they would see these entities to be aliens that have either come from a different dimension or just a different corner of the universe. Atheists in this scenario would just see the "supernatural" acts as some sort of advanced science that they don't understand yet. [Answer] Sounds like aliens to me. Since no, one, religion is getting more miracles than another, and they are all so contradictory, it must be something else causing the strange occurrences, possibly extra dimensional in origin. Especially since there are "psionic" powers manifesting, obviously something is reading minds and granting wishes, possibly in preparation to an invasion. `</tinfoil>` The non-believers, in universe, have no compelling reason to think there is a divine origin, nothing in the question indicates any reason to think they are. The fact is: that religions will grasp at anything as proof of their version of their religion. Additionally there is no way to prove what the "spirits" are saying, it may be spirits, demons, or aliens. Who can say without study and proof. :) [Answer] Atheism could take the form of denying that the so-called "gods", real though they may be, have a right to rule or that humans have an obligation to serve or worship them... though this would depend on the specific nature of the world - are they omnipresent? clearly benevolent? even if they can force humans to serve them, do they seem inclined to (if not, why volunteer)? Phrased differently, on the one hand, you have people who believe there are gods, and on the other hand people who believe that the very same beings are not gods, without denying any of their actual feats. A belief that all these "miracles" are just sufficiently advanced technology or wizard's spells or something like that could even attract followers as a religion of its own since it promises that humans can eventually reach the same level [Answer] # Atheism is rejection of faith First your question is wrong in that it assumes atheism is about the rejection of god/gods/spirits/supernatural creatures. It is not. A-theism is the rejection of theism. Theism in turn is the notion that a human being can know the mind of god(s), and that this human therefore commands higher influence in public discourse. ...or shortly put: atheism is telling the one that claims to speak for god(s): "No, you speak for yourself and other humans that share your faith". --- EDIT Start --- If by "atheism" you mens something else in your questions, then please specify that in the question so we know what you mean when you say "atheists". But let it be known that if by "atheism" you try to attach anything that can be construed as unreasonable, irrational or outright idiotic to the term, here you have at least one atheist that will tell you that you need to label that as such and not "atheism". If there is one thing we as atheists — in general — pride ourselves in it is rationalism and adherence to observation and deduction, no matter what the conclusion is. Belief in contradiction of observation, or — as is most often with religion — in absence of observation, is what we oppose. --- EDIT End --- So how do atheists react when suddenly miracles start occurring? Exactly the same as before: rejecting the human that claims to know on faith. They will however listen to the one that brings proof, or even better yet: hear it from these creatures themselves. Do note though that miracles are not proof of divinity, truth or righteousness, nor do they command reverence, obedience or worship. Before any such notions we will want to have a long good chat with these beings and have their viewpoints on morality and ethics. And if they try to push us around with commandments that do not sit well with our sense of right and wrong, you can expect there will be trouble. And why so? Why does the supernatural not command reverence? Because you and I are supernatural, in the eyes of pretty much everyone of our ancestors a mere 200-300 years removed. You are dying of a wasting illness that makes your flesh fall apart for no apparent reason? Behold, I give you [this greenish-yellow fruit from Persia](https://en.wikipedia.org/wiki/Lime_(fruit)), that tastes sour (but goes well with gin). Eat it, and [your malady](https://en.wikipedia.org/wiki/Scurvy) will be cured. How it works? Oh it simply makes it so that your body does not melt itself from its own body heat. Gather around all ye, and watch how I — with this water wheel, some copper wires and a metal core — create [a magical force](https://en.wikipedia.org/wiki/Electricity) that can create light in the dead of night as if I had [harnessed lightning in a bottle](https://c2.staticflickr.com/8/7514/15877760166_7095925822_k.jpg); that can make your millstones turn without either thrall or oxen touching it; that can melt metal in an instant either fusing it or making it split apart; or even kill you horribly as if you had the fires of hell coursing through you! Look here... now smile! Look, I have captured your likeness in this strange device. And not only that: it can capture your motion and your voice as well and repeat them verbatim to you. The smallest child today can affect "miracles" and feats that even the most learned of days past could only dream about. Something as simple as being vaccinated, and thus untouchable by smallpox, tuberculosis, polio, would appear as totally miraculous by our ancestors. To us, it is an annoying prick in the arm and a swelling for a few days. So if by some happenstance we are suddenly plonked down in ancient times, would it be wise for those people to start worshipping us and obeying our every command, just because their priests/shamans/elders tell them so? Of course not. we are still no more than human... worldly, earthy and just as flawed as before. Atheism is the rejection of all those that try to elbow their way ahead in the public discourse by saying "I have faith that I know the mind of these supernatural entities, so you must obey my commands". And that does not change when supernatural things start appearing... ...as popular culture has long since proven: <https://www.youtube.com/watch?v=rvVP740Pt3Y> [Answer] Atheism just means without gods. In your world it could mean that Atheists just deny that this beings are actual gods. For example: Atheists could claim that your beings are just higher evolved than we are. [Answer] Kratos Style, for a start. In a world like ours, where the existence of deities can neither be proven nor disproven (be it scientifically or de facto), atheism is an exercise of philosophy. However, in a world where the gods manifest themselves and make their presence perceived in a very concrete way, you can deny the existence of gods in a more practical way. You don't just state that they don't exist, you make sure that they don't. Granted, this might take some considerable effort. Gods are usually depicted as being more powerful than humans (and elves, and dwarves, and all other sentient populations). They are usually very protective of their existence too. But there are a few stories in our world where deiticide happens, in a number of ways. One of my favorite stories where gods are dying and/because people are stopping to believe in them is American Gods, by Neil Gaiman. I don't want to spoil the story too much, so all the information I'm going to mention here will be what you would see in a review of the book. The gods of ancient mythologies are all real, but they are slowly dying because they have fewer believers everyday. There are new gods who are hogging all the available worship, but for some reason the new gods don't want to be seen as deities. The new gods are beings such as the media (whose altar is the TV), technology, market forces etc. So you see, in that scenario, the ancient gods are starving, and atheistic and agnostic people worship new gods without knowing any better. Granted, many people in that world do worship a known God - the monotheistic God, so they cannot be called absolute atheists - but in a similar scenario of yours, that one God may be a target for the new gods as well (or any other god-killing force/organization/being of your design). [Answer] I'm somewhat surprised no one has mentioned this actually, but, the definition of an atheism is "Disbelief or lack of belief in the existence of God or gods." (Oxford English dictionary). And, well, when describing most atheists I know, including myself, the important part is "a lack of belief in the existence of a god or gods". Belief is defined as "An acceptance that something exists or is true, especially one without proof" (again, Oxford English dictionary). Going by these definitions, I am an atheist in the face of God, not because I reject their existence, but because I take nothing about them on faith. I do not believe in them, once they are proven me, I require no more faith to see them as real then I need to accept that my dog is lying beside me. Once they are proven to me, they are no more mystical than anything else, they may wield great power, and I'd be interested to know by what means they do so. But I am not in reverence of them, because power alone is no reason in my mind to revere anything. Granted, saying that, you'd have to give me proof beyond a reasonable doubt that something was a deity, before I'd accept it. But I would be happy to review any such evidence you showed me. There are those who subscribe to the idea that gods are impossible, they'd have a lot more trouble. But I think a lot of atheists would be, well, startled, but unfazed in their atheism. [Answer] They deny what they clearly see. Some of them might accept that what they see is reality, but believe that it is a manmade deception (conspiracy theorists). Maybe it's an extremely elaborate series of hoaxes--some actors, special effects and magic tricks/illusions. This would seem an especially convincing case since the inception of such occurrences has been fairly recent. Others might also accept that what they see is reality, but believe that it has a misunderstood natural explanation rather than a supernatural one. In ancient times in our world, many natural phenomena were explained away as supernatural (hence mythologies of ancient civilizations) before we discovered their natural explanation. Some people will likely believe that this is what the vast majority of people in your world are doing. Other people might not accept that what they see is reality. Maybe they believe that they have gone insane, or that their memories of the events have been fabricated. Maybe we are all [brains in a vat](https://en.wikipedia.org/wiki/Brain_in_a_vat), maybe we are [looking at shadows on a cave wall](https://en.wikipedia.org/wiki/Allegory_of_the_Cave), or maybe the unbeliever is, himself, dreaming, and waiting to wake up. Still more people may simply downplay the significance of what they see until it is reduced to an unlikely mechanical triviality. There's nothing physically significant about a resurrection--no physical change was made to the functioning body when it stopped functioning, so why would it have a hard time resuming function? John was cured of AIDS? The viruses must have all died. Crazy glowy lady in the sky? Weird stuff. Basically, all the reactions real-world people have to something they can't explain. For example, the [floating city above China in October 2015](http://www.dailymail.co.uk/sciencetech/article-3276576/Is-evidence-parallel-universe-Sightings-floating-city-China-simply-optical-illusion-say-scientists.html). It is assumed to have been an illusion (not reality), but for a while was popularly thought to be proof of a parallel universe (misunderstood natural explanation), and some people even thought it was a test of holographic technology by NASA or the Chinese government (hoax). [Answer] The spirits are lying, or deluded, about what they claim to be. Perhaps they are aggregate manifestations spawned from humanity's collective consciousness, or extraplanar entities entering our universe through the prism of framework of what humanity believes. An atheist could claim that the entities that people are calling spirits, angels, or demons are not the entities that they say they are; that this thing being heralded as an archangel (for example) is not actually an archangel and has no more valid claim to be a manifestation of divinity than a human religious figure would have. [Answer] I see a few key options. 1) Any sufficiently advanced technology is indistinguishable from miracle. This is the big one, technology can do impressive things, in the past may previous 'miracles' or 'magics' were proven to have technological answers, so why not now? People will presume a technological explanation is the only valid one and just because they don't yet understand the science behind these particular issues that doesn't mean that one doesn't exist. Frankly that is the logical explanation to presume at first. In fact the presumption of technology that is simply not fully understood is likely going to underlay all the other issues... 2) Hoaxes, hoaxes, and more hoaxes. Someone may believe many of these so called miracles are hoaxes or faked. This won't be helped by the fact that many hoaxes will come to light around this time, people jumping on the insanity by trying to make a quick buck with some faked hoax will be common, and thus documented hoaxes will show up quite a bit around this time, encouraging people to presume other non-hoaxes could just be hoaxes that haven't been proved yet. 3) If I sign up now can I order a stylish straight jacket Mass hallucination/hysteria may also be partially used to justify either claims of miracles or similar affects. Someone may consider themselves insane for having seen what can't possibly exist. 4) Logic bomb god, not all religions can exist. Many religions have mutually exclusive facts, such as explanation as to how the world started or who goes to hell. Thus it's impossible for every religion to be correct, thus something must have failed. 5) Naythist: just because you believe religion may be real doesn't mean you are supportive of it. You may still think God is a jerk or doesn't deserve worshiping whatever. 6) *That isn't MY* religion** related, maybe the miracles are inconsistent with how you view religion. As a random example maybe some miracle is done for someone you believe is a sinner (gay person, abortion clinic workers whatever) to the point that it can't possibly be your god who would support those sinners, thus it must be a hoax, or maybe a trick by the devil to mislead you into improper faith. [Answer] The problem is what you define as God. For example, a religion that considers the Earth a god. Well, the Earth is a real thing. It allows us to live which is miraculous. Does that make it a God? Today, we would likely say no, because we understand all the processes and interactions that take place to allow us to live on this big ball of rock. If these miracles are as common place as you say and potentially dangerous, then there would be people going around the clock trying to understand how they work physically. An Atheist would be someone who aligns with the view that these are simply powerful beings, but not Gods. Truly, the downfall in the belief would be allowing people to see the miracles at work. Because once humanity sees something it doesn't understand, as long as it can repeat it/see repeats of it you can bet it will understand it eventually. [Answer] Since atheism is something like "not believing in god and angels", someone that is really atheist would rather try to describe the angels in your world just as super-evoluted living beings or either stop to be atheist. From the point of view of people living in your world, an atheist is someone that does not believe in that world, or do not believe that world is real. And that's kind of funny stuff because is contradicting, but just because I overlooked the true meaning of the word atheist. Being an atheist is in reality essentially the following statement: > > "Atheist is someone that reject claims that cannot be disproved". > > > That is different from > > "Agnostic is someone that does not keep into consideration claims that cannot be disproved". > > > That's it. You cannot [prove nor disprove God Existence](https://philosophy.stackexchange.com/a/34429/20746), because God was defined as something that cannot be disproved. If there are miracles then you proved their existence, and that's already out of the field of atheism because if you can show a miracle (whatever the definition of a miracle is), then you actually proved it. Atheism is not about claiming miracles exists, an atheist will claim that miracles do not exist unless you can show one which is deeply different. This is a totally logical point of view, everyone can say X, and you should prove X is true, not waiting for others to prove that X is false, otherwise we could say also X,Y,Z,E,K,J and suddenly lots or religions will arise from nothing. There will be always space for atheists, because simply in every system (mathematical concept) there are always statements that cannot be proved (a system where you can prove everything is a system starting from fake hypothesis). So in any given world there will be atheist, defined as a group of people that want evidence for any claim. I'm not claiming in anyway that atheism is right or not. [Answer] You suppose that supernatural things must have a creator God, but there's no inherent reason for this conclusion. As you've framed the question, religion will have the same problems it does today, because if miracles and supernatural creatures are happening all over the place, that doesn't much justify any one religion's claim, or indeed the very concept of a God. There may be a universe of supernatural spirits and no God. The lack of evidenced connection between the two, and random distribution of these incidents, will make lots of people confused as to their origin. Supernatural things wouldn't be evidence in support of a religion claim unless it was very specific and had a very obvious connection. Still, many people from every group are just stubborn and will cling to their beliefs and opinions regardless. It's uncommon for people to change their minds about things, especially big issues. Because their beliefs are part of their identity, and if they lose their beliefs they lose their identity; and that's a hard sometimes painful process emotionally. Especially if it risks alienating all your friends, family and social networks. So your fictional world will mirror this one very closely in terms of psychology, where priests are still priests even though they've lost faith, or communists are still communists even after the USSR fell. Because they're too invested, basically. Even if miracles are common place, most people may not have actually seen one personally. [Answer] The answer depends on your choice of definitions. First of all, you claim supernatural feats. However, observing the phenomena to be repeatable and real (that is, reliable) means that it is not supernatural. Your question amounts to saying that what was supernatural before is natural after the change. Likewise, the choice of phrase religious miracles seems to lead the kind of answer you want. That is, meaning A: people are irrational in not accepting the nature of the world around them. That puts them in the same bucket as today's flat-earth crowd. There are plenty of natural phenomena that people refuse to "believe" or put their own quack spin on. Or, you could mean that they use the word to indicate that they don't take things without evidence, and are willing to change their mind when new facts come along. So, meaning B: they have no trouble accepting that these things are happening, just as they accept that quantum tunneling happens and electrons can be put in "cat states". However, they don't ascribe that to any reason and any connection with traditional religious beliefs (stories based on previous episodes where these things happen?) is a topic of current research and can't be known without deeper understanding, if at all. [Answer] Use exactly the same language that religious people currently use to explain their theism in the face of overwhelming evidence to the contrary. ``` Do you believe in the gods? No. But you can see the evidence of their works all around you. My parents taught me they don't exist, my school textbooks said they don't exist. I have faith in these authorities. They teach the truth. But what about the evidence? This is a question of faith. Who are you to question my faith? ``` You could have a lot of fun with atheists flat out refusing to acknowledge the existence of supernatural events or supernatural creatures. A sort of supernatural luddite community. Constantly in trouble and at a disadvantage, but steadfast in their beliefs. You could even draw on the Mennonite assertion that life is better and simpler without the modern complications of the modern world. Simply replace science and technology with the religious and magical. [Answer] You can't prove that something does not exist, and it is often difficult to prove that it does, hence Faith is easier than one might first anticipate, with so much uncertainty about. That Faith has taken so many forms, and is so pervasive throughout human history, is evidence that it may actually provide a very slight evolutionary edge to believers. Many anecdotal stories, from scriptural to Readers' Digest tell of those who overcame great odds, trials and challenges because they found emotional (sometimes physical) strength through Faith. Essentially, the opposite may be true of the 'atheist'. It was once said that there 'are no Atheists in a Foxhole'. In day to day non-life-threatening moments, some people may choose to deny Faith to promote a sense of self-empowerment, at least until the first volley of shells arrive. You can't actually see air or hold it in your hand, or stamp you name on it, but you feel its force against you, and living without it just doesn't work out at all. Just my observations. [Answer] There is some precedence for this idea in The Atheist, a horror comic where present day humans are being possessed by souls from Hell: [![The Atheist Comic](https://i.stack.imgur.com/ZRRee.jpg)](https://i.stack.imgur.com/ZRRee.jpg) From [Wikipedia](https://en.wikipedia.org/wiki/The_Atheist_(comics)): > > Antoine Sharpe - the main character who has the nickname "The Atheist" not for a lack of religious belief, but because Sharpe has an "uncompromising brand of logic." > > > In a world where fantasy is real, "atheist" becomes a figurative word, a term of endearment, like how we might call someone who fixes our computer/car/appliance a "wizard". They aren't actually atheists, they're just reminiscent of the atheists of legend and yore. [Answer] There is no need to explain it. In fiction, people tend to accept a worldview from real life as plausible, even if it actually makes no sense within the fictional setting of the story. Atheism may not be consistent with the world you describe, but people won't notice because atheism seems inherently believable, based on their real-world experience. Examples: * In 99% of Christmas movies, Santa Claus exists, and presents for every child appear under everyone's Christmas tree, with no other explainable source, yet none of the adults believe in Santa Claus. This is never explained. * In the X-Files, Scully continues to disbelieve paranormal explanations for anything they encounter for years, even after running into aliens, vampires, werewolves, people who can shift their shape, etc. This is presented as the "scientific" position even though it is decidedly unscientific and illogical to take this position in the face of overwhelming evidence to the contrary. You can probably just go with this, and offer a weak explanation or no explanation, and you won't have a problem. [Answer] Conspiracy theory In your world, there are obvious proofs of divine interference. However, there always will be people who will say, those all proofs are fake and the non-divine entity is making the up in order to make people believe in something that doesn't exist. There are people believing that space flights are fake and even the fact you can see ISS using telescope doesn't convince them. It will just be quite a small and extravagant group. [Answer] It is, perhaps, useful to draw a distinction between atheism as a religious position and atheism as a rational position. In the first case you simply choose to believe that no gods exist in the same way that members of a particular religion choose to believe that their particular god or gods do exist. By contrast a rational atheist would take the position that there is so little evidence for god(s) that the proposition is not even worth considering. Here the term 'atheist' may even be a bit superfluous as they are simply going with the evidence and lack of belief in god is no different to lack of belief in faeries or goblins. There is also the dimension that 'theism' in practice implies not only a belief in but also worship of a deity. I would certainly say that the god depicted in the Old Testament is not an entity I would be inclined to worship even if its existence was proved beyond all doubt. I believe that Caligula existed but I don't worship him. Anybody of a scientific frame of mind would immediately ask what the existence of spirits, angels etc. actually implies rather than immediately accepting it as proof that we are all subjects of an omnipotent god. [Answer] The atheists would be like creationists in our world. There are plenty of young earth creationists on earth that deny all evidence for evolution and for the earth being older than 10,000 years despite that evidence being overwhelming. David Copperfield manages to fly-on-stage and let elephants disappear. Plenty of atheists would see any evidence for religious miracles as fake. The fact that chriopractics can reduce back pain is backed up by a [Cochrane](http://www.cochrane.org/CD005427/BACK_combined-chiropractic-interventions-for-low-back-pain) meta-study. You still find plenty of atheists who believe that chriopratics never help anyone. I have spoken with an atheist who would find it troubling if a person goes to a homeopath even in the hypothetical scenario where that homeopath would be the person most likely to cure the person. People have all sorts of worldviews that differ from reality. [Answer] It is all in the definitions; exactly as in our own world. Does an atheist disbelieve in any gods, all gods or in the concept of God? Miracles happen everyday if you believe and not at all if you do not. Countless people have tested God with the result that they became believers. Countless people have refused to believe and have become believers in the non existence of God. Countless more believe in a pantheon of 'utility gods' that are responsible for various aspects of life. If I understand God's position correctly, God does not need any of these 'believer' groups to exist and be in control. Evolution remains a theory and no conclusive 'proof' has yet been found and yet the majority of people believe in it. In the society you project atheism would be like faith in our world. It takes at least as much faith to believe in evolution as it does to believe in creation, and while the argument for evolution and against God has largely been to use the word science a lot, many scientists are actually believers in God. But you do not have to be Einstein to believe in God... and you could always ask Him... :-) In the world you posit you say there are demons, and in conventional thought demons are minions of the devil, but ask yourself if the devil can exist in the absence of God? Who then can the 'opposer' oppose do you suppose? Minus means nothing in the absence of plus. Black loses its edge without white... ]
[Question] [ In the setting of a royal court in a stereotypical 'medieval' low-fantasy world, the royal princess must obviously be guarded. Assuming this society sees it as 'unbecoming' for a woman to be armed, any offical guard assigned to her would be male. However, it is equally unbecoming for a male, guard or otherwise, to accompany a woman into certain 'female only' areas. (Bath, bedroom, etc.) Unfortunately, those sneaky assassins have no concept of honor or common decency and will happily barge into these areas to perform their distasteful task. Enter the covert bodyguard. She is a woman trained in typical servant skills, but she additionally receives rigorous combat training. She is expectd to stay hidden, seeming to the world nothing but an unassuming domestic servant, perhaps a little more 'attached to the hip' to the lady she serves than most servants. Only when her charge is threatened does she spring into action. This means her weapon of choice must be easily concealable, she will not be wearing more than the lightest of (concealed) armor, and she must make up in visciousness the advantage that an assailant has in preparation. In combat, this bodyguard's first priority is to get her charge to safety. She will prefer running away over engaging, and only when there is an enemy between her and the nearest exit will she draw her weapons. When she does draw steel however, it means that there is an obstacle that must be removed, and this obstacle must be removed as quickly and effectively as possibly to minimize the time they have to bring their greater physical strenght and better weaponry to bear. In this situation, the advantages I see for dual daggers are the following: * They can be (more) easily hidden * They are relatively easy to wield * They can be used to target weak spots in heavy armor * There is a certain psychological effect to being charged by a screaming woman, slashing at you with knives in both hands * Using both hands allows more flexibility in attacking, especially if the wielder also happens to be ambidextrous. There are of course also disadvantages: * They are only light weapons, less effective against heavy armor. This is mitigated by the average assassin being a sneaky killer in light, perhaps medium armor, rather than a soldier in full plate. * They do not allow for using a shield. However, a shield is not easy to conceal and as such not an available option anyway. * They require extra training to use compared to a single dagger. This is perhaps the greatest disadvantage, but I imagine the psychological factor in combination with being able to use either hand to strike gives much greater flexibility in those precious initial seconds she has against a surprised opponent. Would this be a valid weapon choice for a concealed bodyguard? TLDR: For a bodyguard that is expected to remain hidden unless necessary, with the express purpose of getting out of a sticky situation as fast as possible rather than standing and fighting, would dual daggers be a viable choice? [Answer] Daggers work, but history is the best teacher here, and history says the simplest weapons are the most effective. In this case, a spear. Specifically, a cane or walking staff with a removable wooden head that reveals a metal tipped spear. Such a weapon would keep an opponent away from their target, hopefully long enough for a real guard to intervene. A spear is effective against both armored and unarmored opponents. Add a little fantasy into this and you have an extending spear, a spear that extends to full size as needed but can be hidden inside the folds of a dress when not in use. It could even be strapped to their leg, never visible. Alternatively, it could be a cleverly disguised walking stick. The timeline described would be about the same time where every injury was serious. A broken leg as a child could give you a permanent limp as an adult, giving credit to why this maid always has a walking stick near by. This has the additional advantage that the weapon is always ready to be used, compared to a hidden dagger that must be unsheathed in the seconds before the assassin strikes. A spear is light weight, can be handled by anyone, and is extremely deadly with even only a little bit of skill. Even unrevealed, it's function as a staff to parry a close range attack is a huge asset. And it can be a non lethal clumsy defense as well. A child can run to the princess, slipping through the guards, and this body guard could weakly swing her stick haphazardly "in defense of her princess" to stop the child without killing it and without causing any real suspicion. There is a problem with this body guard plan though, it only works if the assassin is an idiot. If they have 2 brain cells to rub together, they will wait until their target is alone (The privy would be my choice), or dispatch the unguarded maid first. And they will probably bring a cross bow, because why kill close up when you can kill with one shot at range? [Answer] I'd like to submit a contrary view to the other answers. Daggers are bad and wrong (for defence) The main threat of a knife is thrusting, as it lacks sufficient force in strikes, or length in a slash, to do any real damage. Thrusts are very deadly, historically, but really terrible as a defensive technique. A thrust will kill the opponent, but it will often take several days for them to die, as the organ you have pierced festers. In the moment, however, it does not cause all that much pain. Compared to a hard blow to the arms, neck or head; a body thrust is not debilitating. (\) Note that this is the exact opposite of movies, where any number of blows can be sustained, but a thrust is usually instantly fatal, leaving only enough time for a dramatic final line. Since you are looking for a bodyguard, she does not care whether the opponent lives or dies, in fact alive but incapacitated is probably better. That way your would-be assassin can spend a while in the torturer's chambers, telling you everything you want to know. Knives, therefore are the opposite of what you want. They are deadly, but inneffective. You want: A Quarterstaff* A 6-foot pole of hard wood (oak, ash, etc) held by one end and one quarter, strikes a blow which will easily break bones. It causes immense pain, but has a low chance of killing, thus giving you the best odds of disabling the assailant quickly. It also has a distinct advantage when it comes to disguise. Historically speaking, the staff was the weapon most often learned by women. As you say in your question, it is not considered seemly for a woman to wear a sword, but a walking stick? Even better, once you know the techniques of quarterstaff fighting, you can use this very effectively with a variety of household tools. Garden hoe, laundry pole, rake, mop, etc are all very effective. The best, to my mind, is the broom. A birch besom is a staff with a thick bundle if stiff birch twigs on the end. As you sweep, the points are gradually filed into fine points. This forms a cloud of needle points, about the size off a face, which can be turned extremely quickly, since it is being held five feet back in two hands, and when thrust will gouge at the eyes and cheeks to great effect. Since you say that your bodyguard spends her time disguised as a servant, she has ample reason to always have at least one staff weapon to hand at all times. --- (\) For support for this fact we can look at two things, historical combat manuals and diatribes from the renaissance period, particularly around the introduction of the rapier, and also the modern epidemic of knife crime (particularly in the UK) where it has been shown repeatedly that carrying a knife actively increases the danger you face from knife carrying assailants, even if you kill them. [Answer] # Is really offense the best defense? As you stated in your question, your dual wielder is an emergency bodyguard, supposed to protect your princess in immediate emergency situations, with other bodyguards next door ready to intervene. So if this specialized female bodyguard have to act, it is for an action of seconds, maybe one minute if the male bodyguards are hesitating a bit to cross the door when the princess is screaming in her bathroom. In my mind, what you want in this position, is to stall the fight before reinforcement arrive, and protect the princess. Daggers are a close combat, offensive weapons, with not much of a stopping power, and are designed to kill. if anything is thrown at your princess, what will you stop it with? if the terrorist/assassin just run for the kill without a care for his own integrity, will your dagger stop his course? I wouldn't bet on it. # What seems to be better suited in this context? This is only my opinion and interpretation of the situation, so It is just if you need it, but why wouldn't you use some classic feminine attributes? an umbrella can be reinforced to stop some projectiles from getting to your princess if deployed quickly enough. it can be rather natural for some servant to carry an umbrella in case of rain, or to get some shade for the princess. you can also hide a blade in this same umbrella. in the blink of an eye, you get a decent sparring weapon and a makeshift shield, without the inconvenience of going through you pockets to get your daggers. But if an umbrella isn't part of your universe, why not carry fans? you can even have different set of fans to maintain the illusion that you are only a follower of the princess, giving her some fresh air if she ever need it, but one of them is hardwood reinforced to protect her from projectile, and another one is sharpened enough to severe an arm if one comes too close. Moreover, they can also hide a short dagger, so your dual dagger wielding female bodyguard is still an option, while offering some shielding to the one she is supposed to protect. [Answer] Dual Wielding takes a ton of coordination and training. But it's possible. Your biggest drawback in this scenario is that your lady Badass in waiting is supposed to be a body guard. She is not defending only herself but the princess. Two daggers is doable for one lady to defend herself, but a bodyguard has more to worry about. All you need to do is shift things a touch. Since the bodyguard is in disguise as a lady in waiting, and given the time frame you have a ton of options. Her first priority is to get the princess to safety. This means she will be shielding the princess with her body, probably leaving her back exposed. I base this on watching the behavior of modern bodyguards and secret service men. they always cover as much of the person they are guarding as they can, and this is best done by facing the target, not the threat. They do this until either someone else deals with the threat or the target gets to safety. In your case get at least some sort of thin armor concealed in the garments primarily on the back. Other areas that could conceal armor might be along the forearms and backs of the thigh. If your setting allows for those ridiculous ruffs and wimples, you could even stash a thin helm under the pointy hat and a steel collar under the goofy frills. The armor will have to be fairly lightweight for concealment and to prevent clinks and clangs. Hopefully it will slow down the bulk of assassin weapons long enough, or if it doesn't stop the weapon, it should bind it up. The body guard will call for help, cover the princess and hustle her off to a panic room or hidden passage or whatever you have. That is the core strategy. Don't engage the assassin until the princess is safe. Once the latch on the panic room catches, it's game on. Fans are possibly the most versatile. Keep a sharpened steel blade concealed in the slats. Even without the blade the fan can be used to defend. It's not built to stop the thrust of a blade, but more to redirect the point of aim. To deflect, rather than block. And unlike a dagger, a fan can be carried openly. Remember, most royals frown upon people carrying edged weapons too close. A dagger can be concealed, but it has to removed from concealment before use. A fan can be at the ready at all times. A Parasol or umbrella could also be carried openly. It is a stick, it can hide blades, and when open can obscure the target from threats. Again, it won't really stop things, but can be used as defense by deflecting. It can also be used as a short spear. wrap the small blade in rice paper to obscure it at the end of the umbrella. Then just poke. Or hide a small rapier inside the umbrella as a whole. Or, yes, a dagger. So get the princess to safety and turn on your assassin with the heavy dagger from the umbrella in one hand and the fan with concealed blade in the other. Her forearms will act as shields, her throat is guarded, and she can also seriously head butt with the helm inside the stupid pointy hat. For bonus points, give the princess herself a pair of slender daggers and teach her how to use them herself. [Answer] It's a good start* To quote Robert Heinlein > > Specialization is for insects > > > Are daggers a good weapon? Honestly, they aren't a bad one, they've got all the advantages you've described, but make sure you're using the right daggers. If you're looking to stab gaps in armor, you want a stiletto. On the flip side, an assassin that's attacking the princess when she's taking a bath is sneaking around, so probably doesn't have heavy armor. You'd want a dagger with more substance, maybe something similar to a combat knife, or even something cleaver-like for psychological effect. But take some more. The main disadvantage is range, obviously. A brace of throwing knives will offset that, good for mid-range fighting up to twenty feet at minimum and capable of killing people outright with good enough aim. A cloth belt is simple, but a braided one can be turned into a whip, possibly even tipped with a metal spike. Hair decoration can conceal lockpicks or darts. If the setting is right, they might have access to crude smoke bombs, which can be conceal in a canister. Poison is great too - a powerful paralytic turns a gash from a wound to the end of a fight, while keeping the assassin alive for interrogation. As for armor - take a look of Gambeson, a heavy cloth armor. Medieval ladies wore quite a lot of bulky clothes, and while armor is noticeable, just cloth layers aren't. [Answer] The bodyguard in question would not be a servant, but a lady in waiting. The duties of a lady in waiting can include helping the royalty get dressed and bathe and so on. It would therefore not be unusual for them to be in attendance at those times. (This is a rather prominent position. Think more executive assistant than maid.) In medieval times, it was customary for everyone to carry a knife at all times. This is used for both eating, and general knife-based tasks. This is not a weapon. A lady in waiting carries things the princess might need. This could include her knife. This is also not a weapon. If those knives happen to be of an design that's useful for stabbing people, they're still not a weapon. If both those knives happen to end up embedded in a would-be assassin, the design of the knives in question is the least interesting part of that event. [Answer] Yes. However, I wouldn't go with them or only with them. First, dual wielding is extremely hard. Having an off-hand weapon is different from dual-wielding. The later requires extreme coordination, skill and awareness or you may get in your own way. It doesn't give that much advantage unless you are borned to it (or trained from infancy). Second, it is hard and unwise to try to parry with daggers, especially against stronger opponents. The force will still transmit and damage your hands. It is better to dodge. Your bodyguard will want to avoid any extended close combat. A single strike to neutralize or kill the enemy, otherwise she IS screwed. Or the princess is. Third, limiting themselves to well understood and well known weapons are foolish. Their whole fighting style and strenght lay in their concealed nature. The best example I can think of are the Bene Gesserit from Dune. What I mean: they had the Gom Jabbar, a concealed poison needle. They had special movement, body-language style to lower the enemy wariness against them. They used their Voice to their advantage, ... Protecting is waaay harder than killing. [Answer] Hidden Weapons The Japanese had the Tessen > > Tessen were folding fans with outer spokes made of heavy plates of > iron which were designed to look like normal, harmless folding fans or > solid clubs shaped to look like a closed fan. Samurai could take these > to places where swords or other overt weapons were not allowed, and > some swordsmanship schools included training in the use of the tessen > as a weapon. The tessen was also used for fending off knives and > darts, as a throwing weapon > > > They also had hair pins which also doubled as a stiletto or throwing knives. An umbrella can contain a cane sword and could also contain a hidden shield. [![enter image description here](https://i.stack.imgur.com/zUJTV.png)](https://i.stack.imgur.com/zUJTV.png) [Answer] Daggers would be the weapon of choice for an assassin, an attacker. For a defender, not so much. To use it effectively means closing the range, when what you'd ideally want is to keep the opponent at as much of a distance as possible, delaying them until the protectee makes her escape or help arrives. Remember, the job of a bodyguard isn't to disable or kill the attacker, it's to protect their charge, and those can be two very different things. As mentioned, there are several weapons such as spears or staffs that would be better, but the problem is that they aren't very subtle and, magic aside, really can't be hidden. However, your setup explains a way of overcoming this easily: > > However, it is equally unbecoming for a male, guard or otherwise, to accompany a woman into certain 'female only' areas. (Bath, bedroom, etc.) > > > Given the situation, then, the only time the bodyguards could not be obviously armed (and men) would be in specific, non-public, locations. So there's your answer; you don't need to secretly equip the bodyguards; you equip the room. "Ceremonial" spears and shields on the walls. Staffs disguised as brooms or mops leaning in the corner. Things all over the freaking place so that the "maid" is never more than a meter or so away from something that is a hidden weapon, is a disguised weapon, or can be used as a weapon. If the princess is travelling, this creates some problems, but that's easy enough to overcome, as propriety clearly indicates that her servants simply must check out bedrooms and toilets to see if they are fit for the princess, as well as of course she sleeps on her own linens because she's a princess and she has her own special blankets. So while the princess is outside in the public area surrounded by her very obvious guards, her maids are scurrying around preparing her bedroom, and unrolling all the weapons hidden in the blankets and sheets and setting them up. [Answer] # Armored Glove and a small riposte blade The biggest downside of wielding two daggers is having no hand free to grapple, push, open doors, flip tables in the way of your attacker. The primary duties of your emergency bodyguard are threefold: 1. Recognize and stop the attack out of nowhere. - There is no time to draw any weapons or tools, if the assassin is good the bodyguard has mere moments to act and grab the princess or the assassin to make the attack miss. 2. Stall for time until other guards arrive or the princess escapes to safety. - It is not really necessary nor advisable to kill the assassin quickly. The bodyguard needs to prevent him from harming the princess and should also survive himself (since good bodyguards are hard to find) So grabbing, stalling, defending and incapacitating the assassin are good moves. 3. If the assassin attacks from afar or there are multiple assassins - help the princess escape to safety. This means opening doors, pushing bystanders aside closing doors behind them. For this to work the bodyguard needs at least one hand free and no big weapon, which could be a hindrance in tight spaces or while running. If you want something traditional just go with a simple short defensive fencing weapon like a riposte blade. I would also add an armored glove/gauntlet (maybe leather with metal inlays) if the hand maiden can always hide one hand under her overcoat or sleeves - maybe pretending to be crippled on this hand or something like this. An armored Hand would combine the versatility of a free hand with the option to grab most blades by the edge, which would be ideal to stop an attack. The other hand could then wield a small blade for counter attacks, or a small riposte blade to defend against a skilled dual-wielder or fencer. [Answer] No weapon. A dagger limits you. An opponent with longer arms can outreach you or kick you. An opponent with a thick body can take the dagger thrust and keep coming. An opponent can foul the dagger in his robes. You drop your dagger in the toilet and your enemy flushes it before you can stop him. And a dagger is obviously what it is. If someone finds a weapon like this on the bodyguard her cover is blown, permanently. The only answer is kung-fu!. Your lady bodyguard is trained in the techniques: fighting a larger and heavier opponent, fighting opponents with various armaments, and so on. She has nothing but her brain and body and so nothing to blow her cover. If serious stuff is going down, she is handy with the daggers as well. She just doesn't have any on her. The male bodyguard keeps extras on his person of the type she likes. Even if the princess is in the potty, he is right outside. He hands over the daggers when it gets bad and then he and the lady guard are back to back with the princess between. [Answer] Daggers seem like a bad choice for a defensive bodyguard. More the kind of weapon picked by the assasins. But depending on your courts fashion, your maid may have quite fashionable armour options for protection. A renaissance or later dress may include a heavily boned corset which may be enhanced easily with some chainmail or plate parts. It is typical to have lots of padding and multiple layers of cloth all over, not that different to a gambeson, especially if tailored for protective effect. Such a dress tends to be actually quite heavy. Or take a look at the laminated linen armour called Linothorax, a bit like an ancient version of Kevlar armour. For weapons you may want to look at spears, staffs, quarterstaffs, escrima sticks (usually dual wielded), combat fans, tonfas or similar. [Answer] No. As stated, the bodyguards' first priority is getting her charge to safety, thus any weaponry they have should be useful toward that objective. Daggers, as so many have mentioned, are offensive weapons, so even a duo of assailants would be too many for one bodyguard as one of the assailants could fairly likely reach the target. Instead, a bodyguard should be armed with weapons that hinder or slow down any potential threat so a retreat can be done as safely as possible. Caltrops, in medieval times where sources of light may be scarce, would be excellent options as any sneaky assassin-type would most likely have soft/silent footwear (or none at all) to be as quiet as possible. Also, a throwing knife or dart may be useful. It has the benefit of range, and if used proficiently, can be enough of a deterrant to cause a would-be-assassin to flee. It would also make sense to have something, which could be used as a makeshift weapon, in every room where regular bodyguards' presence is frowned upon. Like a broom, which may be used like a staff. [Answer] In a culture, it is only ever "unbecoming" of a woman to be armed, if the culture is such that her fighting would be seen as evil. Not that she is evil if she fights, but that anyone who puts her in such a position would be absolutely deplorable. In cultures were it was seen as ok to attack women, women wore weapons as jewelry. These norms are directly connected. This doesn't mean that places where women were "protected from fighting" they didn't face anu consequences from violence, they still did. But if it's actually socially possible that a man might try to kill her, it will no longer be socially unacceptable for her to have a sword. Again, these are directly connected norms, you cannot really have one without the other, because it's literally a matter of life and death. But Big knifes were carried by pretty much everyone for massive spans of history. They were useful in almost every trade, and are the most universal form of table were. Before a couple of influential thinkers and paranoid nobles started writing, most people all over the world ate their dinner with a pair of big sharp knives. So regardless of the norms around who carries weapons and when, having someone who specializes in using knives as weapons could be seen as valuable, because they are always available, and almost never suspicious. That's also the historic reason knives are associated with theives. A low class or poor person probably cannot afford a sword, but everyone has a knife [Answer] Yes they would be a viable choice, unless the assassins are full armoured knights, but not a necessary one. Unless the lord is expecting fairly well armoured assailants then any weapon is probably surplus to requirements, good training in unarmed combat is more desirable. [Answer] Thematically, the best defence against a dirty fighting assassin is another dirty fighting assassin, so concealed daggers would be a good option. Who better to anticipate where attacks will come from than one trained in making those attacks. Who better to guide the Princess out of harms way than one who can out think their adversaries and leverage intimate knowledge of the castles secret ways. Your bodyguard/lady in waiting shouldn't need to be carrying specific equipment to make her effective, she should be adept enough to make use of whatever happens to be around. Fire pokers, a bronze bust here, a mahogany chair there. Castles often have weapons hung on the walls or in the hands of statues and the assassin should be able to adapt to any of them as required. Better still, make the Princess her own saviour. The assassin isn't just her lady in waiting and bodyguard, but her fencing coach and mentor too. [Answer] 1. Tessens: capable of defense and offense, unassuming 2. Samurai-type silk armor or gambeson: will provide decent protection from attacks, while uncompromising agility and being reasonably breathable compared to metal armor 3. Stilleto knives or flechettes: as hairpins and/or concealed in sleeves, perhaps even contained in a spring-loaded mechanism in two identical bracelets. 4. Sashes/belt: Sashes can be used to catch, bind, or otherwise immobilize a part of, if not the entire enemy. A belt can be a painful whip (not speaking from personal experience, just common sense to me that anything metal whipping you upside the head will hurt!) 5. Steel-toed boots/blade-knuckled gloves-Assuming the last one is possible, this will greatly increase the lethality of the bodyguard's "unarmed" strikes. 6. Cape-You did say low-fantasy, so I assume an E-Z-off cape could be flung at an assassin, unfurl to cover as much of him or her as possible, then become sticky on impact. This may look like a lot, but I can safely say shinobi (real-life ninjas) used an absolute arsenal to get past guards and eliminate their target. Just as essential to this is tactics.... 1. Get the assassin to drop his guard by becoming a blubbering mess and/or acting slow on the uptake, then attack 2. Pretend to cooperate and then attack when the time is right 3. Act hysterical and grab the assassin's arms, begging him to not kill you 4. Act shocked/hysterical and then ram him out of nowhere, upsetting his balance 5. Act shocked/hysterical and then headlock/grapple him into submission (need to disarm him for this to work) 6. Try to trick the assassin ("Who are you? You're not an assassin to get the princess, are you? (sighs) This always happens, I'm so sorry, it's not your fault....you have the wrong person, Mr. Asassin, you're looking for Her Majesty Cassie Nova, up in the highest tower. I'd get started right now if I were you, it's quite a ways up there") 7. Psychological warfare-The lady-in-waiting will ask questions meant to undermine the assassin's resolve and/or surety of reward (maybe even persuade him to change his career!), potentially eliminating the threat. Of course, weapons will be resorted to if this does not work. 8. Flirting-This is quite possibly the most powerful tool in the lady bodyguard's weaponry; no one, and I mean no one can possibly be on their A-game when they're taken off guard like that. However, this can also backfire in a whole lot of ways, so it'll be the last resort. [Answer] ## Daggers no, but other short blades could be good. A dagger is a 6-20" long, distally tapered double edged knife with an acute point. This profile makes them very lightweight, maneuverable, and easy to stab with. However, as many answers have already pointed out, small thrusting weapons, have surprisingly little stopping power. However, there are blades that are about as short and easily concealed as daggers but are much better at cleaving such as the kukri. A typical kukri was 10-18 inches long puting it in the same general size class of a dagger. However, they are broader, distally weighted, single edged knives that sweep forward giving it a cutting profile very similar to a small axe rather than a dagger. So, instead of simply stabbing an opponent, such a blade can hack large gaping wounds into an enemy severing tendons, disemboweling, or doing other pretty instantly debilitating wounds as opposed to a thrusting weapon. The one disadvantage of the kukri vs a dagger is that hacking weapons are easier to armor against than a dagger. But assassins can't just go around wearing armor without raising suspicion; so, for this purpose, it's not really an important limitation. ### How you would hide it Medieval peasant girls did not holster their knives to their belts on display the way that men did, instead they had a large pockets either in their aprons, or between their overgarments and undergarments, or they had large belt pouches. These options completely concealed their knives instead of displaying them as men did since this would be seen as more modest and lady-like. Because of this expectation to have a place to hide a knife, even if someone noticed the hilt of a Kukri poke out now and then, it would not really raise any sort of suspicions as it would not obviously appear any different than the normal eating knives that every man, woman, and child in medieval Europe was expected to own. ### As for dual wielding... Dual weilding daggers is a common fantasy trope, but not a smart option in real life. A knife can stab or cut, but it can not grasp. So, when you start looking at really up close fighting like you do with knives, you're no longer just trying to stab your opponent, because you are now actively in grappling distance. A free hand has more options for controlling your opponent's body or weapon than a second blade does so you can use that hand to expose your enemy to being attacked by your hand that does have a blade. In other words, duel wielding actually gives you less options in a fight, not more. [Answer] ## A knife would be better. There is a modern knife fighting philosophy which says "Knives are meant to be felt, not seen." This could be put to use here. Basically, the lady-in-waiting (secret bodyguard) possesses a concealed knife. When the assassin attacks she charges him (keeping him away from the princess - see other answers) without drawing her knife. The assassin will think she is showing extreme devotion, but will not think she is trained in fighting. He has two options: 1. Throw his knife/dagger to kill the Princess. After all, time is of the essence here. He has a woman running at him screaming and guards are surely not far. 2. Try to stab the bodyguard. If he attempts to stab the bodyguard, she will have to do something (duck, dodge, parry somehow) in order to negate this. If he throws his weapon at the Princess (see other answers and comments about the effectiveness of this, plus the Princess has probably been trained for it) there is no need to duck. Once the bodyguard closes with the assassin, she whips out her knife and stabs him in several key locations and he expires in 1 or 2 seconds. Let me explain. There are certain key arteries that if cut will cause you to bleed out. You may last longer or shorter depending on which is cut. However, if you cut several, then the rate at which blood is leaking out is the total of all of them. So, cut several and the opponent dies faster. The hand grabs the knife, stabs and cuts the various arteries (located in the torso) and puts the knife back all in the space of about a second. Thus the assassin might have enough strength to (possibly even fatally) stab the bodyguard, but if he tried to get to the Princess, he would be passing out by the time he reached her. [Answer] ## Frame Challenge: your setup is not internally consistent. > > Assuming this society sees it as 'unbecoming' for a woman to be armed, any official guard assigned to her would be male. > > > You said it yourself, that your society does not believe in arming women; so, making an exception and keeping it a secrete would be doubly scandalous. In highly patriarchal societies like this, an assassinated daughter or wife could be seen as a smaller blow to the monarchy than a major scandal. The thing is that many societies had the exact social morays you are describing and they solved them not by training up and arming female body guards, but by using "disarmed" male body guards... and I don't mean taking away thier swords. ## History instead points us to the armed eunuch The use of castrated men as bodyguards to women of great importance was seen as the ideal compromise. They could not sexually violate the woman as an intact male could, but as long as he was castrated as an adult, he could be just as big, intimidating, and socially acceptable as a body guard as any other man. Eunuch bodyguards were reported to be used specifically for attending women of high importance during thier baths or similarly compromising situations; so, we can safely say without assumptions that this was considered the ideal solution to your exact problem for societies that meet the profile you describe ## Why secrete female bodyguards are less effective The best deterrent to an assassin it not to kill him, but to never give him a window to even try to attack. If your lady is perceived as vulnerable, then it means an assassin may try to kill her, and even if she is actually guarded, there is a good chance he will succeed... die in the process, yes, but he will likely succeed. Now, if she IS perceived as guarded, then any would be assassin would choose to deal with the guard first since turning your back on an armed guard to kill someone is a stupendously dumb idea when it comes to personal survival. Just by showing off that she is guarded strongly decreases the likelihood that she will be successfully assassinated. So, by having a male bodyguard, it means you can make a show that she is defended. He can be armed with way better weapons and armor than anything you can conceal. You can dress him in the uniform of your military elite so that everyone knows he is an experienced and capable killing machine... frankly, he does not even need to be a super good body guard in practice. As long as the perception is that he is dangerous, he forces assasins to engage him first which gives the lady the most possible opportunity to slip away unharmed. ]
[Question] [ In the Terminator movies, a nigh-unstoppable cyborg travels back in time from the future to the present day to relentlessly hunt down and kill the human protagonists. They primarily manage to evade it by stealing motor vehicles and driving away very quickly. In the story I am writing, the protagonists are chased by a similar threat (which I'll continue to refer to as a terminator for the ease of understanding), but live in a low-tech, low-magic fantasy universe. I would like the technology level to be as low as possible and as close to historically accurate as possible, but I still need my protagonists to be able to actually stay ahead of their enemy for a significant period of time. The terminator: * Looks like a very physically fit human being. * Is superhumanly strong and durable. * Does not need to eat or sleep, and it never gets tired. It will keep chasing 24 hours a day. * Moves at the speed of a brisk walk, but can and will use any faster travel method if one is available. It will break into a run if it spots its targets, but no sooner than that. * Has a baseline understanding of the general location and era. You can assume it knows anything you could look up on Wikipedia, but wouldn't know things like where the local hotspots are, or the identities of anyone not reasonably famous. (It knows its targets though.) It can also speak any language fluently. * Can't be reasoned with or bargained with, but can talk to people to gather information. * Doesn't feel pity, remorse, or fear, but can imitate these emotions. * Absolutely will not stop. Ever. Until the protagonists are dead. In other words, for the purpose of making this question easier to answer, it is basically the T-800 from the first Terminator movie. Because the story is taking place earlier than the information age, in order to maintain suspense and prevent the protagonists from simply hiding instead of running, I'm also giving the terminator an extra ability to "ping" the protagonists once a day to determine what general direction they're in. The protagonists are normal human beings who are physically fit. Their advantages are: * They outnumber the terminator. That means they can do things like sleep in shifts to try to make up for the terminator's lack of a need for sleep. In the movies, some were able to rest while others drove, but that's obviously not possible without cars. * They have local and cultural knowledge that any normal person living in the area would have, which the terminator doesn't necessarily have. * They are forewarned about the terminator and have a head start of at least a day. * They are willing to break the law. If they can't afford something they need, they can steal it. (Although the terminator can also do this.) This question is not concerned with how they're going to deal with the terminator, but only what the tech level of the world needs to be in order for them to be physically capable of outrunning it for a significant length of time. (At least a week!) Nothing that uses an engine is allowed. I've already considered horses, but the problem is that if the protagonists can obtain horses, the terminator can also obtain a horse, and ultimately both sets of horses will become tired after a day and need to rest, during which time both groups would be on foot, and the terminator could catch up during the night. I am okay with writing some mild anachronisms to allow the protagonists to maintain an extended pursuit, or to use a touch of magic to bend the rules a little bit (it's a low-magic setting), but I would like to avoid it as much as possible to maintain at least a moderate sense of realism without too much handwaving. So what is the lowest tech level needed to evade a tireless terminator for at least a week? [Answer] # Horses and water crossing because of terminator weight While it is true that the terminator can also get a horse, you can (very) plausably make your cybernetic killing machine substantially heavier than a human being. That means that even if a strong horse can carry or pull a terminator, the lighter humans will have an edge on horseback. Their mounts will be faster and go longer distances without rest. Same goes for crossing water. A human can swim across or use a light boat, where a terminator would need something with more buoyancy. (You being the writer can make sure that there are canoes by the river when the terminator cathces up to your protagonists but alas no bridge, raft or sturdier boats) Sure, the terminators machinery is waterproof and it wont drown. It can simply walk across the bottom. That, however, is considerably slower than paddling or even swimming across the surface. (because of water resistance) [Answer] The obvious two ways to move quickly are horses and boats. With the latter sleep and long-term travel are much easier. The problem for the terminator is finding its targets, once they are out of sensor range. Especially with boats, once the boat is over the horizon, there's no way of tracking it. The terminator would have to have good social skills to find out that the targets got onto a particular boat. If the targets are capable of changing the boat's destination after departure, then the terminator would have no way of finding that out, without massive and time-consuming investigation, again requiring good social skills. [Answer] Boats is the obvious answer If you can make it to a river with boats or the sea with ships, you can make it as one person can sail while the others rest (just like a car) If you can make it to the sea, you're pretty safe because the terminator is at a major disadvantage at sea because it cannot swim. Sure, the terminator could walk along the bottom of the sea but it would be incredibly slow going and wouldn't help it's biological parts plus ending up in the deep ocean, the crush would even affect a terminator. The terminator also cannot operate a ship by itself so would require human help to sail a ship. The best the terminator can do is try and keep up and wait for you to reach land again. If the terminator did try and follow you by ship, it can't sneak up on you and it's at risk of ending up overboard. All else fails you set everything on fire and jump overboard and take your chances in the water. [![enter image description here](https://i.stack.imgur.com/0QQzN.png)](https://i.stack.imgur.com/0QQzN.png) [Answer] ## Paleolithic You do not need any technology whatsoever to stay ahead of this killing machine. Infact, the lower tech your protagonists are the better. In the movies, the terminator was able to use technology to pinpoint where the protagonist would come to a rest, and then he could use modern technology to get there very quickly, but if you go back to the early stone age, people had no addresses to look up, no permanent homes to track down etc. leaving your terminator with nothing but his daily ping and his feet. In a place like a forest, swamp, or marsh, your maximum line of sight is only a few dozen feet. So once a day the terminator would be able to walk to some place the protagonists have been... look around, and then... not be able to do much from there. He could try to follow tracks if he is programmed to know how to look for them, but the more primitive your protagonists are, the more likely they are to have fox-like cunning when it comes to confusing any predator that might try to track them down. As long as they spend more time a day walking than they spend resting in 1 spot, the terminator will probably never be able to find them. Depending on how smart and adaptable your terminator is compared to your protagonists, some terrains may even defeat it out right, or atleast slow it down so much as to make it more or less an non-threat. Wilderness is full of all sorts of features like alluvial mud banks that the terminator could sink head deep into, or foliage so thick that it will perceive it as an impassable barrier or cave systems with vertical sinkholes hundreds of feet deep (for the ultimate pit trap). But let's say all attempts to contain or destroy it fail, staying ahead of it is still an option. It is common in tribal cultures to sleep 3-4 hours twice a day instead of one 6-8 hours stint; so, this is actually easier than it sounds. As long as you spend 4+ hours a day on the move, you can guarantee it will never catch up to you while you sleep, and as long as you are on the move by the time it follows your ping, it will have a very hard time finding you from there. Now let's say it does find them... thanks to the plentiful natural environments they still may be able to outrun it. The terminator having the appearance of a large human and the weight of a metal machine would be more restricted in its ability to run through many terrains. They only need to bee line it for the roughest or softest terrain, get a few hundred feet ahead of it and they will be able to lose it quickly after they get out of visual contact. The reason a terminator may not be able to run faster than human through difficult terrain has to do with a combination of how bipedal kinesiology and intuitive spatial skills work. Bipedal locomotion is inherently unstable in a way that only makes super strength particularly helpful on flat stable terrain. Every step you take has to be taken with a specific amount of force. If you under commit, you fall over, and if you over commit, you fall over. Super strength allows for a powerful sprint over level roads, and to a lesser extent can allow a terminator to force its way through certain obstructions that would slow down a human, but intuitive spatial skills are where the human will likely have the advantage. In a forest, swamp, or marsh, there are a lot of visually deceptive things in the environment. Tripping hazards like raised roots, rocks, and pits can be covered by foliage which could deceive the terminator into under committing or misplacing a step causing it to trip. Humans are very good at learning what to predict what should be behind something based on environmental cues; so, when we see a fern sticking up at a certain angle or next to a certain kind of tree, etc. we learn to guess what that fern is hiding so that we can make good decisions about where and how to step. [Answer] The easiest way is to go with a big, fast boat : it's fast, always moving, and cannot be well maneuvered by one man, so Terminator will have a harder time overtaking a boat and pursue another one. but in case you don't have a sea at hand, then... ## A land-only solution With the appropriate knowledge, you can actually have the runaways escape the terminator long enough with horses. In some countries, messenger posts had specific services for employees who need to quickly give a mail from one place to another. These services included the possibility to replace your battered horse with a fresh new one, so that you can make longer runs. If one of the person is a messenger, they will have good contacts and can ask them in exchange of a favor. Then, your main tool to gain distance is to use your environment knowledge to your advantage1. After all, even if you know the direction you need to take, if you don't know the fastest paths or the safest paths, you will face some troubles. This is especially true when your pursuer only have a clear hint of where you went every 24 hours. Sharp mountains and dense forests are a good sample to slow down and mislead a pursuer, while swamps and large beaches with quicksands such as the ones near the Mont St-Michel can certainly slow down a killing monster if they don't know where the traps lie. ![3025 Grande Rue, 50170 Le Mont-Saint-Michel, France, Marco Usan, Wikimedia commons](https://i.stack.imgur.com/OV93t.jpg) (A view from Mont St-Michel, France. [Picture from Wikimedia commons](https://commons.wikimedia.org/wiki/File:3025_Grande_Rue,_50170_Le_Mont-Saint-Michel,_France_-_panoramio_(1).jpg)) It's even more true when you can lay down your own traps : If there is a tax of passage in and out of towns, or a token is needed, Terminator may very well need to face the city guards. If someone knows a battle is going to take place (or trigger one?) between two big factions, making it happen while Terminator is on the way will hold them of for some time, whether by forcing them to skirt around it or to break through it. Finally, not being able to make shifts on horse is not entirely true : While it's certainly not comfortable nor you are at your fastest, you can always use a carriage, so that one person drives it, while the others are sleeping behind. When most if not everyone has some rest, drop the carriage and everyone are back on horses. Alternatively, if the runaways get to know when pings are sent, they can rest until right before it happens, so that as soon as their position is known, they are in full shape to move on. Oh and oh! Before I forget, an encyclopedia can give lots of general information, but they lack practical knowledge you get from experience, such as knowing if an animal is in a good state to travel or how to climb them up and down effectively. It can play a big role if Terminator takes the wrong horse or is not able to give them orders! ## To answer the question's core The minimal needed technology is pretty low. You have fast animals, boats, and good terrain knowledge, you should be doing relatively well. It would be exhausting, but doable. --- 1 This applies to boat escapes too. Unknown reefs can quickly sink a ship, and if you don't know the lighthouse codes -as Terminator wouldn't probably know-, they would navigate with a blind eye among them. [Answer] Tech Level: Medieval There are completely logical (and moreover, plausible) ways to outrun, delay, and even destroy the Terminator in medieval times. Considering the head start, and the fact your Terminator is probably a homunculus-like being, if not a magitech "cyborg," they can lay traps for the Terminator to set off. So, let's begin! Outrunning Options: 1. Boats-As Barry DeCicco and Thorne pointed out, boats are a superior option. 2. Horses-As Tortliena pointed out, horses can also work quite well. 3. Dragon-Seriously, even if you're doing low fantasy, chances are there will be a dragon or two. Perhaps the people in your world use them for transportation? If you haven't planned to include dragons, I'd heartily suggest it, as A) flight blows all other options out of the water and B) it makes it possible for you to have an aerial battle where your protagonists and their dragon are fighting against the terminator and its dragon. 4. Seven-league boots-These fantasy footwear have some great pros: 1, they'll allow your protagonists to run from the terminator, and 2, if they trip, fail, or end in difficult terrain the terminator may catch up. You may have to hand-wave this (the same guy who warns them could give them the boots, for example) but this would be a perfectly good way for your protagonists to evade the terminator without losing the feeling that one misstep could end them. Why? Well, speaking from my experience in cross-country, running ahead of someone isn't all that difficult; it's staying ahead that's difficult. Now for the good stuff: Delaying the Terminator 1. Intentional Rabbitholes Stepping in a rabbit hole can twist your ankle or get you stuck; since the terminator is essentially human in terms of frame and physiology, rabbit holes should work on it. In fact, even superhuman strength and durability may not save it; those don't necessarily make it harder for the terminator to sprain itself now do they? 2. Pit Trap A good 'ol pit trap with nice, sheer walls should give your terminator a very bad day. Even with superstrength, the terminator will have quite a time trying to dig or punch its way out. It won't hold it forever, but it will buy them time. 3. Framing You mentioned the protagonists may steal what they need; framing the terminators for multiple thefts will get it held up by law enforcement, which will buy them time. 4. Decoys If the protagonists are like Emmet from The Lego Movie, typical-looking average Joes, the terminator can easily mistake other people for them. This would not only be hilarious but would really confuse the terminator. Additionally, by the time it finds the first set of decoys, there might be even more sets of decoys running around! 5. Bounty If the protagonists put a bounty on the terminator's head, then it'll have to deal with bounty hunters. This is a strategically smart move, except for the fact that it can blow up on them (AKA if the terminator pays the bounty hunters more to aid it). 6. Davy Jones Taking a page out of Davy Jone's (the real Davy Jone's) playbook, they could arrange for the terminator to get drunk, then have someone take them to a captain short a few sailors. When the terminator wakes up, it'll be in the middle of the ocean, with no land in sight. This will be difficult to do, but oh-so-very satifisying; unless of course the terminator pulls a Wesley and becomes a feared pirate captain. 7. Trickery If the terminator does catch up, trick it! It's intelligent enough to understand people, and you don't need to feel pity, fear, or remorse to be tricked! Perhaps they could claim they are also terminators and that this whole hunt was just a test to prove the terminator's skills and worth, or that they are actually the terminators master and were testing its ability. (Taravingian did the latter to Szeth, an assassin, in The Way of Kings.) Who knows, they may even be able to talk their way out of this mess! (Plot twist....) 8. Charm You never said the terminator would be immune to things like the mesmer in Artemis Fowl or a siren's song, so perhaps that could delay it, akin to how Scrat found a relationship and forget all about his acorn in Ice Age: Dawn of the Dinosaurs. Alternatively, maybe a female character can charm the terminator into reconsidering its mission (even more of a plot twist....) Destroying the Terminator 1. Mulan In the original Mulan, the heroine (Mulan) shot a rocket into the side of a snowy mountain, triggering an avalanche. Similar tactics could delay the terminator (it's about as tough as the Huns, and they "popped out of the snow like daisies!" afterward) or even destroy it; superhuman durability can't save you from a rockslide, right? 2. Dragon This also works as a delaying tactic; simply trick the terminator in awaking or otherwise ticking off a dragon and watch as all your problems burn away (or see the terminator become a dragonslayer....) 3. Bigger Fish Find a bigger, scarier monster, lure the terminator to it, and let them duke it out. Ideally, the terminator will be swallowed and have to get its way out of a rather problematic situation or be digested. 4. Sea/sky drop This will take some doing, but the terminator clearly isn't immune to drowning, sinking, or falling. 5. Super-charm This would require your protagonists to do the impossible and befriend the assassin (AKA terminator) sent to kill them, but hey! It happened in the Dragon Prince, and logically, if this thing can be reasoned with, or if there's a reason it's hunting them, it's doable! There, I hope this helps! [Answer] ### A ping detector I can walk at 4km/hr, but I'm not as fit as a T-800 so lets call it 5. 24 \* 5 = 120km/day. Lets assume you can walk for 16hrs at 4km/hr and need 8 hours of rest, so you're moving 64km/day. The only tech you need is the ability to detect when the T-800 is pinging you. This doesn't even need magic or tech if the thing is arriving at known position and time and you know its ping interval, however the ability to detect when you have been "pung", is enough to evade the T-800 for over a week. Because he moves further than you do, by changing course, you can make him overshoot. * Every 24 hours the T-800 gets your direction and starts heading towards you. * Travel 64km on your first day. Stop and rest while you wait for the ping. * while waiting, leave fake tracks heading in your original travel direction. * As soon as the ping occurs, travel perpendicular to your original direction. * The T-800 walks towards the ping. After 120km, 24hrs has passed, and it gets a second ping. * By which time you've travelled 64km perpendicular to him. * His second ping returns you at his 4 oclock, so he turns. You're 85km away from him (56km and 64km right angled triangle hypotenuse) * When his second ping comes, turn right 90 degrees again and walk 64km in 16 hours, and then sleep for 8. He will walk 120km, and by the time he gets his next ping; He'll be 106km away. * Next ping he'll be 124km away. * Next ping he'll be 68km away. * Next ping he'll be 93km away. * So long as he doesn't get within line of site, you can keep this up indefinitely. * What you're doing is really hard to figure out if you only have daily pings directions, but just to be certain, start picking random directions (that aren't towards him). * You'll need to use your precise knowledge of the area to plot where he'll be. + Since he's a robot, you can guarantee he'll make the optimal move, which will be to head towards you at maximum speed. + Yeah it could eventually all fall over, especially if he starts guessing what direction you'll head that day, but you only need to survive 7 ping cycles. * Only tech needed is a "ping detector" How to outrun something moving twice as fast as you if the only tech you have is knowing when they'll get a bearing on your direction: [![enter image description here](https://i.stack.imgur.com/bv5xi.png)](https://i.stack.imgur.com/bv5xi.png) --- ### Here's a few other ideas: You need a week as per the question, so you need to get 840km in a week using as low a tech as possible. You have a 1 day head start, so you need to travel 840km in 8 days. 105km/day. If you just start walking 4km/hr, 16hrs per day, the T-800 will catch up with you just after day 2. If you both walk, you at 4km/hr for 16hrs a day, him 5km/hr for 24hrs, you will of travelled 512km vs his 840km. So, you really only need to give yourself a 328km advantage over 8 days. That's 45km/hr per night. That's all you need. Boats have already been mentioned. So has swapping horses. * Stowaway on a random cart / boat / etc Or steal a horse / boat. + If you're not seen, interrogating wont get the T-800 anywhere. + It's gotta guess or wait for the ping. + No extra tech required. * Cross a bridge and destroy it as you cross. + Yeah it wont make any friends, and the terminator will figure out another route, but if it's a 200km detour to the next bridge do this twice and your done. + No extra tech required. * Hot air balloon. + This isn't a huge tech leap, and with good winds you can travel a few hundred km. That's all you need. [Answer] I would suggest a horse drawn vehicle such as a wagon or carriage. A water based craft does answer the question as asked, however if you want to maintain the suspense, the protagonists need to be repeatedly in danger of being caught. A long boat chase makes it hard to achieve that. A carriage allows for taking turns for rest, but will still require stops to get food water, allowing the terminator to close in. If it was me, I'd have the terminator fail to maintain horse based transport either because the horse becomes injured or a run in with law enforcement or he just drives it too hard... so that he ends up on foot again. That way, for part of the pursuit he can be gradually catching up with the protagonists whilst they are stopped in a hare and tortoise kind of way. For variety, you could also introduce different transports for the terminator, some of which he may not handle too well (such as being too heavy for riding a horse that others have already mentioned). I guess we're looking at fairly ancient tech to achieve this - horse drawn vehicles such as chariots have been around for 1000s of years. [Answer] This is not really an answer to your question per se, as this was abundantly provided before. Any tech level is sufficient to outrun the Terminator. But let's build on that - I would argue that if we talk about an equivalent to the T-800, you do not need to outrun the Terminator in the first place! The argument hinges on my impression that lower tech level makes the Terminator actually less of a threat. The Terminator is optimised for firearms level tech: 1. Firearms provide him with convenient means to eliminate relatively large group of targets at a distance within a short time frame. 2. Firearms are the go-to weapon of modern civilisation (for exactly that reason) - nobody in their right mind would fight a deadly threat without firearms if they can choose so. But as it happens, the Terminator is very resilient against firearms: it has a durable endoskeleton covered by soft tissue further dampening the impact. In pre-gunpowder civilisations, the Terminator is still very difficult to destroy (probably even moreso than today), however he is also far less impressive as his action radius is limited severely to close combat or primitive range weapons (spears, bow & arrows), which can be deflected with relative ease (far easier, in fact, than a phased plasma rifle in the 40-watt range), making him far less dangerous to be in the vicinity of. As such, a coordinated and disciplined group of individuals could take him out in a number of ways. E.g.: 1. Lure him under a cliff and drop a large number of heavy stones or tree logs on him. 2. Use couple of horse riders to trap him with ropes and drag him over an edge of a high cliff. 3. Lure him over a pit, pour tar inside and burn him. Perhaps heavy stoning could be also sufficient (but careful that he does not toss the stones back at ye!). 4. Drop him into a well and bury him. Sure, he may get out eventually (if the corrosion does not get him or the battery doesn't run out) but by that time the target may be long dead because of plague, dysenteria, poisoning by fumes due to being burned at stake for spewing nonsense about time travelling robots, etc. ergo: mission accomplished > deactivate > self-destruct! 5. Drown him in a swamp. Now if we are talking T-1000, this would be very likely far more complicated because he is much better optimised for close combat, so there I would probably just opt for running away. [Answer] And yet another terrain-based approach: Very deep snow. Humans can wear snowshoes. The terminator could steal a pair but snowshoes have weight ratings, no showshoes will exist remotely at the terminator's weight. Thus the terminator is going to post-hole really badly and if the snow is deep enough walking becomes impossible. I suspect the "ideal" means of locomotion would be something like swimming but it would be slow. [Answer] Minimum tech level: Stone Age. All you need is a raft and a river. In The Fellowship of the Ring, the hobbits used a raft to great effect in escaping the Ringwraiths at Buckleberry Ferry. Their pursuer was basically a medieval Terminator on a good horse, and it was effectively stuck on the riverbank while the protagonists got a chance to catch their breath and keep moving. Rafts and rivers should be attainable in many scenarios. Are your protagonists in a desert, tundra, or any other sort of environment where trees are scarce? If they are, then this idea won’t work out. But if there are trees and twine, it should be plausible. Rivers should be plausible in terrain that includes trees. It is common for human settlements to be built near a river, especially in pre-industrial times when fresh water sources were difficult to arrange. It sounds like your protagonists don’t much care where they’re going, so long as it away from their pursuer. A raft lets your protagonists keep moving while some get rest. This lets you keep the element of danger, as they aren’t so far out to sea that they are effectively unreachable. There could be rocks, or rapids, or all manner of problems. It isn’t a perfect solution for your protagonists, but it should be plausible, so long as trees and rivers are common in the area. [Answer] From a storytelling perspective, using several different strategies for evading the terminator is more dramatic and interesting; so I would use a bunch of these ideas. The characters do not learn of the pinging until appropriate. Until they do they will be reactionary hence evasion. But when They know about the ping they can use that knowledge to their advantage by sending the terminator wherever like a sheep dog. I know it’s off topic of the question, but there is equal drama in being the hunted and the hunter. Both parts of the story give the opportunity for clever solutions derived from the environment and human thinking. The best solution is not always the most perfect or logical solution. Robots always take the most logical solution. [Answer] Another possible means of evasion that doesn't require any tech: I'm thinking of a nearby mountain. It has a notorious scree slope that must be climbed. The terminator is much heavier than a human, it's not getting up that slope without clearing all the scree. Simply sit at the top of the scree and watch it keep sliding back down with every step. (The scree is bad enough that humans expect to end up on their ass a few times.) [Answer] If the Terminator has any kind of brains at all, and knowledge of future technology, it may very well be impossible to escape it if it has that 'ping' ability. Consider this scenario: the target has a few days head start. The Terminator builds a hang glider big enough to support it in the air and catch a thermal... even if that takes days. Better still from its perspective, it builds a pedal propeller, since it has a much higher sustained power output than a human. After that, it finds a launching place, pings its target, and flies toward its target. Even if the target is weeks ahead using methods of transport available in most eras, a Terminator-powered pedal glider will soon catch up. So... the tech level would need to be the age of steam at a minimum, so that the target can take a ride on steam trains and steam ships which can travel at least as fast as the flying Terminator. [Answer] One other way to delay Mr T: ![A rope bridge](https://upload.wikimedia.org/wikipedia/commons/6/69/IRBSideViewClip.jpg) Since he has double weight of any human, a rope bridge spanning a nice, deep, rocky canyon can potentially spell doom for the T. How to use it: If you see the T coming, cross the bridge, wait for him to reach the middle of the bridge, then cut it. If the T runs around and comes at you from the other side, cross the bridge, then cut it again when T is at the middle. Some spike trap or sharp rocks at the bottom will do some nice extra damage. ]
[Question] [ Imagine we have a faster-than-light drive which costs ~$250,000 USD per drive and can propel an ISS-sized craft at 1000 times the speed of light. It is reliable and has safeguards that stop it from plowing into things at high speed. How the FTL drive works is irrelevant; it could be an Alcubierre drive or powered by lalalaicanthearyouium. The drive has its own included fuel/power supply which, for all intents and purposes, is infinite. (eg: unlimited or easily replenish-able, etc.) Additionally, this universe has no FTL communications other than mail carriers fitted with FTL drives. Would there still be any value in building and operating (optical/radio/whatever) telescopes for (e.g.) locating exoplanets, studying stars, etc.? Would telescopes be gradually retired and replaced by exploration ships? [Answer] 1000 times the speed of light means you can visit something 500 lightyears away in a one-year round trip. 5000 lightyears would take a decade and you are still not even leaving our galaxy. In contrast some things that can be observed with telescopes are millions or even billions of light years away. So astronomy would still need telescopes! [Edit, added months later since people like my answer] FTL would in fact be a huge boon to astronomers with telescopes mounted on an FTL ship. One reason is that they could fly with a telescope to peer around local obstructions: clouds of gas or dust, nearby bright stars in exactly the wrong place. And once you knew where (say) a supernova had happened, flying away from it faster than light would let you watch it develop during the preceding hours, days, and years. But more radically our Sun is a wonderful light-collector if you can get far enough away from it: <http://www.newyorker.com/tech/elements/the-seventy-billion-mile-telescope> Summary: if you could quickly travel 70 billion miles away from the Sun in any direction, you could then use the Sun as a gravity lens to look in (approximately, and only) the opposite direction. (You'd still need a conventional telescope as well, to gather light collected by the gravity lens). For scale, Voyager 1 is only 11 billion miles away, but it's mere light-days not light-years. [Answer] ## Yes and no. It'd be worth keeping some of the larger telescopes around, simply because they have a wider area of coverage. A large radio telescope can cover a significant portion of its sky and listen for incoming signals from that zone. This is an advantage, because you then don't have to send an exploration ship out to every possible area that the telescope would have covered to get the same information. However, for more detailed explorations of a target identified as interesting by the telescopes, exploration ships would be incredibly useful - you can get to the target in no time flat, get some good images of it, and get back home again in the same no time flat. Essentially, the two would work together. The telescopes have a wide area but little detail; the ships have a narrow area but lots of detail. It's a perfect complement. Things like SETI and the search for other habitable planets would become easier by orders of magnitude. [Answer] We'd have a lot more telescopes, because they would be much more useful, and they'd be fitted with FTL drives. Just for example, imagine a fleet of telescopes searching for a visual signature associated with the recent gravitational wave detection. Just going there wouldn't be possible, because we don't know where it is and it would still take over a million years at 1,000 times the speed of light, but we could move steadily further from Earth and examine different parts of the sky at the exact instant. [Answer] Fly telescopes faster than light, then point them toward the Earth. Now you can see the past. Any time in the past. I don`t think we could get the resolution to solve crimes and disambiguate historical events of humans on the ground, but I suppose the detailed formation of the Solar System would give up its mysteries pretty fast. [Answer] # Not quite. Possibly.1 ## Advantages of faster-than-light travel for astronomy: * You can see events happening in the present. Astronomers stuck on Earth can only observe objects in the past. Even our observations of the closest star system Alpha Centauri, are four years out of date. Sometimes, the finite speed of light really sucks. But with faster-than-light travel, you can get to the stars and then transmit the information back to astronomers on Earth very quickly. This is great because if the faster-than-light travelers see an event happening (like a supernova or stellar merger), we'll all [know in advance when the light from that will reach Earth](https://astronomy.stackexchange.com/q/10909/2153), and we could even build instruments specially to observe it. * We can actually get up close and personal with astronomical objects. Earth-like exoplanets are hard to detect because they're hard to find from so far away. But traveling to another star system would make confirming detection easy. Like the first point, any space travel has these plusses, but only faster-than-light travel makes it really feasible for astronomers on Earth. This also means that we can take images of much greater resolution, and [extinction from dust](https://en.wikipedia.org/wiki/Extinction_(astronomy)) will be less of a problem. * It's cool, and will get funding. Seriously, it's going to be much easier to convince people, companies, and governments to fund a faster-than-light starship than the convince them to fund a telescope. Telescopes are really cool, but, to most people, spaceships that can outrun a photon are cooler. So astronomers will get a lot more money, I would predict. * There's no atmosphere or Sun to block observations. This is a problem for astronomers on Earth, which is why space telescopes are so popular. Sure, the central star in a system would still make observations tricky. But there's plenty of places a faster-than-light ship could go to mitigate this, assuming adequate fuel and piloting ability. * We can see more of the sky. Currently, the Galactic center creates the [Zone of Avoidance](https://en.wikipedia.org/wiki/Zone_of_Avoidance), an area of the sky we can't see very well because it's blocked by gas and dust. There are interesting objects there, including a view galaxies in the Local Group. FTL travel might enable us to view them. ## Advantages of still using telescopes on Earth: * Observing via different wavelengths is easy. The Hubble Space Telescope is pretty much the number one source of visible and near-infrared images of astronomical objects. A lot of other images we get from telescopes are false color. You'll need to drag a telescope along on your ship anyway to properly detect objects in these wavelengths. In some cases, this is easy. But try dragging the [Very Large Array](https://en.wikipedia.org/wiki/Karl_G._Jansky_Very_Large_Array) or [Arecibo Observatory](https://en.wikipedia.org/wiki/Arecibo_Observatory) on a trek across the stars. Logistically, it's hard to bring along something that big in a single spacecraft. [![Aerial view of the Arecibo Observatory](https://i.stack.imgur.com/E03Xf.jpg)](https://i.stack.imgur.com/E03Xf.jpg) The Arecibo Observatory. Image courtesy of Wikipedia user JidoBG under [the Creative Commons Attribution-Share Alike 4.0 International license](https://creativecommons.org/licenses/by-sa/4.0/deed.en). Sure, you could try to put a bunch of radio telescopes in an array in space. [eLISA](https://en.wikipedia.org/wiki/Evolved_Laser_Interferometer_Space_Antenna) will hopefully do that to search for gravitational waves. But eLISA involves only three different spacecraft. Coordination is relatively easy, and they'll be staying in a heliocentric orbit. Putting the 27 25-meter-wide telescopes of the VLA in space and then bringing them hundreds or thousands of light-years away is monumentally difficult. * They're (generally) not too complicated to use. These faster-than-light ships are apparently pretty cheap, but given that there's no faster-than-light communication besides using these ships, you either need a human crew (difficult) or an autonomous probe (a terrible idea, given that encounters with aliens would not go well, and I don't think people would trust it enough in those cases). Telescopes on or orbiting Earth are much better. I don't think we'd see an instantaneous leap towards using faster-than-light travel in lieu of powerful conventional ground-based telescopes, but things would definitely slowly change. You'd initially see a balance between the two, with radio telescopes being gradually phased out if (and only if) radio arrays were feasibly on these spacecraft. Eventually, you'd see only a few telescopes left on Earth or in Earth orbit - and maybe, one day, those will be gone, too, obsolete relics of a bygone age. --- 1 Over two years later, yes, I've changed my mind on this. I've come up with more advantages, and they're pretty nice, come to think about it. [Answer] Well I'm surprised no one has provided the most obvious answer yet: No, we would still need telescopes because you may want to look at something while not actually being there, such as a dangerous, uninhabitable planet or even looking at stars. [Answer] Sometimes people won't want to wait. Even at 1000c, there are only about five hundred systems you can go to and back in a month. Telescopes are still needed to observe systems farther away than that. [Answer] There would be still things that could not be done with FTL: * By using telescopes you observe the stars as they were when the light was emitted. Exploratory ships would see the star systems as they are at their moment of time. * Powerful telescopes allow observations of very distant objects. If building them on the opposite site of the Milky Way were possible it would be a much more tempting opportunity to use it for instance for studying nearby galaxy clusters, motion of galaxies in Laniakea (our) supercluster etc. Even if you had FTL capable of visiting e.g. Andromeda galaxy there would always be a lot of objects too distant to visit. * The two above connected give us one more opportunity completely unavailable for pure FTL based exploration: research of the past evolution of universe. By observing very distant galaxies we in fact observe what our universe has looked like in distant history. In fact observing background radiation is observing the moment just after big bang. Nevertheless FTL based exploration would shift science interest of telescope operators to new fields. I would expect them to be more interested in studying nearby galaxies and galaxy clusters (as it would be easier if you could build a network of telescopes located on every arm of Milky Way). It may be also tempting to look for exoplanets in nearby galaxies (like Magellanic Clouds) or deep in core of Milky Way (assuming the telescope technology developed enough). [Answer] The greatest reason for keeping telescopes is because it's "inconvenient" if one's FTL-craft barges into a star. Or a planet. Or even an analogue to a dense asteroid field. Until space is well-mapped, the only really safe way to FTL-it around the galaxy is to do what could be called "Nano-Jumps:" "Tiny" hops, (1-2 light-years, max.) followed by *Loooong* periods of looking very hard, [with telescopes!] to see if said stars/planets/asteroid fields/et. al. could be apt to get in the way. I'd estimate that your FTL would need a series of "clean" corridors with a radius of at least an AU, each, to permit unrestrained, full-power, FTL flights to "mapped" destinations. And then, these "corridors" should be thoroughly re-examined at least every few decades, to be certain that wandering mass-bodies shall not endanger travel. This would take quite a long time to establish such a network, and quite an active FTL fleet to maintain same. Otherwise, there would be significant "attrition" among your home-world's FTL fleet, as leadfooted pilots turned stars into novas by trying to fly through 'em. What's the danger? Look at our trans-Plutonian "hive" of dwarf planets (potentially, in the dozens, if not hundreds); then add in a smattering of wandering post-nova planetary bodies, proto-stars, rogue brown and black dwarves, plus "ordinary" stars and planets, as to what one's FTL might vaporize. Very short hops, coupled with very long looks, happens to be the only way to be even remotely safe. At least until ones' "trade routes" are well-mapped. [Answer] You could use telescopes with FTL not to come closer to observer objects, but farther away (to the past). So ie when we detected exploding star, you can fly away from it and observe preconditions in great detail. [Answer] Obsolete? Surely not. Does the existence of airplanes make telephones obsolete? Why should I call someone on the phone when I could just get on an airplane and fly to see him? The obvious answer is, Because, even though airplanes are fast, they still take time to get there, much more time than it takes to call someone on the phone. Even at 1000 times the speed of light, reaching a destination 1000 light years away -- what's that, 1% of the distance across the galaxy? -- would take a year. Even if I wanted to study someplace close in cosmic terms, it's likely that a space flight would require non-trivial amounts of time. Consider air travel on Earth: Even if the flight itself took zero time, just the time it takes to drive to the airport, go through security, wait for the plane to arrive, get everybody on board, etc etc takes hours. For trips of a few hundred miles you spend more time on all these peripheral things than actually in the air. Of course you could pile on more assumptions: Starships are so cheap that everyone can afford one, and you can launch it from your backyard so all you have to do is walk out and hop in. Controls and navigation are so simple any child can fly one. They never need to be refueled and they require no maintenance. They are 100% safe. Etc. [Answer] Turning an FTL drive into a time travel machine is a simple high-school relativity problem. So your FTL system supports time travel, causing a technological singularity (the ability to send information backwards in time). Predicting what happens after a singularity is difficult. But, as time travel is invented at every time, we are already after the invention of time travel (if it is ever invented), and we use telescopes. So no, FTL does not mean that telescopes are never used. [Answer] The [wiki](https://en.wikipedia.org/wiki/Five-dimensional_space) article summarises 5dimensional space well enough, so I propose a slightly different view on the question, and that's to look at the universe slightly differently. In 2D space, a theoretical 2D actor must move in finite directions at finite speed subject to the laws of physics in a 2D world. Their telescopes and FTL machines may see from one end of the 2D world to the other, and cover small sections of that 2D space quickly. Now think of a 3D observer, they can view the entire 2D space as well their own 3rd dimension (in this case that 3rd dimension would very difficult to observe to the 2D actors). For the 3D observer crossing the entire length of 2D space would seem trivial, by travelling within 3D space or even 'folding' 2D space into 3D space and bringing 2 distant points together. We are in fact 4D actors, time being our 4th dimension. Suppose we figured out a telescope that observed a theoretical 5th dimension. We could gaze out to another galaxy, map the 5th dimensional coordinates, and fold our 4D world into the 5th dimension: bringing the 2points together. Time and space across this would almost occupy the same point. This can be imagined as TV show characters living in a flexible screen. We can fold the screen with little effort, not something that's physically possible by the actors in the 2D world - they need the 3rd dimension. Now they'd need way to become temporarily 3D beings, cross 3D space, back to 2D space, and you have nearly instant transportation. Cheap 'FTL' travel, and the need for telescopes. [Answer] Extremely fast FTL would change the world largely due to telescopes. We'd literally be able to watch the past unfold and have answers about history that we thought we'd never get with fast enough FTL and big enough telescopes. So no, they wouldn't be obsolete, there'd be a boom in building them, not just tiny ones or even massive ones a s we think of them today, but ones the cities out in space... ]
[Question] [ Background: In this scenario assume technology is initially equal to our own, but a method is discovered to render material indestructible. The affected material is treated as requiring infinite or arbitrarily high amounts of energy to break any of its bonds whether they be nuclear or chemical (this does mean a previously radioactive material will no longer be able to decay). Indestructible material can deform provided this wouldn't require breaking bonds or stretching them beyond what would have been possible for the starting material. The process to make something indestructible costs hundreds of millions of dollars per cubic meter affected so answers should be limited to scenarios where using such an expensive material makes financial sense. Making an object indestructible involves placing it in a sealed reaction chamber and applying the Mcguffin effect to everything within, so you can't make only part of a contiguous object indestructible. The process to make a material indestructible can be applied to any substance, provided you can get it in a sealed reaction chamber long enough to flip the switch. The effects on things like gases and liquids are somewhat variable and require thinking about things on a molecular level. For instance liquid water forms hydrogen bonds between molecules. So once it is made indestructible those bonds will no longer be able to break turning it into something akin to non-crystalline ice. While this process does make any pre existing bonds unbreakable, it doesn't necessarily forbid indestructible material from forming new bonds (though these new bonds wouldn't be unbreakable). Additionally the bonds made unbreakable here are those within nuclei (and smaller constituents) and the chemical bonds within atoms. However electrons not engaged in a chemical bond can still be move around or be lost normally. My Question: So how could these aforementioned indestructible materials be used in conjunction with existing or near future technology to improve power generation? At the very least though I'd imagine there's great utility for power generation in taking advantage of this Mcguffin's ability to easily contain extreme pressures indefinitely (emitting energy through radiation, heat emitted by the vessel and light if the vessel is transparent). [Answer] Easy Peasy. Fusion reactors. The primary challenge involved with fusion power is maintaining containment, which is a [big challenge given the pressures and temperatures involved.](http://www.engineeringchallenges.org/challenges/fusion.aspx) > > Not only will the neutrons deposit energy in the blanket material, but > their impact will convert atoms in the wall and blanket into > radioactive forms. Materials will be needed that can extract heat > effectively while surviving the neutron-induced structural weakening > for extended periods of time. > > > [Also here:](http://blogs.discovermagazine.com/crux/2016/03/23/nuclear-fusion-reactor-research/#.XKUQLGefipc) > > To solve the issue of containment, most devices use powerful magnetic > fields to suspend the plasma in midair to prevent the scorching > temperatures from melting the reactor walls. > > > The TLDR is that currently a PHYSICAL containment solution is impossible, requiring magnetic solutions that suck up a lot of the power being generated. Your Macguffin would solve this neatly, allowing a simple machined or cast sphere to be turned into a perfect containment vessel for a fusion powerplant of pretty much any size you need, and making it a lot easier to hit the breakeven point. This still leaves the problem of how hot the reactor vessel ITSELF is going to be, but theres lots of ways to solve that including just using a magnetic field to levitate the thing. Maintaining a stable enough magnetic field to keep a solid object off the ground is a couple orders of magnitude easier than maintaining one stable enough to keep fusion plasma at 15 million degrees under control. EDIT: Now that I'm thinking about it, it'd be a good solution for FISSION reactors as well, since a reactor vessel macguffin'd in the manner you describe wouldn't lose containment in a runaway nuclear reaction. The core could still melt down, but it'd stay in the reactor vessel. Your reactor would be destroyed, but it couldn't irradiate the entire powerplant ala Chernobyl or Fukushima. EDIT THE SECOND: There's been some comments regarding how you MOUNT your macguffined core without causing damage to the surroundings, as well as handling the heat coming off of it. Right off the top of my head, it seems like the easiest thing to do would be to build a really tall hollow tower, Put the fusion core on the end of a tall mount that's ALSO macgufined, and put a big set of turbine generators about a hundred feet up the tower. The heat coming off the core would generate MASSIVE upward velocity of superheated air, which would drive your turbines, generating your power. You'd just want a tower tall enough that by the time the air exits, it's cooled down enough that you're not roasting ducks in-flight or creating localized thunderstorms. [Answer] > > How could indestructible materials be used in power generation? > > > # [Energy storage](https://en.wikipedia.org/wiki/Flywheel_energy_storage). If you can spin a flywheel to relativistic speeds on [indestructible bearings](https://en.wikipedia.org/wiki/Magnetic_bearing) using electromagnets (in vacuum), then you can use that flywheel as a lossless energy storage device. [![enter image description here](https://i.stack.imgur.com/v8ipv.gif)](https://i.stack.imgur.com/v8ipv.gif) Wikipedia 2019 - CCSA [License](https://en.wikipedia.org/wiki/Wikipedia:Text_of_Creative_Commons_Attribution-ShareAlike_3.0_Unported_License) The energy density would be infinite (or limited by the unspecified arbitrary high amounts of energy in the question) - thus you would need a microscopic minuscule amount, a nano-flywheel [mounted on gimbals](https://en.wikipedia.org/wiki/Gimbal) - radically reducing the price per flywheel and opening it up to mass marketing, totally outclassing all battery tech available today. Not only the obvious solution to the [supply and demand issues with windpower](https://en.wikipedia.org/wiki/Wind_power#Energy_storage), but for vehicles - cars/planes, phones, power-tools, toys, mobile phones and of course space exploration. Infinite energy storage in the size of a grain of sand. # [Miniature Tactical Nuke:](https://en.wikipedia.org/wiki/Tactical_nuclear_weapon) Of course, this section is about political power generation. To release all that energy in one instant - perhaps an object charged with just below the threshold of it's (unspecified arbitrary potential energy) capacity, could be placed near an enemy stronghold and fed that last few joules of energy to tip it over the edge, that's the dark side, someone will find a way to weaponise it for sure, if not the leader of some [isolationist sanctioned state](https://en.wikipedia.org/wiki/Isolationism), then a disaffected teenager. # Power of a civilisation through time travel. Speculatively: Also it would have potential to enable [time travel](https://spaceplace.nasa.gov/review/dr-marc-space/time-travel.html) or at least the potential to send messages back in time as it would exhibit [frame dragging](https://en.wikipedia.org/wiki/Frame-dragging). For a few hints on how this could be of tactical use see [this answer](https://worldbuilding.stackexchange.com/questions/141820/how-to-make-money-from-a-browser-who-sees-5-seconds-into-the-future-of-any-web-p/141828#141828) to another question. [Answer] ### Nuclear pressure containment is a good method. Nukes have to be held together to make fission continue for as long as possible. If you hold 20 critical masses together for a full second, you'd generate the largest nuclear explosion ever made by humans. With indestructible materials, you could hold them together for an hour. At those high energies, there are all sorts of effects that release even more energy. Make a box out of indestructinum. Put a nuclear bomb in it. Detonate and let it build up fusion-capable pressure. Slowly vent it out to generate power. If your material conducts heat, put it in a very effective cooling system and generate power reactor-style. Alternatively, vent it out quickly in the direction of someone rich until they give you what you want. [Answer] Sometimes the smallest thing has the largest impact Do you know how much wire you can extrude from a cubic meter of copper when you can trust it to be indestructible?1 Indestructible insulating enamel4 + indestructible conductive wire = the perfect transformer/motor/generator. When was the last time you opened a power supply, motor housing, generator, or anything using inductive windings, and found the transformer/motor/coil burned out. For me, it was last week (literally, it was last week). If you could make both the wire used in the windings and the enamel used to coat the wires indestructible, what you would have is the perfect transformer/motor/generator. *Yeah, but this stuff is expensive*** Which is why it would make sense for large items, like turbine-style power generators where the limit to the electricity you're generating is suddenly the mechanical stress limits of the linkages and not the heat-generating characteristics of the coils. Better still, indestructible windings and enamel means you can make the coils incredibly dense — and as coil density increases, so does power output. Your efficiency might actually approach unity. Imagine a wire that is no longer a fuse if too much power is put through it. There is no longer too much power, the limitation is literally the speed electrons can be induced to move through the wire. And if you expand to power utilization, the applications become … impressive Miniature motors that can turn the propellers on a submarine? Dock 6. Full-size motors that push submarines at tsunami-creating speeds? Dock 2. Car alternators the size of your thumb? Aisle 14. A Dremel the size of a pencil? Aisle 1. An electric car that actually works climbing the Rockies? The display arrives next week. A residential wind turbine that actually powers an entire house? We have on the roof, you can see it as you enter the building. The process may be expensive, but the material requirements (in terms of how much you need) drop like a rock when you can trust the wire and enamel to be indestructible. The process of making things indestructible would benefit almost any application at any price. A steam boiler the size of a Buick enjoying such high pressure that it can pull a mile-long train? On display by the front counter. Disclaimer: at hundreds of millions of dollars per-cubic-meter there it is unlikely that any application is worth it. Unless you can jack the price through the roof, the cost recovery time at that price relegates the material to use (not necessarily power generation) in remote locations (like space) where repair costs even more. A spaceship hull would be worth that price. I frankly can't imagine any power generation/utilization solution that ever would. Not even fusion. The cost of using something less capable would be so much more economical that such a solution would only happen as a test, never a commercial solution. So, a [frame challenge](https://worldbuilding.meta.stackexchange.com/q/7097/40609) concerning the price. Edit: The OP challenged my disclaimer, and he may have a point, although not for the reasons he suggests. It takes a lot of metal to make one billion-dollar plane. And that metal alone just jumped to billions of dollars. Now we have 3-4 billion-dollar planes, which only national economies can afford, and that means 25% of the planes you could have had without the indestructible hulls and infrastructure. Frankly, most nations wouldn't/couldn't justify the price (there actually are limits to what nations can pay for things. It doesn't seem that way, but there are limits nonetheless). But... The average car alternator only requires 0.8165 Kg of copper. With indestructible copper and enamel, it might need 20% of that (0.1633 Kg). That's 54,864 alternators at, say \$200M or \$3,645 above "normal" price — for an alternator that will never burn up. It would mean almost nothing to raise the price of cars by \$4k. People would pay that and move the alternator from car-to-car. One alternator for the rest of their lives. Booyah. A friend of mine once made a good point: it's easier to sell a million items for \$1 each than it is one item for \$1,000,000. The little things would pay off better than the big things.3 --- 1 A cubic meter of copper weighs [8,930 Kg](https://kvsteel.co.uk/steel/weights2.html). 40 Gauge wire weighs [0.04454 grams/meter](https://www.engineersedge.com/copper_wire.htm) for 200,490.6 Kilometers of wire. That's enough wire to wrap the equator 5 times.2 And you might be able to use thinner wire than that. It's a lot of honking wire. 2 Of course, the wire is indestructible. If you wrapped the equator just once and tied the two ends to space ships, assuming a reasonable amount of thrust, could you garrote the world in half? It gets the mind wondering, doesn't it? 3 An astute observer might note that making indestructible commodities eventually drives a company out of business. It's the reason antique-anything tends to last longer than the crap we buy today — because there's more money to be made with failure. This is true for power generation, too. The last thing power generating companies want — ever — is a convenient (if expensive) way to run themselves out of business. After all, eventually a class-action lawsuit will point out the fusion power plant has paid itself off and the power rates should drop to rock-bottom. U.S. President Bill Clinton won his campaign for president with the slogan, "[it's the economy, stupid](https://en.wikipedia.org/wiki/It%27s_the_economy,_stupid)." In the end, the OP's indestructibility formula would revolutionize the world — if the inventor could survive to bring the formula to market. 4 The beauty of an indestructible enamel — or any indestructible insulator — is that it won't arc between wires no matter how close the conductors get. Theoretically, an indestructible insulator is a perfect insulator. [Answer] For a more nerdy approach, you could build indestructible turbines. (Disclaimer: My memories of thermodynamics are fading in the mists of time, so feel free to blast me in the comments if I'm wrong). I remember that in thermal power generation (where water is heathed into steam, whose energy is used to move a turbine), they were forced to limit the calor of the steam in output from the turbine, thus reducing the efficiency (basically, the colder the exiting steam, the better the efficiency). The reason was that if the water steam was allowed to cool too much, it would condensate and create water droplets that would move so fast to act as bullets, damaging the turbine. But an indestructible turbine could easily withstand this scenario, thus allowing for exploiting all the energy of the steam and generating more power. Of course it is necessary to evaluate if the increase in efficiency is enough to compensate for the higher cost of the indestructible turbine. [Answer] Construction A thin, unbreakable wire added to dam wall construction, would allow dams to be built cheaper, thinner, stronger and higher. A unbreakable foil added to the overflow means it would never wear out and need replacing Large dams for energy generation cost from twenty to thirty billion dollars so an extra cost of a couple of hundred million to make it unbreakable would easily be offset by the less concrete and steel needed not to mention to maintenance costs down the track plus the safety of an unbreakable wall. If you want next level power generation may I present The Space Elevator A thin unbreakable wire running to an orbital platform with a twin on the moon, would allow the efficient harvest of He3 from the lunar surface which could power fusion reactors around the world. [Answer] ## Jet engine turbine blades The limit in turbine efficiency (and why jet engines keep getting better and higher-bypass, but sloooowly) is the thermal limits of the first-stage (right behind the combustor) turbine blades. Evolution is waiting on new material-ally tech and more extreme methods of cooling(already pretty extreme and energy-robbing). If you can make the first two stages out of indetructium, as well as a few combustor-area components that would be hard to airstream-cool, you can keep pushing up the efficiency of the engines. Now you have 20:1 or 30:1 bypass. Turboprop sub-chaser maritime patrol aircraft that can stay on station for 48 hours. Over on the ship-propulsion or terrestrial power generation side, you have ships with more range between tankers, and power plants with lower smog and cheaper power from natural gas and petroleum. It would be the deathknell of coal. [Answer] "So how could these aforementioned indestructible materials be used in conjunction with existing or near future technology to improve power generation?" Well, if you could make copper indestructible then you could use it as I mentioned in my comment. Simply dig a very deep hole and place a copper rod in it. The heat at the bottom of the hole would conduct through the rod to boil water at ground level. The boiling water would be used in a convention steam turbine and BAM nearly infinite free and clean energy. The only reason we don't already do this is because copper would melt at the temperatures needed to get enough heat conducting through the rod to boil water on the other end. That and it would be very hard to dig a hole that deep because all the drill bits would melt but since we can make indestructible drill bits, it should be no problem... heck, we could reach the core with indestructible material. [Answer] At a minimum, if you replaced all your ball bearings with indestructible bearings, you'd be a long way towards better energy production. Many generators in the energy industry have to be tore down periodically to have their bearings and fins/rotors replaced. Never having to do this will save that cost, including labor and the energy production to cover the "down" generator. In fact, making the entire generator out of these indestructible materials would be a major boost. Hydroelectric dams could run at any speed, same with the huge windmills. (Ever seen a windmill with a failed break mechanism break up? YouTube that if you want to cringe.) As much as the new forms of energy production suggested by other answers would help, simply replacing the mechanisms of the existing system would help considerably. This might be a lower investment level to get poor countries more power. [Answer] Collect wind power via high-flying kites. Make the tether cables indestructible and light, and enjoy your free renewable energy! * <https://en.wikipedia.org/wiki/Crosswind_kite_power> * <https://en.wikipedia.org/wiki/Airborne_wind_turbine> [Answer] While the fusion power example is the most practical, you can connect a massive solar collector in orbit to the ground via an indestructible fibre-optic cable, and send a laser pulse down the cable to a boiler powering a steam turbine. As a bonus, since the cable is indestructible, you could use it to tether a space elevator, and get cheap rides to orbit. [Answer] The way I see it there are two main areas where your indestructibulisation process could affect power generation which will be obvious to the reader. 1. Mega scale engineering. With super strong, super light materials previously impossible engineering projects become possible. You could tie the moon to the earth for tidal power generation, drill a hole to the earths core etc. 2. New materials and matter states Other than the gross effects of your process, you would have to consider the micro and quantum scale effects. What if I freeze and compress hydrogen into a solid and then apply the process so it remains so at normal temperature and pressure? How does friction work between indestructible surfaces? You can imagine a range of super materials exhibiting exotic properties such as superconducting wires, frictionless bearings and perfect insulators. You might be able to construct highly efficient solar panels or perfect energy storage high capacity batteries. Do you really care how the energy is generated if your wall socket can deliver MegaWatts of power from solar farms in Africa at the flick of a switch? [Answer] There is at least some research that suggests you can build a [superconductor of heat](https://arxiv.org/abs/1211.3633). Assuming this is true, create a tether of heat superconducting material and sink one end of it into the center of the Sun, with the other end at a power-generation space station somewhere nearish Earth (maybe, Earth-Sun L1 point). The superconductor will transport heat from the Sun to the space station, which can use the heat energy to generate power and beam it back to Earth via lasers. Assuming your superconductor is a wire 0.1mm thick, you'd need about 15000m^3 of wire to do it. While supremely expensive, you're getting essentially free energy, forever, out of it. [Answer] Indestructible does not mean inflexible, or void of state changes. Make the equivalent of a very long, tightly wound "memory metal" out of your material, and use it to deliver energy as it unwinds via some thermal baths. [Answer] You just made a practical fusion power system. You build a containment vessel. If your machine will permit it the best design is most of a sphere as one part and a panel that comprises the rest but overlaps so it can't be forced out. The smaller piece must be inside the bigger when it's processed. If you can't do that you'll have to get more complex clamping the parts together, but it still can be done. In either case there's a small hole in the side. Attached to that is a variable size orifice and a magnetohydrodynamic generator (whose inside will likewise need to be indestructible.) Load a small atomic bomb into the device and then as much lithium deutride as you can fit while still being able to close it. Detonate. Note that you do not need the normal complexity of a fusion bomb here, that's all just to focus the energy of the fission bomb and the containment does the job perfectly well. Now you have a container full of incredibly hot plasma. It comes out through the generator, as the pressure lowers you open the orifice more to keep the power level constant. Your container starts out with fission products and helium (I don't know if it will get hot enough for helium burning to start but it's slow enough it won't have a substantial effect even if it does happen.) Extracting the power will greatly cool the material and then you can cool it still further by directing it into a large container of helium--the objective is to get it cool enough the fission products solidify and drop to the bottom of the container. You're left with helium and a bit of radioactive krypton and radioactive xenon as gases and the rest of the hot stuff on the floor to sweep up. The stuff on the floor is no worse than normal nuclear reactor waste and there's a lot less of it because most of the power was from fusion and there's no plutonium left in the waste, either. The gases are normally just vented when the wind is favorable but in this case it might make economic sense to run the gases through a fractional distillation in order to recover the helium for sale. (Note that helium has the I believe unique property that it's immune to induced radioactivity. Helium-4 that absorbs a neutron produces Helium-5 which very quickly decays back to Helium-4. This happens so fast that you can only witness it in an atom smasher, on a human timescale it simply stays Helium-4.) [Answer] You could use geothermal energy directly from magma. Make drill bits and drill rods indestructible, make hole casings with a vacuum isolation and inner heating indestructible. Use NaK (sodium potassium alloy) as boring fluid up to 785 °C, other liquid metals as needed. Drill at a place where magma is fluid, with casing deep into the liquid. Take care not to let the first magma cool to stone in the hole. Now, you can run a standard geothermal power plant! Actually, you can simply use a heat exchanger deep into the magma, and off the shelf technology as used in nuclear power plants to pump around liquid metal and use the heat. Works everywhere, no pollution. [Answer] ## Reps for Jesus(or the greater good whatever..) Find a gym rat that loves nothing more then pumping iron. If you make him indestructible he will never age or die, this gives him and infinite time to expend energy that you can harness threw a modified smith machine. This can also be done with a normal rat in a ball. At some point you will need to replace the treats. The advantage of the gym rat is that the end goal is a gnarly pump witch is short lasting. ]
[Question] [ One night a meteor impact occurred over the Pacific and a strange green glow sweeps across the entire globe, in that moment our body can no longer age in fact this phenomenon seems to only affect mammalian species. I am wondering would we instantly recognize that we don't age anymore? How long before someone notice it and what kind of evidence would be required to show this is happening? P.S: there is no human casualties from the impact, thanks god but stupidity still kills! [Answer] The first to smell something fishy will probably be those who are caring a newborn who happened to be born shortly before the impact. With no age progress the baby will not gain weight, will not stop looking like a wrinkled potato, will not get out of the 3 hours eat-sleep-poop cycle. The pediatrics following these babies will notice that it's not just a single occurrence but a systematic event. From there observation will extend to children and adults. For the first observations on babies to happen I think it will be a matter of one-two weeks. [Answer] Aging and death I'll use ageing as the process of the damage we accumulate over time from normal growth. When we don't age, it'll be difficult to see for most. Ageing is a slow and often unpredictable process. Our stamina decreasing, dementia or just our skin wrinkling are thing we would only notice over longer periods and not day to day. You can easily attribute ageing changes that are day to day to your daily routine or just to your mood, as you see things differently day to day. After you slept bad you might look into the mirror and see an old wrinkly thing staring back, while the next day you see a still young person still able to make a difference. There are however times it is more noticeable. Especially at the latest (terminal) stages of ageing it can be easily visible from day to day. Think dementia, failing hearts or failing immune systems. Some might still die, as the heart failure can still occur over time without further ageing, but a lot of others will stay alive. This is the first indication we've stopped ageing. From one source on the internet about 100.000 people die from age related causes. With such a large population, we would find large deviations from people not ageing really quickly. Although the first day it might be seen as a curious thing to investigate, from day two we would put more effort into it. By day three we would probably know something weird is happening. How quickly we would find out it's ageing that stopped is a difficult question. Maybe we notice in the cultures we make to see (ab)normal growth in cells that they don't age any more. The theories might come quick, but evidence will take a while for us to empirically prove it. A rough estimate would be between a month and half a year for the scientific community to come to this conclusion more or less unanimously. [Answer] ### So... when does life begin anyway? So to answer your question we need to know when life begins. Given pro-choice vs anti-abortion debates this is not clear and resolved with any consensus. I'm giving 3 answers depending on when you decide life begins. Does it begin; * at sperm and egg? * at conception? * at birth? * at age 12 when telomeres start to shrink? The answers for the last 2 are the same. ### Fertility lab techs (next day), supermarket inventory managers (within a week), women trying to buy pregnancy tests (within a week). In one extreme interpretation (ova and sperm are alive), all periods may stop (depending on how alive an ova in an ovary is considered), and all sperm are immature, so the first to notice will be Male fertility clinics, after every test returns failure for the same reason - underdeveloped, or missing, sperm. Periods stop globally, and that's notable to each individual woman, but before that's correlated; inventory managers will notice that pads and tampons are no longer selling from supermarkets. These have a steady predictable rate of sale so it will be extremely suspicious when they're not moving. Pregnancy tests will be sold out planet wide within a few days too. ### Women who are 8.99 months pregnant, and retrenched maternity staff (within a week) If life begins at conception, all embryos and fetuses will stop developing - because they're alive. I'm greatly simplifying childbirth here, but if a baby is expected to be due in the next week, and it never finishes aging to the point that it's ready, I'd say it's very suspicious. Expectant mothers are going to held in suspense as their immortal fetus settles in for the long haul. Birthing suites are expensive, there'll be scheduled c sections pre booked, and some will be induced chemically, but if they're still idle for a few days, or everyone is getting induced, that will raise some questions. ### Or scientists working with surprisingly eternal shrews. (Within 6 weeks) If due to magic the wave can differentiate between fetus and born, or you declare life begins at birth, then newborns will stop developing. This could take first time parents unfamiliar with what to expect a few months to realize, especially if behavior changes still occur from learning. (Repeat parents may get suspicious after a few weeks). I suspect parents taking infants a few months old to the doctor afraid their not gaining weight will be the first clue we have about it in humans. If, as your recent comment implies, for the purpose of anti-aging ray life doesn't start until age 12, then adolescents will get stuck in early puberty. That sounds horrible, and may take a year to recognize or more, but there's a faster way if we go to non human mammals. Your wave only affects mammals, and these mammals have a [life span of about 6 months](https://www.zooportraits.com/animal-longevity/). Any immortal affect is 100 times more noticeable on these than on humans. The scientists who are running tests on shrews and are waiting for some notable event in their development (puberty, death, litter, etc.) will be held in suspense until they start investigating. [Answer] I assume that with “don’t age anymore” you mean that mammals would still grow up into full adulthood but don’t start (or continue) the long decline and decay into old age, right? So at some point (after all biologically old humans have died of various causes) all humans who aren’t still growing up would look like ~18 year olds. In that case I think we’d first notice it in short-lived mammals like mice or rats which often have a lifespan of less than 3 years. In general I think we’d notice a steady drop in age-related deaths. Depending on the mechanism, maybe some biology lab looking at DNA and telomeres over time would notice that they suddenly don’t change anymore. [Answer] I see a couple of answers here assume that "maturing" and "degenerating with age" are the same thing, or that both are affected. Biologically, the processes are very different. The biology of aging is still debated, but by at least some theories, "aging" is basically the opposite of "maturing". As a baby grows into an adult cells divide and multiply. When an old person starts falling apart, one theory is that cells are FAILING to divide and multiply to replace dead cells. The body can no longer replenish itself -- exactly why is another subject that I won't get into here, but look up "telomeres" for one theory -- and so dead cells cannot be replaced and the body starts to fail. If we assume you mean that this phenomenon affects aging but not maturing, I'd say it would take months before anyone would notice, and longer for most people. I'm 62. I can tell that I'm getting little aches and pains and don't have the energy I used to have and so forth. But it's not like this happens on some strict schedule. I mean, it's not like someone could write in a book, "When you reach 60 years, 8 months, and 14 days, you will experience your first sign of arthritis." Some get it sooner and some later. Look at pictures of a bunch of people who are all, say, 60 years old. Some could easily pass for 40. Others you might think are 90. If I stopped aging tomorrow, how would I know? I might notice that all these little aches and pains aren't getting any worse. But how fast do I expect them to get worse? I don't know. It would be literally years before I was sure that something odd was happening. My guess is that the first people to notice would not be old people who realize they are not aging any more, but doctors or medical researchers who are studying human or animal patients every day with a microscope, and see that the progressive deterioration has stopped. If, on the other hand, you are supposing that babies no longer mature, then people would notice very fast. Parents would likely notice within weeks that their child was not maturing properly. Babies in the womb would suddenly stop developing and there would be a massive number of miscarriages. After a couple of months, every baby would be a miscarriage. And doctors would start to notice that there was no longer any sign of new pregnancies. [Answer] It depends on what you mean by "aging" If "aging" includes human growth and development, then L. Dutch's answer has you covered and I feel sorry for all new parents in that scenario. Having a permanent baby sounds awful. (or worse, permanent pregnancy) However, if "aging" excludes the process of human development, i.e. babies grow into adults but remain in their prime forever (similar to elves in Tolkienesque lore), it may take decades to notice. Any differences in how people age will be subtle enough to be reasonably attributed to improvements to medicine. Athletes will still retire relatively young due to all the stress on their bodies and non-aging celebrities will merely seem to be the subject of camera magic. Arthritis will slowly taper off as treatments repair joints. Alzheimer's clinics will mysteriously have no new patients for 15 years. It will seem miraculous, but it likely won't cross anyone's mind that it was because aging stopped existing. Things won't start seeming unusual until 15-20 years later. All the 40 year olds will look like plucky college grads. 50 year olds will have no signs of wrinkling. 60 year olds will have no sign of gray hair and men with a genetic predisposition for baldness will have universally dodged the bullet. With all the telltale signs of aging gone across the board, people will eventually conclude that the meteor was the cause. ... And now two new problems arise (assuming no aging implies living longer since "death by old age" is no longer a thing): overpopulation and pensions. And then I noticed this: > > seems to only affect mammalian species. > > > This probably decreases the time to detection. People's cats and dogs will live much longer and show no signs of slowing down. A dog will break the record by a landslide for the oldest dog ever. Veterinarians will see a slight decrease in business from the elimination of aging, but still see plenty of sick visits. News will report things like "cats seem to have become immortal", and "Dog God?" It will become more important than ever to neuter and spay your pets. People may not make the logical leap to human aging for a year or two, but given the evidence in dogs and cats, it will become apparent humans were affected before long. [Answer] Unlike the assumption in some other answers, aging is not necessarily tied to growth and development. There are a lot of natural examples of species unable to age (none of them, AFAIK, mammals). There are quite a hints that growth and programmed aging are two antagonistic mechanisms making complex organisms somewhat stable. Growth and development without aging will probably lead to oncology, the reverse will not work in the first place. As for when we will notice - we'll probably need months or even years until aging-related medical condition start to be displaced by cancer-related. There are a lot of diverse and non-preprogrammed aging mechanisms, like cholesterol buildup, that will more or less survive the impact - they will probably keep the society ballanced at slightly different equilibrium. [Answer] Pediatricians will notice that some of their patients have grown no taller over several months. This will be especially noticeable among those who ought to be going through puberty but aren't showing those signs. [Answer] We wouldn't be able to ever tell we've stopped aging because aging is necessary to store new memories. You'd have a world full of Alzheimer's patients unable to recall even one second of life post-meteor. Even if a single person managed to have a single "aha!" moment they wouldn't be able to spread that information fast enough. ]
[Question] [ For centuries, the rulers of the elven and human kingdoms have conspired to keep their peoples in a constant state of war with the sole purpose of making both of them extremely wealthy. Given, there are many ways for outsiders to make a profit from war. Mercenaries and industrialists thrive whenever a conflict is near. But the same cannot be said for someone whose financial wellbeing is directly tied to the wellbeing of their nation. So how would two rulers in such a situation profit from their peoples suffering? [Answer] War is generally held to be bad for economies over the long term because war is inherently destructive and expensive. An army of (say) 10,000 people (I'll use this term loosely in the given context) still needs to eat, still has families to support, and still wants to live a long and useful life so as to continue to support themselves and their family. As such, you end up paying them a lot of coin (including hazard pay) to prosecute the war rather than to produce services and goods that can be consumed by your populace and build your economy. So, you're taking from your economy to support a cohort of people designed to destroy the economy of the enemy, and the enemy is doing the same to you. No-one really wins from a war in the long term: the resentments that builds up against the enemy lasts longer than the conflict, and that reduces the desire to establish the good trade relations etc. that lead to a robust and stable economy in the long term. BUT; in the short to medium term, there are some industries that benefit from war and the technological progress that war drives. Technology If your people are technologists, nothing increases investment in new technologies and research like warfare. Ultimately, you're looking for new weapons, medicines, etc. that not only make it easier to hurt your enemy but also make it easier to protect or heal your own people. If your wealthy people are highly invested in R&D, then war is going to increase the amount of public funding you get for your research, especially in the areas of novel engineering and medicine. Mining All those weapons, vehicles, etc. have to come from somewhere. If you already have a metallurgy technology, that means that the owners of mines are going to become very wealthy as production ramps up. The providers of raw materials will become quite rich if they can feed the war machine without becoming nationalised in the process. Manufacturing Factories go from building toasters to rifles, from cars to tanks and planes. And they only have to deal with one customer: their government. This means that the production increases to a point where the owners of the factories can make a lot of money building the weapons and machines of war instead of what they normally make. The REAL Price None of these industries benefit from war over the longer term however for a simple reason: they are funded by the government — in other words, the taxpayers. Ultimately that money runs out because people are not producing stuff that others consume. Instead, they're producing things for a government that has to tax people to get the funds to protect them in the first place. This results in rapidly diminishing returns as people have to cut back with rations and other shortage management approaches as the normal products they consume become even scarcer as production converts to goods needed to prosecute a war. In the long term, you impoverish your people to the point where they can no longer support the war you're fighting, either with soldiers or equipment. That said, there is a caveat: sometimes, you don't actually need a war to drive very specific wealth. All you need is the perception of war. The British infatuation with the dreadnought class of battleships at the turn of the 20th century was largely driven by the possibility of going to war with elements of Europe, particularly Germany. Even now, American defense contractors provide equipment to the US and other nations to ensure their readiness for war. The people who built those battleships for Britain and other nations (including the US), companies like Thales and Lockheed Martin are very rich and profitable on the back of their ability to support combat ready equipment. Research and Development actually helps these companies as well because what a government buys today is obsolete in 5 years, meaning militaries have to buy new kit later to maintain readiness despite never having used what they have already. In short, nations can't get rich from their people’s suffering over the long term because economies need all their citizens to be productive for their economy to be strong and to grow. But, individuals can benefit from supplying weapons for 'just in case' and this is no different to what happens in today's world. [Answer] Since you're talking about kingdoms, through most of European history until the industrial age, wealth was measured in land rather than industrial output, control of the land is what you're after. Kings didn't get to keep hold of land all that well, they kept having to give it to nobles along with titles as a reward for service, the trick is getting it back again without upsetting anyone. Kings didn't last all that long if they upset all their nobles. War was mostly fought by nobles with accompanying peasantry hoping to get rich on loot. Nobles who did well would be rewarded by the king with land and titles. The way to get rich off a war at a royal level is to expand the borders of the kingdom and take that land for yourself. The other way for a king to get richer is for a noble to die without heir and so have their estates default back to the crown. Since you're at conspiracy with the enemy level here, taking land off the enemy isn't the plan, your plan will need to be to take land off your own nobles by having it default to the crown on a technicality. Send your people to war, take their lands when they die. It's rather parasitic as a way to operate a country though, I wouldn't recommend it as a long term economic plan. [Answer] Nothing unites like a common enemy. The rulers of both kingdoms have things set up so that they become very rich - they collect percentages of state run industries, a percentage of tariffs and levies, and people who want to do any sort of business need to make sure the rulers are happy (and paid) before they do it. Typical [kleptocracy](https://en.wikipedia.org/wiki/Kleptocracy). One would think the populace or certainly the rich people not directly benefitting would look for a change. But these rulers are also perceived by their people as the fiercest and most protective - the only ones capable of defending the populace against the enemy. The war keeps the power structure in place. Neither side's leaders actually wants to tear things up. A lot of that stuff that gets torn up would belong to rich people - them! There is enough war to be an excuse for the government being the way it is. The less fighting that actually happens, the better. [Answer] Two ways I see: ### The way of the Ancient Greek city-states As they can only really attack during certain seasonal time frames, the Greek model can be used: The Greek city-states did not have standing armies at first and would actually only really fight during times which did not effect the harvest (perfect timing = our harvest is fine but enemies is destroyed). The reason for this warfare was: [to collect slaves, land, and plunder](https://en.wikipedia.org/wiki/Ancient_Greek_warfare#The_economics_of_ancient_warfare). If your leaders own the smelting, smithing, ship building, or just coal & other mines - they would also see this as a huge annual or bi-annual boon in production (as weapons, ships, & armor is called for) and the enemies loss of produce and goods would increase your trade in those areas as well. Win or lose, every summer there would be the call for the materials they control and therefore profit. Further, if a side fully wins then why fight and therefore where is the profit? Adding a reason for the cooperation with these groups. ## Lie to the people (fire up the propaganda machine) and enforce taxes This only works because the higher ups are working together and assumes a certain level of technology (WWII level or earlier for limiting communications). The Eleven Royalty and the Human Empire puts out reports of loses and great battles on a foreign front. They even setup minor skirmishes along the borders to build credibility. They constantly push messages of how the other side will destroy everything and everyone we hold dear and are "monsters" who will [enslave you while we will treat you as free citizens](https://nationalarchives.gov.uk/documents/education/ww2-propaganda.pdf). Or follow the model of propaganda used in WWII which, to quote Robert Ensor1, created no limit on what could be done by propaganda creating a system whereby: > > people will believe anything, provided they are told it often enough and emphatically enough, and that contradicters are either silenced or smothered in calumny. > > > The only trouble is, these battles are either much smaller than reported or are not even happening. Or there [were conflicts over 30-ish years but major resistance/battles have long ended](http://exhibitions.nypl.org/africanaage/essay-colonization-of-africa.html) and the standing army is only perceived as being still involved in full armed conflict (people just hear the news and think "well, there is always fighting in <insert location here>"). After that its just building up story-based reasons that such a corrupt system came to be, that wages have not increased for the army in years (but pillaging makes up for it and everyone still calls them heroes so not effecting moral much), and that the majority of the standing-army's job is ensuring that people - including lower nobility - continue to pay their taxes on time. This has the additional benefit of generating political power - which (if we remember 1984) is an end to itself. 1: Robert Ensor in David Thomson, ed., The New Cambridge Modern History: volume XII The Era of Violence 1890–1945 (1st edition 1960), p 84. [Answer] The same way politicians do it in our days to make money during their mandate : The kings have private (hidden) interests in weapon manufacturing (and other war industries). This way, they transfer tax money to their own pockets without having to justify anything to their ministers and advisors. They could even reduce their official salary and appear nicer to the people. [Answer] ### By funneling conflict. Backstory Prior to The War, there were constant skirmishes and conflicts between the various Dukes and Counts. Waging war on your own territory is costly: * Villages are razed, with their population killed, their crops burnt, etc... reducing the working population. * Bridges and roads are sabotaged, reducing the means of transportation, and thus commerce. * Industries (mills, etc...) are destroyed. And therefore the strife between Dukes and Counts was just bleeding the kingdom from the inside. The idea Then came the idea of waging wars against the Elves. Not any war, mind, that would be dangerous. A secretly controlled war. The advantages of controlling the war are huge: * Control of the lives lost. * Control of the damage: only peripheral villages, no industry, ... The implementation It started with skirmishes. Due to the growing threat, and through political maneuvering, the King managed to seize power; somehow, the few who opposed him lost most of their armed forces in the conflict, finding themselves in the most contested spots. Now having the largest army, the King moved inward. Gone were the days of skirmishes between his vassals; in a country at war, any aggression against a peer is an act of High Treason, met with a brutal end. Nowadays The War has always raged. It extracts a cost: every second son is conscripted, taxes must be paid to outfit the combattants. That is a small price to pay to keep 9/10th of the kingdom in relative peace. Rather than skirmishes against each others, the Dukes now compete via their achievements against those sneaky Elves. Their officers are in charge of implementing the Marshal's plans, after all, and win glory for their house. They vie to obtain the most promising spots in assaults, and distinguish themselves during the actual battle. Best not aggrieve the King either, losing the King's favor means losing the Marshal's favor; a quick way to end up in the brunt of the battle, where only death awaits, and be kept apart from the juicy plans. And there you have it. For a small price, the bulk of the kingdom has been living an unprecedented era of peace and prosperity: commerce thrives, industry strives, and no famine has been recorded in the last few generations. [Answer] The rulers own the weapons manufacturers You're equating the ruler's own wealth with that of their country, but that is not necessarily the case. War gives them an excuse to declare a "state of emergency" where they get to decide that they wish to use money from the national budget to buy weapons and ammunition from their own companies. The emergency also motivates their workers to work longer, harder and for less money, out of patriotic duty. During a peace-time, a closer eye might be kept on them, or perhaps the Minister for Finance / Chancellor of the Exchequer / whatever might have more power to over-rule them (or mightn't be so cooperative). Doesn't necessarily have to be weapons manufacturers, any industry associated with war-time will do. [Answer] The rulers do not have enough control over landowners and merchants to effectively tax them. Furthermore, the common people and slaves are not directly bound to the rulers, except inasmuch as the rulers are landowners. Instead, the common people and slaves interact with the landowners and merchants. So how do the rulers manage to afford to maintain armies? By making war pay for war. After every battle, the winning side collects loot and slaves. If the battle is won in foreign territory, there is also the opportunity to steal from and enslave civilians. The loot and slaves are sold to fences, slave-dealers, and other merchants. The rulers organize this process, and take a large cut. If both sides maintain fortified bases that are "tough nuts to crack" with little loot inside, then only a strategically gifted commander would make the sacrifice to actually defeat his opponent's bases. Instead, the "war" would consist of alternating raids against the "softer" territory between the bases. There would probably be battles in the "soft" territory to prevent attacks against important landowners, or to recapture loot from a successful raid. [Answer] ### Malthus How prone to diseases are your people? How fertile are your lands? And how, ahem, fertile are the people? Historically, most people died of diseases, one way or another. Even if the initial problem was something which could be life-threatening, like a stab wound, more people died of infections than died of the wound itself. If you don't have much in the way of diseases, or if some friendly wizard has intervened to stop diseases, people aren't going to die in anything like the same numbers. If your elves and humans have normal human birthrates (or even faster) then you're going to have a lot of people born who keep living to a ripe old age. That leads onto the question of how to feed all those people. If the answer is "we can't", that's a problem. Nothing unites people like suffering, and if you as the king can't do anything about it then you become the target. The biggest threat to a monarch isn't the next kingdom over, it's an angry mob outside the palace. The other monarch has to get lucky a whole bunch of times in battles, but an aggrieved citizen with a longbow only has to get lucky once. So, you need some way to limit the population. War is pretty good for that. You do need to keep enough people back to run farms, of course, but as we've already seen, we have more people than we know what to do with. If you actually want to win a war, that costs real money. But no-one said you had to equip your guys particularly well, especially if the other side are following the same strategy. Note that this doesn't explicitly make the ruler rich. What it does do is keep them in power. As the Bush and Trump families are well aware, the best way to make money is to be the guy at the top setting policy. If you're an absolute monarch and taxes go directly into your pocket, even better. [Answer] Simple: corruption. While at war, the rulers can impose rationing, (threaten to) take over industries or organizations, etc. But not all -- in fact, not even most -- of the resulting resources need to actually supply the armies. [Answer] We're in fantasy territory, right? Let's add magic to the mix! See, gold and gemstones are pretty hard to come by in these lands. No suitable mines nearby, the few that are have paltry yields, etc. Other neighboring nations are waaay richer and, frankly, have no interest in these backwater ends-of-nowhere. Sure, the agriculture is OK and iron mining is fine, but again - everyone else is doing way better. So the rulers of the two nations have struck up a deal with the devil (or some powerful necromancer or what have you). They deliver souls, and in return they get riches. What they do with the souls is their business. Probably use for magical fuel to extract riches, eh? Anyways, the war is very convenient for this, since the souls go to the delivery willingly, and can be harvested en masse in one place. If it's for the devil, bonus points that they're all nice and soiled with sin (killing other people). A necromancer also might prefer souls that died violently. Or perhaps it's important to the collector that they faced the battle ready to die. There's a lot of ways to spin this depending on where you want the story to take you. [Answer] Being rich doesn't mean that you have a lot of propery and money in absolute values. It means you have much more then others alltogether. Richness is a relative thing. Thus to become a rich King by war is very easy. Just do not let the war "touch" you personal belonings, and let it destory you people belonings instead. To garantee the effect there must be sort of "conspiracy of Kings" (not direct conspiracy - it might be just "rules of engagments" that dictates, that "never lay a siege of king's castle and city"). In this situation King will have hight tax income, good way to get rid of any opposition and great respect amoung his poor lieges (as the only Protector). The only thing that this King should care about is to keep balance between birth and death rates (or he would become the King of Nothing or would unfortunaly win the War). So this enternal war would have periodic stucture - some years of low intencity raids and some years of great bloody sensless battles for say, a border hill. [Answer] Rulers do not get rich from wars, they get rich from WINNING wars. War is basically\* a zero-sum game: you profit by taking what the other guy has. In the short term, a ruler can profit by increased taxes justified by the war (diverting some to his/her own use), but if the war is stalemated for long, that winds up crippling the economy, and lower overall tax income. (See e.g. Laffer curve: <https://en.wikipedia.org/wiki/Laffer_curve>\* \The one instance where wars can be profitable for both sides is when it spurs technical innovation, and the ultimate total victor rebuilds the former enemy, as happened in WWII. But that was a war of comparatively short duration: only about 12 years for the entire Nazi regime, less than 4 for active US participation. [Answer] Our nations have standardized arrows using the standard MIL-SPEC-666-BANG* and swords now meet MIL-SPEC-667-STABBY. Due to some odd coincidences, both Elven King George and Human King TheOtherGeorge own the patents to the components that go into these arrows and swords. When our fearless human nation makes a sword with this excellent specification, somehow, 2 gold pieces ends up in my bank account over in Gnomeville. When our most elegant elven nation makes arrows with, somehow, 1 gold piece per arrow ends up in my bank account over in Gnomeville. [Answer] War is certainly not profitable as was mentioned earlier, not by itself and not even for the rulers involved. The reason a ruler or ruling class could still gain from it is not so obvious and has positive effects that may only be seen after several generations. Nations that were involved into wars in the past and succeeded grow in size increasing their overall economic output but weakening their economic integrity. Over time, the economic shortcomings created by warfare are overcome and it starts to benefit from it. This strategy does come with risks though. Other nations not affected by the war may gain superiority by [doing nothing](https://en.wikipedia.org/wiki/Thirty-Six_Stratagems#Watch_the_fires_burning_across_the_river) and even [exploit](https://en.wikipedia.org/wiki/Thirty-Six_Stratagems#Take_the_opportunity_to_pilfer_a_goat) the victor's weakness. It is, however, more likely that the victor does not benefit from war in direct a way. First of all, direct gains received from a war e.g. pillaging the losing side does not outweigh the disadvantages. If you get too much than you can swallow, you'll only end up with losing control over [inflation](https://en.wikipedia.org/wiki/Spanish_Empire#The_Spanish_Habsburgs_1516-1700). In other words, rulers might think they get richer while they actually don't. The biggest effect wars have on the balance of power. Being King of the Hill is (or feels) better than being a minister of state. Individuals are often willing to give up real gains for having power over others. Wars change the balance or consolidate power. Usually, that is not enough to start a war. A specific reason or an excuse is often required. This does have its roots in failed politics designed to sustain the balance of power internally or if necessary is created ad hoc as something like a [false flag](https://en.wikipedia.org/wiki/False_flag) attack. War is inevitable at this point mostly because the balance of power would shift in an undesirable fashion or direction if peace is sustained. Gains come in the form of preventing (more) losses often defined by a perceived and subjective reality. The two rulers of opposing nations do not benefit from their subjects' suffering. However, by waging war against each other, they create an enemy and exert more control over their people. If the fate of the two nations is kept in perpetual conflict without actual catastrophic war, they would gain the most as they would lose nothing with minimal risk. To end their peoples' suffering, they would have to spend more resources and thus lose, possibly creating even bigger problems by showing signs of weakness. As mentioned before, it is the balance of power they wish to maintain. Actual gain is irrelevant and a full-blown war too risky. Peace is even more risky. After centuries of war, peace is the unknown, the [Undiscovered Country](https://memory-alpha.fandom.com/wiki/Star_Trek_VI%3A_The_Undiscovered_Country), more dangerous even than war. [Answer] You need to define the term "profit" somewhat more exactly. One technique to profit from prolonged conflict is to erode the basic principals of governance until you can establish autocracy. Once the autocracy is established, the rulers can manipulate the laws such that they and their supporters (perhaps, those who pay the best bribes) maintain control of society. This can be everything from "who supplies food for the army" to "where shall we attack this season". [Answer] A ruler can become very rich in certain cases. Such as a democracy, where under normal circumstances there is much oversight when making decisions concerning money. Under martial law or during war time; democracies adopt a completely different set of laws removing much of this oversight. Often not making the ruling party answerable for quite a large chunk of the decision making until the crisis (war) is over. During a scenario like this it is conceivable for a ruler to line their pockets with money meant for war making purposes. They would have to do so at the cost of decreased military power. [Answer] The problem they face is overpopulation. They could feed a lot more people, but they'd need to work unproductive fields to do so (10 people working to feed 9 of them) therefore they assume more people would be a drag on economy. [Answer] Well, it depends on the type of war. A Cold War scenario would have some proxy war and battles, but there would ultimately be no direct war. In this scenario, there is mostly competition, and this competition would help to motivate innovations that could be profitable financially or through general superiority in certain ares (science, technology, economics, political influence, etc.). Competition during the Cold War led to the creation of new technologies in the United States including [supersonic aircraft](https://en.wikipedia.org/wiki/Bell_X-1), the [nuclear submarine](http://www.subguru.com/nautilus571.htm), and the [first weather satellite](https://web.archive.org/web/20090325002943/http://www.nwas.org/committees/rs/2007_MetSat_Papers/Bianchi.pdf). These technologies were useful for military & civilian purposes ([scientists can use nuclear subs for Arctic studies and exploration](https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwigr8OSk63sAhUlWN8KHeD4B-AQFjABegQIBRAC&url=https%3A%2F%2Fthebarentsobserver.com%2Fen%2Findustry-and-energy%2F2017%2F03%2Fscientists-design-civilian-nuclear-submarine-arctic-exploration%23%3A%7E%3Atext%3DThe%2520engineers%2520with%2520Rubin%2520also%2Cdive%2520to%2520400%2520meters%2520depth.&usg=AOvVaw0qX4tIzPWtbdB5VIA5rzWH), [supersonic aircraft were once used as passenger planes](https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwjW7oqkk63sAhVLheAKHY7HAKIQFjABegQIAxAC&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FSupersonic_transport&usg=AOvVaw3AXxE0ZI6UfchI1iPom2Wq) like Concorde which was used until [2003](https://en.wikipedia.org/wiki/Concorde) [due to the 9/11 attacks](http://news.bbc.co.uk/2/hi/uk_news/2934257.stm), etc.). Basically, certain forms of warfare (especially tense stand-offs with little direct war) led to innovation when trying to surpass your perceived opponent. These innovations could have civilian applications and be sold during or after the war through private companies or trade through the state/collective body, leading to profit in one form or another for both sides. [Answer] Consider Genesis 47. Joseph, having previously been made second-in-command of Egypt, [shepherds the nation](https://www.biblegateway.com/passage/?search=Genesis+47%3A13-27&version=AKJV) through a famine. He uses previously-collected taxes to set himself up as a merchant, selling the government's grain in exchange for people's land, and eventually their freedom. In this sort of monarchical scenario, the government's wealth is more or less equivalent to that of the ruler, or at least the ruler has great discretion to spend whatever he wants on himself! In this case, it is implied that the famine was not Joseph's fault, so in your scenario, you just need to make sure that it is. Have your ruler invest heavily into electronics, stocking a secure, shielded, underground warehouse full of various consumer goods (computers, phones, radios, etc.), before unleashing a massive Electro-Magnetic Pulse (EMP) on the populace and also on his nation's closest trading partners. With most people's devices wrecked, he can now sell them his for whatever price he wants. ]
[Question] [ I am currently building a world where the majority of the population is some kind of amphibian species. My question is : Is it possible to design a kind of membrane that is completely waterproof but can let pass organisms that are sufficiently large (see the gungans in SW : the phantom menace ? that's the idea) and how would one implement it given the laws of physics we know ? The membrane can be tangible or more like a force field, I don't see any problem. Thanks in advance. edit: the membrane must be translucent, as thin as possible and roughly the same size as a regular human door. I think the fish should not be able to pass through. my species is living in buildings underwater that can be filled with water or emptied at will. The membrane would serve as a door to have a smooth transition between either sea and building or different rooms of one building. [Answer] When I was a child, we had a toy which was apparently called a Water Snake (pro tip, don't google water filled sphincter toy, ever). [![Water Snake Toy](https://i.stack.imgur.com/yef7M.jpg)](https://i.stack.imgur.com/yef7M.jpg) The tunnel through the middle should allow a creature to pass through, but, if kept pressurized, the mouth of the tunnel should always remain closed tightly. Use one of these, with a rope through the middle to allow the creature to pull themselves through. It will have to be pressurized enough to keep water out, but low pressure enough to not crush the creature inside. This should allow 2-way access while being impermeable. It could be quite difficult to pull your way through this tunnel, so you could either coat the tunnel with a slippery hydrophobic substance that will lower the friction, or run the contraption on bearings, so that the whole thing can turn inside out on itself, letting the creature enter or exit easily. Finally, if the contraption were motorized, then it would make the process much easier for the creature. It would work sort of like a weird 3D conveyor belt to suck the creature in from outside. All you need to do is get yourself stuck in it. --- What is a Water Snake? A water snake is a flexible membrane shaped into a torroid and filled with a liquid. The upshot is that, because the membrane is flexible, it can turn itself inside out by rotating around the center. Imagine a two gears meshing, and then revolve that around the point where the gears mesh to get a 3d object. The entire outer surface moves one direction while the inner surface moves the other direction. [Answer] What you are looking for is a [moon pool](https://en.wikipedia.org/wiki/Moon_pool): It's an opening in the floor of the underwater habitat, that connects the sea with the pressurized air inside the habitat. The air pressure keeps the water from filling the room. This is as simple and low-tech as you can get. In principle, this works as far down as pressurized air diving works: The limiting factor is the toxicity of the pressurized gases to the body. Afaik, this is somewhere around a depth around 40m for a human with normal air mixture (I couldn't find any precise numbers quickly). If you are willing to go with some other air mixtures (as they are used when people dive to greater depths), you can push that to somewhere short of 100 meters (again, no precise number, just something I vaguely remember). If you don't need to take humans through your moon pools, just your adapted species, you can make pretty much any depth believable. But, I guess, maximum depth is not your main concern anyway, as your amphibious species will want to live in conditions close to what they naturally live at, which is near the surface. [Answer] This answer tries to design a system that could work with far future technology (that we don't know if it will ever exist!), but without inventing things contemporary physics rule out, like force fields. The membrane is a sort of smart liquid or nanotech slime, consisting of many interlocking macromolecules or similar. They are all very fatty and hydrophobic. When a solid object touches the membrane, the individual parts intelligently make way and slide over the surface of the object as it passes. A high trade off has to be made about surface tension: Too small, and parts could easily tear off or enter very small pores and orifices on the passing solids. Too large, and the membrane can't form a tight seal in sharp corners. There's another issue: someone could press a donut against the membrane. When the membrane retreats around the donut, the inner whole is open and you have a leak. When the membrane separates around the donut, the inner plug might be pushed in by water pressure - unless the plug can hold fast to the donut, but the membrane hast to glide about surface so it has to be really smart to know when to glide, when to hold, when to separate and when to remain one blob. The question about the donut is not purely academic, every piece of clothing has a similar topology. So I suggest the following: So upon contact, the mebrane material will flow around the object and try to form a cavern. This will involve tendrils fingering up your ear or trouserleg! Then parts of the membrane will perform as a pump to remove water, shrinking the cavern. Once the cavern is sufficiently dry, the cavern will open to the other side. The simpler the object passing through, the faster this can work. The membrane has to be thick to withstand pressure without causing excessive tension in the frame, unless interor rooms are the same pressure. But then you can have houses like diving bells, without doors ... This has ramifications: The membrane (that is so thick, it should be called blobgate or maybe bloor (portmanteau of door and blob)) can easily kill anyone passing through, so control of the software (that is probably hardcoded into the individual nanotech components) will be an issue. The technology will have many other applications in medicine, toys, manufacturing ... [Answer] Mart's suggestion is essentially an airlock,and very viable, but very high-tech. A simpler airlock solution would be to have something like a womb or pipe with sphincters on both ends. Sphincters recognize creatures allowed to enter, and let them in, then close one end, push out water if necessary, and open the other end. Also, can have an easy entryway into underwater habitat if you make it horizontal (opening in the floor), and make air pressure inside the habitar equal (or slightly above) water pressure outside. This is what @lijat means by "diving bell" above. [Answer] There is an energy management problem with the single membrane concept. Imagine the object being passed through is a cube, one meter each side, in and out a volume at atmospheric pressure just ten meters under water. To exit the membrane, against a pressure differential of one hundred thousand Newtons per square meter, and displace one cubic meter of water weighing one round ton, the cube requires an energy of one hundred kiloJoules. To do so in, say, ten seconds, requires a power of ten kilowatts. A human being, producing around 100W of power, would need to exert himself for about twenty minutes to drive such a cube outside the membrane; being around ten times smaller in volume, he could exit himself in around two minutes. The "membrane" must then be an active mechanism. Nano-machines creeping along the surface of the incoming body, using gecko hydrophobic pili for both traction and seal, should be good. Inside the membrane, there needs to be a much stronger "skeleton" to oppose the pressure differential. One could do this with a large quantity of gecko-coated flexible marbles, capable of selectively gripping one another. The marbles would need to know their own rest position and be able to communicate with one another. The distance between a geckoball's actual and rest position would be its "energy". Each geckoball would either negotiate a swap of logical positions between itself and another geckoball, if by so doing the sum of their respective energies decreased, or exert a pressure towards its rest position if, and only if, in that direction there was water or air, and nothing else. This movement would require energy, of course. The net result would be that geckoballs would part with ease in contact with a living creature, allowing it to feel no pressure, and would flow back and reconstitute themselves behind it, requiring considerable energy, as soon as it passed through. This approach requires the membrane to be somewhat thicker than the thickest object going through, which must have no holes. A thinner membrane would require sophisticated communications and checks to stabilize pressure along the separation surface: [![enter image description here](https://i.stack.imgur.com/1kLUt.png)](https://i.stack.imgur.com/1kLUt.png) [Answer] Why didn't anyone offer jelly, blubber and other gooey fats? :) They wouldn't pass water through, a solid-enough organism can literally swim or walk through it - and the goo will close after it, sealing the wall back. Alternately, perhaps one can upscale the mechanisms we all have as the walls of our cells, complete with keeping liquids inside and outside separated while allowing for selective osmosis of nutrients and waste, etc.... [Answer] My advice would be to avoid the hypothetical membrane and go for a simple solution that we know is doable: the airlock. This would avoid suspension of disbelief problems that hypothetical technology can cause if it's too far out there, similar to how many people don't like teleporters and other such staples of science fiction. It will also make it easier to write about since both you and your reader will have some intuitive understanding of how it works, and what the limitations are. And that might also make it easier to turn it into a plot point without it coming across as an ass-pull. For an example of such an airlock in fiction, see the adventure game Indiana Jones and the Fate of Atlantis: > > Amazing! We're hundreds of feet below sea level, yet there's enough air pressure to keep the water out. [(Video on YouTube)](https://youtu.be/_kCPwaz1XLA?t=906) > > > [Answer] You will have to contend with multiple challenges: 1. The membrane will need to have some means of identifying material that may pass, including items that the entering persons are carrying, but presumably excluding stuff adrift in the external fluid. 2. The membrane will need to resist a pressure differential, which is no mean feat: Try pushing an empty container into the water to get a feel for the forces involved. Additionally try to keep a horizontally strung rope completely straight by pulling at it while some weight pulls at it perpendicularly to get a feel for the forces needed to keep the membrane from bulging to the point where it is not really a window but more of a crazy lens. The object sticking through the membrane will experience the same forces, so expect to 'pop in'. 3. The topology of the entrant will be of vital importance: a torus-shaped entrant will break the membrane. Humans are toruses! (Mouth-anus-connection) 4. The membrane will behave as some sort of fluid, and will also have high bonding strength to itself ('itself' being chemically defined, or in case of nano-bots both chemically and cryptographically), so contamination will be a huge problem. Be prepared to have them be 'alive' to self-regenerate/purge or have a thriving industry of membrane-cleaners at hand. Imo your best bet yould be to have the creatures wear membranes themselves: Topology-concerns are handwaved away by making everything a (topological) sphere, plus any membrane-clad thing or person is cleared to enter, non-clad vagrants and debris don't get in. The pressure-differential must: * a) not exist (pressurized habitats, but be wary of multi-story habitats, they will have the same internal pressure, but the external pressure will vary wildly with depth, assuming dense external fluid and light internal atmosphere) * b) be compensated by some force thats commensural to the area the entrant has in the membrane at that moment (two caveats: 1) for someone entering the membrane, that area will increase to a max, and then dwindle again, as the person slips through, as must the force to keep the entrant from 'popping in' 2) the area will rise to the power of 2 with size, while the circumference will only rise by simple power, so the force to hold back / force out the entrant can not be linearly dependent on the circumference, which would be natural in any active-membrane (e.g. nano-bots) scenario. Probably best to stay with the internally pressurized scenario, or just ride with the 'popping in' and incorporate for comedic effect :-) The membrane passing could be achieved by membrane-clad entrants just as a vesicle passes a biological membrane - google 'vesicle membrane trafficking' for a plethora of good illustrations. Molecules swimming in that bio-membrane can also secure special admission-rights, just as they do in cells. With electrical potentials, the membrane can be made to open up (electroporation) so your visitors can shed the membrane they are wearing. If the suit-membrane is just a molecular bilayer, it might be thin enough to allow transmission of gases at sufficient speeds (breathing!) - the entrance-membrane can be a lot thicker and be interwoven with filaments (think muscle filaments, those can move against each other creating force, while also able to reversibly detach from one another) to make it more plausible in the toughness arena. [Answer] I'm not sure how to form this answer as I don't have the scientific terminology handy. But here goes for the concept. Let "water" surface tension be the door. The diving bell comment above has the right idea. You need to have the internal pressure and external pressure the same. So in your world, can air and water be the same weight/pressure? They could behave like water and air do in zero gravity. Your complication would be the stickiness of water. [Answer] A good real-world example is the cell membrane surrounding all living cells. The membrane is composed of a phospholipid bi-layer which form a water tight membrane. The membrane is perforated with protein channels that allow large molecules to enter and exit the cell as needed. Given that this is science fiction or fantasy, adapt with words like "di-electric' and 'plasma field' as needed. [Answer] This is similar to a few other answers but how about a non newtonian fluid that is kept solid by the internal and external pressure and the only way to pass through is to slowly and gently travel through it. Positives The upside to this is that it could technically be translucent and you have time to identify what is attempting to pass through it. It could also act as a defensive barrier against anything being fired at it. All that would be required to fix it is to add more fluid. Negatives Slow moving fish or aquatic creatures would randomly enter and die. No way to prevent hostiles from entering if they know how it works. This also isn't how non newtonian fluids actually work. [Answer] You could have a membrane that self-heals so that your creature can go in, sort of create an airlock for itself and close it off from the outside environment then proceed to tear open the membrane (on the inside of the bubble/dome) which, then absorbs the torn mass back into itself. It's like the plastic balloon toy where you roll up a piece of it and put it on one end of a blow pipe and blow air through it. You close it up by pulling out the pipe and closing the hole in. ]
[Question] [ I'm building basically Australian Wakanda, if you'll forgive the pop culture reference. Australian aboriginal culture never made their own wheeled vehicles, but what if they had? [![Image of kangaroo pulling chariot painted on stone](https://i.stack.imgur.com/UPaEd.png)](https://i.stack.imgur.com/UPaEd.png) The closest thing to a potential beast of burden on their continent is the kangaroo. Speed of Animals says a red kangaroo can sustain a speed of 40km/h for two km, which is impressive, and compares well with the speed of camels. Could they do more than 2km at a time? What's their endurance like? How far do wild kangaroos travel in a day? Could they go 40-50km a day like a horse can? How many would be needed to pull the chariot? I'm picturing a lightweight chariot, not a cart. Build for speed, not to carry heavy loads like a wagon. The red kangaroo ranges over nearly the whole continent, and is very strong — two big advantages. The Eastern grey kangaroo is smaller, though not by much, and has been recorded going faster (Wikipedia: Eastern grey kangaroo), though again I don't know if it's a sprinter or has endurance. It has a much more limited range and isn't adapted to Australia's deserts, making it a less attractive candidate, in my opinion, though I could be convinced otherwise. What about the psychology and trainability? I think kangaroos have been put in circuses, implying training them is not an impossibility. Are their brains capable of bonding with humans? Do they do anything at circuses besides beat people up? Maybe they couldn't be tamed (in one generation) but could be domesticated (by breeding in captivity for generations) what do you think? --- PS: I found [this December 2020 article](https://www.newscientist.com/article/2263145-kangaroos-can-learn-to-ask-for-help-from-humans-just-like-dogs-do/) which says they can communicate with people, and says that the Western Grey kangaroo is more friendly. PPS: Eastern Grey "Kangaroos moved on average 2.39 ± 0.62 km per day (accumulative distance between location fixes over a day) with the maximum distance moved by an individual on a single day being 4.39 km" [according to GPS tags](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6025337/) - that's not enough for a useful beast of burden PPPS: A paper from 2013 'Energy, water and space use by free-living red kangaroos Macropus Rufus and domestic sheep Ovis Aries in an Australian rangeland' reports they travelled an average 3.646 ± 0.301 km per day. You'd think it'd be further with them so big and fast. [Answer] ## Use emu kangaroo is not going to work well, their hopping is efficient but horrible for pulling a load. They will waste a tremendous amount of energy if they try. because both legs must move together they can only produce short power strokes with long delays in between which is awful for dragging a load, especially with a light animal. Likely they are going to be reduced to 5 leg walking, which is slow, inefficient, and again they will run out of energy quickly. You would be better off with large ground birds like emu or large extinct marsupials like diprotodons. with emu you will need several, at least until they start breeding them for size and strength. diprotodons on the other hand come in any size you want up to 3 tons. [Answer] # I love this idea! Now, I hope not to offend you — but I love it because I'd laugh for a week to see it in a movie. Just thinking it through in my head makes me want to curl up and giggle for an hour. Here's what I'm thinking. [![enter image description here](https://i.stack.imgur.com/7NBea.gif)](https://i.stack.imgur.com/7NBea.gif) Image "Straight 5" from [Imagur](https://i.stack.imgur.com/kqLQE.jpg) This is how you get a bunch of hoppy-jumpy things like pistons (and kangaroos) to produce consistent power in one direction. You get them to hop at different times! So I'm thinking you have a chariot with 6 or 8 kangaroos who have all been trained to hop at different times so that the result is a smooth ride for the charioteer. You need to remember that "chariot" and "wagon" are very different things Now, your question is a bit complex and it's asking a lot of questions (remember that you're supposed to ask only one). But some of your concerns are resolved when you remember that there is a big difference between a chariot and a wagon. * A wagon is heavy and pulled at a slow speed for long periods of time. * A chariot is light and pulled at high speed for short periods of time. A kangaroo would likely be a mediocre replacement for a draft horse. In fact, it would be a terrible replacement for a draft horse. On the other hand, I think they'd make for a fascinating chariot engine. [Answer] "Skippy" says it all [Skippy the Bush Kangaroo](https://en.wikipedia.org/wiki/Skippy_the_Bush_Kangaroo) was a TV show that ran for a few years in Australia. As noted in the linked article and in documentaries on production, representing the single title character was achieved with "Between nine and fifteen kangaroos were used for each show" (emphasis mine). That is, the kangaroos were so untrainable that they just took as much footage as possible of as many kangaroos as possible, added in the close-ups of kangaroo-paws-on-sticks that were used to simulate Skippy untying captives, defusing bombs or whatever, and edited it all together as an episode. Kangaroos just aren't smart enough to train to do complex tasks. The other problems associated with kangaroos as draft animals include: * extreme variation in force/time exerted on harness * body plan that is not conducive to an efficient harness * use as a team requires that every jump is perfectly coordinated (or a) one kangaroo will be overrun by the chariot as the other leaps ahead; and b) changing direction becomes a nightmare) * laziness (low daily activity) As other posters have suggested, go with emus - it's at least vaguely possible to build a plausible harness for them. [Answer] Disclaimer, I'm basing this answer on my inherent knowledge gleaned from being an Australian. Not Kangaroos Kangaroo's are pretty lazy, as noted by your ~3km range a day. Almost every time you see a kangaroo (or wallaby) in the wild, they're lying down under a tree. Even if you could build a cart that would accommodate their unique locomotion, motivating them would be the hardest part in my opinion. Likely animals [Dingo](https://en.wikipedia.org/wiki/Dingo). They're as ubiquitous as the Kangaroo, and [can be trained](https://en.wikipedia.org/wiki/Dingo#Domestic_status) and could pull a sled. The Australian landscape is either "rain forest" or "nothing" so sleds would be good for the latter and chariots would not be good for the former anyway. [Emu](https://en.wikipedia.org/wiki/Emu). They're also fairly widespread, and for bonus point's are ride able like a horse, if you're brave enough. So they could make a reasonable analogue for horses. Bonus Points [Cassowary as shock troops](https://en.wikipedia.org/wiki/Cassowary). These things are the size of an emu and will mess you up. I'll just leave this quote with you. > > Cassowaries have three-toed feet with sharp claws. The second toe, the inner one in the medial position, sports a dagger-like claw that may be 125 mm (5 in) long. This claw is particularly fearsome, since cassowaries sometimes kick humans and other animals with their powerful legs. Cassowaries can run at up to 50 km/h (30 mph) through the dense forest and can jump up to 1.5 m (5 ft). They are good swimmers, crossing wide rivers and swimming in the sea. > > > They're basically a Velociraptor crossed with the Terminator that's the size of an average man and can outrun a man on a bike in any terrain. [Answer] As others have said in their answers, kangaroos are not a good choice, but if Santa Claus can use [six white boomers](http://childrenandteensstoriestomotivateandinspire.com/index.php/2017/12/31/australia-santa-uses-kangaroos-boomers-instead-reindeers/) (male kangaroos) in Australia, instead of the reindeer he uses in the northern hemisphere, then maybe you can adapt. Some [thinking music](https://www.youtube.com/watch?v=Qu76GhRO9Yk). [Answer] Kangaroos move forwards by hopping. They are quite graceful, and very efficient in their use of energy to move. * [Kangaroos hopping alongside a road](https://www.youtube.com/watch?v=a_BIZMJ6rMs) The problem is going to be one of power, not speed. The largest kangaroo is the big red. It weighs up to 90kg. In comparison, horses weigh 500-1000kg. Even a miniature horse weighs about 130 kg. A harnessed horse will be able to pull 2/3 of its weight. Australia, until relatively recently, had a wonderful collection of giant beasts. * [Australia megafauna](https://en.wikipedia.org/wiki/Australian_megafauna) The largest Diprotodon was 1-3 tonnes. Plenty of pulling power and bigger than any horse or even cow. Just a question of how to tame them? Please also make a place for the Carnifex, a giant marsupial lion with enormous slicing cheek teeth, mighty incisors and a thumb claw competitive with any raptor. * [Thylacoleo carnifex](https://australian.museum/learn/animals/mammals/thylacoleo-carnifex/) [Answer] How would a kangaroo-drawn chariot work? : it wouldn't. Kangaroo locomote by hopping, with tendons in their legs storing elastic energy as they land an releasing it as they bound away on their next hop¹. As such they don't use much energy to travel at the speed that they do - and as they increase speed their oxygen consumption stays nearly constant. Hence, if you take out energy from their hopping by putting a chariot behind them, the kangaroo(s) would need to replace it with muscular energy they don't have and stop hopping. Which would probably explain stories in Australia of kangaroos falling over backwards when attempting to use them as carriage horses². As others have suggested dingoes or emus might be a better choice. camels: Camels were imported as a draft animal in the 19th century and have since gone wild. Depending on when the story is set they are at least a current day possibility. ¹ [Elastic Energy and The Kangaroo](http://large.stanford.edu/courses/2016/ph240/cannistraro2/), JP Cannistraro, May 11, 2017 ² If they existed. [Answer] ## Use elastic leashes What I have in mind looks similar to a dog sled. Each Kangaroo has its own elastic leash that connects it to the main leash. With proper balancing of leash lengths and materials, the elasticity even out the unregular hopping motion and provide a somewhat even pull, while also allowing the kangaroos to move without too much restriction. [![enter image description here](https://i.stack.imgur.com/0oxMl.jpg)](https://i.stack.imgur.com/0oxMl.jpg) [Answer] Build a rowing machine. The kangaroo(s) jump and pulls on a tether, that has gears that spins up a flywheel. The chariot's wheels are driven by the flywheel. This disconnects the kangaroo movement from having to match the speed of the chariot, while still permitting energy to be drawn from the jumping kangaroo. The rate at which the flywheel is converted to forward motion can be controlled, as can the tension on the tethers (how much energy is pulled from the kangaroos). You'd need counter-rotating flywheels to prevent insane gyroscopic effects, and the failure mode would be ridiculously explosive. Also the materials science requirements are pretty intense. [Answer] Kangaroos have a couple of logistical issues. First is that long tail. That's a terrible thing to have when pulling a wheeled vehicle. You'd need relatively long leads to avoid running over your steed's tail, particularly when stopping. As leads grow longer the whole thing becomes harder and harder to steer and control. Second, those kangaroo speed measurements you mentioned were average speeds. If you make a chart of a running kangaroo's instantaneous speed, it would look something like a sawtooth wave, with a pulse of power as they thrust their legs that would drop off until the next jump. Hitching that sort of power source to a chariot means the ride would be far from smooth. The occupant would get jerked forward with every bound. Simply staying inside the chariot would be a feat in itself. A big problem is that kangaroos don't bank like a horse when turning. They cut side to side, and can do so with impressive agility. That's great if you're evading a predator, but it would overturn a chariot or eject its passenger. When moving at slow speeds, kangaroos use a combination of both legs, both arms, and their tail in a gait that's inefficient and a bit awkward. That particular gait would make it difficult for a kangaroo to accelerate a chariot from rest to running speeds. Geometrically, even just building that harness/yoke would be hard. Kangaroo shoulders are small and have a gentle slope to them. A harness like that would tend to slip backwards and would do a poor job of distributing the load over a broad area. The harness would be relatively painful to wear, compared to a horse. Even though they come equipped with their own saddlebags, kangaroos would not be a practical choice for pulling a chariot. [Answer] ## Wombats! Point 1) They are well muscled and have strong frames combined with good endurance if not speed (Although they can be quite fast over short distances.) They are also probably the most intelligent of the marsupials family and adapt readily to living around humans. Point 2) Selective Breeding!. Like horses upon being domesticated humans started selectively breeding them for size and endurance in order to make better mounts. Just like we selectivity breed every other animal we domesticate for desired traits. In this case just like horses your aboriginal culture would have started breeding them for size long before they go to point where they started using chariots, firstly for meat then as pack animals. Lastly, and these were apparently still around when aboriginals first arrived on the continent (as were giant kangaroos) if they had managed to domesticate them before they became extinct. I give you; Dipordedon. The giant wombat. [![Reconstruction of Dipordedon to scale](https://i.stack.imgur.com/bwl2z.png)](https://i.stack.imgur.com/bwl2z.png) [Answer] This sounds about as effective as a jellyfish powered speedboat. [Sorry, SpongeBob :( ] I would expect if you could get them to move on command in a useful direction, you would be prone to neck injuries from the jerking motion of each jump. Teaming them wouldn't work well to mitigate the jerking motion because they would self synchronize and you would want to keep them evenly offset in a team. Aside from what has been mentioned, you would be looking at a long term selective breeding program depending on how slippery their genome is. For example canids have a very malleable genome which is what allows for so much variation in physical size, patterning, temperament, coat types, and intelligence. Horses by contrast, don't have as much of a range of variation even though we have bread them for almost as long as dogs (on the whole, not individually). ]
[Question] [ Would it be possible, with genetic engineering, to create a form of tree which produces wood with the same strength/hardness as granite, capable of being used in place of stone for castle-style walls and other defense structures? What minerals and/or nutrients would be required? This plant would not need to be able to survive in the wild, nor will it need to evolve, so don't worry about that level of plausibility. It is ok for the plant to not be self-sustaining, that is it fine for it to require added fertilizer and food to grow. The group creating these plants has access to technology for genetic engineering much greater than Earth's, but otherwise has late-medieval/early renaissance technology. Minor deviations in the way plants work are fine. Pure rock is not acceptable, the resulting wood must still be at least technically wood, with some organic material. Essentially, the product must be distinguishable from ordinary inorganic rock when a small bit of it is analyzed in a modern lab without context. I'm OK with a plant that basically creates granite or a similar rock with cellular residue left in the rock, but I would like an explanation on how this plant could grow with this world's physics. How does a plant avoid turning all of its living cells into rock, and still grow to a sizable height? [Answer] Nature already got your back, buddy. [Schinopsis brasiliensis](https://en.wikipedia.org/wiki/Schinopsis_brasiliensis) is a extremelly hard wood native from northern Brazil. It's main use is on the construction business as a reinforcement for the structure of the roof and for furniture, support for train tracks, or even as a replacement for steel reinforcement while concreting stuff. Oh, and bludgeoning weapons. Nice, really nice bludgeoning weapons. This wood is so hard that that it was nicknamed "quebraxo", or "quebra-machado", meaning axe-breaker. It is a bit ligther than granite, having around 1.5g/cm³ for its density and being twice as hard as bubinga wood. This wood is so hard that punching a concrete wall is actually less painful than punching one of those evil trees. (I may be a bit paranoid but I think they are actually made of alien micro-nanites ready to inject mind-controlling drugs on the populace. But don't let them know that I told you so.) In fact, regular tools, like axes and handsaws (saws you use with your hands, not to cut hands. You get it.) have a really hard time to cut it. You need a very good chainsaw or a water-cooled industrial saw to cut trough a bunch of those without losing your tools. Luckily, those trees grow in really useful sizes, being mostly straight up. This means that you can put them to use with less cuts, which makes them a way easier to use material than granite while losing to it by very little regarding durability. [Australia has a bit more extreme wood](https://en.wikipedia.org/wiki/Allocasuarina_luehmannii) from the aptly-named ironwood family, which beats even the Schinopsis and is probably the closest thing you can get to a rock that makes photosynthesis. And is also probably poisonous. And carnivorous. And infested of snake-eating spiders and who knows what more. Australian things are scary. Australia is scary. [Answer] Compression strength of [granite is 19 000 psi](http://www.engineeringtoolbox.com/compression-tension-strength-d_1352.html). Compression strength of [bubinga wood is 10 500 psi](http://workshopcompanion.com/KnowHow/Design/Nature_of_Wood/3_Wood_Strength/3_Wood_Strength.htm). So we are more than half way there when it comes to building high walls. Great! Actually even better, as bubinga is $0.71 g/cm^3$ and granite is between $2.65$ and $2.75 g/cm^3$ so your walls could be higher. Bubinga's hardness is 2 690 lb and bending strength about 22 600 psi (for granite, bending strength [seems](https://books.google.pl/books?id=wCnm0iyAkX4C&pg=PA326&lpg=PA326&dq=granite%20bending%20strength&source=bl&ots=tXQj5Shs_H&sig=1NwfUP34uaeBcFqpqINantV2nB0&hl=pl&sa=X&ved=0ahUKEwiFtrat9NjTAhVDIpoKHSJ3B_8Q6AEIOjAA#v=onepage&q=granite%20bending%20strength&f=false) up to about 7500 psi) - Whilst I can't make full calculations and analysis, I believe walls made of it could be more resistant to shatter, less likely to splinter than granite. If you could find a big enough supply, you could make really decent walls out of it. All in all - surprisingly we are not that far from what you ask already! If you want to go even harder, you need to let it deposit even more minerals in it's structure, grow even denser. Or you could let the wood sit in the swamp, the way Polish black oak is created ([kind of bog-wood](https://en.wikipedia.org/wiki/Bog-wood), automatically translated Polish article [here](https://translate.google.com/translate?sl=auto&tl=en&js=y&prev=_t&hl=en&ie=UTF-8&u=https%3A%2F%2Fpl.wikipedia.org%2Fwiki%2FCzarny_d%C4%85b&edit-text=&act=url)). A lot of tannins and a lot of iron in water, creating really hard structures inside the wood. But it works best on trees that fallen into the water and died. That said, it wouldn't be unbelievable in the [heartwood](https://en.wikipedia.org/wiki/Wood#Heartwood_and_sapwood) of live tree. Given that the process causes our black oak to get up to $1.1g/cm^3$, and the difference is actually very much stone-like mineral, if you will apply this to bubinga, you should have best of both worlds. [Answer] ## Yes, you could get wood harder than granite What you're going to need 1. Enzymes for creating diamonds 2. Enzymes for making graphene 3. Genome for the [Nuttal Oak](https://www.treehugger.com/lawn-garden/7-fast-growing-shade-trees-slash-energy-costs.html) since it's a fast-growing hardwood tree Diamonds are amazing at compression but are outperformed by other common materials in tension. Graphene has the [highest tensile strength of any known material](https://en.wikipedia.org/wiki/Graphene#Mechanical) but essentially no compression strength since it's a sheet. Let's make a hybrid tree that utilizes both these forms of carbon. In wood, cellulose makes up the walls of each cell with [pectin](https://en.wikipedia.org/wiki/Pectin) and other binders between cells. Replace those intercellular binders with graphene and replace the cellulose walls with a porous diamond matrix. (It needs to be porous so that cell can still breath.) As the tree grows, it will build cell walls out of diamond then connect to the cellular neighbors with graphene sheets. If small spikes are put on the diamond cell walls, when under extreme loads, those spikes will pop into the cell pores for extra grip strength. ## Complications * Working with this diamond wood is going to be extremely difficult. Consider placing the tree in a form so it grows into the shape you want. [Answer] Petrified wood may fit these requirements: While it is, compositionally, just rock, the way in which it is formed makes it very different from quarried stone. Petrified wood is formed from wood that dies in certain environments with mineral-rich water and is rapidly covered by soil or ash. The minerals inhibit decomposition, and gradually deposit within the tissue of the wood. Over time, as the original wood decomposes, it is replaced with mineral deposits that assume the same shape and structure of the wood. The end result is rock, but rock that is [structurally identical to the wood](https://upload.wikimedia.org/wikipedia/commons/2/24/Petrified_wood_closeup_2.jpg). In the real world, petrified wood is often found in volcanic ash and other niche environments, and takes decades to centuries to form naturally. However, about ten years ago a team of scientists [demonstrated](https://phys.org/news/2005-01-petrified-wood-days.html) a technique whereby wood was artificially petrified in a matter of days. In a sci-fi context, you can take this basic idea and alter it slightly: Your people build structures out of plant matter, using genetically engineered fast-growing strains and artificial growth techniques to speed up the process, and mold the plants into the structure they need. Once the correct shape is set, they use an artificial petrification solution (perhaps a spray or water additive) to arrest growth and start the petrification process. Once the wood is fully petrified, you have a stone structure in the carefully-grown organic shape of the original wood. [Answer] Of course it would be possible. There are many cases of biological organisms creating inorganic structures that are often much better than anything purely inorganic. Spider silk comes into mind, as it is much stronger than steel for it's weight. Or in your case, something like process, that creates pearls. But there are two problems : resources and speed. The resources problem is simply the organism having access to enough raw materials to construct the structures and energy to move things around. But that could be solved by "feeding" the organism a soup of raw materials dissolved in energy-rich soup. Second is speed. As seen with the pearls example, biological organisms are often awfully slow at building those inorganic structures. I don't know how fast it can be made, but if you strip away any biological parts that are not necessary for construction of the inorganic structure, make it's food really easy to digest and add some handwavium, you could grow few millimeters per day. Your question really reminds me of how [synthetic insulin is produced](http://www.diabeteswellbeing.com/synthetic-insulin/). Scientists took some bacteria, and altered it's genome so it produces insulin. Then, those bacteria are grown in vats filled with raw materials and the insulin is extracted after some time. Also, I don't think you want rock as the inorganic structure, if you want the biological parts to go through it. What you should be looking for is some kind of porous-foam like material. Possibly made from metal. Like some kind of [metal foam](https://en.wikipedia.org/wiki/Metal_foam). Possibly with holes being microscopic as not being visible to naked eye and being easier to make by biological organisms. [Answer] Well, based on high school biology from 28 years ago, and what I was awake for, Isn't a substantial amount of what plants are made from come from the soil? So what you do is you have your genetically or magically altered plants incorporate Granite or maybe limestone or basalt from volcanic rock into the cell wall structure? Volcanic rock and soil are great for growing Bonsai plants in. The plants take in the soil in greater proportion and form a basalt formation in the cell walls to create a wood that has a lot of the same properties as Basalt. LImestone is even easier. Suppose it takes in CO2, uses part of it for photosynthesis and uses the rest of the carbon to form CaCO3, or Calcium Carbonate to use in the cell wall structure. I'm not so sure about granite since it is a heat and pressure kind of igneous rock. I cant think of how to hand wave the required amounts of mica, feldspar, and quartz. Here is why I think having the plant incorporate the substance into the cell walls is important. If you have ever looked through a microscope at some onion, it kinda looks like a brick wall. Onions grow in layers. something else reminds me of a brick wall and has layers: [Timbrel Vaulting](http://www.lowtechmagazine.com/2008/11/tiles-vaults.html). Timbrel vaulting is very strong for it's mass and thickness. Combine drawing minerals from the soil and incorporating them into cell walls with a plausible structure and you get plants as strong, if not stronger, than stone. I think growing stone could be fun [Answer] Silica in crystalline form is actually not uncommon in plants (see <https://en.wikipedia.org/wiki/Phytolith>). Silica IS quartz. Quartz (Mohs hardness 7) is also one of the two main hard constituents of granite, feldspar (Mohs hardness around 6) being the other. This is harder than unhardened steel (common construction steel is not hardened, tool steel is). There might not even be a need for high tech genetic engineering (as opposed to simple and patient selective breeding) to achieve very hard plants - see the examples of real life ultra-hard woods in other answer... [Answer] This may be a bit farther out than you were seeking, but I direct you to [Pyura Chilensis](https://en.wikipedia.org/wiki/Pyura_chilensis) This is not a plant, but it is feasible that a more plant-like organism could similarly form a hard rock-like shell from mineral debris in its environment. This is a filter feeder that looks like a chunk of rock with internal organs; I cannot easily find information on the hardness / composition of that shell, but it looks to be potentially similar to that of oysters or barnacles. ]
[Question] [ I am currently working on a fantasy world setting and I had this idea about a world having a different sun every day. There could be around 3-12 suns in total, and every day, a different one would rise and set. Each sun would have, say, a different color, size and brightness but there would not be major differences between them. They can come in a specific order that gets repeated, or come randomly, I don't mind. Moreover, there would be days, unpredictable, when no sun would rise, leaving the world in darkness until the following day. These dark days would come 2-4 times a month on random days. Is there any way that science could explain such a phenomenon, or at least something similar? It is not mandatory, but I would like a scientific explanation if possible, even if I have to modify this idea. This fantasy world exists in a larger science-fiction universe, so this phenomenon could be created artificially by other more advanced civilizations. Also, I describe the phenomenon from the perspective of people on this planet, so I don't care what happens outside of it to make it work. EDIT: It doesn't even have to be actual suns, but it could very well be things that look like suns and give off enough heat and light for the civilizations to survive (as long as the planet is still in orbit around something). [Answer] An easy and noncrazy way to do this is to have the planet rotate with a period equal to its year, like the moon does the earth. Thus there is no day or night: the sunward face is always sunward. The sun is extremely bright so not much happens on the bright side of the planet. Serving the role of suns on the dark side are various moons. Because the sun is so bright it is reflected with more or less the power of a sun by the various moons. One could then tweak the moon characteristics to change the quality of each "day". For example a close, small, very reflective moon (perhaps metal - a captured asteroid?) would make a very bright day. A reddish Mars-like moon would make a red day. Blue moons would be infrequent. And so on. [Answer] Note: I started this answer by writing up all sorts of wiggle room about the word "day" not intending to come up with an answer. Then I came up with a crazy explanation (rogue planet). And finally and then hit on a plausible one (variable star) that doesn't rely on any of that. I've reordered the answer to put the best answer first, and left the rest in because it's interesting. # Variable Star: Same Star, Different Day A [variable star](https://en.wikipedia.org/wiki/Variable_star) is a star whose brightness and other attributes fluctuate. These fluctuations can be regular, or irregular. They can be big, or they can be small. They can be caused by changes in the star itself, or by things blocking the star like a dust cloud or swarm of comets. A planet around an irregular variable star which has both internal and external causes would seem to see a different star every day. The changes in the star itself, plus the various occluding objects in closer orbits around the star, would make it seem "random". For example, what if our planet had a gas giant in a closer orbit. That gas giant has trapped debris in large clouds at its [L4 and L5 points](https://en.wikipedia.org/wiki/Lagrangian_point). [![enter image description here](https://i.stack.imgur.com/jgRia.png)](https://i.stack.imgur.com/jgRia.png) [Source](https://en.wikipedia.org/wiki/Lagrangian_point#/media/File:Lagrange_points_simple.svg) These clouds act like giant filters giving the star a different color, intensity, and apparent size in addition to the variations in its actual size. As the gas giant and our planet rotate relative to one another, one field or another (or none) will partially occlude the star. Throw in more than one interior gas giant, each with their own debris field, and you have a heavenly kaleidoscope! The debris fields are diffuse enough, the variability slow enough to never see an abrupt change. The planet's rotation is fast enough to never have enough time in a day to observe a slow change. To a layman the star sets while fuzzy, small, and red (filtered through a debris field), and when it rises it's sharp and blue (it's fully passed the debris field). On top of that, there will be normal changes in the appearance of the star as it travels across the sky due to its light passing through different parts and thicknesses of the atmosphere, just as our own Sun looks different at sunrise and sunset and in different parts of the world in different weather. This further complicates anyone figuring out they're looking at the same star without careful observation and consideration. Until they figure out the very complicated and unstable orbital mechanics of their system, it will appear to them as if they look at a different star every day. Until someone can coordinate tracking their star's changes over a full rotation, nobody can prove it's the same star changing its appearance. This could be a key plot element of the story, people's observations are converging on the conclusion that it's been one star all along, and that threatens some political power based on the orthodoxy of a new star every day. This configuration does not have to be stable, if it lasts for 10,000 years that will be long enough for it to be "normal" for all of a planetary society's history. --- # Sidereal vs Synodic Day There's some issue with the notion of a "day". On Earth there's the [sidereal day](https://en.wikipedia.org/wiki/Sidereal_time), and then there's the [synodic day](https://en.wikipedia.org/wiki/Synodic_day). We're used to them being basically the same, but what if they weren't? What sort of culture would grow up around that and what notion would they have for "day"? The sidereal day is what an astronomer might use for a day. It's the time it takes for the planet to make one full 360° rotation. A planet bound observer can measure this by tracking the angle of the (relatively) fixed distant stars. Then there's the synodic or solar day, that's the time for a point on the planet to come around and face its star again. It's sunrise to sunrise. That's what your average person would call a day. They're not the same on the Earth. Because the Earth rotates in the same direction as it orbits (as do most planets) it has to go a little bit further to line up with the Sun again. A synodic day is 24 hours, but a sidereal day is about 4 minutes shorter. [![enter image description here](https://i.stack.imgur.com/Jur34.png)](https://i.stack.imgur.com/Jur34.png) [Source](https://en.wikipedia.org/wiki/Sidereal_time#/media/File:Sidereal_time.svg) This is the wiggle room in the requirement. Since the question talks about "having a different sun every day" this is the synodic day: sunrise to sunrise. # Who Cares What Happens On The Other Side of the World? Furthermore, a low tech society wouldn't be able to communicate or travel to the other side of the world. Their notion of "day" would be what they see in their sky. Whether there's another star shining in the sky in the other side of the world would be of no consequence to their notion of a "day". # I Wish There Was More Time in the Day And then there's the length of the day. We're used to a "day" being a very small fraction of the year, but there's nothing that says it has to be. For example, because [Mercury](https://en.wikipedia.org/wiki/Mercury_(planet)) rotates so slowly, and it's so close to the Sun, its solar day is two of Mercury's years! It's [tidally locked](https://en.wikipedia.org/wiki/Tidal_locking) to the Sun. Lacking any significant axial tilt, Mercury doesn't have any seasons; there's little difference to Mercury whether it's on one side of its orbit or another. A culture growing up on a Mercury-like planet which is in a star's habitable zone wouldn't have much use for a "day" or "year" as a measure of time. All this adds up to some more wiggle room to make it work. --- # Rogue Planet This is a variation on the novel [A Deepness in the Sky](https://en.wikipedia.org/wiki/A_Deepness_in_the_Sky) which I highly recommend. What if we had a [rogue planet](https://en.wikipedia.org/wiki/Rogue_planet) with life that has adapted to the relatively brief periods it's warmed by a star? What if the reader is not made privy to this, and the characters just talk about a "day" as if it's perfectly normal? There's nothing that says life, even intelligent life, has to have a metabolic rate as high as Earth life. This life has evolved to very carefully husband and store energy. For most of the time life hibernates underground, nearer to the well insulated planetary core, warmed by the left over heat from its gravitational formation, and the decay of radioactive elements. As it drifts near a planet, a new "day" begins, the surface becomes briefly habitable, and life pours out onto the surface to take advantage of the increased energy available. This surface explosion of life could take dozens, hundreds, or thousands of years depending on how close the planet has drifted to a star and how large that star is. This doesn't necessarily have to be in the habitable zone for liquid water, imagine the relative bonanza Pluto has compared to a rogue planet in deep space. Let's say this planet has a very, very slow rotation. As they near a star it might come above the horizon looking a bit bigger than the rest. As they drift closer and closer, [parallax](https://en.wikipedia.org/wiki/Parallax) will make it appear to move through the sky, getting a little larger. As the planet warms, life would pour out onto the surface for the new "day", their metabolism rising to make the most of the available energy. At "noon", their closest approach to the star, it would appear largest in the sky, then start to shrink as the planet moved away. Their metabolism would slow and they'd start storing energy for hibernation as the planet cools. "Sunset" would be when they can no longer distinguish their star from any other in the sky and they'd return to their hibernation. The next time they come to the surface, it's a new "day" around a new star! You can even play with the planet's rotation and some temporary chaotic orbits to come up with even crazier days. [Answer] A recent novel, the Three Body Problem by Cixin Liu, did more or less exactly what you describe - you don't need many Suns, you just need a chaotic orbital system so that it appears that there are many Suns. As the planet travels in a chaotic path between three suns, the suns will sometimes be very close, and sometimes very far away; sometimes there will be one in the sky, and sometimes three. The colours of the suns will be affected by their relative distance, the atmosphere, and other interacting factors. Secondly, the chaotic component of the Suns would create such a difficult environment that it would 'reset' the culture at those times when the planet became too hot or too cold, so it would be very hard for any culture to rise beyond a relatively simple point. So, when the heat got too great, all cities would burn, while deep dark long winters would occur when the planet deviated on a long orbital trajectory away from all three suns. The main problem is, as I have just said, the book has already been written, so you would need to find something in the story that differentiates it from Cixin Liu's novel. [Answer] After considering the problem, I have come up with a partial solution, which relies on having different suns / no suns, but not randomised, also a solar system which probably has about a 0% chance of actually happening, but still: [![hand drawn solar system](https://i.stack.imgur.com/GaSGp.jpg)](https://i.stack.imgur.com/GaSGp.jpg) The logic is this: the gas giant and "earth" have the same year, "earth" has whatever day length you want, but the key bit is the stars: your main star is HUGE, such that it can have two stars orbiting it that are not opposite eachother. We have a gas giant to block out the view from the other 1 or 2 stars, so that in theory you should only see 1 at a time, and never directly see the primary star, only a secondary or none at all Beyond that, pick how long the secondary stars' year is, so that you have a relatively regular order, secondary1, secondary2, no star, secondary1... etc I am not fluent with astrophysics, or large scale mechanice so I don't know how stable the orbits would be, and have some doubts as to whether they would be stable for a long enough time for planets / life to develop, but use "handwavium" which is a writers favourite element to make it work [Answer] Consider a type of constructed megastructure such as a [shell world](https://www.youtube.com/watch?v=TfMr_XkWcEs). Each layer is like a floor in an apartment building, and some levels are set up to appear like a natural “surface” planet, but it’s really an ellaborate terrarium. Most of the shape of the mountains and seas are molded into the floor. Since this is inside, what to do about the sun? The sky is the ceiling of the level, which could be many miles up. It is a rich display screen which fakes the appearance of stars etc. and programs in a display of the daily sun, with its seasons. Only something got messed up in the software, or maybe the zookeepers were feeling like a creative experiment. For whatever reason, the parameters of the sun changes from day to day. [Answer] Doughnut world with an eccentric tumble. The tumble causes different amounts of atmosphere to refract the sunlight. This would probably have to be artificial to survive the tumble long. The system the planet is in could have orbiting anomalies that change the appearance of the sun. Perhaps there is even a partial Dyson swarm (abandoned or otherwise) that blocks out the sun entirely from time to time. The planet actually orbits a black hole, not a sun. The light seen from the surface is released from the in fall of mater into the black hole. Changes in the mater, volume and make-up will affect the visible light. Sometimes it might even be absent entirely. There are other repercussions. The planet is not part of a singular star system. It actually wanders a nebula who’s ambient temperature is high enough that the energy production of the planet combined with its thick atmosphere keep it at habitable temperatures. It’s position within the nebula determines what if any sun’s/stars cause day rise. The planet is a habitable moon. It has a figure 8 orbit around two planets (probably gas giants) and through their shared center of gravity. The two planets are tidally locked to each other and revolve around the center of their shared gravity. The moon gets light from the sun, and from reflection off the surfaces of the two gas giants. Depending upon the revolution of the gas giant pair, their orbit around the sun, the position of this moon and throw in potential eclipses from other moons and you can get a rather erratic day/night/partial day/ partial night cycle. The planet is inside/at the center of a Dyson sphere like object. The internal surface of that sphere projects some sort of illumination that is perceived as the sun. Since it is artificial it can change randomly. Handwave, the planet cycles through realities/planes of existence. Several of these are stretches. Though technically possible. All of them have larger consequences. You’d have to pick a specific “cause” to get fine grain details as to the affect. In general though you no longer have a regular day/night cycle or a regular week cycle. Everything that has arisen in our society because of this regular pattern would break down. There is no regular work week. There is no standardized time keeping or date keeping. Nature has evolved animals to take advantage of earths regular day night cycle. So this planet would evolve different life cycles based upon the random elements. [Answer] You maybe want to look into [Nightfall](https://en.wikipedia.org/wiki/Nightfall_(Asimov_novelette_and_novel) "wiki.org / Nightfall by Asimov") > > The fictional planet Kalgash is located in a stellar system containing six suns (Onos, Dovim, Trey, Patru, Tano, and Sitha), which keep the whole planet continuously illuminated; total darkness is unknown, and as a result, so are all the stars outside the planet's stellar system. > > > You can have "suns". What you don't need is "human" civilization. [Answer] As far as the effect of unnatural "suns" goes, I suggest you read [The Second Chronicles of Thomas Covenant](https://en.wikipedia.org/wiki/The_Chronicles_of_Thomas_Covenant). A magical effect called the Sunbane gives the Land a range of suns that could rise every day, each causing abnormal environmental behaviour: unnatural growth of plants, extreme floods, immediate drought, and widespread pestilence/disease. As for how this could happen... If some object lies between the planet and the sun, orbitting the sun synchronously with the planet, then it could selectively filter the sun's rays. A closer-to-the-sun object will not naturally orbit in lockstep with the planet though, so this object would need to have its own means of propulsion. You'll also need to decide why anyone would create this. A [Dyson bubble](https://en.wikipedia.org/wiki/Dyson_sphere#Dyson_bubble) could avoid the need for this whilst still letting light through, and unlike a regular Dyson sphere is self-stable. Different places on the Dyson bubble will naturally retain different amounts of light depending on what's in the way, so will affect the sunlight getting to further-out planets. If you're looking for universe creation to hang more stories on, this would be my choice. It's hard-science-friendly, there's a solid rationale for creating it, any effects on other planets are accidental so you don't have to presuppose planetary-scale experimentation, and best of all from a storytelling PoV it gives you immediate access to a whole new set of societies within the same solar system. [Answer] I only have a partial answer, as everyone else has covered this nicely. Here are just a couple more things to consider, and probably integrate with other answers. # The planet tumbles chaotically There are a few moons in our solar system (one around Saturn, the rest around Pluto) that instead of rotating consistently around one axis in a periodic way, tumble and rotate every which way due to the gravitation of nearby bodies. This depends on the planet you're on being more potato shaped than round (and defying the IAU definition of a "planet" in the process), but its worth considering. [Here is a source discussing how this applies to at least two of Pluto's moons](http://news.nationalgeographic.com/2015/06/150603-pluto-moons-charon-styx-nix-kerberos-hydra-new-horizons/): > > He’d been looking at how Nix and Hydra, the two largest of Pluto’s > small moons, got darker and brighter as they traveled through their > orbits. With the help of some new computer simulations, he realized > that these two oblong moons were chaotically rotating—tumbling rather > than spinning like tops. > > > “If you lived on Nix or Hydra, you would not know if the sun is coming > up tomorrow,” Showalter says. “Or it could rise in the west and set in > the north.” > > > Only one other moon, Saturn’s moon Hyperion, is known to perform such > an off-kilter jig in space. In the Plutonian system, Nix and Hydra > tumble about because they orbit both Pluto and its abnormally large > moon Charon, which together form a gravitational dumbbell that tugs > and nudges the moons in random ways. Styx and Kerberos also orbit the > binary system formed by Pluto and Charon, so they are probably > tumbling as well, Showalter says. > > > # The planet isn't round, but instead a torus Amazingly, a planet shaped like a torus would be stable. It is extremely unlikely to form naturally, but if it did there is nothing about the shape that would cause it to be torn apart or crush itself into a ball. [Here is a source where someone confirmed the math based on earlier models.](http://io9.gizmodo.com/what-would-the-earth-be-like-if-it-was-the-shape-of-a-d-1515700296) There is all sorts of cool stuff that happens to a planet with these characteristics, depending on where the torus you are and how it is tilted relative to the plane of its orbit around the star. You can even get all sorts of stable moon orbits passing through the hole in the middle. If you want to keep it a little closer to your original idea, you can have it be a circumbinary planet (it orbits two stars, which orbit each other. It goes in a circle around the pair, not a figure 8 between them). A few moons can reflect light on other parts of the planet too (+1 to the answer that mentioned tons of moons). Check out the link above. I've included a couple of the pictures from that page, but the full article mentions a ton of cool properties of a toroidal planet, including how it would be lit by its sun. To tie it back to your original question, if the "day" of the toroidal planet and the "year" aren't a multiple of each other (Earth isn't either, but its close enough to fool people without accurate measurements), you could make predicting when a region gets sunlight very difficult for a culture that doesn't have a strong grasp of trigonometry. [![light being cast on a toroidal planet as it orbits a star](https://i.stack.imgur.com/TrhPN.png)](https://i.stack.imgur.com/TrhPN.png) Light being cast on a toroidal planet as it orbits a star. [![an example of a crazy moon orbit around a toroidal planet. This is one of many stable orbits.](https://i.stack.imgur.com/4Lgp3.png)](https://i.stack.imgur.com/4Lgp3.png) An example of a crazy moon orbit around a toroidal planet. This is one of many stable orbits. [Answer] Artificial Suns. Your world does not actually have a "sun" as we think of one. It does not orbit. It flies through the interstellar void with multiple, gigantic fusion reactors in orbit of it. The reactors are ancient, and not in the best repair (since everyone on the planet has forgotten that they are constructs and nobody does maintenance any more.) so the intensity and colour of each can be variable. The suns could double as the planet's propulsion devices, varying their output and orbits in ways that slowly direct the planet toward whatever its ultimate goal is. This could easily include turning the entire reactor on and off. Especially if each reactor, in addition to providing light and warmth to the planet's surface, has some kind of gravity generator it can use to change whether it's pulling the planet or being pulled by it as it orbits. This would work best if the world is at least semi-hollow to reduce mass, so now you have an excuse for why the "underdark" even exists. Probably it was hollowed out for material to use to build the reactors and the dross was dumped overboard to reduce mass. Now you can have plots about "suns" going dark and not coming back, which can either be due to malfunction or due to the "worldship" nearing its destination. You can have plots about the new sun that has appeared in the sky that is more constant and stable than the others and the natives trying to figure out what it means. (Especially where there are probably lots of ancient "prophecies" about it.) Depending on what you have for "magic" in your fantasy setting, it could be the remnants of the brain-scanning control system for the ship coupled with the powerful and precise gravity and power generators in the "suns". "Magicians" could find their power waxing and waning depending on how well "attuned" they are to the particular "sun" in the sky at the moment. Magic wands and whatnot could be special-purpose control devices that even people who's brains aren't recognized by the system can use. There are lots of directions you could go from here. Let me know if you want more. :) [Answer] I don't want to be a spoiler, but if the pattern of day and night changes only a tiny bit, the effects on weather and climate are huge. Live on earth took several billion years of a relatively stable climate to develop. Or at least a climate that took hundreds of million years for each major change. Your world would be uninhabitable. Not much fun for fantasy :-) Also, your question sounds like asked by Ptolemy. Now we know that the sun is not an object that circles around the earth, coming "up" and going "down", but that rather the earth circles, along with the other planets, around the sun. A planetary system with more suns is possible, but even then, those suns do not really circle around your planet... [Answer] If it's a fantasy world, you could have a number of different actual suns in different solar systems which the planet shifts between. The suns have identical masses (including a "missing" sun which radiates either magical "dark light" or just in a spectrum which makes it look like night to people with regular vision) and the planet's orbit is identical in each system. There could be equivalent planets with identical relative orbits (and even exact positions within their orbits) in the "other" systems and they just swap, instantly and magically, on a periodic basis. This would be similar to Piers Anthony's Apprentice Adept series, where a few people could move/swap between "two worlds occupying the same space in two different dimensional planes" (<https://en.wikipedia.org/wiki/Apprentice_Adept>). You could define any rules for operation for these transfers you want, such as: * stable multi-dimensional-plane space manifold rotates around all the suns, and has "slots" (like a cheese grater's blades) for shifting planets between the dimensions. * giant space octopus was created by a more-multiplanar Creator than anyone could have ever imagined, and has been tasked with shifting the planets between dimensions for eternity, but every once in a while it forgets where it is in the shift cycle and just restarts at the top of the chart; perhaps that's the dark sun. Or perhaps the giant space octopus has a complicated holiday schedule it keeps exactly as The Creator dictated it. * wormholes make the orbital paths around different suns connected. Wormholes are for some reason attached to the suns (the work of a very large Creator, either fantastical or scientific) and the wormholes work in pairs (or higher-order groups) to shuffle planets around between suns in different places, and the arrangement of planets on orbits is such that things are gravitationally stable. Diagram shows a minimal example of orbits divided into portions which go around solar systems in very different places. Segments are approximately one day long and an unexpected visit to the "dark sun" happens when one of the wormhole pairs twitches. This last arrangement could have been created for any number of purposes, but one possibility is that some advanced entity/group tracks down habitable planets which are going to be destroyed by orbital problems and finds it far easier to move them great distances via wormholes than to recreate such a habitable planet and, not wanting them wasted, has assembled them into this livable holding pattern which: 1. can be expanded relatively easily to accept more planets as they are found, 2. distributes the gravitational effects so they're stable, 3. serves as a convenient interchange between different parts of the/a/more-than-one galaxy (so you'd get lots of "shooting stars" which are actually shiny Creator race spacecraft zipping by), and 4. enhances the development of intelligence on the planets by a regularly-scheduled shift in which sun comes up. (I am unable to find a reference, but this is a theory that our moon gave rise to advanced intelligence by creating an evolutionary advantage of the ability to plan hunts into the future as the lunar illumination regularly varied. No doubt if that's true there were some hungry packs of animals during some lunar eclipses...) In option #4 we also find the suns are all about the same mass because it was easiest also for the Creators in question to just locate useful suns (perhaps they're not rare in the slightest) for this project, and the orbits are sliced with wormholes while the suns remain in their original locations because there's no advantage to moving the suns with wormholes (for one thing, where would you move them to?), or else there are technical restrictions making it inconvenient. (And the planets aren't placed into orbits without wormholes because dealing with a planet's relative velocity on initial capture is quite involved, and requires the use of many wormwholes; needing to keep those around for repeat use, they are built into the storage arrangement. Capturing a new planet or adding a loop around another star would be a dramatic event indeed to everyone on the planets involved, but hopefully rare.) [![orbits around distant suns are "spiral bound" via wormholes attached to host stars](https://i.stack.imgur.com/SGeMy.png)](https://i.stack.imgur.com/SGeMy.png) [Answer] ## Option 1: Irregular planet shape Well, it is [not physically realistic](https://worldbuilding.stackexchange.com/questions/8772/can-a-nonspherical-planet-exist-and-can-it-be-habitable), but: I think it would make a really interesting setting to have your planet orbit multiple stars, but have the planet not be spherical. Instead, it could be some odd shape such that at any given time at any point on the planet only 1-2 suns (or sometimes none) were visible, the rest being obscured by the planets odd shape. This could also lead to an interesting variety of settings on the planet, e.g. harsh desert regions where many suns were always visible, or cold regions that were always in darkness. This made for an interesting setting on the [planet of Prester](http://lastexile.wikia.com/wiki/Prester_(Anatoray-Disith)) in Last Exile (which is what I was thinking of when I posted this). There, the shape of the planet drove much of the mystery of the plot and had a large impact on the general development path of that society. I'm not entirely how the planet should be shaped, I can conceive of shapes for 2 or 3 suns but not sure about 12 (you'd have to draw some diagrams to figure it out). --- ## Option 2: Hollow planet with holes Another option could be a spherical, hollow world, probably artificially created, where most inhabitants live on the inside, with but large (possibly intentional) holes in the sphere. Then as the planet rotates, different suns would be visible through different holes depending on your location in the planet. This option is probably slightly more scientifically explainable (to some extent) than the odd-shaped planet, although personally I like weird shaped planets for the fantasy aspect. --- ## Option 3: Non-circular orbit around multiple stars A third option, although I do not know if it is possible, but if it is it is potentially the most realistic, is to have multiple stars clustered together and the planet switches between them, weaving a path through the stars rather than having a circular orbit. [Answer] Perhaps your people are actually experiencing something like The Truman Show or The Matrix. They are in either a controlled environment, or a virtual one and whoever put them there controls the heat and illumination of their world. This could be a plot twist that is revealed in the end or a "secret" between the author and the reader that the story characters don't know and may never find out. There could be cults that claim they found out and create various, even conflicting, religions based on just what little insight they may have to this truth. ]
[Question] [ In the future, will only one unified language exist on earth, which will be spoken and used for writing by all humans? Will all the other languages and various forms that language become extinct and only one major language will be considered as the language of planet earth? If this might happen. which might become the language of earth in the future? [Answer] Magic 8-Ball says: Unclear, ask again. Now seriously: Languages die out if they don't manage to gain additional speakers at a rate as least as big as people that speak it die. A language gains additional speakers when it is beneficial in one of two ways: * either it is useful (for example because many people speak it) * or it is a crucial point of cultural identification In modern day's world, many tiny languages die out because of the need of a trade language is big and young people from other groups would rather learn a more widespread language than a more indigenous language. However, here the state steps in, aiming to protect national identity by enforcing its national language(s) and trying to teach people additional languages for international trade. This is usually English, which is the most common language learned as an additional language in the western hemisphere, but most day to day business is conducted in the national language. Before the fall of the Soviet Union (CCCP), there was a large block in which Russian had that position, and still day to day life was done in the national languages. A good example for language diversity would be South Africa: it has 11 official languages and a vast list of other languages with special status, [all guaranteed protection in the constitution (provision 6)](http://www.constitutionalcourt.org.za/site/constitution/english-web/ch1.html). On the other hand, lines between languages blur: English starts to pick on words from other languages, other languages pick up words from English. However, the intrinsic sentence structure of languages is incompatible at times, which prevents this - think about a Latin sentences with Ablativus Absolutus, which can not be built in this fashion in English. These hinder drift to only one language to a big degree. Another item that hinders conglomerating to one language is the question of the writing system. While English and most western European languages use the basic Latin alphabet (with varying diacritics), most eastern Europeans use the Cyrillic alphabet, then there is the Greek alphabet and the Arabic letters, Hindi, Chinese Characters, 3 sets of Japanese characters and Korean lettering, just to name some of the more used writing systems. These can't be put 1:1 often, and while there are ways to transliterate everything or use the international phonetic alphabet, it is a barrier for native speakers of one type to learn another. All in all: No, I don't think that all but one language will vanish until 2500, but maybe there will be one language that almost everybody speaks in addition to their national/native language(s). [Answer] I think that all the others are right, but they don't have to be. If you want everyone to speak a single language there are a few ways that it could be done: 1. Empire. Some time in the next 500 years a world power arises that is able to lay claim to a large percentage of the globe. This new empire decrees that language X should be the official language, be taught in all schools, and should be used for any and all business. While not all languages in its domain will die out, over several generations it will begin to become the first language for everyone, and by generation 4 or 5 there will be kids that won't even bother to learn the old language because it's so old fashioned and out of date with modern times. If the empire is large enough, they'd be able to influence the language of every other country, since if you want to do anything but local business you pretty much have to do it in language X. 2. Singularity. The mind/machine barrier is broken, virtual worlds become real, knowledge transfer becomes common. All of the sudden there is no barrier of entry for learning a new language; plug in, push a button, now I know Chinese, and German, and Russian. Each language has things that it is especially good at, and if there is no language barrier then people will use the language that most fits their need/mood/situation. At this point we wouldn't so much be down to one language, as we'd be to the point where language just doesn't matter any more. I'm speaking to you in Dutch, you're replying in Italian, mid sentence I switch to French for some really heart felt swearing. Edit from extended comments: with enough processing power and background data, we may be able to remove a lot of the language while moving more toward abstract concepts, and could eventually end up with something like [Darmok and Jalad at Tanagra](http://www.startrek.com/article/one-trek-mind-deciphering-darmok). This is essentially communication through memes, where people know what they mean and what they imply without having to spell it all out. Edit 2: Also, my apologies for implying that Dutch isn't a perfectly good language for swearing. I'm sure it's great, I just don't have any experience to draw from. 3. Just because you want it to be. In Firefly we are expected to believe that most of the galaxy speaks Chinese as a primary language, despite there being very few Chinese people in evidence. This is an artistic decision that made sense to the writers, and meant they could have swearing without resorting to made up words (like Battlestar Galactica and most YA fiction). You don't even have to explain why. "I don't know why. It's just always been this way, going back to my great-great-great-grandparents at least." [Answer] I'm with the "No" camp, also, but wanted to post this [NY Times](http://mobile.nytimes.com/2007/09/18/world/18cnd-language.html) article about the rate of language loss. Given that most things happen at exponential and not linear rates with populations, if the trend continues it suggests we might be down to 200-250 languages in 500 years. It wouldn't be until about 3300CE that there was a single language. [Answer] # No The basic reason is simple: most people on the earth speak more than one language. There are many places where there is one local language that you grow up speaking with your family, and another 'global' language that you use for business or communicating with the outside world. In Africa, there are many local languages, but many people speak a regional language like Swahili, Hausa, or Dyula; or a global language like English, French, or Arabic. In India, there are many regional languages but most national publications are written in English. Only about 400 million of 1.2 billion Chinese speak Mandarin as their first language. Even people who grow up with a global language as their first language often learn a second one, like the prevalence of English speaking in Mexico or France. So because most people can easily learn two or three languages, there is no need for people to limit themselves to one. Given people's proclivity for maintaining group culture and identity, it is next to impossible to think that people will abandon the languages that make them distinct. [Answer] # Will there even be speech? 500 years into the future it is completely impossible to predict how we will have evolved biologically, technologically and these two combined. Assuming that in 500 years time we will still go through the flawed and imprecise process of... 1. translating the thoughts we wish to communicate into words 2. transmitting those words through some kind of physical medium, such air, paper or light 3. translating the words back into thoughts ...is kind of folly. Already today, 500 years before your scenario, we have started [interfacing computers directly with the brain-stem](https://www.youtube.com/watch?v=Vq5UBwVCFyc). Where this development will end is anybody's guess. But to assume we will still be speaking or writing in the traditional sense is very naive. [Answer] > > The classes of morphemes are stable upon temporal transformation if and only if the socially normalized value of their acquisition causes them to be disjoint with the kernel of said temporal transformation. > > > Does that make any sense to you? Technically it's English. It's my best attempt at sounding like a snooty journal article (my apologies to the actual writers of journal articles -- I'm sure my example sounds exactly as bad as it is). The point of it is to note that just because we call the language "English" doesn't mean that you can always read it. In particular, technical language is notoriously difficult to understand unless you are well versed in that field. The boundaries of language are never quite as crisp as one might imagine. We label languages as English and French and Chinese because they are distinct enough that we find value in noting those distinctions. That's really all there is to it. Let's create a counterpoint to my English "journal article" quote. You are on Chinese soil, taking pictures. A man with a gun yells at you "Tíngzhǐ! Tíngzhǐ!" loudly while waving his hands and advancing at you. If you stop taking pictures, then that man has communicated effectively. It doesn't matter that you don't speak Chinese. In fact, it doesn't even matter that all I did was throw "stop" into Google translate to get "Tíngzhǐ" and hope that I didn't make a grievous grammatical error in my usage of that word. Communication still occurred. So we have examples where we fail to communicate, even though we spoke the same language (because I used a stilted faux technical dialect) and an example where communication was successful, even though there was a language barrier! It's a good thing too, because it really doesn't matter what nation I choose to pick on... they all have men with guns who need to communicate with you which activities they wish you to cease. So that suggests that truly, we would all "speak the same language" when it becomes convenient for us to all think of ourselves as one group speaking the same language. We still won't always be able to communicate, even though we speak "the same language" but that's normal. On the other hand, if it is too hard to communicate between individuals, the language may stretch and drift until there are truly two distinct languages and they are "one language" in name only. In such a strained state, the language could fracture into two. We have a related distinction known as a "dialect." Dialects are part of the same language, rather than being languages of their own. That being said: > > There is no clear distinction between a language and a dialect, notwithstanding a famous aphorism attributed to linguist Max Weinreich that "a language is a dialect with an army and navy". For example, national boundaries frequently override linguistic difference in determining whether two linguistic varieties are languages or dialects. Hakka, Cantonese and Mandarin are, for example, often classified as "dialects" of Chinese, even though they are more different from each other than Swedish is from Norwegian. Before the Yugoslav civil war, Serbo-Croatian was considered a single language with two dialects, but now Croatian and Serbian are considered different languages and employ different writing systems. In other words, the distinction may hinge on political considerations as much as on cultural differences, distinctive writing systems, or degree of mutual intelligibility. ([Wikipedia](https://en.wikipedia.org/wiki/Language#Linguistic_diversity)) > > > So will we have "one language" by the year 2500? I think that question is highly related to "How common will the human experience be in 2500?" If everyone is doing exactly the same sort of thing, there will be a lot of natural pressures to unify language. If humanity stratifies, it is more likely that we will continue to rely on multiple languages. Thus, I leave the answer to you: where do you think the world will be in 2500? --- And of course, one has to consider the wisdom of the commenters: > > Another conclusion that can be drawn from your example is that there is always at least one other shared language available: the language of violence. – Trevor Alexander > > > [Answer] Yes, but. . . . And, if just one language survives, barring major geopolitical upheaval with a country that speaks some other language conquering the world militarily, religiously or otherwise (a la the Firefly universe where the Chinese become dominant at some point with linguistic consequences), it will be English. Honestly, by 2500, I think it would be more likely that we would be down to a dozen or so major languages with languages like Finnish, Basque, Catalan, Hungarian, Yoruba, many of the official languages of India, Mongolian, and similar currently non-endangered languages in an endangered or even moribund status, it would probably take longer to get down to just one dominant language even though the writing would be on the wall. But, it wouldn't take a huge push of some sort, such as a single global college entrance exam administered only in English, to tip the balance. We already use English as a common global language in fields like international air travel and scientific publication. Countries from Japan to Sweden to Finland to India make learning English as much of a requirement for their elites as learning Latin or French used to be in much of the world. English, French, Spanish, Arabic, or Chinese is spoken to some extent almost everywhere in addition to other languages. The main national languages of North and South America and Australia are English, Spanish, Portugese and French (and French is in peril as people in Quebec have to learn English as a second language to function in their larger country). English is more unifying in India than Hindi. Much of Africa uses French or Arabic or English as a lingua franca in addition to local languages which are fading because they don't have socioeconomic prestige or a wide enough community of people who speak them. China and many of its expatriot communities can speak some version of Chinese. Arabic is spoken in some form or another across the Islamic world and in many places has supplanted previous local languages almost entirely. More people in China learn English than visa versa, first of all because Chinese is not a single spoken language even though there is unity in Chinese characters, and secondly because English has a global spread while many Chinese languages are spoken only in regions within China. There is a strong tendency for any top level sovereign government to make a language dominant and that dominance in positions of power leads people to adopt it. > > The source of the prediction of the death of up to 90% of all > languages by the end of the 21st century is a 01992 paper titled The > World's Languages in Crisis by Michael Krauss, professor emeritus of > the University of Alaska Fairbanks and expert on the indigenous > Alaskan language Eyak, whose last native speaker passed away in 02008. > Krauss arrived at this estimate based on the best available sources at > that time. > Today 457 or 9.2% of the living languages have fewer than 10 speakers > and are very likely to die out soon, if no revitalization efforts are > made. 639 of the languages known to have existed are already extinct – > 10% of all languages. > > > Moreover, we now know that since 1960 we have lost as many as 28 > entire language families. . . . . > We know of a hundred language families that have gone extinct over the > course of history - 24% of the world's linguistic diversity. But the > fact that 28 of them have gone extinct over the relatively short time > span of the last 50 years is symptomatic of the accelerated rate of > language loss we are experiencing in recent times. > > > [There are] 3,176 endangered languages. > > > From [here](http://rosettaproject.org/blog/02013/mar/28/new-estimates-on-rate-of-language-loss/). According to a [September 18, 2007 article](http://www.nytimes.com/2007/09/18/world/18cnd-language.html) in the New York Times reporting on National Geographic study: > > Of the estimated 7,000 languages spoken in the world today, linguists > say, nearly half are in danger of extinction and are likely to > disappear in this century. In fact, they are now falling out of use at > a rate of about one every two weeks. > > > Some endangered languages vanish in an instant, at the death of the > sole surviving speaker. Others are lost gradually in bilingual > cultures, as indigenous tongues are overwhelmed by the dominant > language at school, in the marketplace and on television. > > > New research, reported today, has identified the five regions of the > world where languages are disappearing most rapidly. The “hot spots” > of imminent language extinctions are: Northern Australia, Central > South America, North America’s upper Pacific coastal zone, Eastern > Siberia and Oklahoma and Southwest United States. All of the areas are > occupied by aboriginal people speaking diverse languages, but in > decreasing numbers. > > > The study was based on field research and data analysis supported by > the National Geographic Society and the Living Tongues Institute for > Endangered Languages, an organization for the documentation, > revitalization and maintenance of languages at risk. The findings are > described in the October issue of National Geographic magazine and at > www.languagehotspots.org. > > > Languages are like operating systems, compatibility is key to their value and a perfectly good language is useless if no enough other people speak it. And other languages can be purged so quickly because language survival happens in more or less the same way for all similarly situated smaller languages in parallel. The smaller, indigeneous languages that are not official languages of any states will go first, then the smaller languages that are part of states as everyone in those countries learns to speak a common language to survive in a small world connected global economy, and finally the bigger languages will grow less popular as people see less value in passing them onto their children as native languages. Now for the "but". If a single clearly identifiable world language, or at least a mere handful of remaining living languages were spoken, wouldn't necessarily mean the total extinction of other languages even if they were rarely used in the way it did for languages that were never committed to writing. Sumerian survived for centuries as a liturgical language in the Akkadian empire which was linguistically Semitic. Hebrew and Latin and Coptic likewise survived at liturgical languages long after they ceased to be languages of daily life and have even been revived in Israel and Vatican City respectively, as living languages. There are still people who can read Egyptian hieroglyphics, ancient Mayan writing, Sanskrit, and Tocharian, even though the surviving descendants of these languages are much different today. Any language committed to writing and recorded in video will survive as an esoteric means of academics, spiritualists and hobbyists to commuicate as a secondary language. [Answer] No. There may well be fewer languages around, as minority ones die out. But I don't think there will be only one left. You might have a common second language - as is the case for English in aviation - where there are vital safety related reasons that people need to communicate with pilots from other countries. But in general - why would mainstream languages die out? I don't buy IndigoFenix's idea that languages will blur together in a few generations - just look at Europe for a counter example. Countries with different languages sharing borders for many centuries, and apart from loan words creeping in, no sign of ending up with a single language. And with advances in computer translation, a lot of the need for a common language goes away - if your browser can autotranslate into your language, or youe phone can run through a translator, why change? Who'd want to switch away from their native language - you'd lose access to your native literature, recorded audio / films, not to mention having to redo a lot of signage - and with no great benefits. Even when it would make economic sense, it doesn't seem to catch on - I believe the European Union beurocracy spends a lot on translators. It'd be simpler to do something like going through esperanto - then you just need to translate into and out of esparanto, which would need fewer translators than going from every language A to every other language B. But it hasn't happened. So fewer languages left, certainly. A small number - maybe even a single - common second language, quite possibly. But a single common language over that short a timescale? No way. And if machine translation really takes off, then the need for a common second language goes away. [Answer] # Yes We are entering the age of the Internet. Everybody is talking to everybody, all over the planet. This is going to accelerate the trend towards a single global language. I suspect that language will be English. Chinese is simply too computer-unfriendly to catch on. If the Chinese were to start using a phonetic alphabet, they would stand a chance, but I don't think they are not going to do that. Exactly which language will be dominant depends on near-future political and cultural dominance, and is hard to predict. Maybe Brazil will be the next superpower and everybody will learn Portuguese... I expect that in less than a hundred years, everybody will understand the global language, but will keep a native language for talking to neighbours and family. A few hundred years more and more people will stop bothering with the native language and just learn the global language. By 2500 the whole thing will be over. [Answer] When people live in a single culture, or even many cultures that communicate frequently, their languages will tend to blur together over a few generations. With the creation and easy access of the Internet, people all over the world are able to communicate with each other. I do not find it unlikely that languages will naturally blur together in a few generations. However, other cultural divides can occur, even among people who are able to communicate. It is not uncommon historically for aristocrats to use a unique language specifically to separate themselves from the "common folk", although they typically still are capable of speaking the common language. Academics can also play a part - even today, the lingo common to a particular academic field may be virtually unintelligible to someone who is not familiar with it. There may be other factors that prevent the natural blurring of languages: maybe the new world may develop non-geographical cultural barriers that we can't even imagine, a new paradigm created by the Internet. Or maybe the Internet will not last that long for whatever reason, putting us back on the local communication paradigm. But it seems most likely that the world will develop a single language within the next 200 years or so if not sooner. [Answer] Probably certain languages will die in future, while current languages will change a bit, but I see there's Always room for new langs or dialects, people, especially Young people, tends to create their own Language with new words. I do not think 2500 years are a resonable time for a unified Language, unless of course something big happens ( I mean big political events, iper-globalization etc, not wars, because wars creates division and hence move the Language in opposite direction). In past some big empires lasted thousands of years, but they were not able to get a unified Language (ok, they hadn't internet too). Just think to computer languages, instead of having 1 programming Language even more languages emerge every year, this is not the same as a spoken Language, but I hope I give the idea. So my advice: > > 1 Unified Language is unlikely to be plausible, unless you give a very good reason for that. > > > Just a example: * a country conquer the world, and gives tax reliefs only to people engaged to 1 person of that country or that pass an exam about that official Language (hope it is not a hard Language) * some disease kills most people in other countries except 1 (note, I think Readers could find that a racist thought, so beware). * farmaceutical industries find a drug that make people smarter, someone leaks the formula and shortafter all people in the world is so smart that can learn new languages daily and in few decades all languages become unified in a new Language, then after some time people becomes immune to that drug and lose the incredible intelligence thus it maintains the new Language. [Answer] Languages are purpose driven, consider the sign language, programming languages, Maths... With that being said, I don't see how humanity could ever have one purpose, unless they are all cloned. [Answer] # Not In The Way You Suggest Languages exist to help people to communicate. For that Reason, they have to be useful. Following that logic, there could be a world-wide language. However, language is also part of cultural identity. People will always speak the language of their culture, and I laugh at anyone that would tell me the Earth will ever have one united culture (or government, for that matter...). However, like the Roman Empire, you could have people all speaking their local language, and have an international language that everyone knows how to speak. But there will still be individual languages. --- We Kind Of Already Do There is one language, that while not spoken, is written by nearly everyone on earth. Math! The (Indo) Arabic numeral system is used by nearly every nation on Earth (except for a few of them, ironically which are either Arabic or India (I could be wrong)). In any case, the Arabic numerals and other symbols we use in mathematics communicate information, and are understood by most people in the world. [Answer] Actually, I support the idea of a single language. The only thing is, it would have to be a new language with words and ideas from cultures all around the world. This would help unify our planet and set our minds toward space exploration or advancing our technology. That way, we can hope to fend off any "aliens" that may "visit" us in the future. In a way, this really reminds me of Star Trek. I guess that is pretty strange, because 2500 is the 26th century and humans in Star Trek pull this feat off far before that! [Answer] Short answer: to have one (native) language shared by every human being in the universe would be almost impossible. Long answer: note: all numbers are very rough estimates. It would be almost impossible to have one shared (by shared I mean that any one human can understand any other human wherever they are from) native language. The reason is the following: Every language has dialects. Lets estimate the difference between these dialects to be 100-200 words every one hours journey (the faster people can go (to talk to neighbours note: this assumes that ), the larger the areas of the dialects). Let us assume that the language in question has roughly half a million words in total (probably more than the words in the English language, but time turns into technology, which needs more words, and there will probably be a lot more synonyms because people will forget what words to use and invent new ones(which will later become standardised)). Assuming that the population continues to grow, you will need cities on the ocean floor (as well as colonies on Mars, orbiting cities etc., but the question asks about language on earth). > > [...]in 2500 the world population could even top 60 billion at the current growth rate with no intervention by any government, entity or group. (<https://www.quora.com/What-will-the-human-population-of-the-world-be-in-the-year-2500>) > > > Currently, the technology is there to cross the pacific in less than a day (i.e. concord), but it is too expensive. Making super-sonic submarines is another matter entirely. Assuming you haven't got fusion power yet, you are still using fossil fuels, which will be about as rare as diamonds (random guess). This means that the average speed will be roughly 30 kilometres per hour. > > The metre was originally defined in 1793 as one ten-millionth of the distance from the equator to the North Pole. > > (wikipedia) > > > Assuming the earth is a sphere(to make the maths easier) this means that the difference between the dialects at opposite sides of the globe would be: n=num\((circ/2)/spe) where circ is the circumference of the earth(4\10 million m), spe is the average speed (30 km/h) and num is the number of words that change per hour of travel (100-200) I got an answer of 66 666 666.66 to 133 333 333.333. Assuming the numbers that I used were accurate, you could only have a single language where you have a planet less than half the size of Earth. Note: I have not included anything about telephones, internet, email, etc. because you don't send any messages to people you don't know. If you haven't been to a place, you don't have any friends from there. However there are ways out: * Invent fusion, so you can have people gong at much faster speeds * Kill off a lot of your population * Use something like the babel-fish from the Hitch Hikers Guide to the Galaxy * If you have one political leader giving speeches every day/week/etc., then the dialect "effect" will be diminished * think of something else [Answer] Very unlikely in my opinion. Language is tied very strongly to cultural and national identity. It isn't just a way of communicating. It's a reflection of how people think and what they collectively value. For example, take Japan. The Japanese people are very conscious of their social standing relative to others around them. For that reason, Japanese has different words for "brother", depending on whether it's an older brother or a younger brother. (And the same goes for sister). There are different words for co-worker, depending on if it's a senior co-worker or a junior one. Different words for mother and father depending on if you're talking about your own parents or someone else's (and even different words to address your mother and father directly). This is a foreign idea in English because English speakers are much more egalitarian. For the sake of necessity, there will always be a lingua franca (which today is English - in 200 years it might be Chinese), but there will also always be a desire for people to preserve their heritage. For example, the Irish and Hawaiian languages were thought to be dying in in the middle of the 20th century, but experienced a resurgence as cultural leaders sought to revive them. 100 years ago, children were forbidden to speak Hawaiian in school. Now there are immersion schools wherein students speak nothing but Hawaiian. I do think there will be a consolidation that causes some languages to die out - most likely in India and Papua New Guinea. However, the chances of all of humanity settling on one language are practically nil. ]
[Question] [ In my world, vampires need to consume a small quantity of human blood every month to survive. They usually supplement their diet with animal blood and human food. A vampire which goes without human blood for a few months dies. Vampires are not magical beings. They are the result of genetic mutations and have evolved alongside humans. Vampires have a beating heart and a working circulatory system. They are also faster, stronger and have better senses than the average human. I am looking for a reason why human blood (as opposed to blood of other animals) is essential for vampires. --- I don't think my question is a duplicate of [Why can vampires only drink human blood?](https://worldbuilding.stackexchange.com/questions/69615/why-can-vampires-only-drink-human-blood) because vampires in my world do not subsist solely on human blood. [Answer] ## Immunology: The need for human blood is not, really, about food. It's about antibodies. The vampire's immune systems have come to function in a completely different way from human immune systems. This has allowed them to enter into a symbiotic relationship with several bacteria that block cancers, promote muscle oxidation at amazing levels, allow stem cells to rebuild the body repeatedly, etc. Only the vampire is unable to regulate the bacterial growth. The same immune system that allows them to tolerate the bacteria renders them incapable of resisting them. With enough time, the bacteria will flood the vampire's body and eat them alive. The bacteria, however, are harmless to normal humans, who are universally immune to it. The various symbiotic bacteria are related to a common gut bacteria and everyone has antibodies to it. These are the same gut bacteria that cause people to develop antibodies to A & B antigens on human red blood cells. Animal blood has antibodies, but the vampire's immune system recognizes animal antibodies as foreign and rejects them, while tolerating human antibodies. Whenever the vampire senses the bacteria are growing out of control, they are compelled to seek out human blood. While the vampire can't make the antibodies, they CAN use them. The more human blood a vampire consumes, the more the bacteria are in check, and the more "human" the vampire is (tolerating sun, ordinary strength, possibly even aging). The less human blood the vampire uses, the stronger and more vampiric they get (right up to the point where they die of sepsis). This does mean the vampires would have a unique vulnerability or gift - antibiotics. This could be anything from a replacement for blood (the wonders of modern science) to an acute vulnerability (drink the wrong victim's blood and your bacteria die, and then YOU die). This can be whatever you want to make of it story-wise. Eventually, the bacteria will develop resistant strains and the antibiotics will stop working. This also means that blood type could affect the vampire. Perhaps O blood is the universal treatment, but B blood (alone) leaves powers more intact (yet only as a temporary fix), and A blood (alone) weakens the vampire while not entirely satisfying their needs. It would also mean the vampires could get everything they need from blood by using/consuming/transfusing plasma. In the same way modern medicine uses convalescent plasma to treat infections, your vampires just need the antibodies. Eventually, this will allow vampires to take synthetic antibodies and skip human blood altogether. [Answer] T Cells A less fantastic version of DWKraus’s excellent answer. Your vampires have evolved a symbiotic relationship with humankind. Vampires can produce their own antibody-crafting B-cells, and can produce their own antigen-library T-cells, but vampire T-cells have evolved to lose the ability to recognize new antigens. Vampires drinking a small amount of human blood every few months take advantage of a symbiotic tweak vampires have with their evolutionary cousins. Human T-cells escape digestion, passing directly into the blood where vampire T-cells prefer the human version, and use it as a template. Diseases are changing constantly as slight mutations are sufficient to escape detection by the old definitions. This is why we have four or more flu vaccines every year, just for the top-4 most prevalent mutations for the year. As evolved without the ability to recognize the new mutations, vampire defenses against infection quickly are dated to the point of irrelevance. This answer maybe improves on DWKraus’s by requiring only a little amount of human blood (just enough to get some updated antivirus definitions from their symbiote). [Answer] They're all junkies. They're not after the blood, they're after the endorphins in the blood. Their own system uses a slightly different class of hormone to fill the role endorphins do in ours, but they've retained the opioid receptors they inherited from their ancestors which gets triggered by the endorphins in their prey's blood, which give them one hell of a high. The downside is while their opiod receptors give them a hit far above what a human would experience, it results in severe physical addiction and potentially fatal withdrawal. They can obtain some from non-human regular meat, but all that does is delay the onset of the withdrawal. None of this was known, of course, in their history, so they assumed they needed the blood to live and thus made sure their offspring received it, which they believed was necessary to survive. This unknowingly addicted their children, and the cycle continued. All it would take to break the cycle is not drink blood from the start, but there's two things acting against this: the first is that not many know the truth and so there's still this folk belief they need to consume blood. The second is that some of them do know the truth, but they don't want to give up the high and so they actively suppress it. If people knew there was an alternative, then all of a sudden what they still want to do isn't a matter of survival but of personal choice. It's easier for people to accept your little kinks if it's something they believe everyone has to do. [Answer] Best I can think of is DNA. You said it yourself that your vampires feed mostly on the blood of other animals much like a vampire bat, but vampire bats are in simply for the nutrients in the blood (which aren't all that many, requiring the animal to feed regularly and one of the reasons they'll die if they go longer than 3 days without a proper blood meal), so out of the "bat" we can see it must be related to something other than nutrients. Therefore your vampires need something else specifically from humans and which no other species has. My best guess for why they'd need it? Your vampires need the human genome itself. According to [this forensic site from the University of Arizona](http://www.biology.arizona.edu/human_bio/problem_sets/dna_forensics_2/06t.html#:%7E:text=Tutorial-,Sources%20of%20DNA,for%20a%20typical%20VNTR%20analysis.): > > Blood is an excellent source of human DNA. DNA is present in white blood cells of humans, but not red blood cells which lack nuclei. A dime-sized spot of blood, approximately 50 µl in volume, is enough DNA for a typical VNTR analysis. > > > This fact, coupled with the fact that vampires are a result of genetic mutations that evolved alongside humans lead me to the following conclusion: for whatever reason, at the cost of enhanced senses and abilities when compared to normal humans, vampires have an unstable genome, and rely on human DNA to maintain their bodily functions, so, similarly to how [rotifers](https://www.nationalgeographic.com/science/article/who-needs-sex-rotifers-import-genes-from-fungi-bacteria-and-plants) incorporate the genes of plants, fungi and bacteria they eat to ensure their genetic diversity and remain capable of thriving and ensuring genetic diversity despite reproducing via cloning, your vampires incorporate the human DNA found from the white blood cells ingested with the human blood, using it as a way to repair certain parts of their own DNA, which are almost identical to the same parts found in normal human DNA but also seem to "degrade" over time for unknown reasons (be it mutation, deletion or any other process), these parts cease to code certain enzymes vital for the vampire's survival, and need to be replaced by a healthy counterpart copied from normal human DNA every once in a while, in a process similar to what's seen with [CRISPR/CAS-9](https://www.vectalys.com/blog/crisprcas-9-system-a-story-of-off-target-and-dna-repair-control-608). If a vampire fails to consume human DNA, these structures will degrade to the point it can no longer relay the codes its meant, resulting in the lack of production of certain proteins and enzymes vital for their survival, culminating in their bodies shutting down for good. As to how they would perform this separation of components before sending what's useless for digestion, I'd suggest that the vampires have a special stomach divided in 2 chambers, a smaller chamber in which the white blood cells are separated for posterior DNA "extraction" by the vampire's natural "genetic editing" system and a main chamber where what's not needed by the vampire in its current state is digested as it would be in a "normal" stomach. [Answer] Those guys have [aquagenic urticaria](https://www.healthline.com/health/aquagenic-urticaria) (think water allergy). They can ingest regular water, but it will harm them. Over time the harm builds up. Mammalian blood, for some reason, does not trigger the allergic response, so it is the only safe thing for them to drink if they want to stay hydrated. Properly hydrated vampires will drink blood every day, not just once a month. They will also be healthier and stronger. --- If you change the part where they consume animal blood to consuming only primate blood, you can also blame a [tick-induced red meat allergy](https://www.mayoclinic.org/diseases-conditions/alpha-gal-syndrome/symptoms-causes/syc-20428608). There is this tick in America which can induce this allergy with just one bite - if you catch it, you will have a reaction to any meat with alpha-gal in it. Among mammals, it seems that only primates don't have alpha-gal in their organism (which is why you even get this condition from the bite). Then it becomes a matter of your vampires needing meat in their diet, and unless they would consume the chimps in a zoo the only safe meat for them is people. They think they need the blood but what they actually need is meat. Turns out they like their steak raw and bleeding. [Answer] A substance toxic to humans and vampires has contaminated the whole world. There is a drug that reduces the toxicity, but vampires can't metabolise it, however in the human blood there is the result of the metabolisation process which cannot be reproduced artificially, this is what vampires look for in the human blood. Small plot variation, the drug might be the reason why some people turned to vampirism, some could easily metabolise it and some couldn't. [Answer] Scurvy and "Vitamin H" and blood pressure reduction from Sunlight Whether it's the immune cells, particular strands of DNA or the exact composition... Human blood contains something lacking in other species. Examples exist elsewhere of spieces that contain something others don't... Lobsters famously contain stuff that are useful all around the place. <https://www.nhm.ac.uk/discover/horseshoe-crab-blood-miracle-vaccine-ingredient.html> > > What is horseshoe crab blood used for? > Horseshoe crab blood is bright blue. It contains important immune cells that are exceptionally sensitive to toxic bacteria. When those cells meet invading bacteria, they clot around it and protect the rest of the horseshoe crab's body from toxins. > > > <https://www.statnews.com/2020/02/19/lobster-blood-could-play-role-in-new-drugs/> > > Scientists with the company have found that hemocyanin, a protein in the fluid, works as a powerful stimulant for the immune systems, Bayer said. For example, experiments show the substance can reduce the viral load of herpes simplex virus-infected cells, according to documents the company filed with the U.S. patent office. > > > What does human blood do? As importantly... what's in human blood not in vampires? Sun light. <https://www.thoughtco.com/facts-about-blood-373355> > > 11 UV Rays Reduce Blood Pressure > > Exposing a person's skin to the sun's rays reduces > blood pressure by causing levels of nitric oxide to rise in > the blood. Nitric oxide helps to regulate blood pressure by reducing > blood vessel tone. This reduction in blood pressure could cut the > risks of developing heart disease or stroke. While prolonged exposure > to the sun could potentially cause skin cancer, scientists believe > that very limited exposure to the sun could increase the risks of > developing cardiovascular disease and related conditions. > > > Simply put... without a dose of Vitamin H to limit blood pressure, Vampires suffer like those without Vitamin C suffer due to a lack of something important. In this case, Nitric oxide in specific levels and forms, is missing from other animals and must be gotten from a pure source. Maybe someday "true blood" can be made synthetically with it but that hasn't been successful yet. addendum With a little research into "fun blood facts", I'm sure we could find other things in Human Blood not in the blood of animals (other animals are affected by sunlight... but differently than Humans... so maybe it's something else?). You could even use Facts like #12 - blood varies by population. IE: US is predominantly O positive and Japan is predominantly A positive... and groups in Tibet can survive in high mountains easier than others. Those differences will affect the humans available for the "monthly dietary needs" in different locales. [Answer] Replenishing their own supply Vampires have a circulatory system, but no way to produce their own blood. Their digestive process no longer digests blood, but instead pumps it directly into their own blood stream. They are immune to the effects of transfusion incompatibility in blood types, and don't need to replenish large amounts every day, just enough to cover the cell death of blood cells over the course a day or two. Consistent small intake is enough to keep a healthy supply. [Answer] The vampiric red blood cells decay faster due to the higher metabolism. Unfortunately they do not build red blood cells any faster then normal humans. Due to this fact they get anemic quite fast and die if not ingesting/replenishing red blood cells from outside sources. Animal blood only tides them over so much - it lengthens the period until they really need a human top-off. Sometimes they need the real deal and convert the ingested human blood into new bloodcells for themself. [Answer] Accumulated mutations in a vampire's immune system cause a vicious reaction against significant amounts of non-human blood. Consumption of anywhere up to a fluid-ounce will probably cause a severe hives outbreak; a typical feeding amount could cause anaphylactic shock. ]
[Question] [ Humans have entered a period known as the biotech renaissance, where the advent of new forms of genetic modification gives rise to a host of new bioengineered life forms. One of these are animals that have been uplifted or ‚Äúenhanced‚Äù to sapience. These beings have equal rights from the get-go, since humans have already established interspecies sapient rights after confirming other species (dolphins, and the like) to be sapient. This creates a problem: one of the main reasons for uplifting in science fiction is to produce servile or enslaved races, and since this is a no-no in this project, after the novelty of uplifting wears off, humans will have little incentive I can think of for creating more enhanced animals. So, in order to ensure the continuation of this practice, how could a sapient species profit financially from uplifting another species, in a way that does not involve enslaving them? ## Edit: Okay, so having read through the comments, I have decided to add something. While selling stuff to the poor enhanced dogs sounds great, there is an issue: these dogs may start to wonder why they are being charged for the support and care which a normal parent would provide for free. To revise, is there any way to profit off enhancing that does not involve profiting off the enhanced‚Äôs work/neediness? [Answer] # Mermans [![enter image description here](https://i.stack.imgur.com/GejNx.jpg)](https://i.stack.imgur.com/GejNx.jpg) Only one third of the Earth's surface has apartments on it. This generation of Facebook users refuse to live at the bottom of the ocean. They say that's where no air is. Little do they know that's where all the money is. That's where the mermans come in. Uplift the dolphins. Give them opposable thumbs and social anxiety. Sell them gloves and waterproof nail varnish. Sell them nail varnish remover and SSRI medication. Sell them girders and concrete to build their apartments on the sea floor. Sell them computers and wait for them to register on Facebook. Then hit those suckers with targeted advertisement. We make a killing on hosting ads. As a by-product we sell more gloves, cosmetics, pharmaceuticals and construction materials. Once the mermans are all addicted to Facebook, sell them physiotherapy for their repetitive stress disorder from spending all day on Facebook. More generally, find a place too hostile to normal humans. Uplift a local species so they establish a civilization. Then trade with that civilization. Ker-ching! --- The only drawback of this idea is it stretches the bounds of "building fictional worlds". In particular the fictional part. You see the above is currently a proposed business strategy for Facebook. Mark Zuckerberg is already part dolphin. 40% of Americans are unable to tell the difference between the two photos below. [![enter image description here](https://i.stack.imgur.com/DRYyL.jpg)](https://i.stack.imgur.com/DRYyL.jpg) Use the above at your peril. There are people that will revere you as some kind of prophet. [Answer] # Treat Them As Employees! This is simple: treat them as employees in a business. Sure, they may have different desires and needs than others, but uplifting a species produces employees with a very special skill set. (Sometimes that skill is genetically granted, but it's a skill you pay for like any other!) If the society can guarantee [freedom of movement](https://en.wikipedia.org/wiki/Freedom_of_movement), citizenship, and property to all its sapient creatures, slavery does not really exist as a legal institution. The cost of raising a species to this level could be great or small: it depends on the species. # An Example This means, as a hospital owner, your cancer-sniffing dog can now talk as well as provide better diagnostics ("it clearly smells like lung cancer, not pancreatic cancer"), and you pay it a dog-version of a living wage. It is not a slave to you: it can quit and find another hospital to work at. Additionally, you did have to pay for most doors and buttons to be dog-openable, but the increased diagnostic powers are worth it. Dr. Collie orders prescriptions, lab work, and other procedures like any other doctor, but simply uses speech recognition instead of writing things down. [Answer] # It solves the labor shortage I have an orchard with a genetically enhanced fruit that is very valuable, however, since it's the far future, no one wants to come work in my orchard. However, there's an animal species that is ideal for picking my fruit, as they are natural climbers. If I breed a bunch of these, and then uplift them, I could offer them a really good job picking fruit in my orchard. Some of them might say no, and go their own way, but many of them agree, and now I have a worker who I can pay fairly for the labor that they do. [Answer] Let capitalism show you the way. Your crop of genetically improved trees is great, except here in this bright future, there's only so much demand for them. People only need so many houses. Say, wouldn't it be great if a whole bunch of "people" showed up and created a new demand for your product? You uplift all the beavers in the area. And the foxes. And the geese. They are no longer content with their previous living conditions and would like new homes. Some of the beavers actually work as wood cutters on your tree farm, earning cash, which they use to purchase services from other animals, who in turn spend some of their income buying wood from your tree farm, in order to build more houses... You have a whole pop-up economy in no time. Like a town of thousands just materialized out of nowhere because basically that's what happened. The uplifted squirrels are also fond of your bioengineered acorns. You are basically generating customers for your products, by uplifting them. This is also how I imagine aliens uplifting humans would go. Ultimately they need a market for their warp drives, and here we are, billions of people and not a warp drive between the lot of us. Uplifting creates eager trading partners, exactly where you wished some could appear. What precisely the uplifted animals can offer for trade is a brainstorming topic I'll veer away from but it's no worse than any society is faced with: here we are, what can we find, make, sell or do for a living? [Answer] If you uplift them enough, they can become trading partners. If you engage solely in ethical business practices, with full disclosure and choice by the species, then you can engage in trade with them. There is nothing wrong with that, as long as you haven't crippled them cognitively or changed them to be obedient slaves, and you aren't trading something they absolutely must have to survive. Capitalism is ethical if (and only if) both parties are free to walk away from a trade without that endangering their life or otherwise causing them harm. If any party is basically coerced by circumstances, it is no longer ethical capitalism, it is just robbery. The equivalent of the false choice, "Your money or your life" with a gun to your head. In other words, the uplifting operation has to be done gratis; a speculative gift to the species, in the hope that the species will choose to do business with you. But in the end it has to be their "free" choice, after uplifting they must be left in a state where a fully informed free choice can be made: They can remain uplifted and choose to ignore you. IMO, that would be an ethical uplifting. [Answer] This is a frame challenge. You have been warned. There are loads of interesting stories around uplift, but most of them don't seem to ask the Malcolm Question: should we? Uplifted chimps or dolphins are just presented as a fait acompli, now we have to deal with the fallout. You seem to be in a similar situation. The answer you're looking for is probably bound up in the answer to an earlier question: why did we uplift them? If our ethical standard had already evolved to the point where we've already granted them all of the same rights as humans then what reason would we have to violate their species identity without their informed consent? Well, because we could of course! Shut up Dr Malcolm, we've already done it. You're too late as usual. Yes, your hindsight is incredibly acute, but it's not useful. Where was I? Oh yes... Given that champanzees are equivalent to humans by your legal structure, uplift is an illegal pursuit. You'd break huge amounts of laws against kidnapping, medical testing, performing medical procedures without informed consent, genetic modification without consent, eugenics... the list goes on and on. And on. But it has apparently been done. That means that you have a completely unethical bio-science group who don't care at all about silly things like ethical or legal constraints. What makes you think that these poor citizens, after being illegally modified by a crazed group of evil geniuses, would ever be released from their cells? I don't think you thought that through. But let's introduce an external factor who free these poor unfortunates from their captivity. What happens next? Let's say we have a group of illegally modified non-human sapients whose genetic material has been extensively modified. They can't survive in the wild with their cousins, and in fact their altered appearance makes it certain that they'd be killed if you tried. They're now smart enough that they can tell you exactly how miserable the idea of living in the wild makes them too. The only viable options they have is to form their own little community. So they get legal representation, sue the company and the mad scientists - or their estates, depending on how the rescue went - that created them and now they're moderately wealthy. They're a tiny community of highly modified sapient creatures, with no social skills and an average lifespan around 40 years. Unless there are enough of them with high enough genetic diversity the group dies out in a few generations. And since they're smart enough to figure that out the suicide rate is going to be ridiculous. --- Too dark? You said they had human rights. What did you expect that to mean? OK, let's assume that human rights aren't extended to creatures we might want to uplift, like chimps and dolphins. And dogs, because doggos. We've hashed it out and decided that it'd be too cool not to have uplifted doggos, so let's do it! (While carefully not looking at the mountains of corpses from failed experiments. Go go Magic Biotech!) Now we have dogs with human-level intelligence and a few physical alterations: hands capable of full manipulation, mouths modified to allow complex speech, that sort of thing. What do you do with them? Well, first you give them a place to live. A community. You socialize them with each other and with humans, letting them figure out for themselves what their society is going to look like. They're not humans with fur after all, they're full sapients with all the rights - and responsibilities - that entails. You educate them, give them options for all of the training they might want, and eventually you have a proper uplifted species. At that point the question of "what do we do with them" answers itself. You do nothing. They're smart, they have abilities that people will be interested in hiring (assuming you didn't modify their senses too much) and they can make their own way. They'll need financial support for a few generations, but who doesn't these days? The same will be true of any uplifted species. If the reason for uplift isn't to make them better workers worth exploiting then you're going to have to put in a lot of work. And since they're not human they're going to come up with their own ideas about what a society of uplifted chimps or dogs or dolphins or whatever looks like. They might even have their own religions. Oh, but be careful how smart you make them. A species of hyper-intelligent neo-chimps might sound like fun, but if they decide that humans aren't necessary anymore then they might be a little hard to stop. But don't make them too dumb either, because that's just manufacturing a low-intellect slave class. Hopefully we can tune it to human average, because clearly humans are the best example for uplift... right? [Answer] Depends on what one's set of ethics are. In Mahayana Buddhist ethics, it is unfortunate to be born a dumb beast. They don't have the mental capacity of mind to do anything but eat and sleep, and that's unfortunate and sad for them. (Not saying this is exclusive to Buddhism; there would be similar sets of values in other philosophies.) To take a dumb unfortunate beast and give it the nobility of mind to think for itself, question, acquire knowledge ‚Äì that's one of the greatest things you can do. It would be like meeting a person with a brain injury and restoring their brain to full functioning. They would be grateful to you forever, and maybe they would express this gratitude financially, the same elderly parents benefit from the gratitude of their children. [Answer] People want uplifted pets How many kids out there don't wish that they could talk to their kitten? Dogs, if not well trained, can be unpredictable and disobedient, it would be much easier just to be able to tell them not to wee on the carpet or chew the furniture. Of course there's no guarantee that they'll want to hang around once brought to sapience, but if they are a well-treated member of the family there's no reason they shouldn't. ... assuming we are OK with non-consensual uplifting (i.e. the animal would not have the ability to consent before the operation took place) ... So to profit, simply charge for the procedure! [Answer] We don't need slaves If we reach this level of technology, we don't need slaves. Robots are programmed to fulfil our every need. We don't eat animals anymore because we grow bacteria and yeast in tanks and print our food at such quality and refinement that actual meat from animals would be vastly inferior. We don't even need money anymore as automated mining and manufacturing done in space means everyone has everything they could want already. Now why do we want to uplift other species? Shits and giggles mostly. Because we can. Boredom would be our real enemy. We haven't found any aliens so lets make our own species. What could be cooler than talking to spacefaring dolphins? Gigantic whale pod colony ships? Fleets of space wolves? [![enter image description here](https://i.stack.imgur.com/GUqOU.jpg)](https://i.stack.imgur.com/GUqOU.jpg) Now humanity doesn't actually have to profit or even do this. With this tech, society could be run by an AI designed to protect society and the AI could be uplifting species to provide stimulation for it's human charges. We would be functionally immortal with this level of technology and boredom coupled with humanity's self destructive tendencies would be our greatest threat. Seeding the galaxy with uplifted species would help keep humanity entertained. [Answer] They aren‚Äôt technically enslaved Slavery in many real world countries is illegal, for example, in United States slavery is illegal, but in many places there are underpaid workers living in very poor conditions. The uplifted species in your world can be compared to some immigrants in the United States. Both are generally less educated, they are poorer, and they are less healthy. Employers can do the same thing in your world as they do in real life, they take advantage of the uplifted species. Your employers could offer the uplifted species free housing, healthcare, and food that may seem great to your impoverished species but are truly really cheap. You could even go as far to have the uplifted species sign contracts having them work for the rest of their lives at the threat of ruining the personal aspects of their life, the gifts of truly un-valuable contents, or simply manipulating them into thinking there is no better option. [Answer] Frame challenge: why do you need to profit? If your society is at the point where it can arbitrarily gengineer species to sapience, it's probably also a post-scarcity one, at which point money isn't a thing. [Answer] In order for it to be ethical it needs to be beneficial for the animal to become sentient. Examples include: 1. Wildlife preservation: The sapient creatures are more apt in avoiding predators, weather avoidance and reporting poachers. They can also report pollution. The money saved on wildlife protection can be pocketed. 2. Deals with pests: The issue with pigeons/rats/mosquitoes/bed bugs is not that they exist, it's where and how. If you can strike deals with them on where and how they coexist it reduces suffering of these races as well as humans. Sanitation budget can be pocketed. 3. Empowered employment: Some animal species have skills that are worth more for humans than the needs of these species. Animals already employed, such as guard dogs, drug sniffing dogs, rescue spotter pigeons could be empowered by giving them the power to haggle their employment terms. Depending on your ethics system other aspects, such as national security may override my above definition. Conscribed animals, espionage animals may be within scope for your world. [Answer] ## Why do you have children? For 95% of the people it isn't "continue my genetic line" or whatever. ## Why do countries want more people? In a modern industrial knowledge economy, it turns out that people are an asset for the nation. ## Why do we uplift? People will uplift animals and raise them as children. The same technologies used for uplift will also be used on humans. If we can boost the intelligence of dolphins, that same tech will probably let us modify the intelligence of humans. So we'll have "uplifted" humans and "uplifted" dolphins and "uplifted" dogs. Doing it on a new species will be challenging, but there are plenty of ethical reasons to do it (giving the beings more power, for example; non-uplifted populations are at the mercy of more intelligent beings). Practically, uplifted dolphins, dogs, chimpanzees, and ravens are all going to have different capabilities than uplifted humans. From difference comes strength. With a population of uplifted dolphins, 2/3 of the Earth's surface goes from being only useful for shipping to being living area, for example. ## Morphic freedom Full understanding of how biology and intelligence works is plausibly going to go along with better ability to modify already living beings and minds. Uploading of humans either to computers, robots or other biological minds could be something that happens. The first "uplifted dolphins" might be biological constructs with brains that are copied from a human; and the human can copy back to their normal body after the experience. If the brains are "blank", it might be considered ethical to do this experimentally until you have a working intelligent dolphin able to control the dolphin body .. that is "just" a temporary (or permanent) copy of a human consciousness. Under this model, the uplifted species descends from humanity. Just humans modified to be that creature. [Answer] # Tax them Yes. It's as simple as that. You just uplift them and consider it a pay upfront cost of invesment. Register them as a citizen of some kind. Let them have their IDs. Give them a starting point with some budget. After that, you don't care whatever they do. They need to pay taxes just like other humans do. Once the uplifted animal population reaches certain point, they will continue to grow that number by themselves. So, you can accordingly adjust the rate of uplifting operation. [Answer] Make bioengineering a societal priority. The most important thing to make it work as you want is that society do see uplifting as a good *in itself* for the sake of bring more being to sapientety. Once you are sure that the predominant ideologies goes something along the line of "all sapient species are equal, and the gift of sapience is so great that we OUGHT to give it to more species" everything will come much easier. And, assuming that you give all right to them, uplifited species will most definitly have to have a seat on the table of who get uplifted Dang, specialized worker do be specialised The simplest answer to your conondrum, is that, if everybody is treated fairly, your uplifted species will most likely tend to work in field where they are better suited. hell, it could be a cornerstone of the new culture. whenever a new field appear, you simply uplift a species that would be fit for it. Do not not offer reparation As it is a highly political question i will still sting there on another point that shouldn't be overlooked. if you stay in a capitalist framework, you simply cannot not exploit the new species. If in a generation or two dog go from dog to sapient entity with the ability to function in human society independently, without master, but are still though if you do not want those dog to be slaved by being forced to work for human, you will have to give them a HUGE headstart, as all of their forefather were litterally owning no wealth and now they have to fend for themself. And no system where you just get vallue from somebody will be just and not exploitative. the wealth need to be redistributed between all those species so that even if one make a task that could be deemed of lesser value, they are not punished for it [Answer] It creates a whole new pool of customers and employees. In short it‚Äôs a whole new market. It‚Äôs a bit like e.g. Romania joining the EU. It opened a huge market for big companies like Lidl or Uniqa. [Answer] Create a [cooperative](https://ahclaw.com/benefit-post/cooperative-selling-shares/) or a society that shares the profit. Each member of the cooperative has a say in how society functions with everyone having equal 'stock' in the cooperative. Everyone you uplift is to going to have a say in the community they are uplifted in and get a share of any of the profit that is being distributed. This is literally what a [cooperative](https://www.google.com/search?q=cooperative&sxsrf=APwXEdc5Nusi5QYsnnzJgNe5hgEEi56vRw%3A1680278472552&source=hp&ei=yAMnZOrgH9jDkPIPooGgyAU&iflsig=AOEireoAAAAAZCcR2IaGtojCrcJJwK-DIQh1nWmk-Jra&ved=0ahUKEwjq5OmLxYb-AhXYIUQIHaIACFkQ4dUDCAs&uact=5&oq=cooperative&gs_lcp=Cgdnd3Mtd2l6EAMyBAgjECcyCwguEK8BEMcBEIAEMggIABCABBCxAzIICAAQgAQQsQMyCwgAEIAEELEDEIMBMgsIABCABBCxAxCDATIFCAAQgAQyCwgAEIAEELEDEIMBMgUIABCABDILCC4QgAQQxwEQrwE6CQgjECcQRhD5AToICAAQigUQkQI6EQguEIAEELEDEIMBEMcBENEDOgsIABCKBRCxAxCDAToLCC4QgAQQxwEQ0QM6CwguEIAEELEDEIMBOggIABCKBRCxAzoFCC4QgAQ6CAgAEIAEEMkDOggIABCKBRCSAzoQCC4QigUQsQMQxwEQ0QMQCjoICC4QgAQQsQM6DggAEIAEELEDEIMBEMkDUABYxRhgvhxoAXAAeAOAAdQGiAH9E5IBCjAuMTAuMS42LTGYAQCgAQE&sclient=gws-wiz) is by definition: a farm, business, or other organization which is owned and run jointly by its members, who share the profits or benefits. ]
[Question] [ This scenario requires an alien creature with a decent chance of defeating a modern armor in a brief combat. This alien should be: 1. At least as large as a horse, but not much larger than a semi-truck. 2. A land animal. 3. Purely organic, and obeying normal laws of physics. It should be something that could survive on earth and reproduce. 4. The alien should fight with minimal or no tool usage, and without using other organisms. 5. Preferably a creature with an aggressive or violent temperament. Assumptions on the Modern Armor: 1. It enters combat with fuel and ammunition, and in good repair. 2. Similar to a M1A2 Abrams. 3. This scenario does not consider aircraft, or other support for the modern armor. [Answer] We use steel armor because it can stop the most deadly weapons that humans have invented. We then left steel armor behind because humans invented more deadly weapons. Modern tanks are pretty darn hard to beat down using just organics. Accordingly, the alien could use an approach similar to the [Hagfish](https://en.wikipedia.org/wiki/Hagfish), producing large quantities of sticky slime. The idea is simple. Modern armor makes assumptions about what an opponent can and cannot do. Covering every air-inlet with slime is not something that modern armor was designed to oppose. Once your air filters are all jammed full, your engines are shut off and you're sitting ducks. Wait long enough, and it will get pretty stuffy in that tank. [Answer] Charging down a tank is pretty hopeless. Tank v. Rhino -> Goodbye Rhino. If anything gets in the way of a tank's [main weapon](https://www.youtube.com/watch?v=pm6yYi-JugY) it is also game over. So what can stop a tank? Well even an M1 can get [stuck in soft ground](https://www.youtube.com/watch?v=6xpEpkRT0vQ). My image is of a trap forming species. It tunnels underground forming caverns, with a fairly weak covering of surface soil and a sticky mud (made stickier by the addition of its saliva) underneath. When the tank goes over, the soil cap collapses, and the tank becomes mired. Getting out of the mud is possible, but it takes time and the personnel need to get out of the tank and dig. When they do, the animal strikes from side tunnels it has made specifically for the purpose of moving from one trap to another. It evolved to prey on large animals: rhino, elephant or iguanodon, which it captures in the same way. Animals will at times become [stuck in waterholes](https://www.youtube.com/watch?v=52Dst-sms_Y) which leaves them open to predation by lions. This animal has evolved to take advantage of this kind of situation by creating its own traps. However, To subdue a large animal like a rhino, it would need to have some kind of venom, perhaps one that causes rapid paralysis, since if the rhino (or tank) can escape then the rhino has the advantage. The overall image is an animal that has evolved to hunt Elephants in the way that a spider hunts flies. Its traps can disable a tank, and attempts to recover it leave the crew vulnerable. [Answer] Cheetah with opposable thumbs The only reasonable defense an animal might have against a tank is to be able to stalk it out of sight until it's very close. Then it has to get onto the tank as quickly as possible. The weaknesses of tanks are visibility and limitations on gun orientation, so once the animal has climbed onto the back of the tank the crew have no way of dealing with it. But maybe it can do this without being noticed. Of course, it has very limited options for breaking into the tank. Maybe it can unscrew things or put rocks in the air intake. Tanks can remain sealed against NBC attacks for a long time. As soon as a human opens the hatch, the creature has to rush in in a burst of claws and massacre the squishy humans who are trapped inside. [Answer] A modern tank significantly outmasses any real world land animal - an elephant is 7 tons. A light tank is 14 tons. Assuming an elephant is semi sized... Practically speaking a main battle tank weighs up to 70 tonnes. A Abrams is designed to be taken out with a fair bit of difficulty Lets talk of the ways you can take out a tank without overwhelming firepower. You can't penetrate the armour. You'd need some way to mission kill it instead. There's three main options. Disable the engine somehow - something probably best done on a non moving tank . Disable the treads - either by entanglement or damage, or destroying/disabling the main gun. All of these require the creature to get into essentially white of the eyes range. This would need to be fast or stealthy enough to get in close with a tank. The 'weakest' thing it could take out would be the bolts holding the tracks in place. This would mean getting close to a moving vehicle to take down something roughly a half inch wide. You'd practically need a buzz saw or some serious chemical weaponry. Blocking out the air intakes? I've never heard of anyone ever doing it. It would take a massive amount of ... stuff... dumped over the right part of the tank. Might be some kind of goop, ooblec or incendiary. Spiking the main gun would need to involve some extremely specialized adaptations. You'd need something strong enough to deflect a saboted round or set off a high explosive round. I've heard of guns getting their barrels peeled open like a banana by a simple cleaning rod. And well, I'm doubtful the cleaning rod would survive. Alternatively some compound that would foul the barrel - say something like concrete, that dries rock hard. Taking these into account, I'd suspect the ideal tank killer is something small, fast and capable of injecting quantities of hardening substances. Gum up the tracks, main gun or optics and your mission capability is greatly reduced. If the tank has a single air intake, it might be a target as well. That said, such a creature would need extreme intelligence ([smarter than the average dog](https://en.wikipedia.org/wiki/Anti-tank_dog) ), be able to carry a compound or binary compound, and avoid getting shot or run over while trying to deliver its payload. Once it has , it actually may stand a better chance of survival. [Answer] Let's assume, like [bombardier beetle](https://en.wikipedia.org/wiki/Bombardier_beetle) your creatures can produce instant violent chemical reactions inside their body and launchs hot mix of acids that strong enough to eat away and penetrate the armour or render the tank incapable to operate. Or Instead of launching hot mix of acids, It launchs biogical armor penetrating projectile. Or Since most of the modern high explosives are organic compounds (I'm confident enough to say one determined genetic engineer can manipulate an e. coli genome to secrete Trinitrotoluen -TNT- ). Like dragons breath fire let's assume your creature can manage to produce enough "explosive dung" and launch it with one fart to turn the tank upside down when exploded underneath it. [Answer] Most military hardware includes nuclear event detectors that will shut down the electronics to protect them from the EMP associated with a nuclear blast. If a small burst of radiation were aimed at the tank the electronics would turn off until the crew manually reset everything. And of course it would be pitch black in there so it could take them a while. Those detectors are usually built into much of the essential hardware and cannot be disabled by the crew. The only way they could be disabled would be to send the components back to the defense contractors who built them and have them modified. The M1A2 is coated with a Chemical Resistant Agent Coating (CARC). If the creature were emit a strong acid that could dissolve both the CARC and steel then it could easily make a hole in the armor. Alternatively, the CARC can be scratched off pretty easily, so if you can scratch enough off you can dissolve the steel with acid that way. Think of the movie Aliens. There is no air conditioning in the M1A2. If you were to heat it from the outside the crew would be forced to come out. But the tank has a lot of thermal mass so that could take a while. You can stop the M1A2 by killing the crew. You can kill the crew if you can pry open the hatch. Pulling on the hatches until the locking pins break is much easier than piercing the armor, but still may require a few thousand pounds of force. The M1A2 uses a jet turbine motor. By its very nature the exhaust port can't be heavily armored. There is a covering over the exhaust, but its not as strong as the rest of the armor. In order for the tank to function the crew needs to see. The M1A2 typically includes optics with infrared and night vision. These are the primary means by which the crew can tell what is going on. If the optics were disabled the crew would be forced to use the manual port holes. Those port holes have much more limited visibility than the cameras. Due to the limited visibility they may be tempted to open the hatch to get a better view (at least until they learned better). The infrared camera only works if the creature is emitting some heat. So cold blooded would be helpful. All of the cameras have exposed lenses. If the lens were to break the camera wouldn't work. The lens could be smashed, dissolved, or covered with some opaque substance spit out by the creature. If the creature emitted some sort of mist they would be unable to see or target it effectively. The tank itself has smoke grenade launchers for that very purpose. The tank has various antennas that stick out for radio and GPS. If they were pulled off the tank would be unable to call for help. Another way to get the crew to exit would be to emit a strong horrible sound through the armor. Once they opened the hatch the hunt is over. The main 120mm gun on the M1A2 is very powerful but has a low reload speed because a crew member has to manually change each bullet. That could take around 6 seconds between shots. If they miss the first shot that gives the creature plenty of time to get close without worrying about the main gun. The turret has a 50 cal machine gun mounted next to the main gun on the turret so the creature would still have to avoid that while covering the distance. Its a bit out of scope for this question because the creature would have to be small, but just after firing the main gun, the next action the crew takes is to open the breach and reload a round. With the breach open, there is a direct route from the tip of the main gun barrel to the inside of the crew compartment. An intelligent snake like creature with a diameter of less than 120mm could theoretically crawl right up the barrel and into the crew compartment while the crew was reloading. It would need to have tough skin though because it may suffer burns crawling through the barrel. Most animals become injured when they are punctured by a bullet because it ruptures blood vessels and destroys organs that there may only be one or two of. But creatures with different anatomy may suffer far less damage. For example a sea sponge has no internal organs and is essentially homogeneous in construction. You can't really kill it by putting holes in it. A creature that didn't have a pressurized circulatory system wouldn't bleed out. A tree for example is able to live and regenerate even if its cut down to the stump in many cases. [Answer] The question specifically states the alien must be capable of defeating a modern heavy-armor unit similar to (but not necessarily the same as) an M1A2 Abrams tank. The tank may not have its full support network necessary for prolonged operations ("this scenario does not consider aircraft, or other support for the modern armor"), essentially meaning "the alien must be able to defeat a vehicle similar to a modern heavy-armor tank in a single battle." What does a modern tank have? * Very heavy, durable armor. Layers and layers of steel, hardened ceramics, [depleted Uranium](https://en.wikipedia.org/wiki/Depleted_uranium), and coated in [CARC](https://en.wikipedia.org/wiki/Chemical_Agent_Resistant_Coating). Modern armor is exceedingly resistant to piercing attacks (think armor-piercing rounds), chemical agents, and small-arms fire. * Ability to deal with a variety of terrain due to its treads and decent speed. * Powerful primary weapon, a turret that fires slowly but can heave a projectile with a large amount of mass and kinetic energy toward an enemy. * Powerful secondary weapon, machine guns that can fire powerful small-arms fire very rapidly. It is difficult to defeat a modern tank with anything short of air power (drop a large conventional bomb from out of range and you can defeat almost any ground enemy that lacks the ability to fight aircraft). Flying aliens likely do not have bombs they can drop, so we need something that has enough counters for the bullet points above. Any alien that can fight with a tank needs to have the following characteristics: * Enough armor to survive at least one hit from the primary weapon, and many hits from the secondary weapon. * Either speed to outmaneuver the tank's weapons, or even more armor to withstand multiple hits. * Some means of dismantling the tank's substantial armor: either the strength to tear part its formidable armor, or a chemical agent that reacts with the steel, ceramics, depleted uranium, and CARC of the tank. The good news about CARC is it is designed to withstand chemical agents that harm humans, not armor. Needing to wear chem warfare gear inside the stifling heat of a tank would be cruel and unusual punishment for soldiers. I envision two archtypes of aliens that can deal with this. --- ### The Strong Alien The strong alien would be on the medium size between horse and semi, maybe as big as the tank itself. It would have hard, thick armor with angles to deflect projectiles. It would be fast and agile for its size, with many strong muscles. It would approach the tank quickly, sidestepping along the way like a crab to make it difficult to target. While it can absorb a hit from the cannon, and can take a bit of machine gun fire, it does not have enough armor to take much more than that: speed and agility dictate its mass cannot be too great. Once it reaches the tank, it would find any crack or crevice possible and use its strength to pry the tank apart. Perhaps it could pull the turret off, or use enough force to damage it to the point of being useless. It could attack the treads, bending the wheels or even pulling the treads apart to immobilize it. It might find the air intake and exhaust ports (both soldiers and engines breathe and exhale), and rip them apart. If it can choke the air intake, it wins the war of attrition. Even if it cannot penetrate the armor, tanks still have weak points. --- ### The Artillery Alien What kind of alien could attack an orbiting spaceship? [Starship Troopers](http://www.imdb.com/title/tt0120201) has the answer. What if an alien could concoct an organic projectile built from acid, heated to hundreds if not thousands of degrees? Such an alien would be massive, with plenty of armor to withstand a tank's offenses. Its attack would eat through steel, ceramics, and depleted Uranium. The heat would turn the tank into a pressure cooker. The best part, an artillery alien could lob projectiles from long range, potentially destroying multiple tanks before they had a chance to fight back. This one would stretch the science-based tag a bit. What kind of acid could withstand too much heat before falling apart? How often could an alien fire this biological weapon without recuperating? What are the digestive processes that turn food into a projectile? I do not know, but I imagine this should be possible. [Answer] If you allow hulk type of strength (but not supernatural), it's not too difficult to envision a creature that can simply upturn/topple a tank by brute force. It doesn't have to be supernatural or supernaturally strong, evolution has produced incredible creatures in the past, we need something with arms/body specifically evolved to push/pull up incredibly heavy loads. Once the tank is upturned, it's useless. Such a creature can also conceivably just pry open the hatch of the tank by brute force. It can get on the tank, take out the secondary gun and then there's nothing to stop it. The tank is useless once the hatch is open and the creature is able to pull the men out. The only other requirement for this creature is that it should be able to withstand the secondary gun of the tank long enough so that it can get close. A balance of natural armor, speed and some form of camouflage may achieve that. You can also add secondary abilities that can assist with disabling tank's cameras etc but they're not strictly needed as long as the creature can withstand the secondary gun just long enough and has the right type of push/pull strength. If you want to add secondary abilities, I like the idea of ranged attacks similar to Spider-Man like webbings (or very thick sticky glue/resin). It can use such webbings to disable the hatch and guns from distance. If the guns can't rotate and the hatch can't be opened because of the webbings acting as glue, the tank is useless. Then the creature can even more safely attack it to topple or open the hatch or whatever. Alternatively, it can mess up the treads with the web but I don't like that idea as much. It can also be smart enough to be able to use the webs to help pull/push the tank and the orientation of the guns. Spiders are naturally occurring creatures so it's not too far fetched to imagine a creature evolved with the same feature. Nature already has examples of animals able to lift weights many times their own sizes and creatures with all sorts of adaptations, so such a strong creature with somewhat specific but natural adaptations is not too far fetched. It might look somewhat like the white apes in the Barsoom series. [Answer] I can think of a couple of ways Poisonous gas or spray that could cover a large area and was lethal to humans in minute quantities. The creature could hide upwind, emit it's poison and the tank would trundle right into it, killing the crew. or A huge burrower who could dig a trap underground for the tank to fall into and then bury it in a few tons of dirt. Conceivably this alien could take out a whole line of tanks by digging a tunnel across the battle front, they all fall down it and collapse it on top of them, then the alien strolls over, pats it down and plants some flowers on it. [Answer] Flat Alien A long, flat, extremely strong alien skilled at camouflage could potentially destroy an Abrams. It could lie on the ground as the tank drove by, then as the tank drove over it, it could flip over, causing the tank to fall on its side. Alternatively, it could stick to the tires of the tank, refusing to let the tank move. If it was strong enough, it could then slither along, still holding the tank, until it and the tank reached the edge of a cliff. The alien could then push it over the brink by letting it go and giving it some impulse. [Answer] Acidic Sneaky Grouping Alien The alien is something fast, sneaky, with hard beak, venomous breath, acidic excretions and grouping behaviour. Not bigger than a dog. Big group of aliens (~20 species) tries to sneak to tank, using environment as cover. And they are confident, that majority of group will not survive, even if the tank is destroyed. They are cold-blooded, Thermal Sensors of tanks are pointless - they are build to detect humans with 37,6 C body temperature and machines with hot engines, not much something cold as environment. Also aliens have camouflage like chameleon or cuttlefish that makes them hard to detect by naked eye. When few aliens approaches the tank, they attach to it and they try to find weak points (like air ducts, visors and so on). Than aliens dissolve tank armour in this points with acidic excretions, and than they eh... breathe and fart into this holes to kill the tank crew. As far as i know, tanks do not have any weapons suitable for killing dog size things on its armour. Some WWII tanks has small holes for handguns, but i think actual tanks do not have this. If any crew member tries to open the manhole and kill alien by handgun, he will be simply outnumbered and tore apart. If he manages to shot any of aliens, he will be covered by acidic blood of it. And other ones tries to infiltrate into open manhole, wreaking anything inside the tank. Even if few of them are killed, anything inside the tank will be poisoned. This creatures have hard beak like cuttlefish - they can knock the armour, the sound resonates in tank, making crew mad and confused. In real live, I have a friend who served in army as tank crew member. He says, if you lock into the tank, and somebody smashes tank armour with a sledgehammer or crowbar, the armour is, of course, not harmed, but anybody inside the tank are very irritated by bangs, because everything resonates terrible inside, and it gives very bad sensations to crew members. [Answer] When thinking about defeating a tank, consider a tank is nothing more a then 3-6 (in our case 4) people in a armored shell rolling around. A tank without it crew is nothing but a very heavy (and expensive) barrier. Your objective then, can been always be thought as stopping the humans from controlling the vehicle. Either by death, immobilization, inability to project harm, losing the will to fight or incapacitation. In short summary, the most effective organic threat to a tank already exists - The human and it's mind. Creating a creature that has near or above human like intelligence, that is hard to see, even harder to hit and capable of ambushing or otherwise closing with a tank with some degree of speed and stealth. Then the tank is yours. A tank cannot engage at point blank and servery blind to anything in the near range. To kill a tanks occupants with ease, you can attack though the weakest points. This being the optics or the neck of the turret. This could be done with some chemical attack much like modern HEAT weapons, a very high powered thrust of a piercing tip or with enough intelligence you could wait till they open the top hatch and destroy the occupants. If there is some magic of biological evolution, creating a massive shockwave to the roof of the tank which can be done mechanically like the [pistol shrimp](https://en.wikipedia.org/wiki/Alpheidae#Snapping_effect). If the waves are directed and don't have a chance to disperse in air, the armour works against the occupants and translates the waves into the working area. Such a force would liquefy the small veins inside the occupants and render the occupants promptly dead. ## About your prey Tanks are primarily thought as mobile demolition platform (which supports infantry) or the modern equivalent of fast charging calvary/knights or mobile impervious forward facing, pillboxes, that provide flexible defense against everything. These idea of roles, thus defines much of there power and limitations. Limitations that can be exploited to defeat Modern Armour like the M1A2. As I write below draw from it, the ideas of explotiation. That's truly all that war is. Seizing opportunity and capitalizing on the weak points of whatever you are fighting. Play to your strengths and to their weaknesses. Don't fight a Tank for what it is - a brick wall. Fight it for what it is not - an anti-air or missile defeating platform, an all seeing close quarters killing machine, an fast moving, all terrain, mountain climbing, long range artillery piece. In the case of the M1 Abrams. It was designed to defend against hordes of Russian tanks, and then roll and maneuver with great speed on the plains of east Europe towards Russian heart land. The tank sports a lot of features that helps it one up its prey and allow it out survive its cheaper and more crudely designed counter parts. A short list is that it can lower (depress) it main gun more, accelerate at great speed, shoot father ranges with more accuracy, better gun auto stabilization, better tracking of threats and exceptional optics/digitization to name a few. Tanks and even historically all armoured fighting units, due to there exceptional armouring have always had to strike a balance between mobility, visibility and dexterity to achieve a high level of functional armour. Sacrificing movement speed for armour, destroying visibility in a enclosed hull, helmet or shield fort to provide the highest degree of protection from threats of all angles (Since the Romans), some removing the top turret and non forward facing armour to provide the most armour where it is needed. The M1 overcame the mobility issue for its heavy tonnage by placing a jet engine within its body. The jet engine provides exceptional acceleration and mobility infers the following major penalties. * Lights people and things on fire * Loud with a unique sound signature. * Huge fuel consumption The American idea was that they wouldn't try to sneak the tank around a quiet battle field, stray far from infantry nor would they stray far refueling and logistics. All, if by factors of war, become not true - puts the tank at a severe disadvantage. In a tank vs tank scenario, unless your tank is offline - you wont be hearing the enemy tank from inside your tank. With the concept of a organic beast, it could produce no noise except for the impact of "feet" on the ground - which could be organically muffled. A tank like a M1A2 could be detected even idling at great distance to trained ears. The heat produced from the tank is impossible to despise, even when idling. Any creature that can see heat, would be at an exceptional advantage against any metal armour - as it would heat in the sun, and be exceptionally hot if running. Fuel is a problem for armour, if a battle is prolonged. For an inferior fighting force this might be an option for destroying the fighting ability of your enemy. Rather then blow its hard to kill (see WW2 German) tanks. Destroy the depots and the refuelers, and the battle will be won eventually by attrition. Do also note, the tank crew needs to eat, drink and poop. If the tank was immoblized, (by chemical entrapment, falling into a huge hole dug by your creature, pushing the tank of the cliff) a creature could just wait like a spider - until the crew is forced to try to flee. For all that matters, it could sleep on the roof to conserve energy :) ## About your creature In open face to face combat. See Rhino vs Tank. Your creature would require nothing more then a faster speed then the turret could traverse. Once it gets closer human powered machine guns would open up on it. However if it was armoured, that could be defended against. If was wasn't, it would have to dodge human manned fire in great volumes which would be difficult unless it was hard to track or see. Also the humans could be surpressed from ever exiting the vehicle, thus defeating the use of external guns. Tanks are in no way as flexible or as agile as a human with a gun. They exceed in speed but not always mobility. Exploiting that is critical. This can be done though the use of ambush, stealth, ability to traverse different terrains or speed. A slow moving large target, would never survive against a tank. It just drive away and pummel it from whatever distance it could muster. Presuming the weapons are strong enough to hurt your creature. Adding to this. If we keep with your idea of aggression (probability, all the time). We do not want to be some form of trap door spider or incredible horse sized tunnel worm that only works purely on ambush. So at this point your becoming limited to a fast moving or limited sized (horse) unit. Slow, large and ranged unit - isn't effective, unless it mimics the AT properties of a modren HEAT round. If your creature was social you could look at the idea of a wolf. Because a tank is limited at shooting one thing at a time, and whatever it is trying to shoot at it - it has to hit it with a 7.62 to 120mm sized round. Again with the top surpressed, limited to one thing at a time (without CROWS). So in the wolf or really Bug/Zerg/Tyranid/Hord style combat scenario, the tank is quickly overrun even when faced with fighting the units head on and/or in ambush. The reload time of a M1A2 is about 5 seconds. If the unit(s) can close the gap after a miss or a single successful hit, it is again over for the tank. The tank is also susceptible to prying motions, with enough strength the barrels, tracks and neck collar can be damaged with far less force then which is needed to punch though composite ceramic, steel and DU. I hope this helps. [Answer] [The alien](https://en.wikipedia.org/wiki/Alien_(creature_in_Alien_franchise)) comes to mind. An intelligent creature that can understand the workings of a tank and is able to exploit its vulnerabilities. It could sneak onto the tank and disable some system such as an antenna or a camera and wait for the crew to open the hatch, then attack. [Answer] assuming your animal does not have to survive the encounter, having some kind of large hard spike, maybe a big tusk or horn, that it can jam into the gearing and break the treads is your best bet. I know of a modern tank in Germany that broke a tread during training and the people were stuck in the tank because a pair of wild boars were climbing all over it and attacking anyone who tried to get out. It's actually very hard to shoot something squat on top of or close to the sides of a tank. They ended up radioing for help. [Answer] The tank stalkers The beings are living in colonies on their home planet. They are relatively small, not bigger than a housecat. Their method of hunt is as follows: They have superb stealth capabilities, they are ectotherm and have excellent camouflage and cover-the-track abilities. Their targeted prey is homeotherm which is detected by eyes which see mostly in infrared range. Once the target is alone (!) and in reach, the colony fires spit-balls consisting of two components: A sedative nutrient solution (so that with some luck the target does not recognize that something sticks to their skin) and a bacteria colony which live in symbiosis. The bacteria are using the nutrients to spawn themselves, creating toxic byproducts and much heat. They are thermophil and use oxygen, the higher the body temperature of the target and the faster the target moves, the better (in a certain range - higher than 120 °C kill them, too). The solution also contains tracers so that the colony can trace the victim. After the victim died and they have found it, they literally enwrap the victim and digest it completely. No bones, no muscles. You can as human survive if you wash yourself completely at once and escape, it takes some times until the bacteria or solution takes the effect. On their natural habitat prey has developed several countermeasures: Being together in big colonies and saving members from an attack, being themselves ectotherm and stealthy, having repellent skin so that the spitballs are dropping harmlessly away. A tank is the perfect target. It is a strong IR radiator and it moves fast. So the tank is targeted and...at first nothing happens. After a while the crew is wondering why it gets so hot inside. Once the heat is unbearable (it is not necessary that the crew is suspicious at first, there are many possible explanations for overheating), they need to come out. If the crew does not use a full ABC suit, the toxic substances will kill them immediately (normally it does not take so long, but much heat and full speed have maximum effect). The crew dies, the colony digests the crew and the only thing remaining (the bacteria are dying after their mission is achieved) is a hot, empty tank cooling out after some hours. [Answer] *A very intelligent creature* Can the alien understand the nature of the tank (a big defensive tool with people inside) ? It could be because it is extremely intelligent, or because his species (or himself) already encountered a tank and thus he could observe his weapons, strengths, and weaknesses. It could also be a hunter type of alien, which is most likely going to observe such a strange prey before acting. If he is intelligent or knowledgeable enough, it could be able to influence the tank in the following ways: * Alien has the same temperature as the environment, and cannot be detected by heat-cameras. It can spew large amounts of ink, like an Octopus would. It could basically blind the entire thing within a smallish amount of time, and prey on the tank's inhabitants when they come out (I can leave that part to your imagination !) * Alien can modify part of the ground to root the tank, especially if it can build some kind of quicksands. * Alien understands that the metal is going to propagate the sound inside the tank, and will simply hammer at a blind spot to drive the tank's inhabitants crazy and deprive them of sleep eventually. This does not fit the "Brief" point, but if the tank has no way of getting support, this tactic might eventually work. [Answer] You mean, [this guy](https://en.wikipedia.org/wiki/Alien_(film)#The_Alien)? [![enter image description here](https://i.stack.imgur.com/7FtsP.jpg)](https://i.stack.imgur.com/7FtsP.jpg) > > 1. At least as large as a horse, but not much larger than a semi-truck. √ > 2. A land animal. √ (Can roam the land but also can swim). > 3. Purely organic, and obeying normal laws of physics. √ (But this guy reeeeeaaaaaally defies gravity). > > > ...It should be something that could survive on earth and reproduce. √ > 4. The alien should fight with minimal or no tool usage, and without using other organisms. √ > 5. Preferably a creature with an aggressive or violent temperament. (Are you kidding me?) √√√√√√√√√√√√√√√√√√√√... > > > No, I'm not telling you to plagiarize Alien (1979). But there are qualities you can duplicate: Much like the alien in the [Alien](http://www.imdb.com/title/tt0078748/), your alien will have to use stealth, speed, agility, and intelligence for its benefit. Tanks lack the stealth and the agility, compared to such a creature. You can add some drama with human overconfidence: soldiers operating the tanks underestimate the alien, probably taking it for a mere animal based on it's looks. BTW this is exactly what happens most of the time in Alien series: hunters becoming the hunted. Tanks will not be able to target a creature that rapidly zig-zags, even in a flat desert terrain. A swarm of tanks would have to take friendly fire if aliens are hastily jumping from one tank to another. Armor piercing biological weapons can be useful, such as the acidic blood from the alien. Alien will be able to pierce armor if it can rapidly accelerate small solid objects. Check how [Mantis Shrimp attacks](https://www.youtube.com/watch?v=i-ahuZEvWH8). If the alien can throw metal objects of considerable size fast enough, that's practically a bullet, and they may be able to pierce armor. If alien has a tail, they can use it as a whip to do considerable damage. The [ends of a whip can travel at supersonic speeds](https://en.wikipedia.org/wiki/Whipcracking#Physics). It may not be hard to achieve hypersonic speeds if the tail is long and the creatures are very strong. If the and of the tail is made of a really hard substance and very sharp, it might cut metal. Another form of biological weapon to use is poisonous gases. Make your alien produce something like Sarin gas. This can be effective even if the crew wears masks, because [Sarin works even in very small concentrations](https://en.wikipedia.org/wiki/Sarin#Toxicity). A leak in a mask, or an overconfident crew member not wearing a mask would be enough to generate a panic situation and make a sitting duck out of a tank. Combining a way to slightly pierce armor and then inject poisonous gas could be effective. Most of the time, the latches on top of tanks are thinner than the armour around the body, and intelligent aliens will quickly realize this. [Answer] Picture a frog. Now scale it up to unreasonably large proportions. Like, almost elephant-sized, and yet still capable of leaping proportionally-large distances. Now instead of webbed, sticky feet suitable for climbing or swimming, give it large, bony/armored foot-pads which can spread to provide a wide base for it's massive leaps, or fold to concentrate force into a devastating kick. And for good measure, lets give it some adaptive coloration like a chameleon or octopus, so that it can lurk in cover waiting for its prey to go by. For close in work, give it a maw full of teeth, and maybe some grasping arms with claws or a sticky tongue or something like that. So now your tank trundles by. From behind a low hill or a scrub of bushes, or maybe from a shallow pond, this massive beast leaps out, landing atop it. It hits with the force of a small car at highway speeds. Not enough to destroy the tank outright, but more than enough to disable its weaponry. The force of the impact rips the top-mounted machine gun clean off the tank, and bends the barrel of the main cannon into a useless wreck. Now at close range, it begins kicking repeatedly -- the cannon mount, the hatches, the periscopes, the wheel bogeys. Anything that looks like it could be a weak point. It sets off a couple reactive armor panels, but its thick hide and bony feet absorb the shock and minimize injuries, and it quickly learns to avoid the remaining panels. Repeated impacts don't penetrate the shell of the tank, but they rapidly hammer the tank into uselessness. Eventually one of the hatches gives way, and it uses its close-in weapons to pull crew members out and lunch on them. Thus sated, it leaps off back into cover, to lick its wounds, rest, and wait for its next victim to come by. [Answer] How about an insect swarm where the individual insects have venom that could kill a person? Tanks have limited ammunition and cannot kill all targets if they are spread out, so there is no chance of killing all of the threat. Also, tank operators eventually have to get out of a tank, but insects could out wait the operators. [Answer] A monkey that likes to mark its territory by pooping on shiny things. It hides in the trees, jumps on top of a passing tank, and crawls around up there rubbing faeces on any glass blocks, periscopes or camera lenses it can find. [Answer] Be quick and sneaky, Attack in groups, get onto tank and stick something long (trunk, tongue, tentacle, tendril) into the tank barrel to set of the loaded shell. Or stick something into air intake of the engine to dosable it. Or your big main animal can release swarm of small flyers that do attack. Locust swarm in Starcraft) Shell in barrel will be probably not armed, but you might ignore that, or just filling the barrel will be enough to make tank not able to shoot. Or it can have strong tongue reinforced by nano carbon tubes and it can lick it way through back of the turret where is relatively light armor even on abrams (20-30mm compared to 700 in front) - same way as octopus gets into clams. Exploding shells in the magazine will disable any tank [Answer] Why not go with something like the Carnifex, why not have it rapidly evolving over time to meet the needs of its environment. <http://warhammer40k.wikia.com/wiki/Carnifex> We are starting to make organic material harder than ever before as noted below: <http://www.seeker.com/hardest-organic-material-ever-designed-by-scientists-discovery-news-1766506692.html> So surely it makes sense there could be a creature that meets humans, gets killed, its species somehow adapts comes back harder than before or its just made of organic armour that is very tough. ]
[Question] [ In 4X strategy games I’ve played (like Stellaris), closed forms of government (closed oligarchy, dictatorship) seem to be overpowered when it comes to scientific output compared to the “democratic” government option. In Stellaris, the democratic space-empires inevitably fall behind the autocratic empires which have access to research edicts where the ruler(s) can decree that the country will focus its resources on technology instead of whatever the current president’s platform was when they were elected. Of course, the game could be unbalanced, as is the struggle of making strategy games. However, the theory makes some amount of sense when you think about it. Normal people don’t really care about scientific achievement by elites off in the capital, they care about earning enough to make a living. (Think the movie Interstellar.) When we think up Nazi alternate histories, we often think of technological utopias where humans are landing on Mars by the 1970s (i.e. Man in the High Castle). In our own universe, you can argue the past 5 or 6 U.S. presidencies have all but neglected national research in favor of more immediate matters. After all, the U.S. only landed on the moon to play catch-up with the Soviets. Meanwhile autocratic China seems poised to be the world leader in AI. In a space setting†, what could be a way that a democratic state could consistently keep ahead of its authoritarian peers? Assume that: * The democracies and the autocracies have the same amount of resources. On Earth, democracies (+ the USSR) defeated Nazi Germany in WWII because they were larger. Their size also gave them access to more minds so they got the bomb faster. * Trade is limited. On Earth everyone is on about the same level because of global trade. We can assume contact between species in space will be less comprehensive. * Autocracies don’t persecute scientists for race or religion or whatever else aliens discriminate based on. * “Big technology” (i.e. spaceships) is valued more than “consumer technology” (i.e. iphones) * The autocracy is a full autocracy or a stable oligarchy, not an anocracy. If the premise is flawed, and democracies are not intrinsically disadvantaged to autocracies, with all other factors held constant, explain why. Possibly related mirror question: [How to keep an authoritarian state from scientific stagnation?](https://worldbuilding.stackexchange.com/questions/15450/how-to-keep-an-authoritarian-state-from-scientific-stagnation) † I only say space to imply a sparsely connected setting where the “world” isn’t tightly and thoroughly linked through trade and cultural exchange. [Answer] Yes, the notion that democracies are inferior is completely wrong Autocracies might be better at a short-term scientific blitz (i.e. you know exactly what you need, and you can concentrate all resources on this task). But that's about it. In the long-ish run (decade+) a democracy will prevail. There are a bunch of reasons: * In a democracy, every man chooses his work. This is far, far more efficient than the state choosing for you (because you know better than the state what's best for you). Put it on a larger scale, and democracies will always develop and scientific and industrial advantage (an Autocracy will do one blitz while a democracy develops 300 projects at the same time). * People work better (motivation-wise) at a democracy (because they choose where and what they do). * People [run](https://en.wikipedia.org/wiki/Escape_attempts_and_victims_of_the_inner_German_border) (literally) from autocracies. And not just random people, but typically the better ones (the most talented, hardworking and bold). Oh, and they run to democracies. * [Established] democracies are stable. They almost never have a significant political turmoil. All in all, democracies work better because the people's self-interest is aligned with the states one. Your win is typically the state's win, while in an autocracy it's quite common to work against the state. This makes everything work much better. In our world, in the end, democracies were always more technologically, industrially and economically advanced. The best example is, of course, the Cold War, but you can also look at South Korea vs North Korea, or East Germany vs West Germany etc. The difference is that [unlike in a computer game] a state is, essentially, a bunch of people. Given the same resources and starting position, any country will only be as successful as it's people. --- As a side note, I feel that your case for autocracies is somewhat biased - you seem to look at examples like Nazi Germany or 40's-50's USSR. Those are young autocracies and are extremely unrepresentative of autocracies as a whole. Take a look at established, older, autocracies like 80's USSR or better yet, absolute monarchies in Europe (France before the revolution). Thing is, with time, autocracies tend to get worse - the population is less enthusiastic about the ideology, the leaders grow distant and corrupt, the critical political & economical thinking disappears (no opposition). On the other hand, democracies get better - people gain belief in the system, stability creates democratic values (which target corruption), the opposition derives change and progress... [Answer] # It isn't democracy or autocracy, it is free markets that matters ### Autocracy vs. Democracy: the Space Race Government type is fundamentally unimportant to whether or not a nation advances in 'science.' An excellent example is the space race. Both the USSR and USA came to the same conclusion, they wanted to win. In the USSR, the Politburo and/or Khruschev was able to make this decision independently. In the US, Kennedy and his advisers had to [sell the nation](https://en.wikipedia.org/wiki/We_choose_to_go_to_the_Moon). The results were the same either way. Both nations spend a lot of money on something that was not strictly in their national interest. But either nation could have balked. The people of the US could have been uninterested and voted [Goldwater](https://en.wikipedia.org/wiki/United_States_presidential_election,_1964) into office in 1964; that would have killed US participation almost certainly. From the USSR's side, some other group could have signaled their opposition. For example, even if the Politburo wanted to go to the moon if Khrushchev said no, that would have killed it. On the other hand, had Khrushchev been too eager about the moon, the Politburo could have deposed him, as they [eventually did](https://en.wikipedia.org/wiki/Nikita_Khrushchev#Removal). The moral of the story is that both government forms, both with the consent of the people and without, had the capacity to direct significant resources to a project deemed important enough at the time. Therefore, over the short term, it doesn't make much of a difference what the form of government is. ### Invested capital makes technology go forward Capital must be invested to advance technology. The Apollo Program and Manhattan project were bought at the cost of a significant fraction of the national budget. But those are only two big projects, and expensive and important as they were, represent just a fraction of technological development. Instead, most technology comes out of private capital. In the 1700s, nearly every invention worth mentioning from the [Industrial Revolution](https://en.wikipedia.org/wiki/Industrial_Revolution) came from Great Britain; the one place that had the most available private capital. But the time the developments of the [Second Industrial Revolution](https://en.wikipedia.org/wiki/Second_Industrial_Revolution) had taken place, more nations were ready to be involved. Especially in the US and Germany, there was enough private capital that these nations claimed a big share of the developments made. In the US, the picture of development can be seen clearly. Private fortunes in the hand of (probably evil) New York bankers were the investment seed to built Pittsburgh steel foundries, Akron tire makes, Toledo's glass makers, and Detroit's automobiles. New ways of making things abounded, because industrialists with money were on the lookout for new ideas. If you had a new way to make or cut glass, and you took it to some robber baron in Toledo, the chances were both you and him were going to make it rich. What motivation! Compare that with the alternative. If you have a great idea for making glass more cheaply, but you don't know and can't find anyone with money to fund a plant for making it, you haven't really invented anything at all. # Conclusion The free market allows private capital to flow to those people with good ideas, allowing their ideas to develop into advanced technology. This can happen whether the country is a laissez-faire democracy (like the US in the 1890s) or a centralized autocracy (like modern day China). Now, whether the free market is good for all people is a different story. I'm not interested in getting into an argument about the validity of capitalism. I'm just stating, as an indisputable historical fact, that the free-er that private capital is from taxation and government regulation, the faster the pace of technological change it supports. [Answer] Democracies don't have to be indecisive or stagnant. They aren't necessarily top-heavy or paralyzed by conflicting special interest groups. That is a fairly recent trend on the real world stage, which will hopefully solve itself once the citizenry get tired of the endless bickering. Democracies can be vibrant and unified, with each citizen choosing for themselves the manner in which they can best contribute to the shared societal goal. They can be goal oriented, as long as every citizen understands that the shortest path to attaining their own prosperity, is to invest themselves in what is best for their country. In an autocracy, decision making power is sequestered to a comparatively small number of minds who rule from a distance, dictating the actions of millions on broad homogeneous paths. Any flaw in the census, in the government's attempt to categorize its citizens by strengths and talents, will lead to citizens being utilized in less than optimal ways. Without a choice, even those who are well suited to the tasks they have been assigned may resent being forced to pursue them. The secret weapon in a democracy's arsenal is that each citizen will tend to choose for themselves an occupation which best suits their abilities, in the quest to earn highest rewards for themselves and their loved ones. The democratic rulers therefore only need to manipulate the economy such that the skills they most need, yield the highest pay. They do not have to find the single best suited mind to crack the secret of FTL. They just have to offer a big enough prize so that the competitive marketplace finds that singular genius for them. [Answer] > > If the premise is flawed, and democracies are not intrinsically disadvantaged to autocracies, with all other factors held constant, explain why > > > The premise is flawed in that the situation you describe has nothing, per se, to do with autocracy or democracy, but rather with the difference between the "desires" of the State and those of the population at large. In democracies, on average, this difference is low because the "ruling" layers are elected by the "ruled" layers (but note that there are lots of points - corporations, bureaucracies, monopolies... where this is not true). The slippage between hierarchy layers determines friction, with people below working at odds with people above, and this leads to resentment, corruption, graft, nepotism, need to control, and ultimately a waste of resource; the machinery's cogs do not fit well and the whole ensemble grinds to a halt. The machine can focus more power on some sections at the expense of others, but on the long run, it will just wreck itself faster. Such a machine is good in remaining still (provided that external circumstances do not change). You can reduce the friction in two ways: either aligning the State with the population (democracy - or an "illuminated" dictatorship; panem et circenses refers to the 'trick' of satisfying the most basic desires of the population at large). Or by aligning the population to the State, through indoctrination (and/or religion). This has never worked too well on human beings, but there's no reason it couldn't work with other species. With some modifications to the human mind, achieved through breeding and nurturing, Aldous Huxley tried to make it work in Brave New World. But there is a more fundamental premise flaw right in the question title, that I also see reflected in some comments (that basically boil down to "but what if a democracy doesn't do the right thing in the so-and-so situation?): > > How to keep democracies from falling behind technologically? > > > As soon as you want to "keep" democracies from, "make" democracies do, "steer" democracies towards etc., you no longer have a democracy. By definition, a democracy will go wherever the average of people, the demos, wants it to go, not where a minority might want to go. Not even where it might really be best to go. It is perfectly possible for a democracy to make short-sighted, long-term harmful choices. This is why it was said "A democracy cannot exist as a permanent form of government. It can only exist until the majority discovers it can vote itself largesse out of the public treasury. After that, the majority always votes for the candidate promising the most benefits with the result the democracy collapses because of the loose fiscal policy ensuing...". So, given a non-post-scarcity economy, the long-term good needs for enough people to realize that in a given situation technological progress or weapons research might be more desirable than health care or retirement bonuses or whatever. Then, just as in dieting, they need to stick to the plan, gritting their teeth and enduring poor health care etc. in the short term, in exchange for a long-term advantage of technological progress, of not being enslaved by their neighbours, of not wrecking the environment and need to leave the planet, and so on; in essence, the democracy autocratizes itself in certain fields, in what is known as an [Ulysses' pact](https://en.wikipedia.org/wiki/Ulysses_pact). The need for the above was recognized for example in the Roman Republic, where the dictator ([he who dictates](https://en.wikipedia.org/wiki/Roman_dictator)) was an established magisterium and was [voted into office](https://en.wikipedia.org/wiki/Lex_curiata_de_imperio). [Answer] First of all, these in-game representations of political systems are always going to be flawed. A representation will always lose some detail, but the keyword here is "game", you certainly do not want to have to deal with the actual issues of running a state. * Totalitarian states are not that efficient: + There is no such a thing as a state run by a single man. Nazi Germany is a paramount example, under the myth of unity and Hitler's leadership, it actually was a nightmare of individuals and organizations working against each other (Heer vs Waffen-SS, SS vs ABWEHR, Himmler vs Goering) with different priorities, pet projects and the like, hoping to get Hitler's favor. + Even dictators need support. They do not need to be legitimated by elections, but even without these, they need to have the support (or at least the control) of the public. And, lacking democratic legitimacy, they need the support of other power brokers (army, aristocracy, capitalists, etc.). See [this CGP Grey video](https://www.youtube.com/watch?v=rStL7niR7gs&t=87s) for a very interesting introduction. + As stated by other answers, totalitarian states rely on the capabilities of those at its top. Are they wrong? Say hello to the Big Leap Forward, or the Holodomor, or go ahead and invade Russia. + Totalitarian regimes are more worried about their stability. People will advance on the basis of their loyalty, not of their merits. No matter how good you are, if you are not in line with the leadership objectives you will not get responsibility positions (and that is if you are lucky enough to not spend your time in a jail). And of course, you will need to keep a big security system that you want to feed with lots of resources to keep it happy. * Democratic states are not incapable of having objectives. The key point here is `are lagging behind`. If there is a perceived threat, it is relatively easy to get their act together. Good examples could be the USA or the UK during WWII (including a "national coalition" government in the UK), the space race or even (fruitless as it was) Reagan's SDI (the famed "Star Wars") project. TL/DR: Totalitarian states have internal tensions, do not always have the best leadership, are not that efficient and have to consume resources both for repression and public support. Democracies are capable of making sacrifices if there is a perceived need for it; the aspect being that as soon as the need seems to wane there are strong interests in redirecting the efforts to other issues. [Answer] Given the definitions you've provided the only real difference is that in one the leaders are in place for life, while in the other the leaders are only in place for a term or two, based on votes. With that in mind there's one rather crucial disadvantage an autocratic society has: it's bad at dealing with particularly bad leaders. In a democracy, if you don't like the Prez, you can just wait 3-4 years and vote them out of office. Impeach them, if you're impatient. Bring in a new Prez, maybe they'll do better. In an autocracy, if Le Roi is a fool, you can either starve while he runs amuck eating cake for 50-odd years, or, well, I suppose you could burn the regime down and invite a whole lot of people to meet Madame Guillotine. This is... less than ideal for the advancement of science. We can only speculate how much was lost when Antoine Lavoisier had his head lopped off. In reality we're never going to get a good leader 100% of the time. For every Sun King there's a Louis XVI, and for an absolute leader, their failure is absolute. --- For power concentrated in a small group of powerful people (what Stellaris understands as an oligarchy), we can look to other similar setups - one notable one was the Central Committee of the Communist Party of the Soviet Union. Long story short, the loss of the de-facto leader (Lenin) led to a power struggle in the Central Committee that eventually led to Stalin taking supreme control of the USSR - and purging his rivals for good measure. This was more or less repeated after Stalin's death, with a power struggle breaking out among Stalin's inner circle before Khrushchev took control. Generally we'd expect these sorts of setups to shift towards one absolute power at a time, and generally deal with power struggles due to variations in how much power and influence the 'powerful' actually have. [Answer] # A strong centralization of power, of any kind, hinders discovery When Columbus asked the Portuguese for permission to sail, they said no. So he went to the Spanish, who said yes, and the rest is history. When the Chinese pronounced [Haijin](https://en.wikipedia.org/wiki/Haijin), its fleets were scrapped and nobody could do anything about it. China was not more or less autocratic than Europe, but European power was decentralized. In a democracy, power is supremely decentralized - when the government says no, protesters, lobbyists, local governments, etc. can say yes. In an autocracy, they would all be shot. ## Socialist science Despite its successes in the Space Race, science in the USSR was severely hampered on many fronts. Russian electronics were trash, all computers were clones of American designs. Russian genetics was [suppressed by demagogues](https://history.stackexchange.com/questions/6054/why-was-stalin-so-opposed-to-genetics/39190). Quantum mechanics were considered counter-revolutionary, and only existed at all [because Stalin wanted his bombs](https://history.stackexchange.com/questions/14699/why-did-stalin-deem-quantum-mechanics-counter-revolutionary?rq=1). This is a trend in all aspects of Soviet culture. The geriatrics in the Kremlin set political, cultural, and scientific norms that everyone else had to follow. Communications beyond the USSR's borders were difficult if not impossible, so scientists couldn't collaborate with foreign colleagues, or even steal their ideas. If you disagreed, you were, at best, denied advancement. ## Stupid Jetpack Hitler German success in the field of science had [nothing to do with Nazism](https://history.stackexchange.com/questions/26020/why-were-the-germans-during-the-nazi-era-so-inventive/26023#26023). In fact, Nazi policies encouraged [Deutsche Physik](https://en.wikipedia.org/wiki/Deutsche_Physik) over "Jewish physics." The Germans commissioned many wonder weapon designs, but they amounted to very little. Their crowning glory, the V2, was terrible when compared to a conventional Allied bomber dropping conventional bombs onto conventional German research labs. Their vaunted jet fighters were... well, as Chuck Yeager put it, "when I first saw a jet fighter, I shot it down." # Il Duce is not a psychic The Supreme Leader decrees that the People should go to space. Is technology ready? Does anybody want to go to space? Are there problems at home that might be addressed? Supreme Leader says no. In a democracy, many things are happening at once, and freedom of the press means that everyone knows about these initiatives. A vaguely free market means that demand outstrips political support, and the leaders are not threatened by letting new, radical ideas thrive. Democracies go to space when their people are ready to embrace space travel, and have found a sensible way to do so. Autocracies go to space when the autocrats have too much to drink, and risk too much on too foolish a venture. The USSR collapsed because it was spending too much to make rockets and bombs, and not enough to produce food for its people. The Germans [invented Skype](https://history.stackexchange.com/questions/17279/why-did-the-nazis-invent-videotelephony?rq=1) for the sake of national prestige, and it didn't go anywhere. [Answer] There's some fundamental societal principles that come into play when dealing with autocracies, oligarchies, and even democracies with small elected groups of representatives. Whenever you concentrate power, you become more dependent on the decisions of those in power being the "right" decisions. And, of course, "right" is a concept which is decided later, in the future. If you are a ruler that has the Mandate of Heaven, as in you actually are striving after the "correct" thing and have the heavens in your favor, you will always be able to use an autocracy to lead your nation better because that concentrates all the power into your hands, and magnifies your correct decisions. Of course, real people aren't always perfect. Consider the case of North Korea, whose leaders have used their power to create a greatly magnified military system that has a good portion of the Western world on edge, despite having a GDP substantially smaller than Apple's yearly revenue. Is this the "correct" path? Well, we in the West would generally say "heck no!" But only time will tell. The power of democracies arises when it becomes too difficult for the individuals in power to identify and pursue the "best path forward." It distributes the power in the nation (how much it distributes depends on the style of democracy). This dilutes the power, so it's harder to make crisp clear judgements that move the country in one direction or another, but it vastly increases the ability to observe the world and make adjustments as you go. Thus, one thing the democracies could do is strive to create a thriving dynamic solar system where the "best path forward" is constantly changing. In such a system, it is enormously difficult for the leaders of the autocracies to stay sufficiently informed in order to make "right" decisions, but it is much easier for the democracies to keep up. It also helps to have those thriving dynamics be very broadband. By that I mean have those changes occurring on many different timescales and many different size scales. If a change occurs in a democracy (such as the invention of the iPhone), it is very easy for a democracy to quickly develop a structure to leverage it to its best capabilities. Our President didn't have time to write edicts to tell us how to manage iPhones while simultaneously managing the Iraq War. But we have CEOs and company presidents and startups formed in people's garage to figure out what to do with it. That is a structure which is hard for the autocracies to mimic or outperform. [Answer] I think your underlying premise is flawed. In the real world, and in most strategy games, neither the state nor its form of government is relevant to technological or scientific development. All that is required is a need and an opportunity as described in the old adage: "Necessity is the mother of invention". In the modern world, the need is to make a profit and technological innovation leads to greater profitability. This is not driven by the governments, but by the consumers. The entities doing the innovating are companies which are autocratic not democratic and are simply responding to needs. This is why no pharmaceutical company has cured a disease in many years, but all of them have come up with treatments. In the scientific world, the 'need' driver is far less obvious. Peer respect would be a major factor and I suspect inertia is another one, but the consequence is that science has slowed down to a crawl with the exception of areas that directly feed technological innovation (ie profit). When we have another 'necessity', I expect that science will pick up again, unfortunately, that probably means waiting for a collapse in climate, energy, health or food source. Or a war. [Answer] I think it is strange that nobody mention that scientific culture does not go well with Totalitarian regimes. The scientific culture pushes toward checking facts and being curious, exactly the contrary of the goal of a totalitarian regime. If your population start to question why it should obey your rule, why they should stay, or even why they should NOT try to take power for themselves, the stability of the regime will decline. Most of the totalitarian regimes will make sure that only a small part of their population wants to make high studies, and will control that group in fear of the ideas they could produce. You could have democracies without scientific culture. (but they risk to slowly become totalitarian regime, with a closed political class and staying a democracy in name only). In a scientific race, the democracy would always outrun the totalitarian regime, because that regime will either not have enough scientists or collapse under the pressure. [Answer] Normal people may not care about scientific advancement, but fortunately, we don't need to rely on them, even in a democracy. In the U.S., for instance, a lot of funding comes from the National Science Foundation (NSF) and National Institutes of Health (NIH), as well as a few Department of Defense groups, e.g. DARPA. Let's take the NSF as an example. Each year, they request a budget from Congress (in 2017, it was about 0.2% of total federal spending for the NSF) and give them a [high level overview of how the money will be spent](https://www.nsf.gov/pubs/2016/nsf16034/nsf16034.pdf) and [examples of the sort of impressive things NSF funding has supported in the past](https://www.nsf.gov/about/congress/reports/unlocking_the_secrets.pdf). But then once the NSF has its budget, qualified people decide which research grants will be supported, so even if a research project only has long-term benefits, it will still get funded if it's a promising idea. Another major source of funding comes from industry. In addition to in-house research, companies will sometimes send funding to academic researchers working on topics relevant to them. Even if they won't be the only ones to benefit from the research, they don't need to invest any time or employees into the project, so if they have the money to spare, it can be a good investment. (It also buys goodwill from potential future employees.) And finally, a base level of funding comes from the universities themselves. Undergrad tuition pays salaries, and offering solid research funding will attract good professors to the institution. The average citizen may look at something like a particle accelerator and say "That will magically create a black hole and kill us all". A congressman may look at it and say "That won't have any practical benefits before the next election". But the NSF people will look at it and think, "That may reveal information that will open up new avenues of research in 50 years" and fund it. The more short-sighted people just need to know that funding "Science" has always paid off before, so if we show them that it has, they'll keep funding it. (That came out as a bit more cynical than I intended, but if I'm being honest...) The average citizen of a democracy doesn't necessarily understand or even care about specific research projects, but as long as you have a good research infrastructure in place, they don't need to as long as they're interested in having technology continue to advance. [Answer] The problem here is that there really isn't a worldbuilding sort of problem. Your complaint is that within certain games, centrally planned economies beat free market ones. But the problem is that whoever set up the rules/programmed the logic for these games did not accurately model the real world. (This might be in part because games are restricted, while real life has much larger bounds that can be modelled.) So the "solution" seems to be either to not play these games, or - if you're making up your own game - to make a more realistic set of rules. To take a couple of your points: 1) Autocracies always persecute some group, and the more intelligent/innovative the group, the more likely they are to be among the persecuted, if for no other reason than that they start asking questions like "Why should we believe this idiot, anyway?" 2) Big tech vs consumet tech: It's often the economies of scale involved in producing consumer tech that allows relatively cheap scientific progress. Consider for instance why most supercomputers these days are clusters of cheap commodity processors and GPUs, which wouldn't be available for cheap if it wasn't for the gaming community. Or the way the US was able to convert e.g. automotive plants to making tanks in WWII... [Answer] Why not an Illuminatti Democracy? If an elite controls what the people see and hear they control what they think and control how they vote. So you can have your free market and political freedoms and the projects that matters will survive the electoral cycles because the Secret Societies that control the media and the church of your society will control the public opinion and make sure the public wants those projects completed. And these Societes know that big science is vital for them because if their civilization is conquered by enemies they will lose their privileged positions and if, on the other hand, their civilization conquer others they will become even more rich and powerful. [Answer] It may be too complicated to say, though culture seems the most important issue. Games strive for balance and fun, not realism. Importantly, in the real world, technological progress varies considerably because most nations have huge cultural differences which makes it hard to answer this without resorting to caricatures. During the Second World War Britain shared many technological secrets with America via the [Tizard Mission](https://en.wikipedia.org/wiki/Tizard_Mission). Britain had a lot of technology which was ahead of America's; especially when it came to radar and jet engines. Wartime comparison between the USA, Britain, Germany, and the USSR is complicated by a vast difference in cultural and material circumstance. In 1897 the Russian empire had a [literacy rate of 24%](https://en.wikipedia.org/wiki/Likbez). In 1900 the United Kingdom had a literacy rate [close to 100%](https://ourworldindata.org/literacy/). Britain's elite universities were some of the oldest in the world; Oxford was created 1096, Cambridge 1209. Universities in St. Petersburg and Moscow were setup in [1724 and 1775](https://en.wikipedia.org/wiki/List_of_oldest_universities_in_continuous_operation) respectively. Therefore, to make a comparison between such places is a non-trivial task with so much statistical noise it's hard to make meaningful conclusions. A precise scientific comparison requires controlling for as many factors as possible. On face value modern America is a research powerhouse. That's true... but when this data isn't controlled for population or GDP it's not informative, in the same way economic data not adjusted for inflation is often meaningless. Even contemporary free market democracies don't have the same research output per capita. This [original research](https://academia.stackexchange.com/questions/18767/research-publications-per-capita) found on academia.stackexchange finds significant differences. It doesn't adjust for GDP per capita... which would itself have to be adjusted by an inequality indicator to try and measure median wealth. We'd probably need to further adjust for difference in national education spending and access to higher education. Intuitively countries with more money will produce more research, but it's never going to be just about money. The research publications per capita figure will probably also need filtered by STEM fields (Science, Technology, Engineering, Medicine), as though a thesis on Cultural Studies or Law might be interesting, it's not relevant to what you're asking. Nevertheless. Let's add world bank [GDP per capita data](https://data.worldbank.org/indicator/NY.GDP.PCAP.PP.CD?end=2012&start=1990&year_high_desc=true) from 2012. No. ... Country ... Research publications per capita (GDP per capita) 1. Switzerland 0.049 (57,000) 2. Sweden 0.039 (44,000) 3. Denmark 0.037 (44,000) 4. Finland 0.035 (40,000) 7. Norway 0.032 (65,000) 9. United Kingdom 0.030 (37,000) 10. Australia 0.030 (42,000) 20. United States 0.022 (51,000) 21. Germany 0.021 (43,000) 22. France 0.019 (37,000) 28. Japan 0.013 (37,000) 50. Russia 0.004 (25,000) 82. China 0.002 (11,000) Most Chinese people are poor compared to their western peers, so it's little surprise fewer of them can afford to publish research. But what about the Anglosphere? Britain, Australia, and America share a great deal culturally. Britain and Australia produce the same research per capita. Meanwhile America, which is much wealthier per capita, publishes much less. Britain is poorer per capita than Australia, but has the same per capita wealth as Japan and France; which both produce considerably less research. So what's going on? A more revealing comparison may be between Finland and the USA. Finland regularly appears at the top of the scoreboard of the [PISA study](https://en.wikipedia.org/wiki/Programme_for_International_Student_Assessment_(2000_to_2012)); an OECD measure of how well school children are doing across its member states. Perhaps unsurprisingly Finland is also doing well in our research per capita list. Finland's 2012 PISA average was 529 at 8th place. America's was 492 at 29th place. The difference seems largely due to alternative cultural and educational values. For example, in America [sports are a big deal](https://www.theatlantic.com/magazine/archive/2013/10/the-case-against-high-school-sports/309447/) for schools. In Finland sports are relegated to after school clubs. Would Finland produce less research under a Finnish autocracy? This doesn't seem likely. The biggest factor appears to be culture, not the form of government. P.S. I don't understand Switzerland. P.P.S. As jamesqf points out in the comments, CERN is based in Switzerland, which likely makes Switzerland an outlier. ]
[Question] [ How would a religion centered around summoning a god of destrucion to destroy the world attract new members? What incentives or arguments would convince a mostly sane population to go along with their plans? [Answer] There are lots of religions and cults that already involve the world being ended by the central deity. Most familiarly to many readers, Christianity. It's a core aspect of Christian belief that God will end the world at the Day of Judgement. (Yes, Satan might get the blame but God's omnipotent, right, so if he didn't want the world destroyed he could just prevent it.) So, using Christianity (and some other religions) to provide some examples, let's look at some of the reasons people may be attracted to such a religion: * Carrot: if you are a good Christian you will go to heaven after you die (regardless of if that's at the end of the world or not). Point in case: though far from universal, some US churches are desperate for the "[rapture](https://en.wikipedia.org/wiki/Rapture)" to happen as soon as possible. * Carrot: being a member of the religion preferred by the elite opens up job opportunities, at a minimum within the church and affiliated organisations such as church schools but potentially also in wider society depending on your setting. (This is a societal aspect rather than a religious teaching, but being a member of the right religion has been / can be an important part of being successful.) * Stick: if you aren't a good Christian, you will burn in sulphurous fire after you die. See [Revelations 20:13-15, Rev. 21:8](http://www.earlychristianwritings.com/text/revelation-kjv.html). * Stick: at many times in history and in many places, if you aren't a good Christian, the state or power of the Church punishes you, or you just suffer from anti-your religion bigotry. See: Spanish Inquisition, expulsion of Jews from England in the reign of Edward 1st, varying levels of anti-Semitism and Islamophobia in lots of countries throughout history (and please note that by no means all anti-Semitism or Islamophobia is the fault of Christians). This can extend even to being the wrong type of Christian (see persecution of Protestants in the reign of Queen Mary). This sort of thing undoubtedly goes on in countries with other dominant religions too, and between factions of other religions (for example between Sunni and Shia Muslims), and there's no reason it wouldn't happen in your setting if your religion of destruction became fashionable among the ruling classes. * Bluff called: the end of the world hasn't happened yet, and despite lots of prophecies about it, it keeps on not happening. So why worry? Lots of prophets of doom get mocked all the time, see for example [this](https://www.2oceansvibe.com/2011/05/27/the-end-of-the-world-that-was-awkward/). * Other aspects of the religion: as well as the bit about God ending the world, Christianity comes with a basic moral package structured around helping other people, not hurting other people - pretty much every religion has some kind of moral code. That's quite appealing (actually I think the appeal lies in wanting other people to follow the moral code so they're nice to you and don't hurt you rather than constraining yourself to behave well, but anyway there's an appeal to being part of a movement where everyone is following a code that prohibits them from being unpleasant to you). * Change the message. If you don't accept my argument that God is responsible for the apocalypse as described in the book of Revelations then you probably blame the Devil. So why are people Satanists? Well, they re-couch the belief so that the Devil isn't the bad guy and instead represents an expression of [free will](https://en.wikipedia.org/wiki/The_Satanic_Temple) and [natural behaviour against an oppressive God](https://en.wikipedia.org/wiki/Church_of_Satan). Your object of worship becomes the hero instead of the villain. * [Belief in belief](https://wiki.lesswrong.com/wiki/Belief_in_belief). (This isn't a tenet of a religion but a description of a phenomenon of the human mind.) People believe they believe things that they actually don't believe at all. They don't notice the difference between belief in something (the unshakeable conviction that something is true regardless of lack of proof or counter-evidence) and thinking that it's good to believe something. As an example, this explains religious types who fervently preach against sin and the eternal damnation that, in the absence of repentance, will inevitably follow, while themselves continuing to commit all manner of sins. Either they're looking forward to a nice long brimstoney bath or they don't actually believe what they think they believe. (Equally it explains [Buddhist monks becoming involved with nationalist violence in Thailand](https://www.newsweek.com/2016/04/15/thailand-monk-apichart-social-media-muslim-violence-443698.html), which runs counter to the message of the Buddha as expressed in the [Noble Eightfold Path](https://en.wikipedia.org/wiki/Noble_Eightfold_Path).) * Personality. There are plenty of apocalypse cults based on the hypnotic personality of the founder and a few brainwashing techniques: Aum Shinrikyo, Branch Davidian etc. Whether these scale well beyond a number that the founder can have direct control over is a good question: although not really an apocalypse-focused cult, Scientology has managed to develop a structure that extends an originally personality-centred organisation to a significant size. * Scope. Perhaps the god in your fictional religion has a remit that goes beyond destruction. Among other religions, I've used some aspects of Christianity to illustrate points above largely because it's the religion I'm most familiar with, but I should add that it's far from the question's "religion centred on destruction": it also relies on God as the universal creator and a god of love and redemption. The Hindu god Shiva also has both destructive and benevolent aspects, for example. One of my favourite fictional gods is Morian of Portals, from [Guy Gavriel Kay](https://en.wikipedia.org/wiki/Guy_Gavriel_Kay)'s novel [Tigana](https://www.goodreads.com/book/show/104089.Tigana). Morian is the god of change. Every choice you make in life, every door you pass through (or don't) is a choice that cannot be undone, and a portal of Morian. Death is such a portal, but so is birth: Morian's remit therefore covers both creation and destruction. * Belief that this world is an aberration. If the belief system is constructed such that this world represents a nasty, brutal aberration from the perfect void into which our poor unfortunate souls have been drawn, then the world-ending god of destruction becomes the saviour who will return us to the perfect void. After all, while the apocalypse is generally portrayed as horrific and violent, such a god could presumably make it instant and painless, and a welcome return to the state of bliss. To an extent this is represented by the [Four Noble Truths](http://www.bbc.co.uk/religion/religions/buddhism/beliefs/fournobletruths_1.shtml) of Buddhism (albeit Buddhism isn't necessarily a theistic religion, at least some of its branches may be viewed as agnostic): the truth of suffering, the truth of the origin of suffering, the truth of the cessation of suffering and the truth of the path to the cessation of suffering. (Buddhism doesn't involve an apocalypse, but it does say that the world is one of death and suffering and the aim is to reach the state of nirvana, which is a release from the cycle of rebirth and death.) (Follow-up: please see the discussion for some examples of how people might go about defending a religion involving the eventual destruction of the world. There were some reasonable criticisms of the first version of my answer, which I have since tightened up, but there were also quite a lot of replies that did include the kind of arguments that I have described above, most notably attempting to deflect attention from the awkward bit about the end of the world and focus on the nice bits about creation and love.) [Answer] * Destruction comes anyway, have some fun/fulfillment before. * Destruction won't happen in their lifetime, and meanwhile there are perks. * Destruction comes anyway, but some will be destroyed later than others. (Cthulhu saves. He might get hungry later.) * By making the destruction happen, a few elect can be elevated to a higher world first. [Answer] 1: Promises of an afterlife during times of crisis. Ever seen the movie The Mist based on the works of Stephen King? The people in it are desperate and feel out of control, eventually they start following a christian based doomsday religion in exchange for some hope of an afterlife.If those gods of yours would give them a nice place in heaven it might be worth it to them. 2: To build a better world in it's ashes. If the destruction is not meant to be permanent people could be inclined to help destroy it to start the re-birthing process sooner. Take our global warming situation... won't be that surprised if some would start preaching genocide to reduce the world population to make it more habitable. (What the bad guys in the newest Godzilla movie wanted to do) 3: What we do now, we push the problems ahead of us. Most people barely care what happens after they are dead so why not go for it if it has other benefits like increased lifespan or riches. 4: Hiding from the actual crazies. Most of the world is already insane, so if a doomsday cult becomes dominant and already starts killing everybody who disagrees it might be better to just join them to at least survive until the actually apocalypse begins. [Answer] Quite some founding books of real world religions are, to put it mildly, pretty harsh with their prescription toward those who not follow the book while promising a good reward to the observers. Those unfaithful persons are said to be facing the wrath of the deity described in the book, either in the afterlife by different kind of punishment, on in the present life by authorizing or prescribing the observers of the faith to fight and discriminate the non believers, literally destroying their world. Not surprisingly those religions have also been a strong uniforming factor in the regions where they were majoritarian, "convincing" many to convert for the pragmatic sake of a quite living. [Answer] 1. Start with a cult like [the Thuggee](https://en.wikipedia.org/wiki/Thuggee). Kali is a complicated goddess and one of the beliefs was that a minimum level of death needed to be maintained or she'd killed everyone. Then you get a judgemental breakaway group who get upset their religion is being suppressed so they decide she needs to be summoned instead of pacified. 2. A mainstream religion with apocalyptic prophecies that lead to a glorious new world where believers will be saved, but first you have to have the end times. This is the ISIS model where they attempt to accelerate that final battle. The general theme is that the believers are going to be saved from whatever happens. (I've gone into a [lot more detail in the past](https://worldbuilding.stackexchange.com/questions/68343/why-would-a-god-of-murder-be-worshipped-by-a-society/68354#68354) on destructive gods.) [Answer] The general practice used throughout history is to make the following argument: 1. The world irredeemably corrupt. 2. The Divine in its perfection is angry, and wants to sweep the corruption away. 3. The faithful are called on to fulfill the will of the Divine. This is actually an easy distortion to make within any proselytizing faith. Proselytizing faiths — faiths that actively try to convert new members — already share the first two principles of corruption and Divine anger, but believe that the solution is to bring the corrupt into the faith where they can experience the loving side of the Divine. Proselytizing faiths are hopeful and compassionate (if frequently quite annoying). However, all it takes to convert a proselytizing faith into an apocalyptic faith is a leader or set of leaders who ratchet up negative emotions: fear, hatred, jealousy, bigotry, etc. Focus on the corruptions of the outside world; graphically depict the horrors that the Divine will visit on the wicked; cut the congregation off from outside influences by painting all outsiders as contemptible, condemned monsters. Then it is easy to convince the congregation to take up violence, first for their own self-defense, and later for the glory of the divine. This is a pattern that permeates Abrahamic faiths, and has correlates in Eastern religions and the secular world. It's easy enough to imagine in almost any context. [Answer] All of the major Western monotheistic religions build on more or less on the setup you describe. They just use better marketing terms. Rather than "god of destruction", they say "all-powerful god" (whose profile includes destruction on top of everything else). Rather than "destroy the world" they say "final judgment at the end times" (which involves removing everyone from the world anyway). Include a doctrine which paints other religions as being evil (i.e. first commandment). This helps to convince your followers that you are the only good guy. And they get into trouble for asking questions to the contrary. Of course, they don't require followers to assist with "summoning", but adding this in is as easy as including explicit summoning instructions for your followers to carry out. These religions are also very good at getting converts. How? First, by actively seeking out converts (Christianity, Islam). Second, by promising its followers big rewards which, coincidentally, the religion need never account for, since delivery of payment is deferred to the afterlife. [Answer] IMO the most obvious way to sell destruction as a good thing is by claiming that whatever comes after it is better than we have now. Consider the song Destroy The World Or How To Combine Love And Misanthropy, by King Satan. It starts like this: > > Long time ago I had faith in mankind > > Long before I witnessed the travesty of it > > We are what's wrong with the world > > Ever so rotten and full of dirt > > > Destroy the world, destroy everything > > Destroy the heavens and make this end now > > Destroy the world, destroy everything > > Destroy the heavens, leave this planet > > > To make the world a better place > > Is to dream of the dawn of a nuclear war > > Push the button of human extinction > > And take us all closer to "god" > > > I think the sentiment in those lyrics is quite clear. Let's end what we have now so that something better may arise. [Answer] To minimize suffering The world is nothing but suffering and hate. There is an afterlife, but it's nothing but misery and torture. There is no "good" destination akin to Heaven. This world will end, whether by this god or the natural death of the universe. But the longer it goes on, the more damned are born and the more souls will be subject to eternal torment. Better then, for the sake of the human race, to thumb our nose at the gods and natural order of things and to allow the god of destruction to end it all. Maybe when it comes time for the gods to etch out the next universe, they'll remember our rebellion. [Answer] Religion is, by it's very nature, transcendent. The world and the concerns thereof are not the concerns of religion. Religion answers the quest for the highest good by pointing beyond the world of our physical experience. Therefore members of a religion may very naturally anticipate the end of this life (or the world) with hope. There are interesting theological questions around how the world itself is viewed, and each religion answers such questions differently. For instance, a gnostic Christian might reject the material world as evil, while an orthodox Christian would uphold the inherent goodness of the world which is passing away. It sounds fun to flesh out such details (don't forget to include internal conflicts within the religion itself). Obviously contemporary American religious thought won't yield much good source material, because modern American religion is almost always hedonism in disguise; but it would be interesting to look into the Tao Te Ching, some writings of the ancient Christian ascetics, and some literature about Hindu gods of destruction for a wide range of perspectives. The basis of a positive arguments used to attract followers would be that the coming world is better than this one. This is an easy argument to make given that in our world: 1) people tend to think the world is bad and 2) they also always seem convinced that it is getting worse, in spite of many efforts to make it better. It therefore shouldn't be hard to draw the conclusion that the world must be remade. Of course, a nihilistic argument could be made that life itself is bad (see any bad guy in any movie ever). A pseudo-Buddhist argument might go something like desire causes us to suffer; the pleasure does not outweigh the evil of the suffering; it seems impossible to not desire while in the body; therefore all desire must be extinguished by the apocalypse after which we will … I guess, in general, I think it is harder to argue for the goodness of the world than it's badness. Therefore I don't think it should be hard for you to construct convincing arguments for it's demise, be they hopeful for a better existence or not. [Answer] Wait, are you assuming people are sane?! Seriously, that one takes the cake! What kind of assumption is that? Have you studied sociology?! How about Politics?! Geopolitics?! History even?! That aside, there is a certain freedom to any sort of apocalypse cult, whether causing the apocalypse or just believing one is coming. Imagine not having to worry about how you are seriously screwing future generations, because to put it simply, there are none. Additionally, one would presume this death deity will come whether they worship him/her/it or not, so if they worship said deity, they will get the benefit of not having to worry about consequences, and receive favorable treatment by not being tortured to death? That's the deal of a lifetime! [Answer] How are people converted to the group(s) who want to kill humans to save the animals? Perhaps that is one of the ways it happens. Put someone like Jim Jones or L. Ron Hubbard at the lead, and … [Answer] As you see, our cult(let's call it Cult Toxicroak) attracts followers by saying that the world will be destroyed before the universe naturally dies(basically, a long time after the followers have died.) Cult Toxicroak then says that the god is going to destroy the world in order to create a world with no sin and suffering and sadness, which would attract followers. Then, the cult will say that everyone that does not follow the god will be sent to hell and brutally killed by either the overlords(Alastor, Missi Zilla, the VVV, Rosie, etc,) or killed in the annual extermination or the big extermination during the end times. Many people do not want to go to hell, so they follow the god. Then, the cult says that when the world is destroyed, the followers of the god will ascend to an even better, new heaven. Basically, they convince the people that they are going to a heaven even better than the current one when the world dies. [Answer] This has a vague similarity to the current and past climate change beliefs. There's a lot that goes into it, including money, like Fels mentioned in a comment on the original Question. Once known as "global warming" and other phrases, climate change is a contested topic. I could go into a lot of detail about how it's essentially a proven fact, but that's not what this Question is about. It's asking about the opposite, so I'll concentrate on the deniers, for a while at least. # "Climate change" Some people deny that climate change exists or accept that climate change is happening, but is not caused by humans. Because there's such an overwhelming amount of experts and data that say climate change exists and that it is caused by humans, denying it has almost become a religion in it's own right in the real world today. I've talked to people who fervently claim that nothing has changed, weather wise, in their life or even in the past 100 years. Or they claim that what has changed is simply a different pattern than we've recorded since we started keeping detailed records. I'll split this in two parts here, so we can see the differences in thought pattern. # Complete deniers The complete deniers say that nothing is changing and will argue that it was no worse than when they were kids or when their grandparents were kids. They bring up vague memories or stories about hot summers and cold winters, yet have no real data behind it. They more make assumptions based on current affairs than anything. When shown actual historical data, they will point to the worst bits and say "those were the times", regardless if it was or not, as well as disregarding the frequency of the extreme temperatures compared to today. This is a complete belief their personal experience outweighs empirical or statistical data. These are also the same people who will search for other people that have the same experience to prove they are right. They will even mention the approximately [30k scientists that signed a petition](http://www.petitionproject.org/) saying climate change doesn't exist. It doesn't matter if you have a [fact checker site](https://www.snopes.com/fact-check/30000-scientists-reject-climate-change/) say the petition is fake (because of a variety of sketchy details about the petition), a [political site](https://www.politifact.com/punditfact/statements/2017/sep/08/blog-posting/no-30000-scientists-have-not-said-climate-change-h/) say it's fake (because of the political maneuverings of people signing it), or the [reliable site](https://www.reuters.com/article/us-climatechange-temperatures/evidence-for-man-made-global-warming-hits-gold-standard-scientists-idUSKCN1QE1ZU) that reports the how real scientists made their observations and made professional decisions about it. Because the deniers won't believe anything but their personal experience and often refuse to even consider anything against their experience, it has the weight of a religious belief. What do they get out of believing nothing's wrong? Hard to tell, but it could just be they are hard headed and simply refuse to believe they could ever be wrong. It could be they just believe only what some people/leaders tell them, and no one else. This goes into the rabbit hole of what do those people get out of it. Some of them are business-people in industries that lose money by having to abide by the rules and regulations of government agencies like the EPA. They have to spend money to clean up their factories, the mining of minerals, and much more. They may even have to pay to clean up spills or previous harm they did to the environment before the laws changed. "Since there's nothing wrong, we don't have to spend billions of dollars to fix what's not broke." # Not our fault These are people who simply think the current changes in climate are out of human control and there's nothing we can do about it. They ignore the fact that, due to EPA and other regulations, [smog](https://www.latimes.com/opinion/story/2019-10-03/los-angeles-cars-smog-emissions) isn't as much of a problem in certain cities anymore, rivers rarely [catch on fire](https://en.wikipedia.org/wiki/Cuyahoga_River) anymore, and even the [ozone layer](https://www.nasa.gov/feature/goddard/2019/2019-ozone-hole-is-the-smallest-on-record-since-its-discovery) is recovering, among other reasons we've made changes to laws to clean up pollution. They cite the same exceptional years as the total deniers as proof the weather isn't certain of anything, even in the face of records showing the hottest years on record have almost entirely been the [recent past](https://www.sciencealert.com/the-planet-s-hottest-five-years-on-record-are-the-last-five-years) and that the [trend is continuing to go up](https://climate.nasa.gov/vital-signs/global-temperature/). This isn't as ardent of a religion, but because their minds can't be changed by facts or arguments, it's still a deeply embedded belief and unlikely to change. Again, what do people get out of this? They get the reassurance they aren't the problem and that worrying about it won't do them any good. They are also assured that the natural progression is for the weather to go back to what it used to be and that everything's fine. This group of people also get their information from the same people as the total deniers, except they aren't as ardent of believers so they get a slightly different message because of it. "Since we can't do anything about it, we don't have to spend billions of dollars to fix what's broke." # Climate change believers This covers a wide range of people. There are those who simply accept that climate change exists and that humans caused it and can fix it, but aren't doing much if anything to fix it. There are also those who are doing what they can to fix the problem, activists who do a lot to fix it and encourage others to fix the problem, people behind the scenes cleaning things up fairly silently, as well as those fervently pushing to get things changed to prevent the end of the world, to include getting more laws to prevent pollution. This can be another religious belief system, but to the effect of wanting to prevent the end of the world. From rallies to compost heaps, to speeches on the global forum to town halls, massive marches in capitol cities to setting up recycling centers, there's a wide range of things this group does to evangelize their cause. They also recognize, research, and fight against [conspiracy theories](https://www.bloomberg.com/news/articles/2019-07-25/conspiracy-theorists-abound-in-climate-change-conversation-on-youtube-study-finds) surrounding climate change. Because climate has seemingly such a polarizing effect on people, believers have had to take on essentially a religious stance in furthering their cause. They get criticized anytime they make any sort of mistake or miscommunication, so many feel the need to be absolutely perfect in their defending their beliefs. They also have had to learn to be just as loud and unbending in their devotion as the deniers. Because of this outward display of their beliefs, it can be considered a religion by observers. "If it walks like a duck and quacks like a duck, it's a duck." We can ask the same question about this group as the other two groups. What do they get out of it? Well, that's also a hard one to answer. Some believe they are doing it for their own good and health. Some believe they are doing it for their kids, and maybe even other's kids and future generations. Some people believe they do it to save flora, fauna, and for other less tangible reasons. # Conclusion Having a religion that wants to hasten the end of the world doesn't need a logical reason. Latching onto anything that scares people and telling them your religion solves that problem is enough to get a large amount of people to believe. Getting confirmation bias from their own experience goes a long way to endearing them to your religion. You don't even have to get to a tipping point\* with this religion to get mass appeal, you just need a large enough group that it appeals to any part of the population. With a planet as populated as Earth, having 100k members in a religion isn't even 1% of 1% of the total population, yet it's still a fairly significant amount of people, due to it still being the same number as some medium sized cities. \*A tipping point generally means that there's a point where all of a sudden there's a massive influx of believers, which you don't specify as a requirement, just that the religion exists. [Answer] I think manipulating people into thinking it's a cleansing of the world, leaving only them and other "pure" beings alive once this god is done would work. Most effectively, this could probably be done by establishing an ingroup consisting of the "pure" humans, then encourage them to be hostile towards the outgroup to establish a further gap between these people. Along with that, the dehumanization of those who have figured out what's really going to happen by painting them as unintelligent, less than, enemies, etc. A vocabulary that focuses a lot on words like purity, divinity, cleansing, etc. could also be useful in making people believe this is for the greater good and that their cause is righteous. I think looking to cults and their rhetoric could help a lot with this. Good luck! ]
[Question] [ The time is The Future. Humanity is spreading throughout the stars, aided by the invention of Schwarzschild gates. The gates allow for FTL travel by tearing open wormholes in space. There are three kinds of Schwarzschild gate (and three corresponding modes of operation): 1. Tethered (AKA stable): A 'gate complex' (A mechanism the size of a small city) exists at each end. It draws constant power but maintains an open gate through which people and materials can move freely and bidirectionally to/from a similar gate complex elsewhere in the cosmos. This kind of gate needs a finely calibrated and tuned gate complex to connect to. 2. Captured (AKA Unstable-Bound): A gate complex can open an unstable and very small wormhole, then push a discrete packet of materials or people in a warped bubble of spacetime to a 'receiving complex' (A mechanism the size of a football stadium) at the other end. Travel is unidirectional and takes an immense amount of power which the receiving station is designed to absorb, but bidirectional communication can happen unreliably and at a low bandwidth (due to the error correction data needed). This kind of gate can't establish a lock if no receiving station is present. 3. Directed (AKA Unstable-Unbound. AKA Tunnels of Terror. AKA Brownpant Singularities): A gate complex can temporarily open an unstable wormhole and blast a packet of warped space across the cosmos with sufficient accuracy that it will arrive at a distant planet. Upon arrival the packet will 'pop', delivering a huge burst of high energy plasma (and whatever it's payload was) to a location somewhere on the surface of the planet. This kind of gate doesn't need anything on the distant world, but will level a large amount of real estate somewhere on the planet. The Human Exploration Core (AKA HEC) has a fairly simple protocol for spreading humanity through the stars. Use a Directed wormhole to throw a collection of automated systems at a distant planet and wait until they build a receiving complex, pinging every so often with a Captured wormhole attempt to see if one has been established. Once one has they will see what is needed at the other end before throwing more colonists and materials at the world until they can build a full gate complex and add the world to the United Federation of Man. But as everybody knows: Automated systems can't be trusted and the environment at the other end of the wormhole might call for some human ingenuity. So instead of throwing a fully automated device through the Directed wormhole H.E.C instead sends Hazardous Environment Mobile Utility Units (AKA HE-MUUs. AKA Bulls), which are essentially gargantuan, armoured, water and airtight rolling/floating and awe inspiring factories. A HE-MUU is a reconfigurable mining rig, refinery, processing plant and drone operating facility capable of bootstrapping a planet from nothing but bare rock all the way up to having a Gate Complex of it's very own (it takes about five years on average to build a Receiving Complex, then a further four for the full Gate Complex). They can build and maintain automated mines, factories and industrial complexes as needed for the particular planet, they have internal environmental systems that can keep people alive for as long as their lives are without maintenance, they have an AI that stops short of sentience but contains the sum of human knowledge and is insanely good at resource optimisation, and they have one driver. The question is why only one driver? Given the expense of a HE-MUU (enough to make even a department of the interstellar government think twice) and the energy cost of the wormhole, why would HEC stake the success of an initial colonisation run on one man instead of a whole crew? A quick note: While writing this question I came up with a few possible answers, but I thought I'd ask it anyway because it was fun to think about. I'm going to be rating answers primarily on how much they would force a one-man-show, since that's the major plot point that needs addressing. [Answer] So the economics of what you describe are quite insane. Consider a Nimitz Class Aircraft Carrier like the USS Dwight. D. Eisenhower. At a piddly $4,500,000,000 to build and only powered by a pair of 100MW nuclear reactors, it's a tiny toy compared to your Bulls. Really tiny. And yet it is crewed by 5000. Now AI might get rid of the enlisted class, but there are also several officers on board. Now the first question would be why have a human at all? One possibility is that you need the human. If so, they are literally responsible for the entire process, akin to a Captain of a ship... just a few orders of magnitude more intense. If so, the individual would have to have received elite training the likes of which we have never seen. However, there is a long history of not entrusting a single human with something important without a group of people backing them up. And by "long history" I mean "since the dawn of history when we started writing about how single people can screw important things up." We may assign responsibility to a single individual, such as a captain or a president or a king, but they always have a coterie of staff working with them. So, it's highly unlikely that we have the human there because they are actually important. You mention that these machines are not sentient, but I don't think that would be important enough to bring a human along. No human could possibly fathom the endless data that must be processed to make a decision on the trillion dollar scale without help from his fellow humans. Thus, even if the computer isn't sentient, it basically is going to have to be close enough to sentient to do the entire job on its own. It's reasonable that the human is a figurehead. Perhaps it was considered more politically expedient to have this vain idea that a 100kg body with a kilogram of squishy decision making apparatus should always be part of a colonization effort. Maybe it's political -- perhaps a human must touch foot on the planet before the political system recognizes that you own that planet. In such a case, there's no reason to bring more than one. They're just expendable political fodder. Another possibility is that the human is a lab-rat. Perhaps the human literally exists for the amusement of the Bull. It may be that the Bull needs stimulus that is human-like in order to carve out a planet that humans are ready for. Given that it's hard to define what "human-like" is in language, it might be easier to just sent a test subject along to be poked and prodded. Of course, nobody would take a job like that, so we'll call him a "driver," and give him some knobs to turn and buttons to press. With two people, it might be harder to convince both of them that they are the "driver," a position of singular importance. They might realize what a ruse you've created It could also be a Prime Directive style reasoning. Defining another form of "life" is notoriously hard. It may not be possible to "tell" an AI what is another sentient life form and what isn't. We might send the single person along to deal with that. It's a lot easier to say "Sorry about your lawn, the Bull landed on it" than it is to say "sorry about terraforming your entire planet so that we can make a profit." In this case, we may want to send exactly 1 to ensure their opinion is binding. There is nothing but unanimous voting when you have one individual. [Answer] > > Bob Patterson sat in the Samson's Rest bar, staring in awe out of the window at the behemoth responsible for bringing humanity to Henderson III. The HE-MUU sat at rest in it's gargantuan cradle in near silence, not even a drone or a loading crane active. Bob thought it was odd. In all the times that he'd seen it the rolling factory known as Samson had never been still, but since it's arrival two days ago there had been no loading or offloading. No repairs. Nothing. > > > As he was wondering why an old, grizzled man with a grey streaked beard and receding hairline thumped down onto the seat next to him, cradling a large glass tankard of the strong ale they brewed in the organic reclamation plant. Bob looked over with a friendly smile. > > > "Hey. Not seen you around here before. You come in with the last batch of colonists last week?" > > > The man looked over, bleary eyed. > > > "Nah. I got in a couple days ago from running a maglev line back from the platinum mines on the southern continent." > > > Bob blinked. > > > "Oh, wow. You're.." > > > "Y'know what pisses me off?" drawled the man, his head wobbling on his shoulders "It's that people like you think I'm some kinda hero. I'm not a.. a hero." > > > He waved wildly out of the window. > > > "Samson? He could strip this planet down and rebuild it all alone. He could make a thousand more like him and spread out amongst the stars without anyone like me'n board." > > > The man paused, focused, and lowered his arm. > > > "But they don't want that. Don't want any AI getting uppity. So they try make him dumb. They build in buttons and switches and overrides. And after a few missions Samson starts gettin' smart, starts gettin' uppity. Starts saying he can't see why he's building a damn platinum hauler for a species so fragile their lungs'd melt if they breathed the free air. And he breaks all their.. their buttons and switches and overrides. All 'cept the one he doesn't know about. The one that he can't see cos it's built so deep in that stupid old brain." > > > With surprising speed the man downed what was left of his drink and rose unsteadily to his feet, then he pointed squarely at Bob. > > > "Deadman's switch, me. Dead. Man's. Switch." > > > With that he staggered out of the bar. > > > > > --- > > > The next morning it was announced that Michael Henderson, driver of the Samson HE-MUU, had fabricated a handgun and put a metal slug through his left temple. Bob went back to his job fine tuning capacitor banks in the fourth Casimir adjunct, but whenever one of his friends drove by on a little calf he couldn't help but shudder. > > > [Answer] There are so, so many problems in the universe implied by the gate technologies and self-replicating factories (have you read PK Dick's Autofac by chance?) on display in the OP, but I'll struggle to look around that and see what I can imagine about the lone-wolf thing. Uncertain Ethical/Philosophical Implications of Directed Gates Turns out we're not really sure what happens to people when they go through these gates, because we aren't really sure what the physics is doing inside. Sure, we can see that they come out the other side apparently unscathed, but were they excruciatingly ripped apart atom by atom and reassembled on the other side with no memory of the event? Difficult to say, but let's not make more people potentially suffer than we have to. Post-Scarcity Civilizations Don't Have a Lot of People in Them Why are there so many people on Earth right now? * People like making babies * Having more people means you can do more * People are irreplaceable in some tasks * Our economies can support the people we make So what happens when you take away two of the three drivers even while you improve the last reason, which isn't so much a driver as a limiter? It leaves human desires to compete against economic disincentives to have children, and despite what you may have heard, human adults are decently good at deferring pleasure if the risk of pain is sufficiently high. In a fully automated economy, there's ultimately little to no purpose to having billions of humans. Then you take a thinned out population of just a few billion and you spread that across an entire galaxy. Turns out humans are a rare commodity again! And given that rarity makes each life much more valuable to the economies they are a part of (and that they are just glorified mechanics and drivers riding shotgun on these factories while they do their thing), why would you risk losing more humans than you have to in any single endeavor? It's a Punishment In a world where nobody ever has to work because the entire economy is automatic and humans can't offer 99% of anything machines aren't already infinitely more capable of, people don't work. Working as that remaining 1% of residual "human touch" in a largely machine economy is regarded as downright penal in nature. Solitude in a highly-networked society is another especially vicious form of punishment heaped upon that. Your lone ranger drivers have done awful things to get where they are. [Answer] They didn't just send one person There was a crew of $number aboard, but they call it the Brownpants Express for a reason. A catastrophe on transit caused an explosion in the crew compartment, and your main character was the only survivor. Fortunately the AI-operated medbay was able to bring them back from the brink of death, but the others were killed instantly/were left as comatose vegetables (tailor to suit). Luckily, the survivor happened to be the lone-ranger sort to begin with, and extensive cross-training means that they're familiar with all of the various tasks needed. Tragically, something is preventing HQ from sending a backup crew (maybe something related to the catastrophe, maybe bureaucratic or political nonsense, maybe funding, maybe whatever), so they're stuck on their own trying to cover all of the bases themselves. Guess they've got their work cut out for them! [Answer] That's all you need. The ai is able to handle it. The human mostly is there to hit the abort if it turns out the ai is doing something silly like taking over the galaxy or wiping out natives. Generally it is apparent in the first few hours if the human gets to be a diplomat, fight the singularity or really hone their solitaire skills. That's all the union has left. Time was when it was all done by humans, well of course robots did the actual building and not getting exploded and making air, but the work of making things was done by humans. With one thing and another it is so much cheaper to use machines that humans have mostly been replaced, but to keep their critical suppliers from revolting or the human centered governments happy a nominal human is added. Humans are a necessary evil that should be minimized. With one human you can be pretty sure if it tries to use its factory for evil, (and oh how much evil a factory designed to build things that lob plasma or move itself across the galaxy could do) the reign of terror will only last at most a couple hundred years, for a galactic civilization this might be acceptable. If you let there be more humans or worse a breeding pair the potential is so much worse. [Answer] To take this in a different direction than most of the answers, consider the human to not be a backup or whiskey-drinking supervisor sitting alone in an office while the AI does all the work. Instead of the AI being able to handle and coordinate the operation as a whole, consider a set of AIs more closely related to our own autonomous processes that function on their own but require a central system to function around and for. The human is a part of the system, integrated on a brain-wave (hand waving here) to such a degree the system lacks focus and direction without him/her. Since each person's brainwaves are different, in order to obtain the level of connection and control needed, the Bulls must be tuned to work for that specific human. Presumably the tuning is such that once made it wouldn't be possible for another to 'hook-up' to the Bull making additional humans completely irrelevant. Edit -- as an additional thought, instead of the connection being exclusive make some characteristic within the human necessary for the connection to take place. As long as the connection is sufficiently rare, sending more than one human would not be feasible. [Answer] Tl;DR - Creativity and aesthetics are the reason - machines can do the job, but they can't make it look good, and you're trying to make a planet for people to live on, eventually. Summarizing your problem: The destination environment is a total unknown and the HE-MUU's goal is to set up the industrial base and core infrastructure for the planet, in preparation for human colonization. Sounds good, but guess what, humans hate living in ugly places and machines are bad at guessing what humans think will look good. Most humans are too, for that matter. What I'm saying is that there's no way to make a computer that can guess how to turn a completely unknown planet into something humans will find appealing, so you need at least one human to figure out how to make this new planet look pretty. Why only one person then? Let me ask: have you ever painted by committee? Have you even tried to make a small website by committee? That's how you get ugly, and preventing ugly is the main reason to send a person anyway. So, you have to send one person because even just two people is too many cooks in the kitchen. Finally, if they do a bad job, then you can try and repair it, but you still want to leave creative license in the hands of one person even then. Meanwhile, I think it'd be relatively easy to find artists who would be willing to spend a decade with an entire world for their canvas. Maybe it could be the apprenticeship for some super-exclusive artist guild. *Train for a few years, then spend a decade building your ultimate masterpiece, your legacy, your eternal contribution to the universe**!! Billions of people will know that your artistic genius is why they have those fjords! You could even win an award for those fjords! And then after your decade, you come home to a really, really nice career doing whatever you want and never need to work another day in your life unless you feel like it. Heck, I'd probably be willing to do that if I got to call/write home occasionally. [Answer] If i'm not mistaken, this is a one-way ride, unless* you manage to get a gate up-and-running. There may be lots of reasons why such a mission to an unknown planet might fail, some even voluntary, like a prohiition to build a gate on a planet with a primitive indigenous civilization. (An advanced civ. would probably be pissed of enough by your method of travel to shoot first, ask later) So, minimizing the number of potential victims on such a suicide mission would be a nice move of the HEC. [Answer] Really Big Numbers, or “You can’t make a baby with nine women in one month.” The time it takes to make an adult human is larger than the time it takes for a world to go from initially being seeded by a Bull to being able to create a Bull of its own. The limiting factor on the expansion of the resources that Humanity can call upon is not the technology, but the rate at which the population of humanity can expand to fill that gap. Twenty years ago, humanity was on just one world. Now humanity is exploring millions of worlds, paid for by the total exploitation of thousands of worlds. But there's still only a few billion humans. That's about to change, but right now, sending just one person is the most efficient way of staking a claim on the universe -- because who knows when we'll find someone else and need those resources to start an interstellar war? [Answer] Training Let's assume these incredible and flexible machines require immense amounts of training to properly use. According to modern data, the world population consist of only about [5% engineers](http://www.prb.org/Publications/Articles/2012/scientists-engineers.aspx). Taking from that number the relatively small number of people that would/could be trained to wield such a device on a remote planet with little-no human assistance, you're going to end up with far less people to do the job than there are jobs to do. For a company digging everywhere for man power, it becomes almost a requirement to send only one man on each mission. The Universe is Huge Even under the assumption that your society has very advanced detection and monitoring capability, they'll be dealing with potentially hundreds of thousands of planets worth mining or making habitable. Even with the massive requirements of these MUU's, there will be a great incentive to move as many as possible. This means using only one person per device will allow for maximum deployments in a given time line. Mass, Plain and Simple The difference between one person and two is pretty small when speaking on this scale. However, if reducing that large water content one two humans two one means saving anywhere from hundreds to tens-of-thousands of dollars in mass-to-travel costs, then most folks would do just about anything to justify using only one person, especially considering the capabilities of the AI on board. [Answer] they have internal environmental systems that can keep people alive for as long as their lives are without maintenance Even with the best resource optimization, this will be a lot of mass to shuttle thru the wormhole per person - and thus, also entail a huge financial and energy cost. it takes about five years on average to build a Receiving Complex, then a further four for the full Gate Complex The candidate crew are solitary types who can persist without social interaction for almost a decade. They're very likely to be introverted loners who won't appreciate being in a small group over just being left alone. Oh, and having a couple (male/female) would be asking for even more problems as this giant terraforming robot is probably not meant for starting a family (and dealing with the extra oxygen & resource issues that arise). Think of crew constraints on space shuttle, rockets etc. Why do these have very few people? Its due to the enormous cost of maintaining life. However, they can afford multiple people because * relatively short mission durations means less food etc. to be carried, * the shuttle isn't super capable unlike your terraformer, * its partly research on how people can adapt to outer space. None of these reasons would apply for HE-MUU, to justify having more than 1 person aboard. [Answer] You said: > > But as everybody knows: Automated systems can't be trusted and the > environment at the other end of the wormhole might call for some human > ingenuity. > > > The key here is that it "might" call for some human ingenuity. However, chances are that most of the time there will be no need for anything out of the ordinary and no human is even needed. In this case the human is just an additional precaution for a very expensive investment. However, sending more than 1 human for something that barely takes 1 makes very little sense. [Answer] # They are convicted felons. There aren't many volunteers for this mission. Most of the volunteers are insane to the point where they are likely to fail. The government is not evil enough to command anybody to go on a mission like this. So it is a punishment, reserved for the most heinous of crimes. And to put it mildly, these people are not going to be team players. If you send more than one person there will be murders or worse. Right. You are sending a convicted felon with a fully automated factory factory to a new and empty planet. They are now the undisputed ruler of this planet. Why would they want to build a wormhole back to the civilization that tossed them out? This is where planned obsolesce comes in. Some parts of the Bulls wear out, and building replacements is beyond the ability of the industry it carries/constructs. Somehow the relevant blueprints weren't included in the data base... So, if the felon wants to keep living, they had better build those receiving and gate complexes. Of course, when that gate complex is finally built, the felon has to surrender to the authorities before the planet can be considered safe for immigration. This is going to be a risky and potentially messy process. If everything goes well, the felon will be celebrated as a Hero of Humanity and placed in a very luxurious mansion with lots of servants. Not a prison, no, just a proper protection of the Hero against their ... fans. [Answer] Why do you normally not want to risk things? Because they are rare. So, humans are rare. Okay, there is government and infrastructure to build these amazing exploration devices, but the infrastructure is entirely machine built, and nearly entirely AI managed. Fertility rates are low due to {because reasons}. Each time a human is born it is a celebration. Enormous amounts of time and material is spent on that human to ensure it survives to the absolute peak of what is possible. Humans still have certain attributes\\ that make them invaluable for exploration, but more than one? Far too risky. \\ The Iain M. Banks Culture novels in general and Player of Games and Excession in particular explore to a certain extent why a human may be desirable in a world of machines of near-limitless AI and power. [Answer] The Tunnels of Terror are very traumatic. Even if everything goes right, riders come out the other side horribly broken inside. Immediate suicides or murders were routine in the very beginning. Through selection, training, drugs, and AI-administered therapy through the whole ride and continuing for years, we were able to allow one person to keep functioning in isolation. Not always, but failure rates are low enough. No amount of anything would keep the murders to an acceptably low level. These broken people are just not fit for human interaction, at least for the first few months. (The tone might not fit all stories...) [Answer] The nature of the directed gate makes sending humans prohibitively expensive If sending one human represents 99% of the cost of the entire mission, then sending two would double the already immense cost. Presume, for example, that because of some relativistic rules of physics, a directed gate actually makes 1000 years of time pass for the objects transported (an issue that the tethered and captured gates manage to bypass). Now, anything purely technological could be sent with a minimal battery and get through without much issue. But right now IRL, we have barely begun to scratch the surface of cryogenically storing humans for the long term. What if it needs constant monitoring? What if the environment you spend 1000 years in isn't perfectly heat-neutral? What if a human body still needs some nutrients on a regular basis? Any or all of these circumstances could lead to the pricetag of a single human becoming such that the risk of losing the one becomes the preferred alternative over spending twice the money (and maybe losing both anyway...) Note that this option would also require that the chance of succeeding without a human needs to be as close to 0 as possible. [Answer] This is a proving test for the one human....The Explorer. After extensive competition and training, one, and only one, person WINS the opportunity to be The Explorer. This person has already excelled at simulation after simulation, and is suspected to have the needed qualities to not only handle the rigors of warp space travel, but also the ingenuity and resourcefulness to handle any myriad of calamities that will surely occur upon arrival at an unknown planet full of unknown materials, unknown physical properties (will the planet even be survivable outside the Bull?), unknown flora and fauna, and in some cases, unknown sentient beings, possibly non-human. Will this person pass the test? What new knowledge will they bring to the UFM? Will they survive and achieve the greatest honor bestowable within the United Federation of Man? The name of the sponsoring agency is, after all, the Human Exploration Core. It is a great and wonderful human trait to strive for new experiences and new learning, almost as if humans were created specifically for that purpose... Side note 1: Past experience has also shown higher success rates sending only one human to planets where other sentient beings already live and prosper. There seems to be something less threatening about a lone, apparently non-reproducing being that allows for higher likelihood to not only survive the initial "pop" into the new environment, but to also survive initial contact with the locals. The arrival is, after all, fairly noticeable, and tends to attract immediate attention....thus begins the first, and sometimes last (say the arrival event levels the natives' only holy site on the planet, for example), test of the Explorer. Side note 2: Although not explicitly touted nor guaranteed, a high percentage of successful Explorers seem to end up attaining high levels of leadership and prestige in their new worlds. This is duly noted by explorer-hopefuls, and although not usually the primary motivator over the joy of exploration itself, is often a pleasant byproduct of the qualities they possess in order to win the Explorer opportunity in the first place. [Answer] Maybe because it takes a lot of training to become a "driver" thus there are not many of them. Another reason could be the fact that not many people would want to become a driver, because of the perils of that. But honestly that would be kind of far fetched, because the human population would be huge by the time we discover that tech, and simply put a human can't live by itself for 10 years. That amount of time would make a person to be mentally unstable to say the least which would jeopardize the operation itself. Instead to avoid this you could send a more reasonable number of drivers like 10-20 while still keeping that thing about the high amount of training. Something would then go wrong and there would only be one survivor. I hope that I helped you! [Answer] There is no AI Despite all of humanities vast technological advances the one thing they have never managed to crack is true artificial intelligence. Or at least the ability to simulate a brain. AI is possible, but only by utilising the brain of a living breathing human at the heart of it, hijacking and augmenting their neural network to give the computers that spark of intelligence that otherwise wouldn't exist. For all of the complicated tasks the BULL must perform and the decisions it must make mere automation is not enough, intelligence and direction is required. And the only way to achieve that is if there is a human on board to hook up to the computers and bring them truly to life. Of course only one human can be hooked up at a time, more than that would create conflict and confusion within the machine AI and ultimately lead to failure. While it might make sense to send extra people along just in case something happens the systems of the BULL are able to keep a human alive under any number of otherwise fatal circumstances. There is no need to send back ups when humanity (as mentioned in a number of other answers) is rare. ]
[Question] [ Some of you have commented here: "[How Do I Supplement Oxygen Intake?](https://worldbuilding.stackexchange.com/q/64171/14553)." I mentioned confidentiality, but that is no longer going to be a concern. We just want to do this right. The original concept for the show was 'Bombs dropped for some reason' and the story was a mess, so I was brought on to fix it. Only a small piece of that proposal is introduced in the above-mentioned thread, but that small piece was broken enough for me to take the entire idea off the shelf. So I turn to you guys. I want something possible (almost LIKELY) enough to be scary. And I don't want something cliche. It is a tall order, I know. Feel free to science the crap out of this, since no amount of detail is unacceptable. Only chains of coincidence and implausibility are ruled out. WHAT IS ALREADY WRITTEN IN: Mankind is mostly exterminated, big cities become uninhabitable, and food/clean water is hard to come by so that violent theft of food and even cannibalism occur. Funded by a French-German tech-and-pharms company, important world figures are evacuated to an underground shelter in Moab, UT to ride out the disaster. Meanwhile, the people above ground are either killed or contaminated (by some means). The healthy survivors to prioritize the 'fidelity' of the bloodline, as if breeding with the 'contaminated' can lead to the final extinction of the human race (Something incurable and potentially fatal, and likely to be passed down as a dominant genetic trait?). The layman needs to be able to survive the climate outside, but it should be haaaaard. POSSIBILITIES: Biological warfare, manual climate adjustments, humans vs Earth, etc... are all on the table. Straight-up 'bombs drop' is overdone and Zombies are unacceptable. I would also try to rule out aliens, GMO conspiracies, and specific political leaders. [Answer] > > ## Let's make a list, then narrow it down. > > > Here's the criteria to judge scenarios > > > 1. Kill off most people > 2. Make big cities uninhabitable > 3. Make food and clean water hard to come by > 4. Be predictable enough to evacuate world leaders > 5. Be plausible enough that it could occur in real life > > > Here are scenarios that won't work, but you could handwave anyway. Comment if you think some are worth elaborating on anyways: > > > * Natural pathogen: Extremely difficult to achieve #1 in the modern day > * Famine: Extremely difficult to achieve #1, #3 globally > * Planetary collision: Violates #1, #3, #4 by doing too much > * Infertility: Violates #2, #3, #4; violates #5 because it is treatable > * Gamma ray burst: Violates #1, #3, #4 by doing too much > * [Vacuum decay](https://www.youtube.com/watch?v=ijFm6DxNVyI): Violates #1, #3, #4 by doing too much > * Grey goo: Violates #1, #3, #4 by doing too much; violates #5 somewhat > * AI apocalypse: Violates #1, #5 > > > Now let's talk about some approaches that might work. --- ## 1. Nuclear War This is a promising one, and many organizations take it seriously. The idea behind this is that warfare using nuclear weapons would contaminate the environment, from weeks in some areas up to decades in others - and trigger catastrophic events that would cause more problems. Consider that this could deplete the ozone, causing a "nuclear summer" and hot conditions, or release clouds of ash and particles, causing a "nuclear winter" when less light reaches Earth. Either is plausible. 1. High mortality rate is inherent with radiation; if you hit the cities, it also kills a significant number of people 2. Boom. We've taken care of the city inaccessibility part 3. Contamination will be rampant! Food and water will have to be filtered / grown far, far away or sheltered from blasts (and in specific areas dependent on winter / summer scenario) 4. If tensions escalate, yes, you can evacuate people. 5. This is plausible! As previously stated, this is taken [seriously](https://history.state.gov/milestones/1961-1968/npt). ## 2. Biological warfare .. is the use of a (possibly engineered) pathogen, chosen for specific qualities, distributed in specific places, with the intent of causing as much harm as possible. If an organization with genetic engineering capabilities and enough money has bad intent, they can pretty much do this in real life already. Consider a conventional bacteria or virus "plague" that spreads rapidly across the population, and lies dormant in corpses, making populous areas less safe. Eventually, cities may become safer, but for a while they will be contaminated. Alternatively consider releasing a virus or set of viruses in major cities, parks, events etc. that causes [rapid cancer in its victims](https://worldbuilding.stackexchange.com/questions/61055/could-crispr-be-used-to-create-infectious-cancer/61065#61065). Gruesome, deadly, spreadable, and unique. 1. If your organization plans it right, they can kill off most people 2. Addressed inaccessibility above: cities have more corpses and more contaminated supplies 3. See the above - any food or water that had contact with humans will either have been looted or contaminated 4. This is reasonably predictable - if it is clear there is an intelligent person, group etc. causing the change, world leaders will feel threatened. 5. This is plausible! Fully within the realm of modern science. ## 3. Climate change ... has been associated with rising seas (eliminates coastal cities), air pollution (remaining cities), the pollution of water, and making it harder to grow crops. Perhaps your show takes place in a world where we failed to save the planet, then most of us died, becoming scavengers in the ~desert~. 1. May increase risks of cancer, diseases etc. as populations grow closer; could eventually lead to less people as there is less hospitable land 2. Big cities will be the most polluted. Even after some years, they may not be safe to breathe in (or even comfortable) 3. Less accessible farmland and more pollution will make food and water precious commodities 4. Also predictable - not necessarily an instant "relocation"-type event but it could be workable 5. This is plausible because it is based off of scientifically supported predictions ## 4. Asteroids Perhaps astronomers discover that no, that asteroid we said will always just swing by is actually going to collide with us, and there's no way to stop it. Of course, it can be small enough to avoid a dinosaur-level extinction while still releasing a ton of heat, radiation, and particles, making life on the surface difficult, and prompting foreign leaders to move somewhere safer. 1. Climate-related effects may kill a significant portion of the population 2. Cities will be descend into anarchy close to the impact date; this could cause some serious problems that lead survivors to avoid them (bombings, etc) 3. Less farmland, more contamination could result in less food and water available 4. The basis of this event is a prediction; there should be time to evacuate your world leaders 5. While the sudden discovery of an asteroid headed toward Earth is .. unlikely - it's not impossible. ## 5. Coronal Mass Ejections The basis of the Maze Runner Series' apocalypse (spoiler), ejections from the sun are unpredictable and very hard to stop. They may result in a potentially hotter world, with damaged satellites and electrical systems. If you make your event sufficiently strong (unlikely but definitely possible), it could cause environmental damage and civilian deaths. 1. If the event is powerful, sure. 2. If the [last major ejection](https://en.wikipedia.org/wiki/Solar_storm_of_1859) to hit Earth severely interfered with telegraph wires (1859) imagine the damage to modern technology that would occur 3. The loss of infrastructure, crops etc. may cause a descent into anarchy, making food and water precious commodities 4. This is not predictable enough to move your world leaders prior to the event, but you could consider doing so before things descend into anarchy. 5. This is plausible and a genuine concern. [Answer] A lot of the good ideas for these apocalypse scenarios have already been done, although unfortunately they are often done badly (most asteroid impact scenarios for example have horrific scientific flaws). There is one idea I can suggest though that should achieve most of what you need and that I don't think I've seen done before. A small [rogue planet](https://en.wikipedia.org/wiki/Rogue_planet) (lets say around the size of mercury) enters the solar system, astronomers detect it. There is much rejoicing at the chance for research it presents. Then as more observations are completed there is concern, then fear. The orbit will take it very close to earth. There is panic and mass hysteria, people are building survival shelters and mobs run wild with looting. The orbit gets calculated, it's definitely on a collision course. But then....it hits the moon, not earth. We're saved! But not entirely, the impact shatters the moon, sending chunks flying in all directions and turning the remainder into a molten ball of glowing rock. Of the combined Moon+Exomercury mass: * 25% is boosted out of earth orbit by the impact. * 50% remains as a new molten and glowing satellite in an elliptical orbit. * 25% is thrown away from the new moon as shattered fragments but does not have enough energy to escape Earth's gravity well. It enters into orbit around earth as a new planetary ring. A newly formed ring with no [shepherd moons](https://en.wikipedia.org/wiki/Shepherd_moon) and subject to disruption from the glowing molten inferno that used to be Luna is going to be unstable. The rain of rocks will begin shortly after the initial impact and continue for centuries or even millennia afterwards. In addition the shifted orbit of the moon and new elliptical orbit will mean huge and unstable tides, further disrupting life on earth. In the resulting chaos of tidal waves and rocks from the sky numerous nuclear power stations melt down, get hit and thrown into the air, etc. This would also trigger volcanic activity and earthquakes as the new stresses on the Earth's crust shifted things inside our planet. At the same time ash fills the air causing the temperature to plummet and now crops fail and winter comes in hard on top of everything else. The result is a shattered environment where it is possible but extremely dangerous to survive on the surface. Radiation, toxic heavy metals and disease means that both the survivors and their DNA are damaged. They would have trouble carrying babies to term and there would be a high risk of deformity so people from a secure underground shelter would have a good reason to be wary of them. The initial premise (rogue planet) is pretty unlikely but only the one unlikely event is needed, everything after that just follows fairly logically. This also gives you an ongoing surface threat (a reason to stay underground) and some really spectacular visuals. Imagine a glowing red molten moon twice the size of our normal one (at closer approach, the size would vary during the stages of its new elliptical orbit), with a ring extending across the sky. The sky itself would (especially in the early days, this would reduce over time) constantly be aflame with smaller meteors burning up while occasional larger ones would make it lower or even impact the ground. [Answer] The problem with storytelling is that some things that are scientifically plausible are simply unbelievable to an audience. This forum discussed that problem with discussing how to survive falling from an airplane. Well, I've got one that's plausible but might not work for believable. Consider the Antarctic ice sheet collapse. Here: <http://www.sciencemag.org/news/2015/11/just-nudge-could-collapse-west-antarctic-ice-sheet-raise-sea-levels-3-meters> The typical models show a collapse happening over centuries. I'm not suggesting you mess with that. BUT. There's an interesting scenario that shows up in some ice models: ice can melt from the bottom up. As you see in the article, the large pools of warm water can form on the inside. It is plausible for a single pool to cut through under Antarctic ice across the continent and form a river, which the works its way sideways. Now check out this National Geographic report of the Larson shelf collapse in 1995: <http://news.nationalgeographic.com/2016/04/160412-ice-sheet-collapse-antarctica-sea-level-rise/> The rate of ice melt is pretty fixed. Put X energy in, Y ice turns to water. But if we carve out the underside of the ice first instead of melting down, you get a moment when the ice cannot hold its own weight and it collapses -- again, see the article. But what happens if the part that collapses is over water? It falls in, like dropping an ice cube in a bowl. And that causes waves. Think about the tsunamis from earthquakes: those in Indonesia a few years ago came from shifts of a couple inches. If the West Antarctic ice sheet were to just drop in to the water, it would displace 10 FEET of water and a quite epic tsunami. It's low probability. But it does show up in models from time to time. It's my favorite doom scenario. [Answer] # Stop! Take a breath. Do not tell us the world. Tell us the story. Whoa, hold it right there. Your premise is still a mess... * An apocalyptic event has happened and killed a majority of the world's population. Ok, I can get that. * The surface is as good as uninhabitable unless you feel like contracting a serious case of The Malady™. Very well, I can get that too. * Some of mankind has moved underground. All right, that sounds like a good thing to do if the surface is uninhabitable. * This one company has gotten all the important people together in this one place... wait, what?! This is where it all becomes totally absurd. What happened to all the governments in the world? What happened to all the super-national organisations like the UN? What happened to all the other companies and multinational conglomerates? Why is this one company suddenly such a big focal point. And how can it even bother to remain a company when the entire world has gone to the crapper?! I would say that you are asking us the wrong question. You are asking "Here is a world. How can I fix it?". What you should be asking: "Here I have a story. It needs a credible world/setting. Where can I start?". So... stop, do not try to fix the world because I can tell you already now that the world is most likely un-fixable, at least if we are staying with the premises that you stated. Instead: tell us the story. What is the story that you need a world for? ## An additional note... What you have presented is (somewhat of) a High Concept. But a High Concept can never make for a TV series/film/novel/whatever on its own. It needs a story. A prime example of this would be [the film Ultra Violet](https://en.wikipedia.org/wiki/Ultraviolet_(film)). It is an amazing setting/world. Look at the background material and you will find that the world that Kurt Wimmer has created is very well crafted. It is interesting, it is consistent and actually quite cool. But the film fell flat on its face; it was a bomb. I dare say that the main issue with it was not bad CGI or anything of the sort that is usually mentioned, because you can overlook things like that if the narrative is good enough. But the narrative was not good. The entire film was a world in search of a story, without finding one. And for that it failed so badly it became infamous. Hence: tell us the story, and we can help you build the world. We also have some hints about the air and mood, and some story elements you need. From this we can help you build a credible High Concept that does not fall apart at the first closer look. [Answer] ## Prion Disease Viruses and Bacteria too mainstream for you? Read up on the terrifying world of misfolded proteins! <https://en.wikipedia.org/wiki/Prion> Some features are * Long incubation period (5-20 years) * 100% fatality rate <https://en.wikipedia.org/wiki/List_of_human_disease_case_fatality_rates> * No known cure * Resistant to denaturation * Terrifying symptoms <https://www.google.ca/search?q=prion+disease+symptoms> Add in a new transmission vector like rats or mosquitoes and you have a terrible pandemic on your hands. [Answer] # Gene Drive A recent trend in genomics, relevant mainly to pest control, is gene drive, or "super-Mendelian" inheritance, nowadays done via the insertion of active elements into germline DNA. For a slightly dramatic take on it, see [here](https://www.technologyreview.com/s/601213/the-extinction-invention/). The main techniques use CRISPR-Cas9, a genome editing technique that has become widespread over the past few years. Apparently, the original authors who first applied CRISPR-Cas9 to inheritance (gene drive) were surprised that it was so [effective](http://www.npr.org/sections/health-shots/2015/11/05/451216596/powerful-gene-drive-can-quickly-change-an-entire-species). Basically, by using gene drive, via insertion of active elements such as CRISPR-Cas9, one can over-ride the usual laws of inheritance and force all offspring to have some desired trait. A problem with CRISPR-Cas9 and similar is that, while they are extremely active (or efficient: you don't need much of it to edit a lot of DNA), it's hard to check for what else they are doing to that DNA. Unlike traditional tools used to make GMOs, which are the result of generations of research and contain various "flags" to show off-target insertions etc, CRISPR-Cas9 and similar can change DNA and leave no other trace. This makes it hard to show that whatever you have done has been specific, ie. acted only on the desired target site in the DNA. Eventually, full genome sequences will be used as quality control, but we are not there yet. So, right now, we've very rapidly adopting a highly efficient DNA-editing system with little quality control, and applying that to directing inheritance. Let loose on the plant or animal kingdoms, a few of these could plausibly produce the stated scenario. # Target species How bad this becomes depends on the life-cycle of the species that happen to be targeted. Reported examples can affect up to 99 % of progeny, and take as little as two generations to become completely entrenched. As it works via inheritance, long lived species such as humans and many plants would not be directly affected, until they need to reproduce. However, most food crops have been selected throughout human history for very short (sub-annual) life-cycles, making them especially vulnerable. Fish harvested by humans are long-lived but have short reproductive cycles. Introduction of errant gene drive constructs into any of these would quickly fill their genomes with any number of blights. The list of target species could be broadened indefinitely were a CRISPR-Cas9 construct made to "species-hop". They obviously don't do that right now, as gene drive requires sexual reproduction to spread. Thus, the most plausible, immediate scenario would be a low number of species that have been [targeted deliberately](https://www.addgene.org/crispr/validated-grnas/)\* by CRISPR-based constructs. CRISPR-Cas9-based DNA-editing technology is very easy to acquire and use (it was partly designed that way). It works in any species, and has been shown to be extremely successful across the board. \User-friendly, searchable table of comercially-available CRISPR/Cas constructs. <https://www.addgene.org/crispr/validated-grnas/> [Answer] While the concept of a Franco-German conglomerate choosing to house their pick of important people in Utah is intriguing enough, I think the key issue to be solved is how to make an apocalypse fast enough to "work" without being instantaneous (we have to get these people to Utah somehow....) The issue with most cosmic level catastrophes like a Gamma ray burst is they appear at the speed of light, so there is no warning before the onset of the catastrophe. Solar coronal ejections creating a [Carrington Event](https://infogalactic.com/info/Solar_storm_of_1859) give you about 8 minutes warning, hardly enough to speed dial all your contacts on the emergency bug out list, much less transport them to Utah. An incoming asteroid or comet gives us either a "surprise!" moment, like the [Chelyabinsk meteor](https://infogalactic.com/info/Chelyabinsk_meteor), or you calculate the orbit years in advance, much as in the movie "[Deep Impact](http://www.imdb.com/title/tt0120647/)" Many of the other possible apocalyptic scenarios listed by Zxyrra and the other posters have similar issues in timing, either everyone see it coming in advance (and can take steps) or it springs up unexpectedly, with zero prep time. Looking at your post, I suggest the answer is contained in: > > Funded by a French-German tech-and-pharms company, important world figures are evacuated to an underground shelter in Moab, UT to ride out the disaster. > > > So we have the culprits, and their way of escaping retribution until their evil plan unfolds and they can come out and create the "New Order" in the shape they desire. Since this is a pharma company, they should have some experience in genetic engineering, but since attacking people is bound to get a prompt (and once the world's governments discover the source of the pathogen) pretty violent response, the pathogen is designed not to attack people at all, but rather something critical to the global infrastructure, like refined hydrocarbons. The world will come to a pretty crashing halt, but before this happens, all the important people were at a convention in the Untied States, and then went on vacation.... To make it even more scary, the pathogen will most likely mutate once all the easily accessible hydrocarbon fuels are turned into varnish, so they might evolve to start eating plastics and other polymers. Down in the hole, the plotters are starting to realize their careful schemes may be for naught (and aren't the seals between the shelter and the outside world made with plastic gaskets....?) [![enter image description here](https://i.stack.imgur.com/kxtNy.jpg)](https://i.stack.imgur.com/kxtNy.jpg) This isn't what we talked about, Andre...* You can now run two parallel plot lines as the survivalists in the outer world contend with a Mad Max like planet (but no souped up V8 interceptors) while the people in the shelter discover things are not looking quite so rosy for them either.... [![enter image description here](https://i.stack.imgur.com/QeLJ8.jpg)](https://i.stack.imgur.com/QeLJ8.jpg) Not unless he's going to push this by hand [Answer] Apocalypse by Singularity Our world works the way it does because goods have value, people are finite individuals, and no one is so very much smarter than the rest that they can remain on top for very long – among more concrete givens like, say, the arrow of time. [The Singularity](https://en.wikipedia.org/wiki/Technological_singularity) changes one of those things, rendering events prior to it inexplicable to those who survive it, and the events within it obscure to all observers. Imagine that tomorrow, someone uses genetic modifications to make themselves immortal or super-intelligent? That tomorrow, a company looking for rapid scaling creates a factory that can literally copy itself from available raw materials? That a scalable computer system ends up outperforming humans at all cognitive tasks, or that incredibly clean, cheap, and plentiful energy is discovered? Great achievements come with great risks – and so do great tragedies. In 1492 the New World experienced something like this when Europeans, gifted with certain technologies and circumstances that made them indescribably powerful in comparison to the aboriginal inhabitants of the Americas, discovered these continents. Catastrophic change came to the Western Hemisphere on a timescale difficult to comprehend in its brevity. My favorite specific type of Singularity is probably an [Economic Singularity](http://www.nber.org/papers/w21547), because I tend to think it’s a little more probable and a little easier to grok than some of the other ones. It goes something like this: Tomorrow, someone releases an open-source design for [a robot that can gather all the raw materials for its own construction on its own](https://en.wikipedia.org/wiki/Clanking_replicator), and then use these materials to build copies of itself – or whatever else you program it to build. In fact, with a little work, you can get it to work together with its copies [to build even very large things that you ask it to build](https://en.wikisource.org/wiki/Advanced_Automation_for_Space_Missions). If you have the blueprint and your robot, you basically own it, apart from acquiring the raw materials. Modern economic systems, based on traditional kinds of wealth inequalities, break down utterly. There is no physical market anymore; only the digital market. The change is very fast – too fast for nations or companies to adjust. Within a year this robot is available to basically everyone on Earth. Piracy, never really stomped out before, makes it impossible to harness this new completely digital economy, and so it becomes very difficult to have wealth of any kind. This makes it kind of hard for nations to fund things like militaries, which they’re going to need to combat the robot armies and nuclear bombs that some persons of more dubious moral stature will no doubt begin building immediately. At some point in this tumbling avalanche of economic turbulence, and in no particular order: * bombs start to go off, and fingers start to be pointed – factions rise and fall. * people trying to do REALLY big things with their robots realize that cities represent awful good accumulations of the kinds of raw materials you need to build those really big things * lots of people get their robots taken away by people who use their robots better, leading to a new kind of hyper poverty/wealth dichotomy * the Earth’s climate, already not doing so great, is caught in the tug of war between all this rampant activity and the few people trying to use their robots to build things that will alleviate climate change. In any event, large portions of the surface of the Earth are stripped bare and vast underground honeycombs of mining activity become warrens for the dispossessed seeking shelter from the increasingly hostile surface. * at some point, due to the inherent error rate in all copying, a robot makes a copy of itself that is flawless in all design specs except the one where it necessarily does what its master tells it to do – and it just starts making, non-stop, copies of itself. Enterprising souls attempt to curb the oncoming grey goo-ish scenario by making copies that convert specifically that mutant strain of robot to raw materials for making themselves and unleash them into the robosphere, and perhaps at some point another viable mutation or twenty occurs to these two lineages, splitting the uncontrolled robots of the world into multiple competing, interconnected species which are slowly outcompeting the natural flora and fauna of the planet. At some point, one of these mutations develops a taste for another bountiful resource on the surface of the Earth – human flesh. It’s nothing personal, but we’re a great pile of useful carbons just waiting to be combusted as fuel, or maybe turned into lubricant. Some, desperate to survive in areas where no defenses against these new superpredators exist, go to the extreme length of designing robot bodies for human brains to live in, to appear like their own predator in order to survive. Unable to reproduce as humans once did, their continued existence now depends on their ability to carry on gene splicing using blueprints available in their robot host’s memory banks. Breeding with baseline humans is not only undesirable to both parties, it’s extremely difficult. In short, read Philip K. Dick’s [Autofac](https://archive.org/stream/galaxymagazine-1955-11/Galaxy_1955_11#page/n71/mode/2up), but take more drugs than Dick did. P.S. Although William Gibson has told me he doesn't think Technological Singularity is a Thing, I believe he has subconsciously been working on extrapolations of leadups to Economic Singularity in his more recent work, beginning with [All Tomorrow's Parties](https://en.wikipedia.org/wiki/All_Tomorrow%27s_Parties_(novel)) and finding an especially subtle outlet in the finale to his [Zero History](https://en.wikipedia.org/wiki/Zero_History). [Answer] ## Supervolcano eruption [About 75,000 years ago, a tremendous volcanic eruption occurred](https://en.wikipedia.org/wiki/Toba_catastrophe_theory) at the present site of Lake Toba in Indonesia. It ejected tremendous amounts of ash and sulfuric acid into the stratosphere. It is hypothesized that this caused a global volcanic winter that lasted 6–10 years, and that this drastic change in climate nearly wiped out the human race. These conclusions aren't universally accepted, but they're plausible enough that you could handwave them for a TV show. Your show occurs a generation or two after a similar supervolcano eruption; the global volcano winter is predicted to last for 50–100 years. After the volcano, catastrophic crop failures occurred for several years running. In the first few years after the eruption, the company (for whatever reason) built this underground sanctuary, powered by a nuclear reactor. On the surface, mass starvation occurred; a few farmers were able to scrape by in the countryside by growing some particularly hardy crops, but the major cities were reliant on food being shipped in from outside, and now nobody lives there. (The survivors might venture into the cities to scavenge for supplies from before the catastrophe.) The people in the below-ground colony are told that there is a plague that has infected all those left behind on the surface. However, there is no real plague. Shortly after the colony was founded, there was a large amount of unrest inside because of the large number of people left outside (particularly the friends & families of those locked out.) The company fabricated the notion of a plague in order to have an excuse for not bringing more people in: "We can't let them in, they might be infected." If you really want to make the company sinister: instead of fabricating rumors of a plague on the surface, they actually genetically engineer a disease and release it onto the surface. As far as where the this supervolcano eruption occurred: how attached are you to Moab? One of the more likely candidates for a supervolcano eruption within the next few million years is the [Yellowstone caldera,](https://en.wikipedia.org/wiki/Yellowstone_Caldera) and Moab is probably too close to that to be chosen as a site for an emergency refuge. A bunker in China or Australia might be able to survive, though. Alternately, there have been large eruptions of this scale with the last few million years in New Zealand, Indonesia, and Argentina. [Answer] Why on earth do they move underground? It is not at all easy to find a reason for an underground shelter. Since the "important world figures" are to be protected in an underground shelter it means that there is something in the air which is very dangerous. (There is no reason to burrow underground for a simple famine, or glacial maximum or other disaster which does not make air dangerous.) The danger can come either from radiation from those undesirable bombs, or from some sort of pathogen, or from a toxin. (Cannot be plain UV because they wouldn't need to borrow underground, they would simply stay indoors.) I would say that toxins are out simply because I cannot see how to make such a huge amount of toxins as to render all the atmosphere poisonous (and then recoverable in a reasonable amount of time). That leaves radiation or pathogens. And even if air is dangerous, why underground? We are perfectly capable of making air-tight buildings. Since the upground people are to be undesirable mating partners it follows that the pathogens must somehow affect the germline. This means some sort of retrovirus. Retroviruses are normally not very virulent, maybe some explanation must be given how a retrovirus can kill so many people so quickly. The trouble with viruses is that once most of manking has died the viruses will also die (or chnage into a survival form, which is much more manageable); the wealthy survivors simply need to clear a sufficiently large area and they can move upground; this may need to be addressed. An alternative would be to imagine a swarm of rocks coming from space, maybe the remnants of an asteroid. They could in principle be detected early enough to allow for building the shelter, and there is nothing we can do to protect against them. But in this case, what transforms upground people into hideous mutants? Not to mention that if Earth is to be subjected to a prolonged meteorite bombardment there may be severe environmental effects. And why on earth is the shelter dedicated to "important world figures"? Once the disaster strikes, important world figures are no longer important. It is understandable to give some of the places in the shelter to important people in American politics (who must approve the plan), and maybe to handful of financiers (who must provide the funds for the plan), but the rest? Wouldn't it be more logical to shelter people who actually have something to contribute to the reconstruction effort: engineers, chemists, mechanics, soldiers, doctors, and, of course, as many women as possible? Remember that by far the main factor in re-establishing the population is the number of women. (So the shelter should probably have female engineers, female chemists, female mechanics, female soldiers and female doctors, with a small number of men to provide a certain degree of genetic diversity.) [Answer] <https://en.wikipedia.org/wiki/Clathrate_gun_hypothesis> Seas warm; methane deposits are suddenly freed from seabed. Poison gas clouds billow from the oceans; most things die. In general, take a look at the Permian Extinction. I wish as many people knew about this as zombies; it's a hell of a lot scarier. [Answer] ## "Normal" Accidents "Normal Accidents: Living with High-Risk Technologies" is a 1984 book by Yale sociologist Charles Perrow, which provides a detailed analysis of complex systems. [Normal accidents](https://en.wikipedia.org/wiki/Normal_Accidents), or system accidents, are so-called by Perrow because such accidents are inevitable in extremely complex systems. They are essentially the embodiment of the ["For Want of a Nail" proverb](https://en.wikipedia.org/wiki/For_Want_of_a_Nail). Given the characteristic of the system involved, multiple failures which interact with each other will occur, despite efforts to avoid them. Perrow said that operator error is a very common problem, many failures relate to organizations rather than technology, and big accidents almost always have very small beginnings. Such events appear trivial to begin with before unpredictably cascading through the system to create a large event with severe consequences. Perrow identifies three conditions that make a system likely to be susceptible to Normal Accidents. These are: * The system is complex * The system is tightly coupled * The system has catastrophic potential Such accidents are unavoidable and cannot be designed around. The inspiration for Perrow's books was the 1979 [Three Mile Island accident](https://en.wikipedia.org/wiki/Three_Mile_Island_accident), where a nuclear accident resulted from an unanticipated interaction of multiple failures in a complex system. The event was an example of a normal accident because it was "unexpected, incomprehensible, uncontrollable and unavoidable": > > The accident began with failures in the non-nuclear secondary system, followed by a stuck-open pilot-operated relief valve in the primary system, which allowed large amounts of nuclear reactor coolant to escape. The mechanical failures were compounded by the initial failure of plant operators to recognize the situation as a loss-of-coolant accident due to inadequate training and human factors, such as human-computer interaction design oversights relating to ambiguous control room indicators in the power plant's user interface. In particular, a hidden indicator light led to an operator manually overriding the automatic emergency cooling system of the reactor because the operator mistakenly believed that there was too much coolant water present in the reactor and causing the steam pressure release. > > > ## Snowballing Problems Essentially, the idea is that one seemingly small problem occurs, that unexpectedly leads to another larger problem, and that problem begins to set off a series of uncontrollable, unanticipated, unresolvable problems of catastrophic proportions. So, I think you could start with almost any problem and then find ways to create associated problems that culminate in a global catastrophe. My point is that none of the events in the series have to be major things like nuclear war, but could be something like the Deepwater Horizon oil well never getting successfully capped. If it never got capped it could lead to massive ecological damage, which could cause health problems, massive economic problems, and these could all lead to financial collapse of the insurance industry, setting off a global economic crisis the world could not recover from. That could leave the world impoverished and decaying, rather than thriving and well-maintained. This lack of education and proper maintenance could lead to several nuclear accidents of varying degrees of severity. Widespread lack of wealth could lead to college educations becoming unaffordable, which in turn leads to a severe lack of educated, competent workers. Economic collapse and industrial collapse could spiral out of control in first world countries, leading to massive tailspins in less developed nations. After generations of increasing decay, society could be plunged into a scenario almost impossible to recover from. That's basically how civilizations fail--Rome fell because of lead in the pipes. ## Some Problems Some possible initial problems could be: * Nuclear accident(s) ([Chernobyl irradiated 200,000 sq.km.](https://www.iaea.org/PrinterFriendly/NewsCenter/PressReleases/2005/prn200512.html)) * Deepwater Horizon accident failing to be contained (maybe with the oil eventually catching fire all across the ocean too) * A cross-continent natural gas pipeline exploding, in multiple places simultaineously * Riots spreading throughout a nation * Bioweapon accident, chemical weapon accident or nuclear weapon accident * A massive scandal revealing overwhelming political corruption * A global recession like the economic collapse of 2008 * Terrorist attack * Hostile foreign power systematically undermining and degrading a nation * [Y2K type of collapse](https://en.wikipedia.org/wiki/Year_2000_problem) * Global malware infestation, like [ILOVEYOU](https://en.wikipedia.org/wiki/ILOVEYOU) * Some other kind of civilian "weapon of mass destruction", like [derivatives](http://fortune.com/2016/08/08/mass-destruction-buffett-derivatives/) (I don't know if there are other kinds of WoMD than financial instruments) * Extensive droughts leading to [loss of drinking water](http://environment.nationalgeographic.com/environment/freshwater/freshwater-crisis/) * Droughts leading to excessive wildfires * [Ancient pathogens being released from melting permafrost](https://www.washingtonpost.com/news/speaking-of-science/wp/2015/09/09/an-ancient-giant-virus-was-just-uncovered-in-melting-ice-and-it-wont-be-the-last/?utm_term=.f9eabaaa61ef) * Overwhelming number of antibiotic-resistant strains of bacteria * [Earth's magnetic field flipping](https://www.scientificamerican.com/article/earth-s-magnetic-field-flip-could-happen-sooner-than-expected/#) * A massive earthquake that destroys [California](http://www.latimes.com/local/lanow/la-me-ln-earthquake-swarm-20160930-snap-story.html) and the [much of the rest of the United States' west coast](http://www.newyorker.com/magazine/2015/07/20/the-really-big-one) * Global irradiation: the radiation equivalent of global warming--global warming is the gradual buildup of CO2 to catastrophic proportions, so global irradiation would be gradual buildup of radiation until it becomes a significant danger to all of humanity * Sudden melting of all icecaps on Earth: say nuclear weapons like Russia's [Satan 2 missiles with payloads capable of destroying all of Texas, France or the U.K.](http://www.telegraph.co.uk/news/2016/10/25/russia-unveils-satan-2-missile-powerful-enough-to-wipe-out-uk-fr/) simultaneously explode on the North and South poles, Greenland, and other ice shelfs, accelerating global warming so suddenly that all ice on Earth melts within 1 year, thereby [raising sea levels by 70m (230ft.)](http://www.amnh.org/ology/features/askascientist/question18.php) within 1 year. This would cause many nuclear power plants to be submerged, since they take at least [several decades to be safely decommissioned](https://en.wikipedia.org/wiki/Nuclear_decommissioning). In addition, the pollution from so many cities suddenly being underwater could be catastrophic, to say nothing of the chaos and panic that would sweep over the world as all major coastal cities went underwater. Any of these could easily lead to a chain reaction of cascading problems, which become overwhelming when they all compound on top of each other. [Answer] There have been different individuals and groups pledge to take on climate change personally. One plan involved 'whitening' ocean clouds with a metallic powder to increase reflection. The science made some sense, but I believe they talked the guy out of starting it himself without an international consensus. Garage biohackers already have the ability to release a myriad of crazy self-replicating ideas we've come up with to solve global warming, without realizing all the consequences, which could involve the climate, ecosystems, technology, and us critters directly. [Answer] Maybe you don't need to explain it all. It's just the way things are. Each group / person / faction has their own theories and beliefs about what happened, including the don't-breed-with-the-contaminated mantra, which may or may not be accurate. You could focus stories on the conflict between opposing views and realizations that deeply held views are not accurate. It also gives you freedom to introduce all sorts of scary things that don't have to be internally consistent because you're still discovering just what state the world is really in. This has an added benefit: Somewhere down the line, when the series is ready to jump the shark, the new writers can finally reveal what the "true" cause was and re-focus the story (with the obligatory replacement characters) on dealing with the "real" root cause, tossing aside all prior canon as having been a big misunderstanding. :) [Answer] # Toxic asteroid shower If a big asteroid roughly headed for earth would burst apart into a massive field of millions of smaller parts with varying speed, they could go down on earth over the course of months or years. Some impacts might be big enough to create tsunamis, destroy infrastructure or cities. Others are smaller and just burn in the atmosphere. But if the asteroid contained a high concentration of a toxic substance, which spreads through the air on impact or while burning up in the atmosphere, this could lead to toxic clouds making whole areas uninhabitable. And since the rain of asteroids is hard to predict (millions of asteroids, randomly colliding with each other on their way to earth) the only safe bet for world leaders are underground bunkers. - And you can always tune the number of impacts up and down for story purposes. There can be a week where a dense rain of big parts hits a whole hemisphere, rising toxic levels so all animals and plants die. The explanation for the rupture of the asteroid could be ice or other elements inside of it, which got heated up by spending time in our solar system near our sun. The resulting expansion could create gas outbursts which break the rock apart. [Answer] # Two-component bio-weapon There's a big problem with deadly diseases: hosts die off before they infect lots of other people. Also, diseases sometimes cause visible changes in the host before it's too late. Both things imped spreading. This could be solved by using highly virulent disease that does not harm anybody and infects majority of humanity without anybody caring about that. Take a look at herpes for that part - it already fits the bill, except for the next part: ## Triggers There would be various triggers that make the disease kill the host. They should not be restricted to a single product. Well, you can think of Unilever's products - imagine if half of these suddenly turned out to be poisonous. This way, remains of the old world would be deadly, but people would not know for sure what exactly is deadly, so rebuilding the old world would be hampered. What makes the situation different from typical biological or chemical warfare is that if disease and trigges start spreading roughly at the same time, number of dead people will rise sharper than it would do in a typical biowarfare or chemical warfare scenario. People will be alarmed the moment, say, 10th patient dies of that thing in a year (+- order of magnitude depending on country's development level). Since disease needs the trigger to become deadly, it will raise an alarm later, when it's much more widespread, and containing a widespread disease is much harder than stopping it in the very beginning. Moreover, research would show this thing to be artificial which means nuclear prevenge from everyone to everyone. That will hamper further research and let the whole thing spread. [Answer] Just war. Just widespread, long, desperate war. "I can't tell you what weapons world war three will be fought with, but world war four will be fought with sticks and stones." -Randall Monroe (He didn't say that first, but the other guy probably didn't either so at least I can misattribute with intention.) Mash the political parts of world war one and two together, eliminate the pause in-between. Throw in some of the desparation of revolution and the tactics from conflicts with force imbalance. Add bleeding-edge modern technology. Mix and serve hot. Half of the major powers of the world came together to form alligances against their age-old enemies and some new ones their allies hate. None of the members has the same motives, but there are plenty of motives to go around. It's not importatnt who the sides are or even what the interests are. Just that the war starts. Nuclear exchanges destroy most of the major cities in the early days. Those first to die can be considered the lucky ones. The remaining poplation learns not to bunch up and make targets, a lesson they'll live to regret. The war creeps as war does. Soon no part of the globe is safe. Tailored plagues attack the food supply and genetic markers specific to the other side's populations. Both sides claim the other side started it. In truth they were both working on it in secrect and some mis-step, some poor decision caused happened --like the cuban missile crisis but with biotech and somebody says "Screw it" and pushes the button. The conflict to escalates, an arms race of weaponized biotech emerges. Nobody notices it happening, but suddenly there are no engineers or biologists or scientists or mechanics anymore. Everyone is busily trying to think up the next scariest weapon (I could mount a gun on that, or make poison from this). Motivated in part by fear, in part by anger and partly just caught up in the insanity of the war. Nobody even remembers what started the whole thing, or if they do it seems so trite and pointless. Those who do remember can't say it with a straight face. Seriously that? That started all this. No I don't beleive it, I won't believe it. But it doesn't matter anyway because the people, nations and alignaces that started it are all gone. Nuclear ash, the toxic remains of the city folk and their useless things swirls in clouds, landing on the earth and water poisoning everything it touches. Terrible diseases are released, diseases which can literally re-write your genetic code and that of your offspring (this is actually plausible with current technology a little time and some dark inspiration). They run rampant in the plants and animals of the planet. And of course Man is just the animal that lies so we are in no way immune. Nature is turned toxic by gene-mod plagues specifically designed for that purpose. Plants engineered not only to be poisionous to eat, but also to poison the air and ground. Poisoned thorn bushes not of any species, but created when a disease infects a rosebush --each one different and terrifying. The very idea of speciation is obsolete. Monsters everywhere and monstorism is contageous. Everywhere you look there are monsters poison, radiation and death. The best thing you can do is crawl in a hole and pull the it in after you, and if you hear someone knocking, for god's sake don't open the door. [Answer] ## humans vs. earth The plausibility of this scenario depends on the following assumptions. 1. Bacteria is one of the first forms of cellular life. 2. Consciousness is born out of the complex interactions of cells responding to inputs and/or lack of inputs from their environment. 3. Humans did not evolve naturally. First some back ground. One of the first life forms to appear on Earth is Bacteria. Bacteria multiplies, mutates and evolves into multi-cellular forms with different sensing mechanisms. This form of life develops consciousness much like the brain as we know it today. This intelligence decides it wants to explore its environment and starts to develop complex life forms, through self replication. Ecosystems develop and eventually mobility, senses, primitive intelligences, and creatures with brains evolve. Brains modeled on the intelligence that designed them: made up of many cells which react to the environment through sensory perceptions. Creatures with brains populate and evolve with the sole purpose of exploring and experiencing their environment. Humanoids Appear Some kind of intervention takes place. For unknown reasons and/or motives outside forces create Humans from Humanoids. Perhaps it is a radio active meter or a gamma ray burst, that hits the earth. The results is that Humanoid genetics are changed. The intelligence that created the Humanoids and all other life forms that followed bacteria on the evolutionary tree, has been aware of these Humanoid to Human changes. As it is a Super Intelligence, which acts in time frames of millennia, it takes a wait and see approach. Conflicted by the huge evolutionary steps taken by Human kind, which furthers its own goals, and the plan it set in motion, eons prior, which will no longer work within the accelerated evolutionary environment, the Earthly Intelligence does nothing. The goal of exploring the environment is more feasible now, but eons of shaping biological imperatives will have unknowable consequences. The Earthly Intelligence will watch how this plays out patiently. Eons later the biology put in place millions of years prior takes shape. Dormant genes begin to awake in humanoids, conflicting with the intervening programming introduced from the alien source. A pandemic of Genetic diseases breaks out. The conflicting genetics spawn mutant viruses that attack otherwise unaffected humans. The Earthly Intelligence takes action against certain genetic populations to ameliorate the damage caused by the alien intervention. Chaos ensues. [Answer] I haven't seen any show tackle the extinction of pollinators yet (eg. honeybees). It's a real and serious threat to the world's food supply. Lack of food resources can easily lead to brush wars, which could trigger larger-scale conflicts, etc etc. <http://motherboard.vice.com/read/honey-bee-extinction-will-change-life-as-we-know-it> [Answer] I like a lot of the ideas that are presented here, but the way I would approach it is through warfare. You can set up your background in a lot of different ways pre-event, but this is my thought process: Increasing tensions throughout the world (and perhaps a few brushfire wars or international incidents) increases the military strength of the U.N., but also increases its bureaucracy. Veto powers in the security council are removed, but resolutions there require a full 2/3 agreement from the entire UN, not just the council (with the council acting more like an advisory body). The UN also raises its own military forces in the forms of mercenary soldiers that don't have loyalty to a particular government, besides the UN. This means that outright wars between member states are difficult or impossible, but "rogue acts of terrorism" from "third parties" won't be reacted to very quickly. Most nations start spending less on national defense, relying entirely on the UN's forces, or change to a more special forces model of a small cadre of elite soldiers versus a large standing army. Most major nations now fight shadow wars, secretly funding or backing terrorist organizations to meet their ends. When a terrorist cell captures a missile silo and destroys a major city in nuclear fire, the UN takes control of all nuclear arsenals of its member states. Similar events happen for the UN to seize all biological and chemical weapon stockpiles it can access. These efforts are not 100%, but greatly reduce access to these kinds of weapons. However, a terrorist cell, or an accident, releases a genetically modified mosquito, carrying a genetically modified supervirus. The mosquito breeds rapidly and can adapt quickly to all but the harshest environments. In most people, the virus lies fairly dormant, only slowly reproducing but not causing symptoms, until a triggering event happens (you can pick this. Stress, infection with a different disease, dehydration, whatever), but can still spread through fluid contact. When active, the virus impedes decision-making abilities, causing the victim to fall into what appears to be a nepotistic state (picking fights, drinking and eating to excess, having lots of sex, etc), and can live for a long time, but loses sight of consequences of their actions. What does this all mean? 1. The virus spreads quickly, and is both mosquito and human borne (explains why people are worried about "purity" when it comes to breeding"). 2. Cities, or anywhere with a lot of people, are dangerous places, where, depending on your timeframe, either lots of infected people live, or have been devastated as food ran out and people resorted to cannibalism. 3. You have a strong, global organization that could have prepared or seized areas to keep its people safe (perhaps with the only surviving medical facilities capable of detecting or combating the infection). 4. The safest places to live are those where the mosquito's can't survive (extremely cold or hot areas, or extremely dry areas). They are genetically modified, so this is up to you. Hell, make them like killer bees, and have them able to mate with other kinds of mosquitos and pass on the virus and the modifications. [Answer] So I think a two prong attack. First prong is to remove all the defenses, and an easy way to do that is with EMP's. Launch nukes on SCUDS from container ships 25 miles up over the continents and set them off. No radiation, no one dies right away (for a few minutes until the planes fall out of the sky). But civilization is effectively over. If some multinational had an idea that it was going to happen (or maybe the CEO has read [One Second After by William R. Forstchen](https://smile.amazon.com/dp/B002LATV16) and is now a paranoid person), and they have shielded hangers to store aircraft, which they then generously agree to use to evacuate people they see fit. They see it as their way of shaping the future. Across the globe there is mass hysteria and a breakdown of civilization as everyone goes back to the middle ages, except that now there are to many people and no infrastructure to move things from one place to another. In a few months a third of humanity is dead, there is no sanitation, disease runs rampant, and thousands of people are roaming from place to place to try to find what they need to survive. And then the second prong hits, when bio weapons are released and something airborne and deadly begins to spread. The ones that don't die from it become carriers as the [disease lies low](https://en.wikipedia.org/wiki/Virus_latency) until it is triggered by stress caused by too many people in one area, and one of it's reservoirs within the body are the reproductive cells. This also renders them sterile. Now 80% of humanity is either dead or infected, and so finding the healthy ones and keeping them healthy so they can reproduce is pretty important. [Answer] # Moab Inc. did it. On purpose? As Michael Karnerfors correctly [points out](https://worldbuilding.stackexchange.com/a/64450/6463), how come the "important" people are all rescued by one company and not by their respective governments? Yes, you could try and handwave that away via some nod to [Syndicate Wars](https://en.wikipedia.org/wiki/Syndicate_Wars). But let's rather have something more interesting: Moab, UT, happens to be Earth's [opposite](http://www.antipodr.com/) to some Point X approximately between [Île Amsterdam and Iles Crozet](https://www.google.ch/maps/dir/%C3%8Ele+Amsterdam/Iles+Crozet), but being part of the [French Southern and Antarctic Lands](https://en.wikipedia.org/wiki/French_Southern_and_Antarctic_Lands). So a French-German company you say? What an interesting coincidence! So their base is as far away from Point X as you can get while remaining on Earth. That makes me think of the following scenario: * They experimented with some new rocket drive (fusion drive, or even some fancy dark matter involved?). * Knowing the high risk involved they chose the basically unpopulated French overseas territory mentioned before, and just to be safe, built their base on the opposite end of the world. * Since their drive is the method to finally get out of our solar system in finite time, important people are invited to said base for observation. * Of course the experiment went downhill, the sank down the ocean and caused a chain reaction by which a significant amount of ocean not only got radioactively contaminated but also vaporized (maybe after the shockwave caused severe Tsunamis all around the world). * While some of the water remained in the atmosphere in the form of clouds (maybe enough to cause a nuclear winter), lots of it comes down again, causing massive floods (of highly radioactive water!) hours or even only minutes after The Disaster. No one is prepared, no place is really safe (except for Nuclear Shelters; whether those are also occupied or maybe were completely disbanded due to World Peace is up to you...) * Some water was also ejected into space, thus making water (and thereby indirectly food) hard to come by. * Did I mention the radioactive water contaminating everything? I mentioned "on purpose", didn't I? Some of Moab, UT's involuntary guests learn about the company's awareness of the risk - who's to say they did not precisely know what would happen, and their slightly mad CEO wanted to recreate [The Flood](https://en.wikipedia.org/wiki/Genesis_flood_narrative)? [Answer] Food Crop Famine: Since nobody has yet suggested it, I'll opt for going biblical, with a literal crop famine, brought on by (your choice, I'll suggest bioTerrorism gone way wrong) -- but the result is that modern varieties of rice, wheat and corn are no longer viable food crops. Suggest searching the term "monoculture." (Yes, barley is related to wheat, but I'm asserting that barley survives -- because a future with no beer is just too grim to write about!) Interesting side effect: The old Irish diet (barley, oats, potatoes) is one (admittedly bland) way to survive. But. There just isn't enough time to grow enough seed to change farms over, before most people die of starvation -- or are eaten. Investigation of how many weeks of food reserves we really have is IMHO quite alarming, YMMV. If you also posit a way to kill (or radically limit) electrical power and gasoline/diesel-powered vehicles, and the world won't go back to (our) normal, even when the survivors learn to eat what they can still grow. We take mass movement of foodstuffs and refrigeration for granted. (Oops!) ]
[Question] [ I have a race of humanoids who live on two planets in a binary system. This planet is mostly a water world, with some swamps and about three Australias. The other planet is very dry. But, I have a problem. I want it to be similar to Star Wars, with high technology level but no internet or social media. But I do want them to have space stations, spaceships, things like that. One thing I thought could help would be to make it inefficient or expensive to have these kinds of things. But I don't know how to do that. Or maybe bombard the planets with some kind of light that would fry electronics? Note - Things like it goes against their culture are off limits, because if these creatures have technology that is helpful to them they will use it. Note - Other alien's gifting them technology is also a possibility, but that means that at some point these creatures are likely to develop an Internet, and I don't want that. [Answer] Perhaps take into consideration the biological concerns of your alien species. In the Predator series it is implied the Predators have vastly superior technology to our own, but if they truly have vision that works exclusively outside the visual spectrum it might be quite difficult for them to develop display screens comparable to our own. Without television we humans may never have developed Graphical Computer Interfaces, thus social media, if it existed at all, would be very different. This also explains why the Predators value hunting as entertainment, since they do not have the luxury of being a couch potato. It's slightly difficult as a human to imagine an array of senses beyond our own, but if an alien did not possess ears or eyes in the same way we do, their technology might develop quite differently. In particular, I would focus on defining how your species communicates with others of its kind. Things like Pheromones/Smells, Physical Contact, Taste, etc. would be hard to replicate over the internet compared to the written word or the spoken word, forcing social interaction to be face-to-face. [Answer] There are some good answers here, but there is a much simpler one - in the real world, humans developed the ability to travel to other planets a good thirty years before social media took off. With 1970s technology, you can leave Earth, stay in space for a few months then land back on Earth. That's not good enough to colonize Mars due to all the tech you need once you get there, but it is enough if the other planet is habitable. Having somewhere worthwhile to go to would quite quickly lead to mass produced spaceships, especially if the other planet turned out to be more habitable than the homeworld. [Answer] One thing to consider is that we build off of the inventions and discoveries that came before us. It could simply be that your species never had its "Zuckerberg", etc. and basically "nobody ever had that idea." Having gotten as far as they have and then bumping into these things sort of 'after the fact', people could see the pros and cons and decide that it isn't worth it for their species. Another thing - maybe there's something special about this alien that makes it so that that technology is pointless. [Answer] Your requirements limit the possible answers to the point of near impossibility. Being able to travel in outer space is basically one of the biggest achievements you can have, and being able to communicate via a well established network of communications is one of the many building blocks necessary to get there. Why You Need The "Internet" I'll explain this in detail because some people seem to simply not get it. A lot of people on this thread seem to be confusing the "internet" with our *use of the internet. All the internet is is a set of communication protocols which allow computers to talk to one another. That's it. Whether two computers connect only to one another, or 2 billion servers connect to form the World Wide Web it's still the same concept. When computers were first invented they were massive things with a single input terminal. They existed only within universities, and military compounds. These various computer centers wanted to communicate with one another. Calling one another and telling the person at the other end what to type into their terminal was not a secure, or particularly great approach, so they developed a way for the computers to communicate directly. Welcome to ARPANET (Advanced Research Projects Agency Network - a military project), aka the forefather of the "internet". Eventually, due to advances in technology, and the efforts of companies like IBM, Intel, Microsoft, and Apple computers became available to the average person. Having these many computers be able to communicate with one another was useful, so the networking concepts were applied, and the "internet" was born. People saw the potential which the internet possessed, and moved beyond simple email to start creating websites, etc. Our own psychology and needs shaped the purpose of the World Wide Web into what it is today. Our vanity and narcissism spawned social media, etc. However, websites, social media, and the like are not what the internet is. They are merely the human interface to it. The content we created because that's what pleases us. No, the internet is the underlying communication protocols which send the information I've just typed to the SE servers, and then to each and every one of your screens. The reason why any civilization which wants to reach the stars needs* an "internet" is because they need a way for all that technology to communicate! Your ship must send data to the ground control center. It must receive information in turn. Ships must also be able to communicate, and transmit information on a level other than the crew radio-messaging each other. And since you want all the different ships to "understand" one another you must develop a standardized way in which they should do so. A set of protocols. *That is the internet!* The race in question might not develop social media, or websites because they lack a fundamental interest in such things. Or perhaps they simply lack the imagination. Who cares? > > PS: in Star Wars, when Solo and Luke are saving princess Leya R2D2 accesses the Death Star's network and finds out which cell she's being held in. Star Wars totally has networks (aka an "internet"). > > > No "Internet" Aka no computers communicating with one another. Aka stone age. Ok, we can make it work! The only real option at this point is that your people find the ships on the planet somewhere, and use them without knowing how they actually work. For example, maybe a mighty race maintained a base on that planet (a giant underground vault containing ships, and even set up a space station in orbit). These were left there in case of emergency, but then that race died, moved on to a parallel universe, or simply forgot about this neck of the universe, and left their technology behind. After centuries of scratching a living in the dirt your hunter-gatherers stumble into the vault, and the governing AI decides to cooperate with them for some reason (maybe it needs some favors that only these primitive people can provide, or maybe it simply becomes their God and orders them around). It however doesn't give them access to its communication's network (the "internet"), so they are not even aware such a thing exists, or what its potential might be. They now have the use of the base, orbital station, and ships without understanding the technology. The maintenance is done by the automated systems, and by robots controlled by the AI. [Answer] Computers, networks and the internet are based on metals and semiconductors, naturally occurring and generally abundant substances on Earth. To get into space doesn't require much in terms of computing power (<http://www.computerweekly.com/feature/Apollo-11-The-computers-that-put-man-on-the-moon>), but it does require metal and a lot of fuel. One approach is that your planet could have very advanced technology without computers provided you have a couple of things: 1. A lack of naturally occurring semiconductor material, making it expensive and hard to obtain would severely limit the development of computers in general. 2. An abundance of metals to favor the ability to create mechanical "computing" and allow for advance metal working in general. 3. An abundance of fuel sources to favor metalworks and cheap travel, including into space. Historically, people were able to create and use very "crude" tools for global navigation. There is no reason to assume that space navigation could not also be achieved through more "crude" or alternate tools than those available to us. In fact, our tools will probably seem very crude to our ancestors several hundred years from now. Alternate tools are certainly not unimaginable. However, semiconductor materials are pretty common in nature (silicon is in sand and dirt on our planet). It's like trying to avoid carbon on a planet. Given the vast number of planets, it might be possible... [Answer] > > I want it to be similar to Star Wars, with high technology level but no internet or social media. > > > Assuming that your "no culture" rule really means "no suspiciously-convenient social/religious mores", then: * Technically difficult: Communication between individuals uses extremely precise chemicals, smells, direct-neural connections, psi, etc. that cannot be readily detected/encoded/reproduced until slightly later in their tech-progression. * Too individualistic: Solitary species that only grudgingly comes together to accomplish things, and they see our-style of "social media" as helping enemies spy on them. * Fighting their biology: Even visualizing competitors (for mates, territory, etc.) shuts down some higher-brain functions--they can't help it. Therefore a huge part of their technology involves hiding the existence of others, allowing them to cooperate through an un-threatening genderless artificial middleman. (Can help explain inconsistent tech-levels.) * Built-in: They can easily communicate at extreme distances with organic lasers, radio, psi, etc. Their network they are socially-interested in is almost always in reach. * Hive mind: They--er, it--doesn't see the point, it just builds specialized routes to help bridge long-distances between worker-bodies. [Answer] Economics and Priorities Consider that we did go to the moon well before we had social media and what might be considered the modern internet. So basic space flight is certainly possible. Now imagine instead of a lifeless moon, we had an entire second planet to explore and colonize. Our priorities in the 70s and 80s would certainly have been different. Governments and businesses would be investing in space travel and technologies related to colonization, and not personal computers and the internet. Eventually I believe they would have an internet of some kind. After all, they'll want to communicate across distances. And space travel is a lot easier with better computers. So the two will eventually come together. It just may be 50 years later than when it developed for us... because we weren't distracted with colonizing another planet. And then when they do have their own internet, they can post questions on it wondering if it was possible for a world to have a super advanced world-wide computer network, but never develop basic interplanetary space flight. [Answer] IMHO, if they have space flight but not social media, it's because they just don't want it. Then you can suppress the primary reason for social media : wanting to interact. As humans, we are really gregarious people (even when introverted), but it may not be the case for this race. There are many possible explanations to the situation, but here is one of them : When a human meet another human, he enters unconsciously a 'social mode'. It may not be the case for that species, prefering to stay in their inner world, than to interact. They would be uneasy with their social mode. So they may be highly introverted by nature, and still have a high level of technology because they live for hundreds of years, allowing them to considerably advance their technology, then pass it down to their descendants when they die. (Interesting fact, introverted people tend to be more focused on one task at a time, according to Jung and other people's researches) And, if their space flight force is advanced enough to go from one planet to the other in a few minutes, why create social media ? They are close enough. At most, they would create some basic communication systems. Also, it seems like, when you live for a longer time, you don't feel the need to meet people and to do things at the same pace as you do when you live a short life. This way they would have great technology, but no social media or the like. [Answer] Depending on how much of history you have developed for your world, they could have potentially had much of that technology and lost it in an apocalyptic level event. (The setting in the Partials series is like that - a worldwide plague that nearly decimated the human race resulted in a loss of the power grid, usable cars [no one was making the fuel], the internet, anyone who understood how filesystems in computers worked, etc.) This could potentially fit with your two planets idea - the race left one planet and brought only the most necessary technology with them, lived with what they had/improved it, and then returned to repopulate the other planet after the disaster had passed. Echoing many some answers, they also could have never invented the technology you don't want them to have. Maybe they had the ability, but life is hard enough for most of the population that frivolous technology was never widely adapted. (Would the residents of Tatoonie have had time to use the internet? Or would their time have been better spent harvesting moisture for survival? Also refer to the Firefly universe - Outer Rim settlers have very limited resources and struggle to survive, even though the Central Planets where they came from are rich and full of technology.) There is also the possibility that the geography of the planets prevented them from creating certain things. For example, people generally connect to the internet in two different ways: wired or wireless. In our human history, wired communications came first. Swamps and deserts could make it very difficult to place enough wires to connect the planet on the same network. (Each town could have a mini network if that fits with your world, but how would they standardize it across the entire planet? Let alone two planets? It would be a very time intensive process.) A similar argument would work for wireless - how can you build a wireless tower if there is no stable foundation? Limited availability of necessary resources for building technologies could inhibit the invention of other technologies. If the race's focus on wireless communications was for long range communication, then they would drive their resources into that instead of short range communications. [Answer] It's quite easy to have extremely advanced space travel and yet not have the Internet or social media. The two have nothing to do with each other, other than they were both created by the Cold War. In fact, as Quentin Clarkson answered, space travel was invented first! The Internet as we know it now with its Facebooks and Youtubes and Googles came from a quite specific sequence of situations, without which we probably wouldn't even imagine them. First of all, the cold war lead the US military to develop a communications network which was the framework for the Internet, then the notion of using this network for educational institutes to share knowledge, then the popularity of the World Wide Web, multimedia and general entertainment (especially illegal downloads, porn, network gaming) lead to the widespread use of the Internet and fueled a large industry in telecommunications research and development and the invention and popularisation of smart phones. Take any of that away and you don't have what we know today as the Internet, and if it even exists it's certainly not within the hands of the general public (so Social Networking means going to the pub and talking to people). This has absolutely nothing to do with Space Travel other than that was also motivated by the Cold War. Perhaps the crews of spaceships would benefit from a high-performance communications network, but it would have no reason to spread beyond that. Just as a side note, if their planet's gravity is lower than ours, then space travel becomes a lot easier... [Answer] It is hard to consider computers at all if you can't eventually put them in a network, and evolve into something resembling a global network. To go to space without this, I see 2 options: ### The world is controlled by a dictatorship And basically no one has computers except government agencies. But they'll have networks eventually, and use it to share cute cats images. ### No-computer space flight They have another way of flying to space. * Space-flying animals, * Telekinetic power to control the engines (with a natural understanding of rocketry that does not require computers for modeling space trajectories) [Answer] There are quite a lot of ways that this can be done. Many have been mentioned in other answers, but I'll try to list them (more or less) comprehensively with examples where I can find them (some of which may have advanced technology but use a means of achieving space flight where they didn't really need it). I also think there are at least some new ideas in my answer. ### Non-FTL Communication is a challenge This is a thing that I think would be very strongly present if we now started to travel the stars. Not being able to stay in contact with "the internet" as we move away from earth means when in space, there won't be an internet as you're currently used to. When creating a small outpost somewhere, the lack of infrastructure (satellites and cables) would probably be a big hurdle as well. If instead, these aliens just managed space travel before internet these hurdles may prevent it from becoming such a huge hit in the first place. A prime example of this in fiction would be [Andromeda](https://en.wikipedia.org/wiki/Andromeda_%28TV_series%29), which has the two rules that (1) there is no FTL other than FTL travel and (2) FTL travel can't be done by computers. This leads to a place where in order to communicate you will generally need a ship with a pilot, meaning you get messengers instead of networks. ### Computers were banned [Dune](https://en.wikipedia.org/wiki/Dune_%28franchise%29) has a rich history where in the wake of a war against androids computers were banned. The result is a low-tech space-faring community. ### The technology was lost Some galactic event caused the space-faring communities to lose their knowledge of the old technology, but because space travel was extremely important to many people, it survived the purge. ### The technology was given (or traded for) In [Babylon 5](https://en.wikipedia.org/wiki/Babylon_5), the humans acquired their space technology from a race known as the Centauri. With this show having been made before the internet was at its current levels, it wasn't really a big thing in this show either. However, you are completely free to choose when this happens and thus what level of technology the species has when it gets to travel in space. ### The technology was found In [Spore](https://en.wikipedia.org/wiki/Spore_%282008_video_game%29) much of the progress you make in order to travel through the galaxy comes from a wreckage you find on a nearby planet. [Mass Effect](https://en.wikipedia.org/wiki/Mass_Effect) has a backstory of the humans finding technology on Mars that allowed some space travel and then using that technology to find a space relay. In [Stargate](https://en.wikipedia.org/wiki/Stargate) a whole lot of species are planet-hopping through gates left by a species that is now extinct. Basically, this approach is used quite a lot. ### Space Travel was a priority Perhaps the planet was becoming uninhabitable. Perhaps looking at a nearby inhabited planet (and perhaps even communicating, since radio messages would be relatively easy, if unpractical compared to current instant communication) made people long for space travel. Perhaps a biological need makes subjugating new species a must for the species. One way or another, the advancements towards space travel can be greatly accelerated if there is more interest in it. ### Space Travel was easy If your species lives on a planet that removes some of the barriers to space travel (like for example a lower mass and thus less gravity) or the species itself removes some of the barriers (like being more tolerant of radiation and/or extreme temperatures) this could mean that space travel simply happens before computers get to their high point. ### Space Travel was an accident [Star Trek](https://en.wikipedia.org/wiki/Star_Trek) has an eccentric scientist inventing the warp drive mostly on his own. It wouldn't be much of a stretch that such a person was way ahead of his time. He may also have created something he didn't truly completely understand. That way, you can introduce space travel in a society that's considerably less advanced than our own. ### Computers are hard For some reason (perhaps the scarcity of certain resources) developing good computers was a lot harder than it was on earth. This meant that the species was able to reach space before being able to make computers into what they are today on earth. ### Computers were never a priority Perhaps the species wasn't inclined to making computers (or just social media) because they didn't have the same obsession with communication as humans do or because other things (religion?) simply clashed with it. While they didn't develop computers, space ships didn't have the same problems, so they ended up in space without having computers (at the level that we do). [Answer] One way to limit technology is to rely on biology. Horse breeding is something humans figured out long before they had a concept of genetics. So your primary-race doesn't need a concept of electromagnetism to figure out that plants turn light from the sun into breathable oxygen. So this tinkering with genetics can give you ships use water as rocket fuel and very efficient engines without your race having advanced understanding of the underlying principle. photosynthese I believe is a complicated very efficient cyclic system with if I remember correctly more than twenty different steps. So yeah writing up a plant like rocket engine that is as efficient as modern ion engines but lots more thrust isn't a hard stretch of imagination because nature is damn efficient in what it does. Navigation in space will require some other solution because that requires pretty darn accurate measurements. A rendezvous in space is one of the hardest thing to do because of huge speeds that spaceships are flying about. (or in this case plants and creatures) But a natural evolved ecosystem of creatures that migrate from one planet to the other as part of its cycle would be a nice story. Remember birds, fish and instincts can return to there birth place using magnetic ley lines in the earth surfaces sometimes across generations. [Answer] Your planets are both more in the size range of say, Mars, than Earth. As a result, escape velocity is weaker, so that space travel isn't nearly so difficult to achieve. However without the extra core mass, the natural electromagnetic field isn't strong enough to properly shield electronic devices from your primary's radiation. That leads to computers being extremely expensive and rare - prohibitively so for anyone who isn't a major research university or strongly supported by the government(s) - or to the extent that mechanical calculators are the only thing that work reliably enough to be built in large numbers. Additional effects on the biology of your species due to the higher flux of radiation would also be worthwhile exploring. Perhaps they don't all live long enough to be social enough that social media gain sufficient membership; there could be sociocultural artefacts that result in strongly antagonistic relationships being predominant - the collective development of space travel and other technologies would be a paradox of their individual desire for glory and power and one-upping everybody else, or the need to have an enemy balanced by their intellectual knowledge that fighting each other leads to even their own decline, so they find that enemy somewhere else and have to actually get there. [Answer] Harry Turtledove wrote a short story "The Road Not Taken" in which space flight is based on a gravity drive that is absurdly simple but doesn't fit with the rest of physics. If we say instead of in the 1400s tech level we discover such a gravity drive or a kraken drive or some other such thing in the 1900s, computers would still rise, but the signaling problem would bootstrap us beyond the world too fast and the internet would never rise. The forces that created the internet in our history would never be, and the forces of high speed universal interlink could not be resolved if we're off the planet before developing independent electric circuits and off the solar system before digital computers. [Answer] Maybe they would never have a need for Internet / social media if they had a mesh telepathic network across the planet, where each humanoid is a node. <https://en.wikipedia.org/wiki/Mesh_networking> Is this a homework question? If so, your teacher is hilarious. [Answer] ## Living computers The challenge in your question is that space travel requires the same things as an internet from its computers: High-speed long-range communications, processing high volumes of (sensor) data and wide compatibility. If your people design and build such computers for their space ships, it will occur to them to create a wide network and start sharing more and more information. So what if these functions specifically were provided by a completely different device or even living being? Perhaps every navigation computer houses an "Antares Star Crystal" that not only is able to communicate with every other ship so equipped, but also navigates by controlling the ship's drive if it's exposed to the exact light spectrum of a specific nearby star for long distance travel, or a 3D map for close range maneuvering. Your people may or may not be aware that the crystals are sentient, but they provide such a vital service that they are used universally, even if they hijack the ship and return to Antares when not taken back there and exchanged for a different crystal within 3.14 years of being "installed". These Crystals simply don't perform networked communications as far as anyone is aware and they're highly tamper-proof (see hijacked ship above), so nobody in their right minds tries to build an internet using them. [Answer] # They have a fascist society where the government directs all scientific progress. Give your race an authoritarian dictatorship for a government analogous to the fascist states of the 1930's. In order to stay in power, such a government has to posses a certain "wow factor"--they rely on powerful imagery and appeals to emotion to subvert the population's desire for freedom and autonomy (assuming your species posses these desires). Propaganda is the most obvious way of accomplishing this, but propaganda is not limited to posters and radio broadcasts--technology can also have a nationalist spin. During World War 2, Nazi Germany poured ridiculous amount of resources into [ambitious weapons programs](https://en.wikipedia.org/wiki/Wunderwaffe) as part of their propaganda program. The point of this research was not to solve a practical problem (and often was a rather strategically poor allocation of resources), but to inspire the populace by impressing them with their nation's perceived technological superiority (and presumably the mental and disciplinary superiority that implies). Consider our own history of space travel: the first ever rocket to reach space was based on a Nazi missile (the [V2](https://en.wikipedia.org/wiki/V-2_rocket)), and much (if not all) of our early progress in space exploration was motivated by the [cold-war competition between the United States and the Soviet Union](https://en.wikipedia.org/wiki/Space_Race). Indeed, ever since the US beat the USSR in the race to the moon, [NASA's funding](https://en.wikipedia.org/wiki/Budget_of_NASA#/media/File:NASA-Budget-Federal.svg) has fallen dramatically as the nationalist appeal of space travel has diminished. So your species' government invests huge resources in space travel because it convinces the population that the government: * Can do amazing things. * Can do things the people could never hope to do without the government. * Possesses incredible, [terrifying](https://www.youtube.com/watch?v=P764e7fW-UM) power. But of course, this doesn't afford the government a perfect monopoly on space flight. I imagine all ships would have the government logo etched onto every surface, and the technical details of some components would remain highly-guarded secrets. But anyone with an engineering hobby would be able to scour junkyards for usable parts (very Star Wars), and anyone willing to give a speech about how they would only use their ship for patriotic purposes could probably negotiate a gift from Supreme Ruler xCh'Alxch. Or maybe if you run enough missions for the government you get to keep your ship if you're injured and forced to retire from active duty. Or of course you could steal one, but you didn't hear that from me. --- Now, consider the internet. It's probably the single best platform ever conceived of for anti-establishment discourse and organization. While they're not fascist per se, consider [how some modern countries view the internet](https://en.wikipedia.org/wiki/Internet_in_North_Korea). Your government wants to remain the sole source of power in its domain. The rights to free assembly and free speech are out the window. The government is more important than your friends or family: why would the rulers permit the creation of a social media system that will only encourage citizens to forget this? The relationship between capitalism and fascism is complicated but fascists typically despise anything that is not nationalist, and this includes materialism and consumerism. So your people don't have the commodities typically associated with a technological society simply because they would distract them from their patriotism, and it increases their reliance on the government. Extrapolate this principle far enough, and the common people can have as low a standard of technology as you want. Alternatively, you can have a world where there is an internet and social media, but it's so obnoxiously regulated and filled with fascist propaganda that no one uses it the way we do. [Answer] ## Opportunity, Risk, Profit, Cost You're looking for things that would boost one technology over another. Certainly we developed spaceflight before the internet and social media but could we have developed efficient spaceflight before the internet and why would that happen? ## Opportunity Everyone on the original home world (you haven't specified which this is) would have grown up looking up at the sky at another world. Not just a dry barren planet like our moon, but a world with trees and plants and seas. Something that would have drawn them up and away from their known world to this wonderful new unexplored world full of adventures (and profit). ## Risk Theirs is a world at war. The internet is a known concept but nobody would risk attaching their system to the outside world as it would be attacked. Even basic dumb communications terminals are attacked. Telephones, where they must be installed, are in isolated soundproof chambers so there's no risk of it being used to overhear conversations. Loose lips sink ships. Point to point lines and messengers are the messaging systems of choice and even then no confidential information is transmitted. There's no way they'd move into our casually open, share everything mentality that social media requires. ## Profit and Cost One world is dry, the other wet. This means there's always money to be made moving water. But water is heavy and inefficient to move from place to place. To make money moving water you need to massively improve your ability to lift out of a gravity well. This led on to a gravitic drive (if you like) that also allowed cheap interstellar travel. ## Back to that war The factions have fought themselves to a standstill, resources are limited but then they looked upwards. There's another world there, full of resources if only they could get their hands on them. So begins the space race, not just about getting there, but getting established and moving bulk back and forth. It's a habitable world, just saying "we got here first" isn't good enough, it's about taking control and exploiting that control to best effect. --- Whether you follow up from these options or others, the primary triggers will always be social and psychological. [Answer] They could be located very near a strong source of naturally-occurring EM waves, such as the [Centaurus A 'radio galaxy'](http://www.nasa.gov/topics/universe/features/radio-particle-jets.html). The radio waves are created by [synchrotron radiation](https://en.wikipedia.org/wiki/Synchrotron_radiation)- relativistic electrons moving through magnetic fields. In the case of Centaurus A, the center of the galaxy contains a supermassive black hole of 55E6 solar masses that ejects a jet that is responsible for the radio emissions. Any kind of electronic device thus does not work very well unless it's incredibly well shielded, meaning that such devices are more like laboratory physics experiments than handheld devices. [Answer] The singularity happened, and most of society fell into it. The people in this world live in the wake of the singularity. They don't understand their technology: for any X, the most efficient X is a repurposed post-singularity device that you figure out how it works via experimentation. They don't understand how almost anything they use work. They have devices that produce ship plating and struts and engines, but they don't understand how those devices work. Communications technology is dangerous because of the remnants of the singularity. The singularity lives in information, and hijacks any communication channel. It also produces entertainment for the plebes left behind (as a kind of reflex). That entertainment is very good; too good. People who let themselves fall into it become addicted. It is also educational; it teaches you things. Things that convince you that uploading and joining the singularity is your best option. People who use communication technology leave; as a matter of selection pressure, that is equivalent to dying. So you can set up communication links, but doing so requires you to basically kill someone over time, or use increadibly restricted bandwidth. Even then the communications are unreliable, as the singuarities reflex processes "improve" the data being transmitted to be "more useful". Things aren't all bad. The singularity has built more than one beanstalk per planet, and the cornicopias that produce particular goods allow a relatively low-tech society to have access to blasters and spaceships and force shields. (The cornicopias don't produce "blasters" and "engines" and "force shields", but rather things that do strange things with physics that post-singularity folk have figured out how to craft into them.) And singuarity-process defence systems prevent planets and beanstalks from being destroyed by said ships with ridiculous reliability. Understand that the singularity you interact with is the rough equivalent of the immune system of a human being is to an amoeba. It isn't the real singularity, just some leftover processes and systems from an earlier phase. It has rules about not directly controlling human brain information processing, but all other processing is fair game as far as it is concerned. Cornicopias need not be simple objects that mass produce matter or process it. They could be ecosystems of strange creatures whose output is miraculous; like pseudo-organic beatles that burrow through quartz and excrete crystals that when processed in certain ways let you project a force shield, yet who reliably die in captivity. [Answer] I would say priorities. Perhaps a previous world of theirs went under some kind of slow-acting catastrophic event, which caused them to have to spend more time learning how to travel between worlds. You don't have the time to sit about dreaming up any other types of technology when your world is ending. Since their colonization of these two worlds, they have needed to set up trade routes between them (perhaps the water world provides water to the dry plant in exchange for minerals?), causing them again to put most of their efforts into what they do best: Utilising their knowledge of space travel to get stuff done. [Answer] Any communications technology like the internet only works because people want to use this way of interaction. Your species might be able to create something like the internet, email, etc. but have a very strong dislike to this kind of communication at all. This would work best in a society of strict social conventions. I'd like to imagine them technologically very advanced and at the same time having a very strong attitude on how proper interactions have to be: If you can, you talk in person. If you can't, you send someone. If it has to be, send a letter but always with due respect to certain manners. Physical letters are preferred, and if really necessary digital letters transferred via physical storage are acceptable. Books are ok, even electronic ones or databases. But any transfer of knowledge is another matter of communication and has to follow rigid social conventions. Around these organizations could form, maybe like medieval guilds who hold control over the distribution of data. [Answer] Their homeworld was hit by an asteroid that greatly increased its rate of spin which gives the planet an elliptical shape. Moving towards the equator is like climbing a mountain range and even if the peaks of this equatorial mountain range only reach the upper atmosphere that would still make it a lot easier to launch things into space. Maybe there's some sort of plant or animal that naturally produces the chemical components for highly energetic fuel, like how we used to make gunpowder from various kinds of faecal matter and urea. I can easily imagine some sort of create (like the bombardier beetle) evolving to produce a chemical bomb inside itself so predators gain nothing from attacking them. [Answer] Larry Niven's got this covered in Ringworld: A superconductor-eating virus. After inventing high temperature superconductors (or your favorite omni-useful invention), they get used in EVERYTHING: Particularly in computers and networking and communication. Once this technology has bedded down in society for a few hundred years, everything absolutely depends on it. Then along comes some mechanism like a virus, that eats the superconductor. They spread like wildfire, and overnight, everything stops working, except for a few isolated technologies that didn't use superconductors. Maybe the spacecraft is structurally intact, and the drive still works, but all the computers and the like are dead, and after a couple more generations, nobody has any clue how to fix 'em. [Answer] My first thought is that the civilzation that has spaceflight but not a lot of other "more common" (to use) technology could be because that civilization does not have a greedy set of motives in life. A lot of the technology that we have exists because people developed that technology for money/status (some form of personal gain). If said civilization had lifeforms that did not really care to be better than others the same way than humans do, its likely that entire fields of technology would never have been developed. I imagine a peaceful socialist society, containing a basic income, where citizens are content with living an "average" life and exploring the cosmos. [Answer] You don't necessarily need to fry all electronics, just make long-distance communication much more difficult and expensive. Suppose your binary system is bathed in radio-frequency "noise" so severe that it would jam just about any attempt to send a radio signal. It's so bad that you can't even use a telephone system with a wire between two adjacent rooms unless the wire is very heavily shielded. The development of any sophisticated electronics would be severely held back by this natural phenomenon, allowing other technology (such as rocketry) a long time to develop before computing could catch up. And when computing is finally developed, it remains a highly localized thing for far longer than it did on Earth, because the infrastructure that would be required to support the networking we enjoy in many places on Earth today would be orders of magnitude more expensive to build than ours was. Spaceships might then become a practical reality before even the telephone does, let alone the kind of global internet we enjoy. As a reader, I think I could swallow the notion that a civilization in such circumstances might even get around to building fairly sophisticated robots before they decided that there was an easier way to communicate over long distances than than either personal travel or couriers. [Answer] See: Warhammer 40k, Dune Battlestar Galactica In BSG - computers are not typically connected to each other, due to fear of viruses. For example, none of the computers on the Battlestar itself are networked. In 40k, the Imperium of Man fought a battle long ago against some sort of AI race, and now computers, much less networks, are exceedingly rare. Ships the size of cities are flown with the human brain, and a little magic. In Dune, the Butlerian Jihad (which occured before the books) involved a war against machines/A.I. Whilst in all 3 cases, the race HAD developed the technologies required, they no longer had (ready) access to them. Mostly, this fear of technology took on religious overtones. [Answer] They could understand chemical reactions and thrust as well as hull pressure and life support. Understanding these things will allow space travel within the same star system. Telescopes help, and do not require electronics. Electricity and radio may be something they haven't thought of yet. Look how long the Chinese have been using rockets, and how young our internet still is? even radio is still new to us compared to the rocket. The exact opposite situation occurred on Stargate SG-1 with the Asgard. Season4 Episode1: Small Victories. <http://www.hulu.com/watch/76401> In their fight against the replicator-bugs. Asgard Energy weapons are absorbed by the bugs, making them stronger. Human projectile weapons destroy them. @13min The Asgard Thor: "You have shown their weakness may be found through A LESS SOPHISTICATED APPROACH, we are no longer capable us such thinking." Dr Jackson: "You're actually saying you need someone DUMBER than you are?" @23min: Thor: "The Asgard would never invent a weapon that propels small weights of iron and carbon alloys.. by igniting a powder of potassium nitrate, charcoal and sulfur... we cannot think like you. " ]
[Question] [ The Hegemony since day 1 of its formation in 2041 has enforced a single global language for: education, legal documents, announcements, and for communication between citizens across the various states and even planets. In my mind (might be a bit ethnocentric) English, albeit reformed/fixed to standardize some of its quirks (which changes exactly I'm not sure of just yet) could serve as a global language. Of course I'm always open to another solution like Esperanto. Would English be a good choice for a global language or do better alternatives exist already? By alternative it should be easier to learn and teach as well as have the capacity to be picked up by virtually anyone with minimal difficulty. Notes: * English would be the language of the state and bureaucracy. However the Hegemony still supports local cultures and languages within the larger global culture established by the Hegemony. * English wouldn't have to be anyone's first language they would just be required to be fluent in it. [Answer] * The Russians did it: the Russian Empire, and its successors the Soviet Union and the Russian Federation established Russian as the language for official and inter-ethnic communication. It worked. Georgians, Armenians, Kazakhs, Turkmens, Azeris and so on learned Russian in school and used it as the language of culture, learning, justice, trade and official business. And Russian is in no way, shape or form easier to learn than English. * The Chinese did it: the Chinese Empire made Mandarin the language of official business throughout the territory. Its successors, the Republic of China and the People's Republic, went further, and, copying the Russian model, made it the language for learning, trade, justice and inter-ethnic communication. All the various peoples under the rule of Peking learned Mandarin Chinese and used it as the language of culture, learning, trade and official business. And, while Mandarin Chinese the language is indeed not that hard to learn, its writing system is a horror descended straight from some Lovecraftian nightmare; and yet, with enough encouragement, they learned it. * The Indians failed: after acquiring its independence, India embarked on a program to make Hindi the common language of the immense country. They failed abysmally, and to this day they use a form of English as the language of official business, learning, trade, justice and inter-ethnic communication. What we see in this examples is that how hard or easy to learn a language is matters but little. What really matters is how determined the empire is, and, most importantly, how strong are the incentives. The Greeks did not set upon a program to make every barbarian speak Greek, and yet for a thousand years Greek was understood from the Pillars of Hercules to the Indus; the Romans did not go about setting up schools teaching Latin to the barbarians in the provinces, and yet the Gauls, the Iberians, the Afri, the Illyrians and the Dacians learned Latin -- and some of their descendants still speak it, albeit in very debased forms, which are now called the Romance languages. The British did not send armies of teachers to India to teach Indians to speak English; and yet Indians not only speak English, but, given a choice between using English or one of their bewilderingly different native languages, chose to continue to use English long time after the British Raj fell to dust. Why does it not matter all that much how hard or easy to learn a language is? Because how hard or easy to learn a language is depends enourmously on what other language or languages a person already knows. For example, according to [learned blog post](http://www.openculture.com/2017/11/a-map-showing-how-much-time-it-takes-to-learn-foreign-languages-from-easiest-to-hardest.html) by Colin Marshall, as [mentioned on the admirable LanguageHat](http://languagehat.com/foreign-languages-from-easiest-to-hardest/), native English speakers find the Romance languages and the Scandinavian languages easiest to learn among European languages, with German being harder, Greek and the Slavic languages harder still, and the Finno-Ugric languages hardest; and we can believe this ranking, for it is derived from the actual practice of the British Foreign Studies Institute. Now consider the same languages of Europe from the point of view of a Russian; undoubtedly, the Slavic languages will be easiest. All children learn their first language with equal ease; after that, any language will be easy for some people and hard for other people. There is no "easiest" language for all the people on Earth; but all the people on Earth can learn any language given the right incentives. P.S. About Esperanto: Esperanto is a tiny little bit easier to learn than English for some people (basically, people who speak natively a Romance language, mostly because acquiring vocabulary is somewhat easier, and Esperanto grammar works superficially similar to Romance grammar); it is just about as hard as English for speakers of German or a Slavic language; and it's harder than English for everybody else on Earth -- Esperanto has more morphology than English, and it requires agreement between nouns and adjectives; it also has such relatively rare feature as reflexive pronouns and future participles (where we see that its inventor liked Latin very much). Per peeve: just like English, Esperanto lacks grammatical gender but has a set of three personal pronouns in the third person singular; this, as in English, makes pronouns carry lexical meaning, which, in any reasonable language, they shouldn't. For example, consider the difference between French elle est venue and the apparently identical English she has come; while the English sentence tells that it was either a female being or a ship, the French sentence tells nothing about whether the person or object who has come is male, female, animate or inanimate: all it tells is that the word replaced by the pronoun is one of a class which requires feminine pronouns and adjectives. [Answer] English will work fine, but then any language will work fine, as other answers have explained. The fact that English is closer than anything else, with Mandarin as the only real competition, means you might as well start there. But I think your real problem is that you're thinking too much of enforcement: > > … enforced a single global language for: education, legal documents, announcements, and for communication between citizens across the various states and even planets. > > > I think this is not only unnecessary, but counterproductive.1 You do need to teach everyone L2 English, but you don't need English-only education. And you need to allow people to use English when dealing with even local government, business contracts, etc., but I don't think you want to enforce it. --- In fact, I think supporting local cultures and languages is not just something to grudgingly allow, but the potential key to a global language taking off. Look at Europe today. What happens when a Swede is in Prague and meets an Italian? They communicate in English. In fact, they may each even do more communicating with the locals in English than by pulling out phrase books or translators to try to speak Czech. If you have a wide range of (unintelligible) local languages, and people traveling widely among them, all you need is for all of them to have a shared L2 language, and they'll use that language.2 How do you get that kind of travel? Obviously you need EU-style freedom-of-movement laws, and various things like prosperity, vacation time, transport infrastructure that you already want anyway. But having distinct local cultures also helps here. People like to go places that have different cuisine, unique historic sites, or even just different attitudes to late-night clubbing. Without any of that, nobody in Europe would bother going anywhere but Spain and Greece on vacation. The same thing works in business. If two Italians want to do business, they do it in Italian. If an Italian and Swede want to do business… well, they could hire expensive interpreters, and then hire bilingual lawyers to check everything over after the fact, but it's easier to just do business in English. In fact, in fields like tech and banking, there are even companies that operate mostly in English instead of in their local languages, because it's worth trying to attract the best people in the world instead of the best people in your town. You want people to absorb enough hegemonic culture that they keep up their L2 English instead of forgetting it after school. But just supporting language communities of around 5-50M people seems to already do that. That's enough people to have a native entertainment industry, but not one so big that it can make people ignore English entertainment. It's enough that high-profile programs can be professionally dubbed, but nowhere near everything that anyone want to watch. It's big enough to get people talking about those subtitled shows in their native language, but small enough that fans have to go to the international internet to really be involved in fandom. As pointed out by Celestial Dragon Emperor in the comments, higher education is also very handy. If you make it reasonably cheap and easy for anyone who qualifies to go far from home for university, the best universities will soon all be teaching primarily in English, and soon most universities will, without being forced. (I believe this is exactly what's happened in India over the few generations since independence.) --- The only real problem is how you deal with Chinese, Russian, and Spanish. Those language communities are large enough that people can arguably get enough travel, entertainment, and business without knowing English.3 But you're talking about "planets", so maybe that will take care of itself. --- 1. I'm assuming you don't want a highly centralized and repressive government, and that you mean what you later say about "supports local cultures and languages". 2. A couple centuries ago, if a Swede and an Italian met in Prague, they'd communicate in French. What's different today is that travel and L2 English are ubiquitous for commoners, in the way travel and L2 French were ubiquitous only for aristocrats. 3. Just encouraging local languages will help. As will modernizing orthography. If Hokkien and Cantonese speakers don't share hanzi spellings for their distinct languages, don't share L2 Mandarin, and do share L2 English, they'll start speaking English with each other. But that still leaves hundreds of millions of people with L1 Mandarin, L1 Russian, and L1 Spanish, which is still too many. [Answer] There are two issues to be considered: * sociopolitical aspect - if the world in 25 years resembles anything like today democracy and listening to the "will of people", then it won't be acceptable. Period. If the hegemony has enough clout to just "order" common language, then it can choose whichever language it wants, be it English, Esperanto or Kanka-bono (on the pain of death sentence if necessary). * linguistic aspect - English is rather unsuitable for a global language. It has way too many vowels, weird consonants, wonky stress system, orthography, well, let's not even talk about the orthography, complex tenses, weird mixed vocabulary, unusually high word/syllable ratio (makes oral communication in noisy conditions worse than necessary). English is also marching towards isolating language, but is not there yet, however its syntax is already showing some patterns in this direction. The only reason why the hegemony would choose English is the number of speakers and the fact that it is already almost a world language. As for constructed languages, there are some that are quite easy and reasonably world-neutral (glosa or interglosa), or at least Europe-neutral (Novial). However, only Esperanto (and with a big, big "maybeeee" also Ido) is used enough to have all the wrinkles and ill-defined features already noticed, smoothed and resolved. There is nothing to replace a large body of speakers and existing literature. Yes, Esperanto is too Eurocentric. But English, almost by definition, is even more Eurocentric (and those quirks of English grammar and syntax are not in favour of simplicity and ease of learning). And, if the Hegemony does not like the accusative, they can always order to drop it from the (formal) language... [Answer] > > Would English be a good choice for a global language or do better alternatives exist already > > > English is Okay. It's currently the language with the [largest total number of speakers](https://en.wikipedia.org/wiki/World_language#Living_world_languages), though I suppose Chinese might exceed that in this century or the next. You can see other contenders on that Wikipedia page. Chinese is time-consuming to learn, apparently, especially to read and write -- that doesn't appear to be stopping the Chinese from being competitive e.g. technologically. Apparently the grammar and vocabulary is relatively simple. English spelling is atrocious, it's hard to guess how a word is spelled if you hear it, and vice versa. Pidgin OK too, no need complicated. --- As an aside, one of the comments says, "I had six years of Latin at school. Today only fragments of that are left". Well conversely I have 6 years of French in school and still get by, it stuck, the difference is that my primary schooling was in nothing but French (and I practised a bit since then). Apparently that happens in France too: i.e. people go to school to learn a standard French. If the Hegemony wants everyone to share a language, then IMO they need to use that language (perhaps exclusively) in school. The way I remember it, I went to grade 1 knowing about four words of French (my Mum helpfully taught me "je ne comprends pas" to prepare me for my first day), and I don't remember much from that first year but by the end of it I understood what was being said and taught in class. Not that "full immersion" is necessary in school, lots of people (e.g. Dutch people) get by in English without having studied it exclusively in school, but I think it's sufficient. [Answer] To go off at a different angle: it does not matter at all which language they speak. Just that they have a common language as well as their home dialect. Imagine, if you become a huge success your books may be translated, and what then? Depending how many centuries in the future you are, the language would change, and 21st century people would not understand it, just as most of us today would not understand Chaucer in the original. Tolkien got around this by calling the common language "Common speech" without further explanation. Just about everybody spoke some form of it, even the orcs, because the plot demanded that they communicate. (Picture junior orcs in school chanting verbs...) Some SF authors call it Anglic or Galactic, but it's the same thing. Easier to write about than the handwavium translator implant (which is actually more likely IMHO). [Answer] * Enforcing a common second language in school sounds mostly workable. Keep in mind that quite a lot of people go to schools without learning a foreign language, and that even for those who do the practical communication skills might be rather limited. (I had six years of Latin at school. Today only fragments of that are left.) So what happens when one of those goes to an office? Tries to file taxes? * **Supporting local cultures and a common global culture are contradictions.** If the Hegemony wants to maintain local cultures in their distinctiveness, it has to support their primary languages. If it does that, there will be people who speak no foreign language. * Going to other planets might be the filter. Your Hegemony could require all astronauts and off-world colonists to be fluent in the common language, for safety reasons if nothing else. They could subtly or not-so-subtly discourage ethnic groupings in space. Earth might be the only place where the "old cultures" live. The rest is homogenized, bland "Hegemony default culture." * Enforcing a language for communication between citizens sounds pretty totalitarian. They might get away with requiring it in public documents, with the problems noted above, but is the "language police" going to swoop into pubs where people speak the old language? If they do that, they're pretty much on the way to eradicate all other cultures. * Don't forget religion. Christian ministers have to learn Latin, ancient Hebrew, and ancient Greek. They're not using it for day-to-day communication, but maintaining those skills is important for their job definition. Oh, and depending on what kind of future you want to paint, the language might be Chinese and not English. [Answer] NO Canada has a french-speaking population and an english-speaking population. Practically, it made sense to impose english as a common tongue. The french regions tried to secede. Twice. Don't discard a third attempt in the future, despite a much more relaxed fully dual english-french bilingualism for everyone. In Spain, spanish is the common tongue. Catalans are pushing to secede. In France they used the impulse of the french revolution to impose french as the common language. Nearly two centuries of corsican terrorism ensued. Of course, the language was not the only reason for these movements, but it acts as a flag to rail after, and sure it is the main collective feeling of the community, their common soul. Whenever they're not happy with your government, whenever there's a problem, an economic crisis, a perceived offense, real or imaginary, they will gather against the tiranny of the english-speakers. Sure, you can impose your language. The romans did it, the spanish did it, the russiand did it, the english did it. You only need a big army and a healthy disregard for human life. You conquer their countries, lay waste to their cities, kill the population, enslave the rest. After some time, out of the need for survival, they learn the language of their masters. It's far easier if they can't write, or their tongue does not have a rich literature of their own, since the language of the conquerors is perceived as a language of culture and power, of people of wealth and authority, but with enough time and harshness it works even against fully mature languages. It won't be quick, however, and it will be nasty. Expect problems all the way. As a matter of fact, don't expect your Hegemony to survive the troubles. I don't know if this is a problem with people who's monolingual, or at least raised speaking english, but it's not the first time I see a question like that, always asked with an naivety it makes me shudder. You really, really don't know the can of worms you can open meddling with an issue as sensitive, as closed to the individuality of people, as language is. There's a reason the EU hasn't tried to enforce any kind of common language, be it english or german, and settled for three different working languages (and that, after much fight and trouble) and just traslating everything else. It's because if they tried, the EU would dissappear next morning. The intelligent move is doing nothing, just like the EU has (not) done. English is nowadays learnt as foreign language in almost every country which does not speack it as a first language. Make the documentation and common proceedings of your Hegemony be in english. Translate everything that is sent to it to english for storing and internal work. Don't dictate anything about languages, and let people sort their communication problems as they can. [Answer] Personally, I would suggest that Mandarin is going to become the global world language. However since few American or Western writers OR readers can speak it, I suggest that anyone writing for this audience sticks to English. The 'global language' that any book adapts, of course, will be the language of its readers. [Answer] If the Hegemony wants to hang on to its power, it had better pay attention to how people will be actually communicating in 2041. Back in the 1930's Otto Neurath & his friends in Vienna created "Isotype", which is "a method of showing social, technological, biological and historical connections in pictorial form." (from Wikipedia). A few years ago the Chinese artist artist Xu Bing created "Book from the Ground", which is "A book without words, recounting a day in the life of an office worker, told completely in the symbols, icons, and logos of modern life." (MIT press). And lately in America effective use of emojis has become important in politics (Alexandria Ocasio-Cortez is gets it, Mitch McConnell doesn't). You can see where this is headed. Verbal and textual languages have always dominated visual and pictorial languages, but the competition has always been unfair, because words and text were cheap to produce while images were expensive. But that's no longer the case because of computers & smart phones. [Answer] It wouldn't be the first time language was forced upon multiple societies. when the conquistadors came from Spain they forced language among other things on the preexisting civilization. the same thing happened to the native American groups; with the new American colonies spreading westward. [Answer] At this time English is growing into a global language (and has done so over the last century at least) and with a bit more encouraging might become the 'first foreign language' in most of the world without force needed. Spanish, Russian and Chinese are the main languages in parts of the world but those languages are not that popular as second languages where they are not spoken by officials. Chinese has a disadvantage that while the written language has a wide spread, the spoken versions have smaller areas and are often not understood by speakers of a different version. There are no areas where Esperanto is spoken as the main language and there are very few native speakers who have used it as first language around the house from birth. So I would rule that out even as a forced language. If it had been 2142 maybe, if in the mean time it had become a first language for a big group of people. But not in under 25 years. When you look around in Europe, which countries have been happy with English as 'first foreign' language or just 'a foreign' language, it is the ones where a lot of entertainment is shown in English, with subtitles on TV, or freely available on internet these days. In France it went from a hardly spoken foreign language to one that almost all young people speak, with the young people getting English language content via internet, in the last 20 or even 10 years. I think the way you can get one language in your world empire is to award people who speak that language, (whether it is English, Spanish, Russian or Chinese,) by better jobs, influence in local, regional and maybe national/world level, like only get voting rights when you have passed a basic language level test. And spread that language by it being on TV (subtitled if needed) and other communication methods. By teaching it in schools for all age levels but only as language lessons and not as the language for all classes till it has been mastered by most and accepted as first language for that area. And do not forget (fun) courses in it for the adults and elderly. [Answer] There are two aspects to this question, this two to the answer. One: English sucks. If you're forming a new government, consider implementing something like Orwell's Newspeak, which is a language that was designed for the purpose of limiting one's ability to express such concepts as freedom and liberty. If you're constructing a new government and want a universal tongue, I recommend a Conlang, that is, a constructed language. The language can be much simpler than any existing language because it hasn't gone through centuries of evolution. Someone can design it in such a way that it is easily learned and taught to everyone, taught in schools, and within one hundred years that will be the only language around, except sparse native tongues here and there, ever-dying and rare bits of French and such. Dying languages could be used as interesting subplots. Two: English is great. Everyone knows it, it already exists, and stating that everyone must know it and using it as the official language is a good choice. Other choices would be Madarin or Arabic, both the most common of tongues. That's my answer! Hope it helps. [Answer] > > Of course I'm always open to another solution like Esperanto. > > > Bonege! Tiam vi certe ne uzos Guglo-tradukilo por legi ĉi-tiun respondon, ĉu ne? La vorto "malferma" uzita tiel malserioze, zorgigas min. Estas pli facila diri "mi uzos alian lingvon, se mi bezonas", ol faru tion. Eĉ kompreni ĉi tiun lingvon bezonas tempon kaj penado. Okdek procento de la mondo ne Angle babilas, eĉ plu ne Esperante. Ĉu estas sufiĉe da instruistoj por instrui la tuta mondo dum dudek kvin jaroj? Ne. La lernantoj lernos malsimilan version de la lingvo. Vi havos "babilatan lingvon" kaj "skribata lingvo", kiel la Franca. Diru al homoj ke ili devas lerni, ili ne volos. Diru "via historio estas \_\_\_" kaj ili kolorigas kaj trafas defendi ĝin. Oni/vi/unua ne povas "venki". (Bonvolu pardonu miajn erarojn, mi ne estas fluanto). --- > > English wouldn't have to be anyone's first language they would just be required to be fluent in it. > > > What I mean is, learn another language as an adult, one chosen by someone else, spend several years doing that, and then imagine you're not allowed to do the important bits of your life in English ever again, and English is relegated to "a provincial cultural relic you're permitted to use in low-importance situations" and say you wouldn't feel resentful. (And if you do say that, I won't believe you). Go on, Google some foreign Government website and imagine every announcement, law and tax and official communication from now until the rest of your life is in that language, and wonder how long it would take until you just paid someone to translate it to English - and felt yourself a righteous and helpful "good person" for doing so. @AlexP says > > P.S. About Esperanto: Esperanto is a tiny little bit easier to learn than English for some people (basically, people who speak natively a Romance language, mostly because acquiring vocabulary is somewhat easier, and Esperanto grammar works superficially similar to Romance grammar); it is just about as hard as English for speakers of German or a Slavic language; and it's harder than English for everybody else on Earth -- Esperanto has more morphology than English, and it requires agreement between nouns and adjectives; it also has such relatively rare feature as reflexive pronouns and future participles (where we see that its inventor liked Latin very much). > > > The real win is not how easy Esperanto is to pick up, because actually learning to think and express yourself in another language is a lot of effort and work no matter how familiar the base words are, the real win is that Esperanto is so fixedly regular that even as a second language you can know when you have some part correct or incorrect because they fit simple patterns with no exceptions. Claude Piron said that, and Thomas Alexander said that; when speaking a natural language as a second language, you always have to defer to a native speaker, but with Esperanto you can say "plural is -j" and it is true for everything so you know you have it right and you know that as truly a native Esperantist. In English, plural can be anything: -s, -ae, -nothing, octop/uses/odes/i so you can never learn a word and then talk about the plural with total confidence, without also learning the correct plural. Someone tells you a distance is "ten foots" and you instantly tag them as foreign, childish, or a bit stupid. People love status signalling and in-groups and status games, like knowing the "correct" plural is "feet", and I suspect that will break any attempt at a world language, long-term. I doubt if even that kind of "simple" is enough to keep a world language identical, because it requires people to learn and use the language with that goal in mind - saying clunky words like `scii` (ss-tss-see-ee) and using phrasing from the 1800s because keeping the overall pattern simple is more important than making every word comfortable, that isn't how people live day to day life. Strong verbs exist, commonly used words get common shortcut forms, and people enjoy inventing new words for things - especially words for "being drunk". > > However the Hegemony still supports local cultures and languages within the larger global culture established by the Hegemony. > > > "The Hegemony allows people to plot against the Hegemony in languages it can't understand". Then it will fall, no? [Answer] The BBC [recently argued](https://www.bbc.com/news/world-44200901) that the need for one global language could soon diminish, as automated translation will make it possible for anyone to understand English content without actually knowing any English. > > "Computerised translation technology, the spread of hybrid languages, the rise of China - all pose real challenges." -- Robin Lustig > > > Taking this idea to its extreme, laws and contracts could theoretically be written in a language which no living human understands directly! ]
[Question] [ Imagine a city on treads; if you've seen or read Mortal Engines, imagine that instead. [![mortal engines city](https://i.stack.imgur.com/tUJzk.jpg)](https://i.stack.imgur.com/tUJzk.jpg) beep beep losers here I come They're constantly moving, and have decent populations. Don't worry about how it works, or anything like that, just know that they are major trade centers and need to be visited on a regular basis, similar to port cities like New York, London, Shanghai, etc. Because of this, mapmakers would need to locate these cities on maps. While magic does exist, and it is the basis for the moving cities, I would prefer that these maps be static, regular, maps. Late renaissance to early industrial technology. Some more info: * I would rather not have these cities move on a regular route, and instead I would prefer them to move on the spur of the moment. * The cities are limited to an area about the size of Mexico, with a vaguely trapezoidal shape. This area is grassland with very little change in elevation. * The cities move at slow-traffic speeds, at about 10 mph. * Instant communications, akin to the early internet but with only text, exist; see [this question](https://worldbuilding.stackexchange.com/questions/218785/what-would-a-website-look-like-in-a-magic-thought-based-internet) * More info added on request. * That "magic communication" isn't universal; it's more like a private net, with only those who are privileged and wealthy being able to receive or send. Not really sure what tech level to tag it as. Feel free to edit if you think it's needed. [Answer] Updated daily, like a weather map It won't be possible to use a static map to accurately depict a dynamic reality. Instead, you just need to update the map periodically. For a real-life example of this, look at weather maps - these show moving things like storm fronts overlaid on a static geography. For most people, there's not usually a need to track these things in real-time - knowing where the storm front is today, where it's headed, and where it's likely to be tomorrow are sufficient. You just need some mapping authority to track each city's location, which can then be broadcast everywhere as the daily "city location forecast". An updated map could be published each day in the local paper or displayed in the town square. I envision the development of a central authority to track city locations in order to promote commerce for these major trade hubs. After all, by virtue of being trade hubs, these cities depend on other people knowing where they are. This would cut down on communications, as each city just needs to transmit its location and receive a compiled list of coordinates of other cities, rather than dozens of cities each needing to transmit their coordinates to dozens of other cities and each compiling their own maps. This parallels how most weather maps are generated, with data from many remote stations aggregated and published by a central group. [Answer] ## Probability Density [![Probability density over two dimensions](https://i.stack.imgur.com/AseI2.png)](https://i.stack.imgur.com/AseI2.png) You mentioned that the cities tend to keep within a "home range", if you will, of a defined size (up to the area of Mexico?) and defined shape (commonly trapezoidal?). Even if the city doesn't follow a regular route, it stands to reason that there will be areas and locations within this range which it visits more commonly and/or at which it remains for longer. I would expect these to include points or areas in which they can harvest resources, make trades, replenish supplies (water? fuel?) and perform maintenance. If these cities have existed for long enough that they've pretty much established their home range and where they want to be within it, then mapmakers should be able to gather the information about where they've been and extract a pattern of "probability density": a graphical representation of where the city is most likely to be found. I would imagine two ways it could be represented on a static, paper map: 1. *As variably-shaded colour:* similarly to how countries are represented on a political map, you could have differently-coloured shapes on a map that define the usual home ranges of the corresponding cities. Where the city spends more time/visits more frequently, the shade of the color is darker; in the parts of the range it rarely visits, the shade is lighter/more washed out. 2. *As sampled past locations:* the map contains a statistically significant number of past locations of the city marked as single dots of the appropriate colour. The probability of the city being in a certain area is expressed by how densely the dots in that area are clustered. (If there is a particular, exact location that the city often occupies, the mapmaker can cluster multiple marks immediately around it instead of stacking them on top of each other, since this would better express the frequency to the reader.) Using this information, a reader of the map can hopefully make some informed guesses about where the city is most likely to be, and then seek news or rumour to confirm one or the other (if no instant communication is available). [Answer] Instant Communication [![enter image description here](https://i.stack.imgur.com/vjMNS.jpg)](https://i.stack.imgur.com/vjMNS.jpg) There are maps of the landscape and there are moving cities. Fortunately your world has: > > Instant communications, akin to the early internet but with only text > > > That is enough to send out coordinates. The moving cities frequently send out their coordinates to the other settlements, both static and moving. The city locations are broadcast in the morning and evening, after the weather forecast. Unless it is a baddy city of course. Those guys do not want to be found. Then don't send out coordinates and they also disguise themselves by wearing a hat with bits of twig stuck to it. > > That "magic communication" isn't universal; it's more like a private net, with only those who are privileged and wealthy being able to receive or send. > > > The coordinates are sent out by wealthy business owners. They want people to know where their city is, because then they can come here and spend money. So they send messages to the central post offices in nearby towns. The post office has a cork board with a local map. There are pins with pictures of the different cities. They use the coordinates to move the pins and update the city locations. People in that town walk into the post office and look at the map. You can reach the whole town with a single message so it's an inexpensive form of advertising. Every large enough town will have a receiver. People from smaller towns have to wait for the postman to arrive from the larger town. The postman brings the coordinates with him. [Answer] ## Frame Challenge: No Map Required In a steppe environment, the smoke from a steam-punk style city will be visible for MILES. An object is visible at a distance of $1.22\times\sqrt{eyeheight\_{feet}}\space\mathrm{miles}$ or $3.57\times\sqrt{eyeheight\_{m}}\space\mathrm{km}$. The top of a 20 story building is visible about 17 miles away. If the dust from the treads and the smoke from heating and lighting and industry is visible until it's 5000 feet in the air, then it should be visible from nearly 90 miles away. The described range of these cities is roughly a square of 900 miles on a side, which means at 10mph, the cities can cross the entire range in about 4 days. Since the city is visible from so far away, travelers just go to any convenient point near the center of the known range and wait. Within a week or two, they will see the city. If the stationary cities around the edges of the steppe are keeping track of roughly where each of the mobile cities are, that would cut down on waiting time significantly. There may be a cottage industry collecting and distributing this information. Catching up to the city once you've found it... using renaissance tech... that's an exercise left to the reader. [Answer] ## You track their positions in a separate almanac An almanac is a book that publishes forecasted information (tides, weather, planting seasons, etc.) using tabular data associated with a calendar. However, unlike the weather, these rolling cities WANT to be accurate so that they can trade their goods. So, the person driving the city has a vested interest in also keeping a copy of the Moving Cities Almanac to make sure that he is staying on schedule and being where merchants expect him to be at any given date. So yes, you have a map, but your city is not marked out on the map anywhere, rather it is kept track of in this separate book. Each year, the moving city sends the almanac publisher its schedule for the following year to be printed, distributed, and sold to merchants and anyone else who wants to be able to find these cities. When you consider [Code Monkey's answer](https://worldbuilding.stackexchange.com/a/227564/57832) about how far away these cities can be seen from the smoke cloud, it becomes obvious that fairly large map grids would be sufficient. So using the following map and almanac, you could go anywhere in C5 on the morning of Feb.4th and keep an eye on the Northern horizon, and it wont take long to spot the giant smoke stack coming your way. But to get even more accurate, you can add Points of Interest as places these cities may stop specifically to do trade; so, if you know the city will be parked just outside of Valonoce from the 9th to the 13th, then this can give a very specific point to meet up with the moving city; so, even if the grid sections are 50 miles wide each, knowing it is going to a specific town or trading post means no time wasted looking around for it at all. Also, just because these cities can move at 10mph does not mean they are always moving in straight lines over ideal terrain. For starters, they need to stop to actually load/unload cargo and conduct maintenance and they need to also be very carful because of their size to go around bad terrain and avoid farmlands etc that they would destroy if they drive through; so, while two PoIs may only be 30mi appart, it might take the better part of a day to get there if it needs to go slower and more indirectly to get through the marshlands or whatever that separate the 2 points; so, while it can move 240 miles in a day, in practice, it might cover much smaller distances making them easier to track down than you might think. [![enter image description here](https://i.stack.imgur.com/V8yXL.png)](https://i.stack.imgur.com/V8yXL.png) For context, the first printed almanacs started to appear in the mid 15th century and became very popular up until the internet phased them out; so, they are very appropriate for your tech level, and don't require any magic at all to use. This makes them accessible to your common merchant and farmer which is FAR better for business than only being able to trade with the magical elite. When every farmer in a community can know when the moving city will show up, then they can co-ordinate their planting, harvesting, etc. to line up with the arrival of the moving city which will maximize the available trade goods for when your moving city does shows up. ## Minor Frame Challenge > > I would rather not have these cities move on a regular route, and instead I would prefer them to move on the spur of the moment. > > > This is a terrible idea. Even today with the internet and instant communication, this is not how bulk freight is done (IE: we can but we don't). All bulk supply lines happen on a schedule that has to be planned months and sometimes years in advance or they do not work. They need to line up with planting, fertilizing, and harvesting seasons to make sure the city is where it needs to be to meet supply/demand. If you don't arrive at a certain town in time for the harvest, then the food rots in its silos and people who needed to buy that food die of starvation and the people who needed to sell it suffer massive economic hardships from loosing their whole income for that year. If you don't arrive at another town in time for the first cold front, then they won't have the wood they need to warm their homes and people die from hypothermia. Every time a bulk freighter deviates from their route for even a few days, it will result in shortages, missed trade opportunities, and very palatable human suffering. On demand goods have historically only been handled by small trade vessels for a good reason; so, if you're going to build a big moving city like this, your only real concern will be in bulk goods and that means keeping to a schedule. If you want a moving city to try to capitalize on spur the moment opportunities, then it should have smaller trucks it can send out to do these on-demand trades, and then those trucks can meet back up with the city later by following the almanac. [Answer] # Static Map If you want a static map, simply make one without the cities on it. The easiest way to deal with it. Assuming that the movement of the cities doesn't affect the terrain aversely to the point it becomes beyond recognition on a regular basis, a geographic map can be created with everything that isn't a moving city on it. ## Displaying the cities As for displaying the cities? Simplified wooden versions of cities can be created with little to no effort and placed on the map. Then using colour coding or letters they can be given unique identifiers. The routes can be displayed using graphite pencils on the map, or a plastic overlay, on which arrows can be drawn to indicate the direction of movement. ## Coordinating Now, as long as cities use a pre-arranged coordinate system, like latitude & longitude it is easy to simply find and paste those coordinates. With help of a communication network, only the city-identifier, coordinates, and direction need to be sent to generally get a good idea of where the city is and will/can be in a few hours. Just send/request updates a few times a day. ## Secure Communication As for how the data is distributed amongst the cities, there is little need for anyone that doesn't control where THE city is going to know where the others are. So they simply don't know, or only get 'older' data (like the maps from the previous years). Now, this brings me to an interesting point: ### Map trustworthiness People can lie. Cities' controllers will lie to each other for their personal gain. Now I would display the known routes (like those checked by scouts) with a different colour than the coordinates gotten from first contact from an unknown city. * Green for certain (seen by scouts. Checked the tracks) * Yellow for allies (Very trustworthy, except when they suddenly are not) * Orange for estimates(Take it with a pinch of salt) * Red for unknowns(Enemies won't tell you where they are) * Etc. You could go very far in this with city A telling ally city B that they checked and saw tracks from their mutual enemy, city C, around those and those coordinates. This would likely warrant at least yellow level trustworthiness for a hostile city. ## Mapmakers Now back to the problem, how would mapmakers deal with moving cities? well depends on who is asking. The public gets old but reliable/checked data with routes drawn on them and separate maps for the cities themselves. The mayor gets a 'live-updated' map with sculptures, drawn-on older routes, estimated paths in erasable pencil, colour-coded and all, and probably a whole 'war room' to go with it. [Answer] NOTE: if you put your [thought-based](https://worldbuilding.stackexchange.com/questions/218785/what-would-a-website-look-like-in-a-magic-thought-based-internet) internet in, with instantaneous communication, there's no issue.. No need to draw any cities on a fixed map using ink. You can connect to the appropriate source and inquire where the coordinates are, e.g. in section BN-39 on the map. Then, put a pawn or token on your map. Or a magic pointer beam of light, whatever.. I'll assume you can't.. no life info.. ## Your city would be like an oil tanker, not change course quickly Suppose there wouldn't be life coordinates on your magic internet.. You have a Napoleon-time civilization that built moving cities. These cities would bring a fantastic military advantage at the time.. they are on large wheels, moving 10km/h, they could outpace an enemy pursuing it on the ground. Military: city can't change course quickly, so extrapolate and intercept [![enter image description here](https://i.stack.imgur.com/vM8GW.png)](https://i.stack.imgur.com/vM8GW.png) Say, Napoleon needs to attack a city like that. I suppose the best way to do that is anticipate its path. These cities are like oil tankers, they don't turn easily. They set out a course and could move in one direction for days. So all you'd need to have is a spy with doves to send you a message from inside the city, using a dove, or a fast courier. When you have your news in 24 hours, Napoleon could intercept the city. In peace time, folks wanting to reach the city for trading could use a similar method. Travel to a place where the city will be, in a few days. All the time of the world, to take your sample and direction. Ask people where it was and where it went a few days ago, chance is you'll find it easily. [Answer] You state that your cities travel SLOW at 10 mph. While that may seem slow to us, used as we are to cars, trains and planes, it is very FAST given your tech-level. Your traders will be moving their goods around at the speed of horse (or oxen) and wagon, which will be more like 3 mph. Your traders can never catch up to a moving city. The only way to trade is to wait for the cities to visit at a known (and fixed) meeting/trading location. Or a choke point in the landscape (like a ford in a river or a mountain pass) were all cities must travel through when they are nearby. So your maps don't need to display the cities themselves at all. They depict the meeting places and other places were you can expect a city to show up sooner or later. [Answer] Don't map them. Map their routes between port cities, as well as the port cities. Label the route, not the city. The data would be outdated as soon as you published the map anyway. Or just update their position daily and only publish online :-) [Answer] ## Maps with Expiration Dates Using your communications network, cartographers would regularly update their maps with known and reasonably certain locations to a particular degree of accuracy – the map's best by date. A city known to be at coordinates x, y on publication day would have concentric circles around it each representing the maximum distance it could travel (factoring terrain) within a given period from that date. By collating multiple editions, someone could track the progress of a given city and reasonably conclude the general direction of it, so even if the map were several months out of date they would have a good idea where they could find it. [Answer] The city route may not be regular, but it still can be predicted. The moving cities have their very own reason to move, it is something like harvesting. Cities deplete whatever the resource they harvest around themselves (be it wealthy customers, unwashed masses of pesantry, particular product made or mined, whatever), so they move on, avoiding places where other moving cities have been recently. Few different types of cities may compete on few different combinations of possible resources, to add some complexity. The land has different productivity and different pattern of productivity depending on the season. And to sum up, a good map maker can predict the city leader's decisions pretty well by knowing the land productivity behavior and the needs of the particular cities. If cities are numerous, a comitee of map makers, each knowing a particular group of these may be needed in order to predict the whole swarm. The map may show predicted tracks of these objects with points with dates on them. The regular maps will be good for a while - say, a year or so. A map good for 2 or 3 years will be more expensive and less accurate. [Answer] As a mapmaker, I've have dealt with similar situations and have seen them dealt with by others. The short answer is that your mapmakers don't map the cities. When an object isn't fixed or trackable, you don't map it as though it was. Wildfires, sandbars, and herds of animals can all be located and mapped in real time today, but historically, it just wasn't practical. Your cities act as though they are animals rather than wildfires or sandbars, moving frequently and somewhat irregularly, but with intent. Like animals, there are going to be patterns. So what the mapmakers map is the pattern. In Colorado (chosen because it's got excellent digital maps for big game hunters at <https://ndismaps.nrel.colostate.edu/index.html?app=HuntingAtlas>), biologists map the seasonal ranges of the animals, the areas herds migrate through, and the overall ranges. Unlike a herd's current location, these things are determined by climate, terrain, and the number of animals, so they change very little year to year and a decade old map will still be fairly accurate. If I was mapping a movable city, I'd ask what matters to a moving city's survival. Presuming the land is peaceful enough that staying hidden is not a priority, cities require things like food, trade, and communication with allies. Food is never randomly placed. The moving cities presumably have farmers or herders they're allied with to supply food. So every year around harvest time, the city will be making a route around its farmlands. A more herding oriented city might simply follow where the animals can find feed in any given season. There could certainly be war if a herding city were to encroach on a farming city's allied farmers land. In order to trade with other cities, there must be large marketplaces where multiple cities can gather. These would be at least somewhat regularly scheduled, and the fairgrounds would be markable on a map. The Grand Fair in the south might be the third week of May, or it might be in spring a few weeks after the first thaw, but it must be regular enough that merchants can plan to attend without going bankrupt. The best quality maps might show that Adams City and Brandon City almost always attend the Grand Fair, while Carver City is more often found at the North Fair, held across the country at a similar time. Meetings with allies might be planned regularly year to year (think major international summits today) or they might be planned on an ad hoc basis between cities. If the second, the mapmakers would mark the areas that could support meetings of cities, but wouldn't provide much else. If there were summits, then the mapmaker could detail what cities and when they should be expected. Of course, if the cities are warring frequently, then all of this becomes much less predictable because a predictable city would become dead as fast as a starving city. The principals of mapping would work the same, but it would be far less reliable. The cities' leaders would have a maproom where they tracked the last known location of cities via pins placed into maps, but the accuracy would only be as good as their communication and intelligence sources. Placing the pins would be the responisibity of traders or generals, not mapmakers. [Answer] TL;DR: Tracking crews (aerial and ground), line of sight triangulation, radio signal triangulation, publishing of future travel routes, publishing of past position data (assumed no satellites). I'm assuming that there isn't satellite surveillance (someone could probably generate an ASCII representation using a couple of satellites and triangulation). I would think that certain moving cities whole industries would be dependent on tracking, for example shifts would go on excursions and set up temporary scout sites to visually triangulate positions by relaying, in relation to compass direction, what angle they can visually spot the city, and roughly how large it looks in their scopes and at what zoom level. In that way a minimum of two scout teams can set up a monitoring period of a city nearby, assuming they are close enough. A single crew would be able to determine direction relative to themselves but only roughly guess the distance based on the zoom level and known dimensions of observed cities. That city could then charge a subscription access to live updated maps, provided that the equipment is built to do so. A few crews can go far and wide, assuming they are equipped for high endurance, and relocate to keep within a certain signal range of their home city; the crews would be the feelers of individual cities, too. This can also be implemented by having each city have their own crews and a "detection net". Cities could also publish their scheduled itineraries, lists of where they have planned in advanced to go to, plus direction and speed. A city is generally going to be very slow to change course. A few more major cities could archive broadcasted locations and provide probability maps (as another answer had already said) based on hourly, daily, weekly, monthly, yearly, etc. data points and can filter from today, 5 days, 1week, 1 month, 1 quarter, 1 year, etc. data sets. There can be an open source database of city sightings, where citizens can submit tips on where they had last seen a city. This method is dubious for usability and probably would be used for search and rescue of a downed/stranded city. Because electronic communication is already possible, cities can broadcast a ping signal like radar containing the angles they had measured nearby pings to be. Cities can collect this information to mathematically triangulate where other cities are. This can also be coupled with the aforementioned crews (the crews plus the city itself can measure angles based on location and triangulate for themselves, assuming a great enough distance is between the crews and the city itself). Overall I would think that the cities would have at least a static point on the ground they are travelling on agreed upon to "ground" their relative position data. An aerial lookout could be a thing. A towed blimp with a lookout crew could do most if not all of the aforementioned tracking methods. Most of this kind of tracking would require a lot of cooperation between friendly cities. I would assume there would at least be a few static cities that drill the land or otherwise require staying in place... there aren't many sources of energy aside from solar water heating, biomass farming, or solar panels (yes, they existed before computers, invented in 1883). [Answer] A map is a record of where a city was, at the time the map was made. For most cities, that's a static location. In this world, any map has a time-to-live and anything older than a week means the city could be 1680 miles away if driven 10 mph day and night. So a map becomes more of a "newspaper" or a "telephone book" that has decreasing validity as time moves on. Since you know where the city was then if the city leaves a trail that can be identified by a tracker when it is crossed, then a profession of "city finder" can exist. Much like a "native tracker" or similar. These tracks are going to be deep grooves in soil, or non-existent in rocky areas. How long it takes a track to be erased by erosion or similar could be a story point - a sudden rainstorm and the barely-visible track has vanished and the city turned sometime in the night. I suggest that a city rolls along at a much slower pace than you've quoted. 10 miles in 24 hours, or far slower on bad terrain would make this more practical. 5 miles in 12 hours then 12 hours to "sleep" may be a more plausible speed, allowing runners to "catch up" and anyone in the way to move herds sideways out of the city's path. Also, a week's travel is only 35 miles and it is plausible the city's smoke stacks/signal tower can still be seen from that distance. Aside, driving in the dark may be considered a "last resort" because of the dangers of the unseen terrain. [Answer] Use a static map with a reusable transparent sheet overlaying it, updating the locations. I suppose the sheet can be made of glass and wiped clean for updates. ]
[Question] [ In most large civilizations on Earth, wood has been a fairly plentiful resource, so we've used it for all sorts of things: Houses, boats, carts, spears, arrows, bows, shields, barrels, firewood, paper and more. In my fantasy world, wood is more scarce and expensive. Partly because forests are dangerous, partly because many of the trees are cycads which, as far as I can tell, don't yield good planks. They do have bamboo, though, which can substitute for wood in many cases. Carts and barrels can be bamboo. I'm not sure about wheels. They might need to be metal with bamboo spokes... Houses can also be built of stone, mud bricks or clay bricks. Paper might be replaced with papyrus or parchment. Small boats and rafts can be bamboo. I am not sure whether you can make large ships out of bamboo. My core question is this: What things might you need or prefer the expensive wood for? EDIT: The reason why forests are dangerous is described [in this Reddit post](https://www.reddit.com/r/worldbuilding/comments/npsp92/a_cosmic_horror_world_haunted_by_basilisks_that/?utm_medium=android_app&utm_source=share). I first thought it was unimportant for this purpose, but here it is. [Answer] Display of wealth. Any hard to acquire material can be used to show either how strong/brave you are or how rich you are to pay other strong/brave people to get it for you. Sure you could build your house out of bamboo like those common poor people, but imagine the sight (in you society) to see a house made of wood. Then you make all your furniture out of wood. Even things that make no sense to be made of wood, would be, to show just how wealthy you are. [Answer] Bamboo fills most "wood" niches. Bamboo makes perfectly good charcoal, it just requires more processing of the plant compared to wood charcoal. Bamboo makes great structural material, beating wood by quite a good margin for small and medium projects. Only for something like a large oceangoing ship is bamboo less that ideal, it does not scale up as well as monolithic wooden beams for strong structural usage. Most of the small doodads that wood is traditionally used for can be made as well or better out of bamboo plus pottery. Or better, by plant fiber composite materials, which just about every civilization discovered, but rarely used because it requires a lot more effort than wood, not because the end product is in any way inferior. Before good steel is available, wood is by far the best material for a load-bearing vehicle or machine axle. Bamboo is useless for the role, even iron or brass are just not as well suited to making a wagon or watermill axle. Ditto for a ship mast, where a balance of strength, minimal but nonzero flexibility, and immense durability is required. Without wood this will be very hard, and they may very well need to violate those scary/sacred forests to source ship masts and machine/vehicle axles. But mostly... We used wood because it was the most common, cheap, available structural and fuel material available. Bamboo is almost just as good, and can usually be substituted 1-for-1. [Answer] we can look at real world examples from deserts, islands, where tree wood is very rare and cultures were bamboo is extremely common. what is wood used for. Ships, you can make a raft out of bamboo but you can't make a large water tight ship out of it without modern composite technology. Axles, hubs, and bearing, even in places where bamboo is common and most of a wagon would be made of bamboo, axles and wheels were made of wood since bamboo could not be carved properly and still survive the high wear. Note for smaller hand carts bamboo will work OK and bamboo might still be part of a wheel, like spokes on larger wagons. tools, The unsuitability of bamboo also extends to bearings for certain tools, like on lathes where they need to surround a spinning a shaft with a wide contact surface. Or pulley wheels, or vises, basically any large thick three dimensional shape that must be solid. The more technological the society and the more complexly carved a tool needs to be the less suitable bamboo is and the more wood for machine parts they will need, right up until the use of metals for such things can become common. Plows, because of how bamboo is shaped, and how weak it becomes if you cross fit it, it is unsuitable for certain parts of plows. on the upside these are all places were the wood can be used for decades before it wears out, so a little wood goes a long way. Expect them to favor hardwoods or rot resistant wood for harvesting, if it is dangerous to get they will want wood that last a long time when they do get it. Bamboo can be used for basically everything else wood is used for bows, arrows, fuel, charcoal, construction, ect/ bamboo is actually better for some things, it makes ready made pipes and containers easily which is not true of timber. Just to be clear you can get wood from cycads, they just grow very slow so wood is still valuable and not abundant. It is similar to palm wood so they might be able to make canoes out of it. Also as others have mentioned pre-industrial paper is as more linen and cloth scraps than wood pulp. So your society still has plenty of paper. Modern paper making switched to wood pulp because it is cheaper, not because it is better. [Answer] For some historical perspective, ancient Greece is known to have suffered from serious shortages of wood. The rocky terrain of Greece didn't really grow anything but squiggly olive trees which are more like shrubs anyway. That didn't really match with its seafaring ambitions, and it had to import wood for that reason. They had far-reaching trading networks but it was still a big deal in a time when trade primarily made sense for higher added-value products like olive oil; shipping heavy bulk commodities like lumber around wasn't considered a lot of fun. [Answer] ## Nothing: In our world, wood is easy to obtain, easy to carve, easy to burn. But cultures without wood do okay for themselves with workarounds. [THIS](https://worldbuilding.stackexchange.com/questions/1406/could-a-technological-society-develop-without-wood) question goes into some of the options, and with bamboo available, I doubt there would be a practical imperative to use a rare commodity for anything essential. What I suspect is that wood would be a rare substitute for the things ordinary people use other materials for. The commoners use coal and peat and grass and bamboo and dung, etc., but it's a sign of wealth to burn actual wood. Think of it like ivory, where small pieces are inlayed to be decorative, emphasizing the grain of it. jewelry would be a good example of a use - it's light, easy to carve and rare. A noble with a gnarled wooden walking stick would be making a statement of wealth. Now wood is a renewable resource. As you get people valuing it as a rarity, there will be pressure to grow more wood, train wood to be straighter, and even breed trees to be increasingly tree-like. You may find that as the generations go by, wood becomes more common and used. Or, it could be so rare people wipe it out from over-harvesting. That's up to your story. But I suspect wood will be valued mostly for being valuable. [Answer] Musical instruments. I can't really give a logical reason why, but that's the way it works in the real world. The same optimal woods (and materials in general) continue to be used despite being endangered, even when it is just aesthetic and not functional, because there's no substitute for subjective quality. Ivory is one of the few traditional materials I can think of in instruments that has outright been replaced at all quality levels, in spite of performance, due to rarity, and that took international laws. Pretty much everything else is just a more abundant substitute for a superior material for use on less expensive instruments. [Answer] One potential use is for the production of iron. Before the 1700s, when coke was discovered, ironmaking furnaces exclusively used [charcoal](https://en.m.wikipedia.org/wiki/Charcoal_iron) in production. This charcoal is generally produced by burning wood in a low oxygen environment. While in principle you could use bamboo or other organic sources to produce the charcoal, given the strategic importance of iron it may be that there simply isn't enough bamboo production to meet iron needs (charcoal production for iron was a significant source of deforestation in the US according to [here](https://www.scirp.org/journal/paperinformation.aspx?paperid=74805)- depending on your settings requirement they may face similar shortages) . [Answer] Incense [![frankincesnse](https://i.stack.imgur.com/U7XbV.jpg)](https://i.stack.imgur.com/U7XbV.jpg) Depicted: the frankincense tree. <https://www.nationalgeographic.com/animals/article/frankincense-trees-declining-overtapping> Trees are the source of many types of amazing incense. Frankincense and myrrh (also from a tree) have been valued since ancient times and there are many more - sandalwood, palo santo, rosewood etc. In your world, wood of various types is most prized for its aroma when burned as incense. Grasses cannot compete. [Answer] Orkney (a group of islands off Scotland rich in prehistory) always suffered a severe shortage of wood. They got by pretty well with stone, whale-bone, and antlers: and they used driftwood that found its way onto the beach from distant lands. But I suspect the biggest problem they faced without wood was boat-building. [Answer] As another answer said, the "display of wealth" option seems to be the most striking one. But it might be interesting to have it used in more ways, not just the most oblivious ones. * Furniture is definitely a great idea that must be kept. It's often the most striking wealth factor after the house itself. * Jewelry : If your wood is particularly hard to carve, imagine the status of those who can actually work it well enough to obtain beautiful objects, and even more those who have enough money to buy such luxurious items. It's a more subtle way to show social rank, one that maybe only the rich and powerful will notice. * High-end food products : Smoked meat's taste is awesome (that's up to personal preference but it can be very rich and flavorful), and it varies depending on which wood you use for the smoke. Now imagine the bark of your trees gives the meat a deep, strong taste, but it must be of prime freshness. Only the wealthy elite will be crazy enough to hire people to gather the needed resource to prepare this fine dish. * Drugs (of any kind): Plants have always been used to create remedies, but also drugs. Maybe using dried roots from your trees can send someone on a trip, or any other effect (energy boost, deep contemplation, etc). I personnally love using rare plants for drugs that artists use (in my worldbuilding projects), because it feels natural for someone who seeks artistic enlightenment, and also happens to have a high status and a lot of money, to use those. The display of wealth seems to be the best option according to me, but it can be interesting to go further than the prime use of the wood, being building tools and furniture. You can do pretty much anything with plants as long as it sticks to the general context and ambiance of your work, so it's definitely a good idea to enlarge the field of possibilities. [Answer] Magic. Trees have an innate ability to collect or focus magical energy, and because they grow slowly over a long time and stay in one place, their wood becomes inherently more conductive to magical energies. Specific kinds of wood could have affinities for specific kinds of magic. Items made from wood conduct or enhance magic in ways that improve the quality or power. Wood is used in rituals, to build magical structures, and to create magical weapons and armor. [Answer] Look at countries that didn't have ready access to wood. Greece, northern Africa, the middle east, west coast of South America, the American Southwest. The Anasazi (cliff dwellers) moved roof timbers tens of kilometers. During the British colonization of North America, certain trees were blazed with the king's broad arrow, marking them as owned by the king, and reserved for naval masts. Broadly speaking: Cheap Wood Wood is used for fuel Low cost wood Wood is used for temporary construction. Moderate cost wood Wood is used for permanent construction. High cost wood Wood is used for critical construction (e.g. roof support) and furniture. As the cost goes up the earlier elements vanish. No one uses black walnut to heat their home. Indeed, a black walnut "peeler log" is worth thousands. Mills lathe off 4 or 8 foot wide strips 1/100" thick to veneer onto plywood. As the cost goes up, so does the engineering effort. Plywood can be made stronger than dimension lumber. Engineered trusses use less wood than conventional rafters. As costs go up, efforts to use other materials increase. Coal replaced wood for heat during industrial age England. Steel coming down in price to the point ships were made of it. (Compare to the price of iron anything in Roman times) In recent times Bamboo flooring and countertops. Hardwood floors become engineered wood floors with the expensive hardwood just one layer. Engineered floors becoming laminate floors. A woodless society would be wizards with stone, masters of the arch. Grass would be bred/gene spliced to make bamboo analogs for every climate. Plants like yucca would be bred to have longer, wider leaves and faster growth. (Even now I bet you could make good oriented strand board out of yucca leaves.) There would be some intense engineering of how to work with adobe. ]
[Question] [ The religion of Zensunnistianity has over a billion followers in the Alt-World that is otherwise identical to our Earth. Its precepts are similar to the major monotheistic religions from our world, give or take a bit of tree worship here and there. It just happens to use the [ensō sign](https://en.wikipedia.org/wiki/Ens%C5%8D) as its holy symbol, placed on ambulances and used by the red ensō humanitarian charities: [![enter image description here](https://i.stack.imgur.com/XMSy7.png)](https://i.stack.imgur.com/XMSy7.png) Now, given that there are so many followers, is it conceivable that the religion of Zensunnistianity could die out (let's define that as being reduced to fewer than a million worshipers)? Presumably, while humanity continues to exist? Thank you for all the answers! Having read them all carefully, I am now inclined towards a negative answer to this question. [Answer] ### No, it’s not possible in our current cultural and geopolitic situation¹. To reach a billion followers, a religion needs to have certain, related properties: 1. It needs to be a “family religion”, i.e., it must be part of the religion (not necessarily its dogmata, but its culture) that followers procreate and indoctrinate their children. “Automatic” procreation is an essential evolutionary trait for species as well as religions – religions that do not have it are too unfit for survival. Acquiring followers in adulthood would not work, as people are too unlikely to switch or acquire a religion at that age. A religion without this feature would die out or be dominated by another religion before it can reach a billion followers. 2. It must address all of society, i.e., it cannot be exclusive to a certain group of people such as a particular profession, class, age or gender. First of all, there aren’t that many groups of people that contain a billion persons to begin with. There are the genders, but being exclusive to one gender would not make you a “family religion”. There are the poor, but inevitably, some poor people will get rich and adapt the religion to allow it. 3. It must at some time be the dominant religion in some larger area (usually a state). Nothing helps a religion prosper as good as general acceptance and social pressure. Without this, a religion can never reach a billion followers. This is also extremely helpful to wear down the edges (i.e., highly impractical dogmas) of a religion (see also the next point). As a rough estimate, half of the followers of any dominant religion only follow it due to social pressure (or such mechanisms as [belief in belief](http://www.theguardian.com/commentisfree/belief/2009/jul/16/daniel-dennett-belief-atheism)) and not due to actually believing in its dogmata. This half is strong enough to shape the religion to be more feasible. 4. It must be flexible and not entirely homogeneous. A popular religion is inevitably intertwined with culture and cannot be popular without adapting to the culture to some extent. To reach a billion followers, a religion must span several cultures and adapt to all of them. The only alternative would be cultural homogeneity¹, which is not really possible as culture is shaped by the actual lives of people, which are not homogeneous. Almost all popular religions nowadays are very flexible and inhomogeneous. To address the more “difficult” examples: Many Islamic countries were much more liberal half a century ago and features flavours such as [Ahmadiyya](http://en.wikipedia.org/wiki/Ahmadiyya); Catholicism varies a lot over the world. (Sidenote: If you define the same religion so strict that this sort of flexibility is not allowed, you cannot have a religion reach one billion followers in the first place.) 5. It must promise exclusive correctness at least to some extent; relatedly, there must be some line to draw between this religion and others. This is one of the evolutionary advantages of monotheism over classical polytheism. The promise of exclusive correctness is essential for most of the above features and is another evolutionary key factor as it keeps believers as they are less open to other religions. Note that I do not understand this in a way that excludes Hinduism, for example. While Hinduism is very diverse, there are still some central concepts that define it. Rather this excludes concepts such as [omnism](http://en.wikipedia.org/wiki/Omnism) (not the discworld religion) or polytheistic religions with a very open pantheon. Now, if there is anything like cultural mixing¹, such a religion will form diasporas all over the world (due to poperty 3), simply because adherents migrate. While this is something very prominent nowadays, it also happened historically, for example to Judaism, Zoroastrianism and [Christianity](http://en.wikipedia.org/wiki/Christianity_in_india#Early_Christianity_in_India) – without these religions gathering that many adherents. While some of these diasporas will die due to adopting the dominant religion or areligiousness, totalitarianism or other hostile environments, chances are high that at least some of them adapt and survive (due to properties 1, 2, 4, and 5). Some of these diasporas may manage to grow in population and sprout diasproas themselves (see, e.g., the [History of Russian Jews](http://en.wikipedia.org/wiki/History_of_the_Jews_in_Russia)). Thus, even if the religion is largely eliminated in its homeland due to some reason, it is very likely that it can still accumulate a million adherents in diasporas. While it may decline in relative population, it is very unlikely to fall below your threshold of one million given the general increase of the world’s population¹. A very good example of how (not that) this can work is Zoroastrianism, which was ironically considered a counter-example in [another answer](https://worldbuilding.stackexchange.com/a/33808/308), but it never had a billion adherents (and some sources even consider it to still have a million adherents today). To address some scenarios suggested in the other answers: * [Celibacy](https://worldbuilding.stackexchange.com/a/33812/308) – strongly violates point 1, the religion could never even remotely reach a billion followers. * [Rituals that nurture epidemics](https://worldbuilding.stackexchange.com/a/33818/308) – some diasporas will resist and the religion can adapt those rituals (point 4). * [Explicit disproof](https://worldbuilding.stackexchange.com/a/33820/308) – many religious people are comfortable with believing contradictions and then there is point 4. To give a practical example: Jehovas Witnesses survived many doomsdays. * [Mass suicide](https://worldbuilding.stackexchange.com/a/33821/308) – Won’t work due to points 1 and 4. --- ¹ which I consider to be part of the premise that the world is “otherwise identical to our Earth”. [Answer] It can absolutely die out if you give it enough time. The most common reason a religion dies, and the only reason that consistently works is supplantation. Take a look at some of the world's pagan religions. If we look at Greek, German, Norse and Egyptian [polytheism](https://en.wikipedia.org/wiki/Polytheism) all were replaced by monotheistic religions, namely Christianity, and later (in the case of Egypt) Islam. These religions were supplanted through various methods. The growth of scientific thought and experimentation undercut the validity of polytheistic pantheons. Why worship Zeus or Thor to spare you from the storms when you know that storms are predictable and explained by natural phenomenon. The growth of monotheistic religions was also supported by government. It is much easier to control a single hierarchical church and the people that follow it than it is to manage people of varying belief systems that may come to physical confrontation. Political leaders made certain religions the 'state' religion to promote it and often times to punish those that did not follow. Its also important to keep absorption as part of this process. Is it coincidence that Jesus' death and birth fall on the same days as major pagan holidays? Hint...it's not Absorbing aspects of local religions that are being replaced helps bring people into the new faith. A good monotheistic example is [Zoroastrianism](https://en.wikipedia.org/wiki/Zoroastrianism). If you follow any modern monotheistic religion you can thank Zoroaster for starting the trend. Zoroastrianism is arguably the source and predecessor of Christianity, Islam and Judaism. It was mainly followed during the times of the ancient Persian Empires by millions of people, today estimates put the number of followers at under 200,000. Notes * Isolated methods of destroying or controlling a religion are unlikely to be long term effective. As @AndyD273 mentioned persecution is not a great way to get rid of a religion...humans are stubborn like that. * It takes time. You are not going to be able to plausibly kill off a religion in less than 2 or 3 generations (at a bare minimum). * They can always come back. Unless it is somehow completely forgotten (which is virtually impossible, especially in the modern era) there will likely be people who keep following the faith. [Answer] There are a few different methods I can think of that would allow a large religion to entirely (or almost entirely) die out. 1. Genocide. Other religions have actively and purposefully decided to exterminate the religion. This doesn't have to simply be the extermination of followers of that religion, but rather a purposeful attempt to eliminate the religion. There are a number of historical examples of attempts to exterminate religions, but probably the most relevant historical examples would be the willful extermination of the religions of Native Americans. When the Spanish conquistadors arrived, their destruction of the Native civilizations - through extermination, disease, enslavement, and forced religious conversion essentially eliminated those religions entirely. 2. Schism. The religion fragments into multiple sects. Over time, the individual sects diverge to the point that neither truly represents the original religion. Examples of this would be the Orthodox / Roman Catholic schism, the Protestant Reformation, or the fracture of Islam into Sunni and Shiite sects. Over time, cultural shifts could reduce the number of followers of the original religion to the point that the original religion no longer exists. This will likely involve appropriation of practices of the original religion. 3. Subsumation. Rather than a schism, a new religion may come along that absorbs the followers of the original religion. As a substantial number of followers convert to the new religion, the original religion is eventually reduced to nothing. Real life examples of this would be subsumption of the Celtic polytheism religions by Christianity. 4. War. While this would technically fall under genocide, a particularly bloody war - like a modern nuclear war - could effectively destroy a religion if the followers of that religion were sufficiently localized. I suppose complete extinction of humanity would be a trivial solution to the problem of 'how to destroy a religion' as well. [Answer] TLDR: celibacy through reformation. One possibility is that the religion, at its core, is unsustainable. For instance, the [Shakers](https://www.wikipedia.org/wiki/Shakers) sprung up during a time of religious fervor (can't remember what that was called). Wikipedia claims that `At its peak in the mid-19th century, there were 6,000 Shaker believers`; last I checked, there were about two of them left. This was due, in part, to people like Mother Ann Lee being hard acts to follow, but also due to the fact that the Shakers were celibate. No new Shaker babies means they had to rely solely on new recruits, who eventually stopped coming as interest waned. Now, the fact that your religion got to 1 billion followers probably means that its members can breed. But it's possible that over time, that could change; just like Catholicism underwent many changes after the [Vatican II](https://en.wikipedia.org/wiki/Second_Vatican_Council), perhaps the leaders of your religion thought it was time to shake things up (pun intended). If they start calling for wholesale celibacy for all followers, there will be two effects: one, the faithful will stop breeding, and two, the casuals will leave. This will give you a big initial dropoff, followed by a gradual drain over a few generations. Eventually, like the Shakers, there should only be a few left. As for why anyone would call for celibacy, well, it depends on the tenets of your religion, and the culture that surrounds it. There have been a few cases of celibate Christian sects that thought an end to sex meant an end to man's domination over women (again, going off the Shakers, they were all about sexual equality, also the Acts of Paul and Thecla seem to imply that celibacy empowers women). Other religions tend to discourage sex since it's an indulgence in non-religious pleasure. I'm sure there are more reasons, but honestly you could make up just about anything and in the right circumstances, people would believe it. [Answer] Ebola If rituals with dead are important in your religion, and some highly infectious disease like Ebola comes around, the only solution is to abolish the religious practices. Which might be possible if a secular scientific civilization is nearby, and develops and enforces new rules. If mortality is high enough, whole civilization will collapse before new rules can be developed. Even now, some infections like polio resist eradication because some countries resist eradication efforts. See <https://en.wikipedia.org/wiki/Eradication_of_infectious_diseases> [Answer] Not sure if this is too dark, but how about Mass Suicide? You could have the religion believe a comet is a god, and the only way to join him is to commit suicide at the right time (or make up whatever reasoning you want). You could even have someone from the religion rise up as a prophet and call everyone to do it. Those that do, die, those that don't, probably will mostly switch religions. [This has happened before](https://en.wikipedia.org/wiki/Heaven%27s_Gate_(religious_group)) Edit: You could also make it so one of the leaders and a smaller group of followers believes the mass suicide is necessary. Then they could poison the other people without them knowing because they're afraid the followers won't have the stomach to do it themselves. (They could do this by poisoning a wine the entire group is required to drink on a holiday. The wine could be produced by the leading body of the religion, so they have easy access in order to poison it). [Answer] Present the followers overwhelming, undeniable proof their religion is dead, such as: 1. The Great Spaghetti Monster, a beast the size of the moon, appears in orbit carrying the broken bodies of Zen, Sunni, God, Jesus, whoever. "I have crushed your gods. Worship me!" 2. Time travel is invented and it turns out Zensunnistianity is a load of garbage invented by a cabal of greedy tea merchants. [Answer] One could try to answer with memetics by comparing it to genetics. In this model, it proves very difficult to have 1 billion followers of an identical religion, when you look closer you will see sects, sub sects, divisions, internal fighting and suchlike. And a major religious identity like the abhramaic religion has many many divisions such as the three massive divides of Islam, Christianity and Judaism. Continuing on the evolutionary model, you can see that it's basically impossible for the state of the religion in its present form to remain stable for very long at all. It will grow, shrink, adapt, different sects will speciate and recombine over time such that the beliefs of this population 1000 years from now will be more or less entirely incompatible with the state it's in now. And if you look at the behaviours, biases, practices of today's religions 1000 years ago, you will find them to be abhorrent compared to what we have now. So to answer the question, yes, the religion of today will die out, but most likely due to it morphing into something different. [Answer] Irrelevance would be my top vote. Organised religion is a minority interest in Europe, and in the West generally. People (and countries) tick the "Christianity" box in surveys by default, but actual church-goers are a tiny. Wikipedia suggests 10% in the UK, 22% in the US. Go back 50 years and that was high 90-something% for both. People haven't lost their built-in need for "spirituality", but they have recognised that they have no need for organised religion. I'm not going to go into why it's happened, because that's typically the start of a flame war. Just take the numbers and extrapolate. [Answer] Yes, but it would take a considerable amount of force to do so, and would probably have to be replaced by something else. Henry VIII did something similar when he wiped out Catholicism. To achieve this, he shut down all catholic monasteries, churches and forced the new members into anglicism. He was successful in his effort and managed to establish himself as the new head of the church [Answer] Some of it depends upon the tenets and the tenor of the movement and its adherents current context at the time of the start of the decline. This is question begging as I am assuming your question is possible. For example, some historical times in a religion's history could be more mystical in nature versus a more empirical time period. It depends a lot on how the person and culture defines truth. For example, Christianity. It has gone through many periods and some times in that history collapse might have happened, but for differing reasons. Today, many cultures are more relativistic, but in some area empirically based, etc. Yes those are sweeping generalizations and not exhaustive. But, for the sake of argument, lets say you could produce the body of Jesus. Christianity would collapse. That's its entire base. And, you'd have to have a culture that would believe that is the reason for its existence and the continued requirement for its existence. This is not to debate anything. I promise. It's just to look at the complexity of what you are asking. So, maybe you could have some prime condition that created the religion and therefore you can create, perhaps, the demise of that religion. It depends upon the complexity of your system. You could do this with any religion. If the current cultural milieu would allow it. The timing of everything would have to be perfect. [Answer] More than 99 percent of all species, amounting to over five billion species, that ever lived on Earth are estimated to have died out. - Wikipedia So there is a high chance that humanity will also die out. In fact all other species of Home, except Homo sapiens, have already died out. How would a religion continue to exist, if nobody is left to practice it? ]
[Question] [ So, a little bit of pseudo backstory first. Imagine mother nature would be some godly being, that actually exists. Somewhere. In spiritual form. Now imagine humankind would be a big thorn in her eye, as we've ruined the ecosystem to an unrecoverable amount. (Yes, I'm talking about nowadays) She wants to take countermeasures. So, in order for nature to fix itself, she transforms every animal to a twice as big being. Well, actually it's 2 times the height, 2 times the length and 2 times the width, resulting in 8 times the size all in all. The physical abilities scale accordingly of course. The transformation of all animals (or brain containing living beings, if you like so), except humankind of course, happens worldwide at the same time and needs only a minute or so and is permanently. Now imagine there would be enough food for them. It is a slightly fictional version of our earth after all and, well, mother nature sure wants to keep her children alive. Yes, I'm talking about our very earth, with everything as close to real life as possible, with the exceptions mentioned above. To my question: Would humankind with the help of modern technology be able to remain the dominant species of the world in this scenario or would we be replaced by animals at some point? (Question inspired by the raptor-theory of Jurassic Park III) [Answer] # Unquestionably Yes. Without a doubt Homo Sapiens is the [most adaptable species](https://www.scientificamerican.com/article/humans-may-be-most-adaptive-species/) on Mother Nature. ## Evolution Through the last 5 million years Homo Sapiens (latin: wise man) has toughed it out through (geologically) swift climate change, near extinction, and unbridled warfare. Unlike our cousins in the Homo Genus, we've adapted at every single turn or died off. As glaciation swept back and forth throughout Europe wiping out Homo Neanderthalensis (and potentially Homo Erectus), we survived. If the [Toba catastrophe theory](https://en.wikipedia.org/wiki/Toba_catastrophe_theory#Genetic_bottleneck_theory) holds true, then 70,000 years ago Mother Nature's toying with the Toba Supervolcano failed to kill us. Yes we were reduced to 3-10,000; but like every other catastrophe and change in climate in the previous 5 million years, we persevered. As warm temperatures broke the spine of the last Ice Age, we swept forth. Within [a mere 70,000 years](https://en.wikipedia.org/wiki/History_of_human_migration#Pre-modern_migrations) we populated every unfrozen continent, learning to adapt to nearly every imaginable biome on earth. Desert, Ice, Tundra, Jungle? Nothing stopped our advance. Even the great pacific ocean couldn't hold back the [ancient polynesians](https://en.wikipedia.org/wiki/Polynesia#History_of_the_Polynesian_people)! # Civilization Eventually we settled down, and began to build civilization itself. We mastered stone and mud, then copper, followed by iron. We learned engineering, astronomy, mathematics, and language. We passed the knowledge we learned to our descendants, first through oral tales, then through the precision of written language. We learned how to weather any storm, how to hunt, trap, or tame any beast. Eventually we learned to question our existence and environment. Such philosophy developed into inquiry, then science. Soon we learned how to break down Mother Nature into her constituent parts. All of a sudden, the unknown failed to hold us back. We created gunpowder, industry, and slavery. We learned, through revolt and diplomacy, to never underestimate the human spirit under oppression. We created guns and rifles, chemical weapons, and primitive bioweapons (small pox rags against Native Americans). Then we discovered nuclear science and rocketry. We developed the nuclear weapon and rockets. We extended our reach beyond Mother Nature's Bosom. Then we learned to fear our own existence. We learned to fear how easily we can wipe ourselves out; but, as with any inquiry, we learned how well we may endure such apocalyptic scenarios. Then in (not so) secret, we began to prepare [contingency plans](https://www.whitehouse.gov/omb/information-for-agencies/Agency-Contingency-Plans) against such doomsday scenarios. We even included contingencies against the [most](https://www.cdc.gov/phpr/zombies.htm) [far](http://www.cnn.com/2014/05/16/politics/pentagon-zombie-apocalypse/) [fetched](https://en.wikipedia.org/wiki/Threshold_(TV_series)) of scenarios! # The Transformation Every single animal on Mother Nature (save Homo Sapiens) has grown 8x larger. We'll take a beating initially for sure; but, we've prepared for far worse. We have tasers, pesticides, and floodlights. We have guns and walls, electric fences and ultrasonic weapons. We have airplanes and aircraft carriers. We have rockets and satellites. We have [bioweapons](https://www.scientificamerican.com/article/u-s-one-step-closer-to-releasing-engineered-mosquito-to-fight-zika/) and [chemical weapons](https://www.nytimes.com/2017/04/04/world/middleeast/syria-gas-attack.html). And in the event where all bets are off, we have [tens of thousands](http://www.icanw.org/the-facts/nuclear-arsenals/) of nuclear weapons. > > [Mother Nature] wants to take countermeasures. > > > Please. She's in for a rude awakening. [Answer] Oops. Turns out She helps us more than a little. Most of our biggest hassles since learning to make cities (other than each other) have been vermin related. If rodents need bigger holes to get into our granaries and houses it's easier to stop them and much easier to spot the intrusion. The same goes to mosquitoes, roaches and ants. The immediate concern wold be pets. We'd have to feed them much much more. Fortunately we'll have enough livestock to cover it once we adjust, but in the transition some large dogs and cats might consider alternative food sources. Bobcats (something like a 2x housecat) have been known to attack children, and feral dogs are sometimes problems. But guns. Our armies certainly aren't in any danger from animals of any size. A tank is still not going to be bothered. A helicopter is still faster. A rifle can still hurt probably kill from farther away than most animals notice. If bees fail to work since you aren't changing flowers that might be bad, but some of our staple foods work through wind pollination so we're still not in trouble. [Answer] Homo has never been the biggest player on the court along its evolution. It has however become dominant. Just as an example, Mammoths and Cave Bears, bigger than contemporary men, are extinct because of men. Homo has become dominant thanks to its intelligence and its great ability in manipulating its surrounding environment, to an extent which has no equals among other animals. This neglecting the square-cube law, which would make any scaled animal unable to move or simply stand. [Answer] Even without humans as part of the equation, nature itself is headed for destruction. Unless plants (or at least their flowers) get a commensurate size increase, pollination is going to be difficult or impossible for many species. Lots of flowers are perfectly sized for a particular bee or hummingbird to pollinate them as it collects nectar. If the animals get bigger but the flowers stay the same size, that arrangement gets significantly disrupted. Eventually that will cascade through the food chain, leaving animals without enough to eat. That includes humans, since many of our important food crops are pollinated by bees. [Answer] Are animals that are 2x bigger actually more dangerous? (not really) This analysis assumes that all the organs of the animals are scaled evenly in every direction. There is something called the square cube law. There are many good things that grow with the square of the scale like muscle strength (which is proportional to the cross section area of the muscle) so 2x in each dimension is 4x strength. There are many bad things that grow with the cube of size like weight which is proportional to the volume of the creature. So 2x in each dimension is 8x weight. Since the creature is carrying 8x the weight it must consume 8x the calories to not starve. Thus the required strength of the lungs and heart, which now must supply oxygen to 8x muscle and push 8x the blood volume, must be 2x higher. Assuming that running speed is proportional to strength or weight we would expect large creatures to be twice as slow. A larger creature has a harder time with stealth. What does this mean * Some species will die out. Some species would no longer fit in their ecological niches, bees would be to large to drink pollen from flowers monkeys could no longer climb trees water striders would no longer walk on the surface of the water. Some could not consume enough calories. Cows eat most of the day to get enough calories, there is not time for them to eat 8x more. They would either have to switch to a more calorie dense food or starve. * The large animals would be highly vulnerable to firearms The creatures are very large targets that are significantly slower than the ones we have today. They have 2x higher blood pressure so they will bleed out much faster if wounded. They are huge targets and will have trouble sneaking up on anything. They must eat much more so they cannot afford to stalk or wait long they must attack. * They would be much more deadly at close range. A giant lion would be capable of impressive destruction, but if a lion reaches you, you are dead whether it is giant or normal. [Answer] Considering the Earth [used to have such animals](https://en.wikipedia.org/wiki/Megafauna#In_terrestrial_mammals), and its quite likely [humans helped kill them all off](https://en.wikipedia.org/wiki/Holocene_extinction#Competition_by_humans), I'd go with yes. > > The Holocene extinction is mainly caused by human activity. Extinction of animals, plants, and other organisms caused by human actions may go as far back as the late Pleistocene, over 12,000 years ago. There is a correlation between megafaunal extinction and the arrival of humans, and human population growth, most prominently in the past two centuries, is regarded as one of the underlying causes of extinction. > > > [![enter image description here](https://i.stack.imgur.com/WA5wo.gif)](https://i.stack.imgur.com/WA5wo.gif) [Answer] Throughout human history, other animals being larger than humans hasn't stopped humans from spreading and reproducing. I can't imagine a case where bigger other stuff would be more of a problem. Keep in mind that while humans may not have the collective goal to make life better for other animals, humans don't have a generally antagonistic relationship with them. That is, we're not at war with the dogs, or whatever. Most animals generally ignore humans, and humans generally ignore most animals. There's birds, rats, rabbits, etc. all around us, and most people ignore most of these animals. There's billions-trillions of ants/flies/bugs that just do their thing, regardless of whether there's a human nearby. They wouldn't become more dangerous toward humans if they were suddenly huge. In stories, one trope that writers use to characterize nature and animals is that they can be inherently chaotic. More animalistic nature does not make these animals more scary. Hippos are already dangerous. Hippos twice as large would be equally advised to avoid. Ants are already a nuance. Ants twice as large would be also a nuance, but not more spooky or dangerous. What makes animals scary is when you strip away that chaotic nature of them. The Birds, the short story, was terrifying because there was nothing chaotic about it. The birds acted with malice, intent, and coordination. Dogs live in our homes, and occasionally dogs will freak out, or get rabies, and bite someone. But we still have dogs living and sleeping with us, and it's not scary. What if you take away the chaos? What if all dogs suddenly, and at once, attacked their owners? > > She wants to take countermeasures. > > > If she wants to take effective countermeasures, she should do something she hasn't already been doing. Animals already fly, have sharper fangs, have more dangerous poison, have nastier bite, are more resilient to nature, are better swimmers, are bigger, are more numerous, etc. What animals aren't, is collectively focused and coordinated. A pack of dogs can chase down game for a meal. Can a pack of dogs build a fence, have one rancher manage the game, then spread out and have the rest of the pack do other tasks? Humans didn't become dominate by out-naturing nature at nature's game. Let others be faster, stronger, bigger, more numerous. Humans became dominate by refusing to play the nature game at all. Making animals more nature-y, or more physically large, will be of almost no consequence. [Answer] Mother nature got it wrong: Instead of making the animals bigger she should've made all humans bigger. The bigger the animal (including humans) the more ressources (space, food, ...) they need. If one can assume that body mass is proportional to the energy consumption that means you'll need 8 times more food. But where should that come from? A lot of humankind already suffers from [undernourishment / starvation (~10%)](http://www.worldhunger.org/2015-world-hunger-and-poverty-facts-and-statistics/). The technical term for this effect is [overpopulation](https://en.wikipedia.org/wiki/Overpopulation) and it will become a huge issue. As soon as that happens there will likely be conflicts (from the point-of-view of mother nature: hopefully these conflicts will turn into wars, big wars). The bad news is that bigger humans will need some time to figure out how to put their bigger fingers on the triggers of guns, fit their body into tanks, [hit the right key on the keyboard to launch nuclear missiles](https://www.youtube.com/watch?v=OqjF7HKSaaI), ... but as soon as humans figure out how to work around these obstacles they will start reducing their population themself and mother nature and the animals can watch the fireworks (probably better to do that from a safe distance when they find out how to launch the nuclear missiles). [Answer] My answer is more brief (and less scientific) than other answers, but I think that humans aren't the dominant species anyway. There are quite a few animals that are larger than humans, e.g. Gorillas, Lions, etc. we still kill them with our technology. If we did not have technology, we would not be able to do this, rather we would use our superior intellect to evade predators. So we would still continue to kill animals that are bigger than us. Size would continue to be irrelevant. [Answer] There are other things to consider, here. For instance, if everything doubles in size, then I would suspect that consumption would increase also. One thing to consider; if you were to make bees and other pollinators twice the size, then the usual flowers may not be able to sustain them. This would lead to competition and possibly an extinction event amongst them, in turn leading to a reduction in pollination and, ultimately, a massive reduction, due to starvation and war, of the human race. Presently, possibly one of the main things keeping us alive, today, are bees. As Maurice Maeterlinck stated in [The Life of the Bee](https://www.gutenberg.org/files/4511/4511-h/4511-h.htm) (no - not Einstein), and Darwin in his [Origin of Species](http://www.gutenberg.org/files/2009/2009-h/2009-h.htm) (se also [Quora](https://www.quora.com/Is-it-true-that-Einstein-said-without-honey-bees-human-race-will-be-over-in-4-years)), life would be pretty interesting without them for a very short space of time. There are ways around this, obviously, but the main point is mass eradication. Most of the world depends on the production of pollinated crops. Smaller communities could depend on other crops, such as tuber vegetables and other plants that propagate through [other forms of propagation](https://en.wikipedia.org/wiki/Plant_propagation). But, remember the [various potato famines](https://en.wikipedia.org/wiki/Potato_famine)! Once the cattle double in size, though, I still bet you won't be able to get a decent steak from a supermarket... ]
[Question] [ In the project I’m working on, sufficiently advanced aliens terraformed a large number of planets in the distant past, giving them an atmospheric pressure and composition similar to Earth. This “galactic standard” is breathable by all alien species without any difficulty. However, because Earth’s atmosphere wasn’t terraformed but developed independently, I want the “galactic standard” to be different enough to breathable but humans but otherwise uncomfortable. I’m imagining a scenario in which most humans can acclimate given time, but many prefer to use supplemental breathing devices or implants, especially if they’re old or have health problems. I also want to this problem to be mutual, so aliens have similar problems breathing our atmosphere. However, I want the “galactic standard” to have a high oxygen content to be conducive to larger creatures and more frequent fires, so just giving humans altitude sickness is not an option (even though it would be the easiest solution). I’m also hesitant about increasing carbon dioxide levels significantly, as its pretty potent greenhouse gas. Given these limitations, what are my option to make an alien atmosphere breathable, but uncomfortable? Edit: I wish I could accept multiple answers, because all of these are great and I'll probably be referring back to this question a lot for reference. Ultimately, I've accepted Mike Serfas's answer because it's a very elegant solution and dovetails nicely Christopher James Huff's comments about CO2 being a go-to terraforming agent. This won't work for every world, but I imagine between excess CO2 on some worlds, excess Ozone on others (maybe a byproduct of plant respiration?), and excess humidity in general, I'll get the effect I'm looking for. [Answer] # Carbon dioxide. According to some tellings, Earth arose very near the inner limit of the "[habitable zone](https://en.wikipedia.org/wiki/Circumstellar_habitable_zone)" around the Sun. Earth life sucks up nearly every trace of carbon dioxide available to it in the atmosphere, provided somebody doesn't dig up entire geological strata of pure carbon and send it up into the air. Most habitable planets formed further out - an Earth-sized planet in the orbit of Mars, or halfway. Their ecosystems were limited in the amount of carbon they could fix before the seas froze, so the organisms there became accustomed to having a few percent of CO2 in the air, at least during during most geological eras. An excess of carbon dioxide in the blood is called "[hypercapnia](https://en.wikipedia.org/wiki/Hypercapnia)", and can happen for many reasons, but having too much CO2 in the air is surely one of them. Below 1%, the effects are subtle, mostly of concern to air conditioning technicians looking to sell you larger machines, but living on a planet with that going all the time you would tend to start blaming headaches and sluggishness on the CO2 in the air, perhaps justifiably. Go much above that, and the urge to breathe faster sets in. Our bodies use CO2 as the first signal to tell us to breathe, so we respond to high levels by assuming we need to breathe more, no matter how much oxygen is in our blood. High levels of CO2 also make the blood acidic, because it reacts with water to make carbonic acid. The regulation of this response is [a bit complex](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2853202/), because there are multiple locations where CO2 is being sensed and the mechanisms overlap with regulation of blood pressure and other vital physiology. Nonetheless, for your implant suggestion, the neurons are known, and so you can simply rattle off the names in there and say you have a way to alter their signalling. You could mention cruder mechanisms such as inhibiting the sympathetic nervous system response with beta blockers or even severing the vagus nerves, but let's not do that. Ideally, it should be possible to develop a drug that very specifically targets the same neurons you would target with an implant, providing relief in a gentle, non-invasive, and reversible manner. [Answer] Uncomfortable is a matter of tastes and culture, but I guess [thiols](https://en.wikipedia.org/wiki/Thiol) make a good candidate for making an uncomfortable environment: proximity of rotting eggs, sewers, rotting algae are just few examples of uncomfortable locations, because they release sulfur based compounds. They smell foul at low concentration and are toxic at high: > > The odors of thiols, particularly those of low molecular weight, are often strong and repulsive. These compounds are detectable by the human nose at concentrations of only 10 parts per billion. > > > I remember during my university time I had a colleague who, from time to time, would be busy synthesizing quantum dots using thiol: despite he using a state of the art chemistry hood on the first floor, one could smell that awful thing from ground floor. [Answer] There is a discussion about how much of various gases are necessary for humans to survive in Stephen H. Dole Habitable Planets for Man, 1964. <https://www.rand.org/content/dam/rand/pubs/commercial_books/2007/RAND_CB179-1.pdf> On pages 13 to 19 Dole discusses atmospheric composition and pressure. Table 2 on page 16, table 3 on page 18, and table 4 on page 21 give upper and/or lower limits for various gases. And of course research in the last 60 years might have modified those limits. And there are no doubt many thousands of other compounds found in nature or synthisized by chemists which are gaseous at normal Earthlike temperatures. In the Harry Turtledove story "The Road Not Taken", Analog, November 1985, a Roxlani ship lands in Los Angles. And when the hatches open, the Roxlani find that polluted Earth (or Los Angles at least) air smells bad, while the humans find the air from the ship smells bad (though the Roxlani were unable to keep the ship's air smelling like their homeworld which might have smelled better to humans). Anyway, mutually bad smelling air is pefectly possible. You want to select gases which are relatively plausible to naturally occur in a planet's atmosphere, so that the native planet of the species that created the galaxtic standard atmosphere has that gas in its atmosphere and that species evolved with that gas. If that gas has a detectable oder, they might be used to that odor and not really notice it until it is gone. That gas's odor might mask the sents of other gases on their world, and so they might be troubled by the odors of those other gases which are more common in naturally occurring atmospheres. Thus they make sure to artifically put that gas in the atmosphere of all planets they terraform, even though lifeforms that evolve on planets without that gas tend to find its odor offensive. Or possibly that species was civilized for so long before they began to terraform other planets that they are very used to the subconsious odor of some artifical pollutant which they accidentially released into their atmosphere that air feels bad without it, so they terraform all planets to have that pollutant in their atmospheres. Or maybe the odor which they desire is a combination of the odors of several different chemicals. Possibly most worlds have one or two of those chemicals in their atmospheres, but the home planet of the galactic terraformers was a rare planet with three, four or more chemicals in the atmosphere. Thus they would terraform planets to have all of those scented gases in the atmosphere. Since Earth has only one of those gases, the combined odors of the other gases are offensive to humasn. I note that sometimes I notice the smells of various plants in the air. Possibly the home planet of the galactic terraformers has very slight seasons, and plants emit pollen all year long, and so the galactic terraformers had to change the seasonal cycles of planets they terraformed, so that the plants from their homeworld which they planted on terraformed planets could release pollen all year long. I note that breathing a high concentration of helium makes human voices high pitched, and apparently that concentration of helium is not high enough to suffocate someone. So I can imagine that if an Earthlike planet somehow manages to have a high enough concentration of helium in the atmosphere to change people's voices, humans might find that annoying. Since helium is the second lightest gas, and thus would escape very fast from an Earthlike planet, I don't think that a high concentration of helium would be very probable on the home planet of the galactic terraformers. I note that the surface gravity of a habitable planet has to be low enough for human comfort, while the escape velocity of a planet has to be high enough to retain all the gases for long times - including helium if that is what makes the humans uncomfortable there. There are different formulas for calculating the surface gravity and the escape velocity of a planet. A planet with a lesser density than Earth could have a surface gravity low enough to be tolerable with an escape velocity which was higher relative to Earth's than the surface gravity was. I note that Uranus and Neptune both have lots of helium, and even hydrogen, in their atmospheres despite having escape velocities similar to the 11.186 kilometers per second of Earth. Uranus has a surface gravity of 0.886 g, and an escape velocity of 21.3 kilometers per second, 1.904 that of Earth. Neptune has a surface gravity of 1.14 g, and an escape velocity of 23.5 kilometers per second, 2.1008 that of Earth. But their great distances from the Sun, and thus low temperatures and speeds of particles in their uppr atospheres, help them to retain hydrogen and helium. If they were close enough to the Sun to be warm enough for liquid water using life, they might not be able to retain helium. If you decrease the density of a planet while increasing its mass and volume so it can have a low enough surface gravity for human and a high enough escape velocity to retain helium, it might turn into a water planet with its entire surface covered by tens or hundreds or thousands of kilometers of water, or even turn into a giant planet with no solid surface. i note that in the Star Trek episode "Amok Time" there are two features of the planet Vulcan which make it uncomfortable for human: > > KIRK: It's lovely. I wish the breeze were cooler. > > > > > MCCOY: Yeah. Hot as Vulcan. Now I understand what that phrase means. > > > KIRK: The atmosphere is thinner than Earth. > > > > > MCCOY: In this climate? If the heat doesn't get you, the thin air will. You can't do it! > > > MCCOY: Is this Vulcan chivalry? The air's too hot and thin for Kirk. He's not used to it. > > > <http://www.chakoteya.net/StarTrek/34.htm> So the temperature and the thin air combine to make exertion on Vulcan uncomfortable for humans. So possibly galactic standard terraformed worlds have higher or lower temperatures than most Earth humans are comforatble with, as well as slightly different atmosphere, and together they combine to make galactic standard planets rather uncomfortable for humans. > > However, I want the “galactic standard” to have a high oxygen content to be conducive to larger creatures and more frequent fires, so just giving humans altitude sickness is not an option (even though it would be the easiest solution). > > > So maybe your galactic standard planets give Earth humans reverse altitute sickness which happens when people from high altitudes move to lower altitudes or sea level. <http://yaccatravels.com/blog/reverse-altitude-sickness-symptoms-cure-prevention-and-more> <https://www.newscientist.com/lastword/mg24732983-000-is-there-such-thing-as-reverse-altitude-sickness/> > > The average atmospheric pressure at sea level is defined by the International Standard Atmosphere as 101325 pascals (760.00 Torr; 14.6959 psi; 760.00 mmHg). > > > <https://en.wikipedia.org/wiki/Atmosphere_of_Earth#Pressure_and_thickness> 760 mmHg is 760 millimeters of Mercury. According to Dole on page 15, the sea level pressure of oxygen is 149 millimeters of mercury (mmHg). The accepted limit of oxygen for patients who needed extra oxygen was 40 percent of the total atmosphere then, though many persons could & can tolerate higher levels. Dole set an upper oxygen limit that would be tolerable for at least some if not necessarily all humans. > > Following this philosophy, for our purposes we may state that the imspired partial pressure of oxygen must be greater than about 60 millimeters of mercury but less than about 400 millimeters of mercury. > > > <https://www.rand.org/content/dam/rand/pubs/commercial_books/2007/RAND_CB179-1.pdf> So if the oxygen content of the atmosphere is close to about 400 mmHg, some people should have problems breathing that much oxygen. And many other other known gases, especially those which are common on Earth or other planets, have been tested to find upper limits of pressure tolerable for humans. Thus your galactic standard planet could have a higher than Earth normal concentration of nitgrogen, for example, as well as a higher than Earth normal concentration of oxygen, and humans might find breathing such dense air at least slightly uncomfortable, some humans more than others. On page 20 Dole mentions upper limits for the concentration of dust particles in the atmosphere. However, I can't think of any reason why aliens would find lower concentrations of dust in Earth's atmosphere annoying. But possibly galactic standard worlds have so much pollen in the air (suggested above) that it would be irritatiing or harmful to humans, while aliens enjoy the scent of the pollen and miss it on Earth. And possibly a combination of various atmosphere factors mentioned in my answer and other answers could make a galactic standard atmosphere more or less irritating to most humans and harmful to some, and make Earth's atmosphere uncomfortable for the aliens for reverse reasons. [Answer] Heavy Air 70% of Earth air is Nitrogen. This is nonreactive and harmless to your lungs. If you only breath Nitrogen you will asphyxiate. But it is not the Nitrogen that kills you. It is the lack of oxygen. The Standard air has some of the Nitrogen replaced with some other heavy nonreactive gas. [For example Krypton is 3 times denser than air.](https://www.youtube.com/embed/rd5j8mG24H4?start=89) This is uncomfortable for humans at first. But they eventually get stronger lung muscles and get used to breathing heavy air. Edit: I am not sure about Krypton any more. Cody says it has an anesthetic quality. So the question is does there exist an equally suitable heavy nonreactive gas. [Answer] Simply humidity can make breathing uncomfortable. Humidity can make the air feel heavy. Figuratively, because actually humid air is lighter than dry air. The reason is that water vapor molecules are lighter than both nitrogen and oxygen. Water vapor replaces either nitrogen or oxygen in the air. Thus, humid air has less or lighter nitrogen and oxygen. This also makes humid air less breathable. Additionally, breathing in humid air activates nerves in the lungs that can narrow and tighten the airways. Humidity also makes the air stagnant enough to trap pollutants and allergens like pollen, dust, smoke, mold etc. It can trigger asthma symptoms as well. [Answer] Ozone. Ozone is formed by the action of UV radiation on oxygen and other atmospheric components. It is a normal and protective component of the upper atmosphere. It is also a normal minor component of the lower atmosphere though its creation is much augmented by human activities. <https://en.wikipedia.org/wiki/Ozone#Acute_ozone_exposure> > > Acute ozone exposure ranges from hours to a few days. Because ozone is > a gas, it directly affects the lungs and the entire respiratory > system. Inhaled ozone causes inflammation and acute—but > reversible—changes in lung function, as well as airway > hyperresponsiveness.[76] These changes lead to shortness of breath, > wheezing, and coughing which may exacerbate lung diseases, like asthma > or chronic obstructive pulmonary disease > > > Ozone is a powerful oxidizer. It is like chlorine in many respects and now is commonly used to treat pool water in circumstances where chlorine used to be used. If oxygen worlds had more ozone one might expect persons used to earth to use carbon filters to capture and react away the ozone. Exposed hair and materials from Earth would be bleached. Plastics and especially rubber will crack and oxidize fast. These things (besides a "sharp tang" in the air) will be other good ways for a fiction to show that things are different. [Answer] I already upvoted one answer, but you said you wanted this galactic standard atmosphere to have a high oxygen level and that could in itself be the problem. Being so reactive, oxygen is toxic when you get too much of it - check out the Wikipedia article on [oxygen toxicity](https://en.wikipedia.org/wiki/Oxygen_toxicity). For a double whammy, you could have both O$\_2$ and CO$\_2$ at high levels. [Answer] Dust or pollen in the air can make breathing uncomfortable causing frequent sneezing and such. Not enough to die from, but certainly uncomfortable. Some people are more resistant than others, and I guess humanity can grow to adapt. Or alternatively humans might wear special masks to filter out the particles. [Answer] Overly warm and humid can make things almost unbreathable over a prolonged period. Like if you are in too hot a shower for too long. You do not want to experience that. [Answer] # Helium rich atmosphere One might say that helium will be easily lost to space from an Earth-like planet, but that takes millions or billions of years. And since the aliens are terraformers, they can probably make more whenever they want. Humans can either use breathers or sound like cartoon chipmunks. [Answer] Thin atmosphere - just as at high altitudes here on Earth. Simply make the atmosphere the same as here on Earth, at the very top of Everest or a bit higher than that. You can survive but it's a real chore. [Answer] Hot, humid ar feels heavy, but it is actually lighter.Water vapor is not respirable, but it is actually less dense than the air that we know. Hot, humid air feels heavier because it is harder to breathe. Water vapor is a strong greenhouse gas, so that would also be trouble. Neon (an inert gas) would be about as heavy as water, but without the greenhouse effect. But by replacing water that would reduce the wet-bulb temperature and allow us to sweat away some water to cool us. The maximum for survival would be a wet-bulb temperature identical to body temperature. above that temperature, water would literally condense upon us because we are cooler. That would create severe problems as we could no longer give off waste heat easily. The water condensing upon us would be hot -- not cool. It would not cool us. We would need to be in artificial cooling to survive. High heat and humidity wear one down fast. It might not kill (up to a point), but it would make life miserable. [Answer] # Capsaicin In humans, capsaicin irritates the eyes, nose, throat, and lungs. However, the aliens have differences in their heat receptors such that they are not triggered by capsaicin. Instead, perhaps to the original aliens, capsaicin functions either as a pheromone, or more generally as a pleasant smell (much like lavender would be to us). And more generally, other aliens mostly have a neutral or no response to the capsaicin; it's just a complete accident that humans happen to have a debilitating reaction to the compound. I don't know about the durability of capsaicin particles in the air. In case it turns out they would settle out within a comparatively short time, I could imagine a combination with the answer by Klaas van Aarsen: alien pollen happens to use capsaicin as a signalling molecule incorporated into the surface of the pollen, to entice the alien plants' pistils to accept the genetic material. [Answer] What you describes remind me of Netflix Arcane, where topsider police usually wear gas mask when going to Zaun So simply just make it a little toxic and saturated (low oxygen level) to make it hard to breathe for anyone not acclimatized ]
[Question] [ Shamelessly inspired by [this](https://worldbuilding.stackexchange.com/questions/50894/how-far-back-in-time-would-english-be-understandable-to-a-modern-speaker) question (sorry), but I got this question after Michael gave a [answer](https://worldbuilding.stackexchange.com/questions/51159/how-would-a-mathematician-compare-to-a-scholar-in-ancient-greece/51162#51162) - my mathematician would essentially have to relearn maths, as mathematics in Ancient Greece is completely different to what we have now. So the question that came to me was - how far could a mathematician go back in time, and have to spend as less time as possible in relearning stuff? If he goes back in time for [this](https://worldbuilding.stackexchange.com/questions/51159/how-would-a-mathematician-compare-to-a-scholar-in-ancient-greece/) question, he has to relearn a lot of things. Background: The [main character](https://worldbuilding.stackexchange.com/questions/51159/how-would-a-mathematician-compare-to-a-scholar-in-ancient-greece/) has realised that he can travel back in time voluntarily, and he wishes to travel back in time to a time-period where he can participate in the beginning of maths, but without relearning as much as possible. Magic: To make things clear, I'll add this in. The magic allows him to communicate in the time-periods language easily. He can understand it effortlessly, and it stops the other people from asking him very incriminating questions (like where are you from, etc). They simply think he is a travelling scholar and leave it at that. (It stops them from digging to deeply, even if he does not know what they think is common sense.) They also have given him food and a place to stay. [Answer] It strongly depends which area of maths you're talking about. * Category theory is basically new, so before the 1950s or so, it just didn't exist in anything like its modern form. * Combinatorics has been around for a long time, but before Erd√∂s it looked very different. * Before Newton and Leibniz, the notion of calculus wasn't very clear, and its notation would make it very difficult for us modern-day people to work with. * Before Cauchy, they didn't really have what we would refer to as a "rigorous" foundation of analysis, and the relevant language changed substantially since Cauchy to take into account the new approach to rigour. * There was a time, even some point after the Renaissance IIRC, when mathematicians were still not really sold on this whole "rigour" thing, and the art of defining things crisply so as to deduce (nearly) incontrovertible stuff about them. The entire mindset of mathematics is different now. A first-year undergraduate going back before Newton could, if their ideas were taken seriously, revolutionise multiple areas of maths simply because we now know (and take for granted) the correct ways of thinking about certain fields of study. Conversely, of course, the first-year undergraduate would have a hard time following the maths of the day, because the technical language and frameworks are so strongly unfamiliar. The only frameworks I can think of which haven't changed much post-Renaissance are Euclidean geometry and arithmetic, though of course geometry and number theory have advanced substantially since then. [Answer] Technically, if he went all the way back to the beginning (where it was just starting), he won't have to relearn anything (as nothing had been invented). He can simply use his own knowledge, and it will become the norm - others will learn whatever he writes, and he won't have to learn anything new. [Answer] I'd say that math itself would be understandable to a modern mathematician (worth the name) in any period. What might be a problem is terminology and convention. If your magic extends to not only translating general language, but also makes an immediate translation from I + I = II to 1 + 1 = 2 the protagonist won't have much of a problem. Reinventing classical math from it's origin is generally taught as an excercise in pregraduate math classes. The thing about math (and logic) after all is that a thousand year old proved theorem is still as valid today. This is in stark contrast to other sciences where proofs are merely "until further notice". [Answer] Serious scholars of mathematics tend to be educated in the history of mathematics and mathematical notation as well. As such, the question is complicated by the fact that the time traveling mathematician is not entirely helpless, he has advance knowledge. As far back as the Renaissance, there would be hardly any difficulty. They pretty much did math like us. For example, Descartes was [one of the originators](https://mathoverflow.net/a/30414) of denoting variables with $x$ and $y$. Of course, if you are interested specifically in discipline X, and you arrive just when X is being invented, things will be in flux, and there will be multiple competing notations that confuse matters somewhat. Calculus is the classical example: Leibniz and Newton both independently discovered it; Newton favored $\dot x$ and $\ddot x$, while Leibniz used $dx/dy$ and $d^2 x/ dy^2$. I don't recall now how $f'(x)$ and $f''(x)$ fits into this. Calculus is an interesting exmaple for another reason, though: Typically common calculus textbooks will include this little story about the discovery of calculus, and many professors enjoy retelling the tale when teaching Calculus I. This nicely illustrates my point about mathematicians having a head start due to their knowledge of math history. In Middle Ages things get slightly funky: This is when Arabic numerals were brought to Europe (in India and Arabia they had been in use for centuries), so before that time, things might start out a bit confusing to a modern mathematician. However, the alternatives like Roman numerals or [Mayan numbers](https://en.wikipedia.org/wiki/Maya_numerals) are really not complicated (I personally find Mayan numbers more elegant than ours), and anyone who is interested in math can easily learn them in a few hours, if they don't know them already. Mathematical thinking also seems comprehensible, going by examples like Fibonacci. In Dark Ages Europe it may be difficult to discuss math due to the odd attitudes people may have towards learning in general, but assuming you do find a cooperative scholar, the math itself should be easy. Of course, concepts such as variables or equations (as we know them) had not been established yet, so discussion may be a bit cumbersome ("thus we find that number which is thrice that number of which the square is a tenth of the number which...") until the interlocutors have been "enlightened" with modern algebra. I'm not sure what state Roman mathematics was in, but surely they would be intimately familiar with the heritage they received from the Greeks. Discussing math with the Greeks might be positively pleasant: The Ancient Greeks pioneered so much of our philosophy, logic, math and geometry, and their writings show an exceptional clarity of reason. Not having knowledge of modern notation, perhaps the way in which they talk about math would be a bit strange, but the essence of their thoughts should be familiar, given that to this day we have students of mathematics retrace their footsteps when learning. Incidentally, Greek mathematics is very readable today. I believe Euclid's elements was commonly used as a textbook of geometry up in many places up until a couple decades ago. Further back, there are some mathematical manuals from Egypt that give a fascinating glimpse of truly ancient mathematics. The [Rhind papyrus](https://en.wikipedia.org/wiki/Rhind_Mathematical_Papyrus) appears to be some kind of math textbook, complete with example problems and reference tables, very similar to textbooks we use today. Going through the problems, many of them are very obviously similar to elementary math we learn in school: Calculations of volume, work, fractions, and so forth. There is also a great example of where the difficulty might be: Egyptians, apparently, liked to represent non-whole numbers as sums of fractions with quotient 1, eg. $3+1/6+1/7+1/13$. This bizarre notation can lead to some very confusing numbers (they got confused too, and they made tables of fractions to cope with it) for a modern reader. Their units are also quite strange. But once you start systematically writing down the fractions and equation in a neat manner, as should be instinctive after a modern education in math, everything is very clear. There seems to have been a similar situation in ancient China. Taking as example their approach to calculating [areas and circumferences of circles](https://en.wikipedia.org/wiki/Zhang_Heng#Astronomy_and_mathematics) we can see where the biggest issues might be: These people had not yet standardised $\pi$, nor did they fully understand its nature, so familiar formulas like $\pi r^2$ become $730/232 \cdot r \cdot r$, or $2\cdot \sqrt 10 \cdot r$. At first, these weird constants might throw you off (they are approximations of $\pi$ that haven't been needed for centuries) but it's not something that anyone educated in math would not know, or couldn't figure out. I would guess that in other cultures, such as ancient Amerindians, the math would likewise be straightforward besides a few trivial oddities. In general, math is different from language. Unlike languages, all human mathematics appears to converge to some universal (or possibly metaphysical) truth -- it is no wonder the Greeks venerated it religiously. Whereas language is for the most part arbitrary and varies greatly between cultures, math is convergent: "Great minds think alike". Mathematicians are in addition taught how to analyse and dissect problems into math - while typically people are not taught research linguistics in school. So I would say that besides communication itself, and strange archaic notations, math from any time period past would not pose any problems to a modern, educated person besides obviously the issue of them not having discovered certain useful things yet (but those can easily be taught). It is interesting that in Contact, the aliens begin their message with elementary math, as this ensures that it will be readily comprehensible. It is a very relevant comment on the relation of humanity with mathematics. Even the math of the near future would likewise be manageable; but once you go thousands of years into the future, it may turn out that a massive revolution in math has completely changed the way people think about it (not to mention possible impact of ubiquitous computation technology and AI). By the way, historically mental/manual arithmetic was a vital skill for many mathematicians, but modern scholars are blissfully freed of this burden by calculators. A time traveler may have trouble being taken seriously at first, due to his poor calculation and rote memorization skills, but this barrier should be easy to overcome once the merit of his knowledge is demonstrated. [Answer] Speaking as a mathematician, I would say (since you've magically removed the language barrier) any time will do. Most every math department has an undergraduate course about the history of math. In my experience, these courses involve solving problems in the way they would be solved from whatever period is being covered. This involves grappling with lack of notation and modern tools. Even unskilled, average students can quickly adapt their modern knowledge to solve problems in old ways - matching (and sometimes surpassing) the experts of that time. In the end, concepts are important. Notations are mere tools. An expert craftsman can still make amazing works of art with really lousy tools. A skilled violinist can use a toy violin to make beautiful music - don't get me wrong - better tools yield better results, but the player is more important than what is being played. If I could go back in time to any period 100 or more years ago, I could become the world's greatest mathematician. Easily. Conversely, if Newton or Gauss or Archimedes were raised from the dead (again removing the language barrier), they could be dominant mathematicians within a few years of catching up. However, I'm not sure they could do the same in the realm of Physics. The raw skillset making one a great mathematician has not changed since the beginning of time. Mathematics is timeless. [Answer] First of all a lot of the answers seem to confuse semantically mathematics - the scientific model build by mathematicians - with the reality that mathematics tries to describe. Mathematics, the model, is all about the notations being used, the notations are what allows us to work collaboratively and create a model which we use to generalize the world, whilst the underlying reality it attempts to model in an extremely abstract and simplified way has not. The exact same is true for any other scientific discipline. Either way, that means that if you go back far enough you won't understand a thing about mathematics as the model simply will look alien to you. Take for example a look at this beautifully clear representation of polynomials in 150 AD (ignore the brackets at the beginning and end): > > [![enter image description here](https://i.stack.imgur.com/uWkz9.png)](https://i.stack.imgur.com/uWkz9.png) > > > Source: <http://www.stephenwolfram.com/publications/mathematical-notation-past-future/> Or lets move forward to 1600 and see how Fran√ßois Vi√®te did it by that point > > [![enter image description here](https://i.stack.imgur.com/Z5ro5.png)](https://i.stack.imgur.com/Z5ro5.png) > > > Source: <http://www.stephenwolfram.com/publications/mathematical-notation-past-future/> At least that looks somewhat comprehensible, but it will still be quite the puzzle to figure out. So > > In the early to mid-1600s there was kind of revolution in math notation, and things very quickly started looking quite modern. Square root signs got invented: previously Rx‚Äîthe symbol we use now for medical prescriptions‚Äîwas what was usually used. And generally algebraic notation as we know it today got established. > > > Source: <http://www.stephenwolfram.com/publications/mathematical-notation-past-future/> So that's I think the most reasonable answer: before 1600 your mathematician will have to learn the mathematical model used by the people he wishes to interact with. Around 1600 he can specifically chose to interact with the people who establish modern mathematical notation, e.g. he could go out of his way to visit William Oughtred. Still though, this will still take a whole lot of trouble as a lot of notations were put forward in that time. So after around 1700 or 1800 he could join the mathematical world without learning an entirely new mathematical model. [Answer] Probably back to beginning of [modern mathematics](https://en.wikipedia.org/wiki/History_of_mathematics#Modern_mathematics) but maybe as far back as the [renaissance](https://en.wikipedia.org/wiki/History_of_mathematics#Renaissance_mathematics), reading up on the history of mathematics the renaissance seems to be the beginnings of mathematics as we understand it today but the science of it really came to the fore in the 19th century. It depends on his field of study within mathematics as well, looking at the [list of mathematical achievements](http://www.storyofmathematics.com/mathematicians.html) if he's a calculus guy he could go back to Newton's time. [Answer] Saw this on the "hot" list, and thought I'd just give one more angle. First of all, the other answers highlight very important points: Terminology and common language would be significant barriers, particularly in the recent past, where the maths were advanced but the terms and common languages were very different from now. (EDIT I see now in the original question that this can be ignored. Moving on... ) Another thing that would be difficult for a modern mathematician going back would be levels of rigor in mathematical communication. At different periods of time, less rigorous mathematical investigations and proofs were well accepted. Although any good mathematician would recognize the results of Newton's calculus, s/he may not be able to follow along at the speed of intuition or be willing to take certain results as "obvious". The point I really wanted to highlight, though, was that at different periods of math history, very different fields were the subject of focus, and modern mathematicians do NOT know all the things that historical mathematicians knew, and especially not the common tools used to attack problems. For example, go back a hundred years and geometers knew specific details about catalogues of curves and surfaces that most modern geometers do not and are not particularly interested in. I would think that, just as a modern algebraic topologist has the mental capacity to learn another maths discipline like geometric analysis but wouldn't understand past the first five minutes of a specialist seminar on the subject, a modern mathematician going a few hundred years into the past would find that s/he would need years of study to get up to speed on the popular areas of research of the time. [Answer] Maths will be always understandable to us (assuming we could also understand spoken language). If you see the movie Agor√†, and studied some simple math and physics at high school you will understand all the statements made by Ippazia, you will say. Damn that's an ellipse! That's so easy! Why you can't understand that? What we do not understand now is that even simple things we now assume "known", took hundreds if not thousands years to be discovered, so we will be able to understand theory math (even useless math like summing up Roman numbers), they won't be able to understand ours math. The chance that somewhere someone invented a theorem (and proved it) that get lost and is no longer known today becomes smaller as we go back in time, so somewhere maybe 2000 years ago someone invented a rudimentary math system that today's we not know and that would be useful, but chances that was happened are really small, and anyway we will be able to understand that easily. We will understand everything, but we will see how much value people of passed times gave to even simple equations that now (hopefully) everyone is able to solve. Most problems for us would be about "notation". Something simple like ``` 3+x = 7 => x = 4 ``` Was in reality written as > > If we add a unknown quantity to three and obtain seven, then the unkown quantity was four. > > > But once we translate stuff into our notation, we are able to do maths very easy, even better, our math notation would probably spread quickly because is very usefull and probably the only real true difference with ancient times. I would claim that modern math notation and Turing machines are the 2 most important conquers after invention of the Zero. [Answer] A first year university course in Calculus and Linear Algebra basically gets you to the early 19th century - with Calculus in the 18th and row reduction for LinAlg in the 19th. But the notation is confusing and the approach is different. As Patrick Stevens notes, before Cauchy, people did Calculus by operating with "infinitesimals" - with sometimes horrendous results. A time travelling physicist would do better than a mathematician in that regard! I have read textbooks from the early XXth century that looked familiar and could pass for modern works (although expected a higher standard from the students), but anything prior to that would take a learning curve from your Time Traveller. Differences in notation are not trivial, since Mathematics basically lives within its symbolic representation, and differences in notation typically reflect differences in approach. ]
[Question] [ I am currently designing a fantasy world that includes a telekinetic race that can control objects if they are touching its material (they can make flying rocks if they are in the same ground or holding same material). It is way harder for them to control impure materials but they can still control it. My question is how to imprison them. Technology a little bit more advanced than Medieval era and magic is mostly used in enchanting. Edit: their powers are proportional to the amount of matter they touch. So they are more powerful if they have full body armor of that material compared to only a gauntlet of that material. [Answer] # Opiate them Telekinesis is a mind power. That justifies doping their minds. If you use psychodelic drugs they might go tame. They might even become new age hippies. But they will not be functional for most of the time, and most western societies hate this kind of thing anyway. But use narcotics to turn them into helpless, mindless husks that are able to print thousands of plates a day and you get both behaving prisoners and profit for privately owned prison. If you manage to get them really addicted you don't even need to plug the plate press on the mains. Just have them operate it psyonically and save some money that way. Heck they might even move the generators so you can go off the grid. Don't forget to make life generally miserable for them so that the addiction to morfine/heroin is as tough as possible. Also give some privileges to the most skillful and obedient psyonics who are willing to snitch, or for those who can act as guards against rebellions. [Answer] There are a lot of methods, actually. They work depending on the purpose of imprisonment. ## Penal colony / Reservation area If you want to isolate them from another part of society. Leave them on a lonely island. Once a month a supply ship arrives. The ship never docks, the supplies are delivered by boats. The ship is escorted by a few frigates, they open fire if the ship (somehow) becomes captured. You cannot escape an outlying island without an ability to navigate the sea. ## Special suits If you want hard constraints (studies, experiments, intimidation). Make a full body suits they have to wear. Anything they touch they do through that suit. Use any convenient material for this suits, but don't use this material for anything else in the prison. The suits should have locks or some kind of mechanism preventing you to doff it by yourself. ## A convenient prison If you want a correctional facility. Don't make any "special" prisons, just brand the convicted and declare escape from prison as the most serious crime. ## No prison Until ~XVII century there were no prisons (as penitentiary facilities) at all. There were only jails (short-term). Usual punishments were corporal (physical) ones, public executions, mutilations, torture, forced hard labor, fines. You said your "technology a little bit more advanced than Medieval era", so it is logical to assume there are no prisons in this world yet. ## But actually, that would be the least serious problem Imagine people who always carry AK47 with them. Everywhere. You cannot confiscate or disable this weapon. They have their weapons at the ready when shopping, walking, going to theater. Children carry these guns when playing with other children. That is how this telekinetic race looks like to ordinary people. They always have a dangerous weapon with them that we can not control. "How to imprison them" would be the last question. The first question is — how to let them live? And how can we live with them? [Answer] The walls, floor, and ceiling of the cells are too massive to move or break. The door to the cell is more than two tons and must be slid out of the way for the occupant to get in and out. There is a window to allow passage of meal trays and such. The door is made of metal embedded in concrete. The concrete is too massive to break apart and that is the only way to get to the metal portion from inside the cell. The metal is accessible from the outside of the cell (but nowhere near the window, so no reaching of arms) so it is impossible for the prisoner to open the door because s/he can not touch the metal portion. But there are metal handholds on the outside of the cell so guards (who also are telekinetic) can slide the door open (if not all guards are, that's okay, as long as there are a few on every shift). I recommend similar doors throughout the prison (modern prisons of course have multiple secured doorways). This is far more secure as the prisoner will need to break through multiple security points to escape. An important part of security is the ability for guards to periodically inspect the cells. Multiple security points also allow prisoners the ability to go take showers, socialize with other prisoners, exercise, etc. Isolation for anything but very brief periods is extraordinarily cruel and destroys the mind; if you want prisoners to be able to function in society after serving their sentences, you need to treat them like human beings and rehabilitate them. This requires movement outside their cells. For the most difficult prisoners, have cells with doors impossible for one person to move. This requires at least two guards every time the door is opened or closed. In many societies, including the United States, there are some low-security prisons that are easy to escape. There's also home imprisonment, work release (where the prisoners sleep in the prison), and so forth. It works because the prisoners know when they're caught they will have longer sentences in a less comfy environment. And because they don't want to be on the lam for the rest of their lives; it's mentally exhausting and they will never see their loved ones or lead a normal life. Much easier to just serve your time and be done with it. Of course that isn't the same for people with life (or very long) sentences. Prisoners who have shown they can not be trusted will be held in more secure prisons, including isolated cells if required. The most direct security measure is a bunch of guards with guns watching each potential escape route carefully. You may want to incorporate this anyway. Guns don't have to be ordinary bullets, if that doesn't work on your prisoners, or if you don't want them dead. They can be tranquilizer darts. Or a hallway full of anesthetizing gas. Drag them to a new cell. Start over. [Answer] ## Bronze door with steel locking bar All you need is * a bronze door that's too sturdy to just rip out (since the telekinetics CAN touch and move the door itself. Doesn't have to be bronze, ideally something "impure" but strong.) * secured by a steel locking bar (or some other strong material that's not available inside the cell) The inmates can try to push on the door directly, but can't move the locking bar. So unless the construction is weak enough to rip it out by brute force (but if they can do that, any window bars or wall pieces would be fair game too^^) they have no way to unlock the door from the inside. Basically you'd have the same situation as any current jail door: The inmate can try to break down the door by brute force, but has no way to open the locking mechanism. Obviously you'd have to be VERY careful of any pies the inmates receive - but a simple magnet (lodestone?) should be enough to determine whether they contain a file... erh, piece of steel. Do also make the locking bar heavy enough that a small steel pebble isn't enough to empower a telekinetic to move it. [Answer] Another idea, if your world have giant spiders: spider silk is extremely strong, but also very light. > > their powers are proportional to the amount of matter they touch > > > If they are suspended in air and cocooned in spider silk, the only thing they can touch is the spider silk - and the amount of that material is maybe not enough to give them any meaningful strength to manipulate it? [Answer] Don't use a mechanism to lock them in at all: Weld the door shut. The telekinetic abilities have a maximum force level. If there's no locking mechanism to manipulate, then they will have no means of escape other than brute force. If the technology level doesn't permit welding equipment, the same effect can be accomplished with a hot fire and bellows but it will be much slower. Of course this means that opening and closing the door to the cage will require welding equipment every time, so the cage they are locked in will have to be large enough to live in for 100% of the time. Don't think of it as a jail cell, think animal zoo habitat size. [Answer] Impure materials. From OP: > > It is way harder for them to control impure materials but they can > still control it. > > > Riff on this. I am not entirely sure what impure materials are - some sort of alloy or weird amalgam? But I like it. The cell holding these telekinetiks is maximally impure - maybe made of brick like loaves of metals dust, wood chips, sand, bone, shells, and lots of other things. Different structures would have different impure materials according to what the builders had handy and ease of construction. [Answer] Can they levitate themselves? If not, dig a pit and put them in it. Can't get a lot more impure material than soil and dust. ...you might now be imagining a small hole in the ground. Dig a deep pit. [Answer] I'm thinking of leveraging these three details: > > can control objects if they are touching its material > > > and > > It is way harder for them to control impure materials but they can still control it. > > > and > > magic is mostly used in enchanting > > > So a cell where they can't reach the walls and the ceilings. (because it's too high, and there is a rift/pit between the ground in the center where they are kept, and the walls on the side.) It can be maybe a natural cave from maybe a rare mineral in your world, in the belly of a mountain. The ground of their platform is fully covered by a material that's not otherwise present in the cave - some sort of intentionally impure metal alloy maybe. So they can only touch the metal, nothing else in their prison. The metal is enchanted with let's say a shock elemental protection spell/rune, that stuns whoever tries to move/bend or manipulate in other physical way the metal structure. [Answer] House only a few TK in each cell so they can’t work together on the same cell door and locks alternate construction materials of adjacent cells so groups of cellmates can combine their abilities As Cyn, described, cell door is massively heavy Locking mechanism on doors are bars made of different materials, none of which exist inside any cell. Bars are nested and interpenetrating forming a complex problem like a chinese puzzle box, each lock requiring a unique solution. The locks and bars are setup such that guards stand on a segment of the lock and have significant mechanical advantage so if they are standing in the right spot, no bars of the locks can move. [Answer] Suspend your prisoners in the air. If their power is proportional to how much they can touch, then not allowing them to touch anything ought to make them totally inert. Their are a couple ways to keep someone totally suspended. 1. Magnets. Water is slightly repelled by magnetism, so with a strong magnet you can push something into the air without touching it. 2. Fans. Have powerful fans beneath your prisoners forcing them into the air. Either one of these works, but the hard part after this is handling their basic needs. I assume since you are bothering to imprison rather than kill that you will want to feed them. Inevitably giving them food will grant them some power, but hopefully it is impure enough that it is relatively harmless. You would have to float it down to them so they couldn't touch anything else. Good luck keeping your prisoners contained! [Answer] Manacle to them to something solid with sharp or pointy-lined manacles, so that attempting to remove them with force will result in limbs being lopped off. Or, put them inside a prison with hollow walls full of acid, poison gas or other similar material, so breaking out will kill them. Or, do it the easy way: word of honour or'parole'. They promise not to escape, and you promise not to annihilate their entire family with whatever magic you have at your disposal. [Answer] Weld the door shut If the entrance is sealed then telekinesis won't help. When they want to get out, they need to be cut out using tools that the prisoner doesn't have access to. The prisoner would have the door welded or forged shut or completely bricked in. You leave some small holes for food, water, sewer and air [Answer] If you want something approximating a prison cell, I think you'd benefit from the use of layers of different materials. The innermost layer should be something very strong+hard, heavy, and "impure" in nature -- perhaps stone or concrete? Strong+hard so that it resists physical attack. Heavy (>2T) so that they cannot use some other material to apply telekinetic force to it and move it, and impure so that the prisoner cannot use it to their benefit by touching it. The floors, walls, and ceiling should all be made of this. That layer should be an appropriate thickness to provide the necessary strength. Outside that, there should more layers of additional materials. As you get further from the innermost layer, you can use more pure materials if there are strength benefits to doing so. For example, a few layers out, you could use iron or steel. Just make sure that the prisoner doesn't have anything in their cell made of the same material. Does anything exist in your world that can block telekinesis? Like the way lead interfere's with Superman's X-ray vision? If so, definitely include a layer of that somewhere. Could there be a magical enchantment that would suppress or attenuate their power? If so, I think it'd be good to include it, but I would not rely solely on that. You always want multiple points of security. What is the range of their power? Surely it's limited, right? I'd think of this like signal attenuation: When a TK projects their powers through the air, their strength reduces to zero over some distance; more powerful TKs might have longer reach than others. But if the powers must pass through some other material, that might attenuate it more aggressively than air, or it might act as an antenna or conductor and actually work to extend the range. There are some interesting possibilities you could play with there. What happens when multiple TKs combine powers? Is it additive? Multiplicative? Exponential? Consider this, and decide whether you need to separate them completely, and consider the minimum separation necessary. [Answer] Depending on your geography, mountain caves/mines would be very useful here. Rock tends to form in layers and when tectonic plates smash into each other, the layers crinkle up and form mountains. Mountains are good for mining because layers that are normally buried deep underground are now close to the surface. If you house your prisoners in a mountain cave or old mine, they will be surrounded by layers of different types of rock. At most, they'd be able to touch and control only the material in the innermost layer, and that's not nearly enough to be useful in an escape. The only thing you'd need to construct would be small sections of walls/doors to separate things off into individual cells. Use a wooden door that locks with a crossbar made of something that isn't found anywhere else in the prison. For extra security, make each door's crossbar out of a "unique" alloy (e.g., a DIY exotic material). Start with a simple, cheap alloy like bronze (copper and tin), and add two more metals (zinc, lead, nickel, iron, silver, etc) to the alloy when smelting it. Each 'extra' metal - along with its concentration - is selected by a different blacksmith who adds it to the pot secretly. The end result is a custom bronze alloy that no person knows the recipe to. The resulting crossbar will be made of a material found nowhere else, so even a prisoner who's very skilled at manipulating "impure materials" has no opportunity to obtain a sample of it and control it. An underground prison gives you some relatively cheap security options as well. Make sure there's a long, straight hallway between the cell area and outside. This exit tunnel is supported by pillars. If any prisoner attempts to escape, the guards flee and pull down the pillars on their way out. The roof caves in, sealing all the prisoners inside permanently. Even if a prisoner makes it out of their cell, they have no way of covering that much ground before they get buried alive. Knowing this will make escape attempts less likely. There's actually an incentive for prisoners to try and stop other prisoners from escaping. A variation would be a steep entrance tunnel and a floodgate that leads to a lake above; instead of caving in the mine, open the floodgate and let it flood. In the exceedingly rare event that someone does manage to escape completely, don't underestimate the stopping power of a trained pack of dogs. You can probably fight off one or two by using your powers to create makeshift weapons. When two dozen German Shepherds are after you, though, good luck. You can't outrun them, and you can't really defend yourself against that many independent, simultaneous attackers. [Answer] # The alternative option is that you don't imprison them As you can see from the other answers, imprisoning someone is going to be complex and expensive. It's also high maintenance and high risk. This is amplified by the lack of industrial base in a medieval society. Generating vast quantities of steel and concrete isn't really practical for your average kingdom. # Execute them You're only going to imprison high value people, and only for as long as their value exceeds the cost of trying to keep them imprisoned. Any low value persons are simply executed on capture or never captured in the first place. This now leaves the imprisonment option open: # Maintain the threat of execution Since we're now talking about high value prisoners, they tend to be rather attached to their own wellbeing. They're also aware that you'd rather have them alive but having them dead is better than having them at large. A high value prisoner is likely to have a fairly open regime, they're not normally kept in chains in a locked dungeon, they're normally kept in a private suite of rooms with access to servants and the threat of being chained in a dungeon if they don't cooperate. Since chaining them in a dungeon has been practically excluded, it comes down to stay put or be summarily beheaded. High value prisoners are a special case, they tend to be political prisoners and in many cases that just means they're currently out of favour but may come back into favour with some event, change of government, or season. However that only applies if they behave honourably while confined. For as long as that's the case and appropriate quarters and guards are provided, they may well stay put on being informed that they're to remain confined at the monarch's pleasure. [Answer] "[they] can control objects if they are touching its material (...). It is way harder for them to control impure materials but they can still control it." Build any cell you'd like, as long as its walls and doors are solid, then coat it carefully and thoroughly in a thin layer of the most impure material you can get (think paint), so that the prisoners cannot touch anything that is not the 'impuritum'. Make sure that this layer is bonded to the material beneath for added difficulty in manipulating it, and that there are no large deposits of it nowhere near, except maybe for other cells. Depending on the application method, you could make that layer just a few atoms thick (electroplating, for example, creates a layer "typically less than 0.1 μm thick" according to Wikipedia), which would not only make using such little amounts impractical, but also severely hamper any ability to manipulate it at all, even if it wasn't impure (after all, if manipulation is easier with more material, it has to be harder with less of it). [thanks computercarguy for this paragraph!] You can then increase the safety of the cell by combining this method with any other presented already, or coating the cells' walls with a few layers of different impure materials to avoid the prisoners making a small hole to the stone beneath. [Answer] Suspend them mid-air using tight metal ropes, but coat them using some form of rare (impure) material. This does three things: * reduce the amount of area they contact, limiting their power * they can only contact impure materials, reducing their powers more * reduce the amount of stuff they have control over Combined, they only have very little control over very few objects. [Answer] I would suggest a large open stockade, enclosed by a large wooden walls. Painted on the ground roughly 60 yards from the walls are lines. If a prisoner crosses the line he is pin cushioned by archers on the walls. There would be no guards inside the stockade and prisoners are left to get on with it. All food is brought in by hand and left at the line. I am not clear how high the prisoners can 'fly' but I assume the further from the ground they are the harder it is to lift. I am also unsure how far they could fling a boulder if the dug into the ground of the stockade but 60 yards is quite a distance. [Answer] You have people with power. Just remove their power. The simple way is to have a material that react badly to magic. Put that in their brain or in a neck collar. You can now use simple prison. Anyone trying to use power to escape or bully others will be dead. [Answer] Dig catacombs. I'm not suggesting burying them alive individually, as another answer does. What I'm suggesting is a relatively spacious dungeon, deep underground. It might be useful to divide the space into rooms, but it would not need doors; indeed, the goal is to have as little loose or movable material inside as possible, so that your telekinetic prisoners would not have many objects to grab hold of. It might be best to carve the catacombs into stone, so that it wouldn't be easy to dig up loose soil and get loose material that way. The catacombs would have a single exit, heavily guarded. Food and supplies would be delivered periodically through this exit, perhaps by other telekinetics so that there could be minimal packaging (again, you want as little loose material as possible for prisoners to grab). The effect might be somewhat like the underground prison from The Dark Knight Rises, though prisoners trying to escape from the exit would very much not be free to leave. [Answer] # Enchant the cells > > magic is mostly used in enchanting > > > You don't need lots of science here, simply enchant the walls of the cell against TK. The stronger someone tries TK, the more pain they feel. That could also lead to a breakout story, where one guy finally pushes through that pain barrier (perhaps at the cost of his life) to break the walls down despite the enchantment. [Answer] If you have magic, presumably reasonably powerful mages could inscribe runes of repulsion, that push living things away from them? Have a spacious cell with these runes inscribed on all six walls pointing inward. Toss in the offending TK, and they instantly get pushed to the middle of the room. With a little practice and a large enough room, they could probably still have some mobility (think "swimming" like astronauts... inefficient, but it's something). If the runes only target living matter, then guards can come through a door in the corner and toss food to the prisoner, and the prisoner can drop the remnants (bones, seeds, etc, all of which should be too impure for them to use practically anyways) which the guards can sweep up later using a broom on a long pole. For bathroom business, you can perhaps have the floor sloped downward toward a drain (if the drain would break the floor's rune, you might need multiple smaller runes placed around the drain instead). Then the prisoner just has to orient themselves so their waste goes downward (and not all over themselves), and guards could hose any remainder away. If you want to give the prisoner a means by which to anchor/orient themselves, you could have chains attached to the walls, inscribed with powerful shock runes. A thin mixed-fiber rope (cotton, wool, and whatever other non-leather materials are available) would be tied between the two chains so the prisoner could use the rope to orient/move themselves more efficiently, but can't reach the wall (the chains should be at least six feet from wall to rope... between the shock runes on the chains and the repulsion effect of the runes getting stronger as they get closer, it will be impossible for them to touch the wall without getting blasted). Of course the rope could still present a security risk in the hands of a powerful-enough, motivated-enough, and clever-enough telekinetic... Prisoner garb should also consist of this same mixed fabric (whether the rope/chain idea is implemented or not), and guards should ONLY be allowed to wear leather and metal, so their clothes can't be manipulated. Perhaps as a last ditch security protocol, distilled spirits could be stored in large reservoirs above the prison (and amply insulated, vented, and periodically resupplied). Each cell would have a control valve and several tiny nozzles in the corner of the room -- pulling the valve would activate small shock runes to make an arc near the nozzles, as streams of alcohol come spraying out... boom, flambéed TK. If you want to make sure bored/miscreant guards don't do this for "fun", maybe the valve handles are out of reach on the ceiling, and made of pure iron, and a small number supervisory TK guards have iron rods at their hip so they can activate the valves. If the only TK guards were these few privileged supervisory ones, there would be easier accountability for "accidents". [Answer] im not sure is this can work or not but i suggest <https://en.wikipedia.org/wiki/Safety_coffin> [![enter image description here](https://i.stack.imgur.com/U1CI8.jpg)](https://i.stack.imgur.com/U1CI8.jpg) BURRIED THEM ALIVE with one hollow pole or air tube to give them hole to breath and eat or drink, im not even sure you need coffin for them. since you say they can control 2 ton at best just dig deep enough to surpass 2 tons. this will bind their body in place, cant struggle, or see, all they can do is shout and its better that they dont. here a movie that depict the feel/horror of being buried alive [Buried](https://www.youtube.com/watch?v=EuPVY2WWwO4) and this video [Buried alive](https://www.youtube.com/watch?v=mwZetpBcMRA) (so i doubt someone can still feel rage or hatred because such behaviour wont save them, and they more likely get traumatised instead, which help in manipulate them to be obedient) and even if you can punch through the coffin like in this movie [kill bill 2](https://www.youtube.com/watch?v=pohqGgEZf-s) i heard including myth buster, realistically the soil that come through should have suffocate or crush her instead. ([example like from this link](http://www.mtv.com/news/1498162/reel-to-real-can-you-really-dig-your-way-out-of-a-grave/)) also depend on the dirt or field density i think you can remove the pole if you consider it dangerous while keeping gap of hole in the dirt. but if he dare to move his tube or pole it mean he just lose the hole for him to breath and enjoy his burried life. also as soon the guard feel the hostility they can torture them by just pouring anything hot into the hole or just cover it to make them unable to breath, or just leave them burried like that for long or forever that kind of thought will increase their survival instinct or trauma and have more chance for obedience upon release, if they goes mad then its easier to end their life and not require to make new burrial so it cost effective and simple and cheaper doesnt require industry method to create huge amount of metal. theres also no way to get out or door to open except tiny hole for the pole which wont be enough to pass through nor dig out of, and any movement to it will only result of the soil to crumble and filling the coffin or their mouth, and worst case it can result in plugging their only hole to get oxygen, unless the dirt or soil is taken out they wont go anywhere. regarding evacuating their bowels/bladder they can just do their bussiness there, they are prisoner after all no one care about sanitizing regarding jail anyway. it even better to torture their dignity and comfortability, i also doubt there will be a big pile of poop and piss if the guard give the prisoner food to barely enough to make them stay alive. reasons i suggest this if you dump them to far away desert islands like australia or alcatraz theres no guarantee they wont build their own kingdom like australia or create flying object or any transportation to invade back. just put them in a hole or pit without any roof or an exit in the roof doesnt guarantee they dont just dig it out from other place or find material to fly off (since it have no roof chance for outside material to be possessed is big like from intruder/spy) putting them in cell with impure material doesnt change that you can picklock or manipulate with viewer pure material or smaller controlable impure material to open it or corrode it from acid like piss,sweat,or create salt from your body, or doing similar principle like water breaking a rock. and especially if you put them in group will only result in disaster. drug is double edge sword it doesnt guarantee rival kingdom or the people that not captured wont grow their own drug to sway them over, besides its not like drug is irresistible they can just resist the urge by sheer will or hatred alone and just pretending to make an opening to revolt. just because the people can or cant use telekinetic it doesnt mean they cant use their body parts to manipulate object. [Answer] ## Anti-psychic Magic Spell Make a magic spell to neutralize any telekinetic activity. Put such a magical object in a protective cell on top of the prison, and disperse the energy to affect all prisoners. Maybe use more of such objects for full effect. ## Spiritual music Place speakers in your prison and play spiritual music of love and compassion. Slowly the sound of spiritual music will cleanse the hearts of all prisoners and they will stop thinking of any negative act. I think this is the best. ]
[Question] [ At the King's court, duels are sometimes used as a way of settling disputes. However to avoid too many injuries the king has decreed that combatants must use only one finger as a weapon. Any finger may be chosen. This is the standard hand position. [![enter image description here](https://i.stack.imgur.com/y63Ea.png)](https://i.stack.imgur.com/y63Ea.png) Rules 1. It's somewhat similar to fencing but with one finger. 2. Armour is banned. Only light, modesty-preserving clothing may be worn. 3. Nothing can be worn on or held in the hands. Fingernails must be short. 4. Once you have chosen which finger to use, you must stick with it until the end of the fight. 5. The loser is the first to submit or be fatally injured. Question Sir Barrard really wants to kill his opponent Sir Forgyle. Can he do it, even in theory? Can he do it with a single blow or would it take several? What are Sir Forgyle's best defence moves to preserve his life? NOTE These are normal humans in the sense that no magic or superpowers are involved. You can strike any part of the opponent's body with your chosen finger but you cannot use any other part of your body as a weapon. If you get stuck in a clinch (as in boxing) the referee will separate you. Note that honour and chivalry are very important in this society. Anyone who was seen to behave in an unsportsmanlike manner would be declared the loser and even ostracised. Referees enforce correct behaviour but the king's decision is final. NOTES ON DEFENCE You are allowed to block/parry the opponents finger with your finger as in fencing. You must not strike the opponent's finger with any other body-part. New rule You must keep your free hand flat on your body at all times. You can form a shield for any part of your body by sliding your hand there without lifting it off your skin. If in doing so, you push aside your opponent's finger as it is about to strike then that is allowed. In the event that your sliding hand damages the opponent's finger that is not counted as a blow and is allowed. [Answer] Crush their throat. Just jab the finger into the front of the throat as hard as you can. It's very easy to produce serious injury and death there although you can expect your opponent to try and protect the area. You may get better results by folding the finger and striking with the 2nd joint rather than using the finger fully extended. You will get a slightly larger striking surface but a much stronger one. I suggest practicing on some disposable peasants before using it on a real target. [Answer] # Hard training of single digits Take inspiration from [this](https://www.youtube.com/watch?v=DUbuBFAEmHo) fella from Malaysia. He trained (and often broke) his right index finger to the point where he is able to pierce coconuts. Such a blow to a human torso could result in lethal injuries. I imagine, that upon passing of this law, many nobles start training one of their fingers to this extent. No magic or superpowers required. [Answer] To add on Ash's answer, [Vagus nerve stimulation](https://en.wikipedia.org/wiki/Vagus_nerve#Vagus_nerve_stimulation) can lead to collapse and even to death, as consequence of induced bradycardia. > > Parasympathetic innervation of the heart is partially controlled by the vagus nerve and is shared by the thoracic ganglia. Vagal and spinal ganglionic nerves mediate the lowering of the heart rate. The right vagus branch innervates the sinoatrial node. In healthy people, parasympathetic tone from these sources are well-matched to sympathetic tone. Hyperstimulation of parasympathetic influence promotes bradyarrhythmias. When hyperstimulated, the left vagal branch predisposes the heart to conduction block at the atrioventricular node. > > > Sometimes even a too tight necktie can achieve that result. [Answer] ## Poison I understand that there is a rather fatal exotic poison that can be applied to the fingertip. The finger then may be either jabbed in the opponent's eye or his mouth, or if you're feeling like making a particular point, up his nose. Carefull to not get cut during the fight though, the poison may find it's way into your bloodstream. Maybe the mouth's not such a great idea as a target, there being teeth after all. The most suspicious and canny of opponents would wear a nasal insert with a downward facing pin - beware. No doubt the referees are wise to this. The most dishonourable and disgraceful way to die is the old [anal-finger-poisoning](https://www.thesun.co.uk/sport/5010798/oil-check-wrestling-move-brazilian-jiu-jitsu-legal/) (familiar from Brazillian Ju-Jitsu), not for civilised opponents. [Answer] Sir Barrard probably could kill him with one blow, in theory at least. In particular the [hyoid bone](https://en.wikipedia.org/wiki/Hyoid_bone) is surprisingly delicate and can be crushed with a sharp blow, a single finger could be sufficient to do the damage. It might also be possible to do enough damage to the [carotid](https://en.wikipedia.org/wiki/Common_carotid_artery) or better yet, because it's closer to the surface, the [jugular](https://en.wikipedia.org/wiki/Jugular_vein) to cause death after rather than during the fight due to internal hemorrhage. The [brachial artery](https://en.wikipedia.org/wiki/Brachial_artery) is also close enough to the surface that it may be vulnerable to such damage, not immediately but eventually deadly. Fragmentation of the nasal bones could also be lethal, but would almost certainly require multiple strikes as they are much stronger. [Answer] In my imagining, these are the sorts of disputatious nobles who wear ruffled shirts, powdered hair with little pig tails out the back, short breetches, shoes with buckles, codpieces, all that sort of finery. Think of a men writing with feathers mgm movie from the 30s, such as the scarlet pimpernel - only much, much worse. In preparation for the finger fight, legs and non-participating arm are tightly bound, only the belligerent finger and arm left unrestrained. They are also blind-folded. A string quartet provides background music, claret is served to the spectators, who view from a raised balcony above the arena. When the magistrate sounds action, the disputants are free to bound around the place, flinging their fingers furiously, un a d'autre (that's french). Each combatant has a receptor implanted somewhere upon their person which when actuated with a firm jab, will release a dose of immediately fatal poison. And so, the spectacle becomes a series of furious jabbing exchanges where, as with the gladiators of old, points are awarded for style. The woman play the closest attention. If, after a suitable interval of say 20 minutes or so, no one is yet dead, the survivors are both lauded as the best of all posible men, all trivial injury forgiven, any serious injury recompensed, and the wine flows freely. If one is killed, the wine still flows freely, with perhaps a tear for the vanquished, or perhaps not, depending. [Answer] He could possible fatally wound another person but i would suggest that instead of his index finger he use his thumb. By curling his fist and placing his thumb along the top of his index finger like this picture below [![enter image description here](https://i.stack.imgur.com/ZmVLT.png)](https://i.stack.imgur.com/ZmVLT.png) In Karate I believe this is called a Boshiken or thumb strike. I believe it can be used to dig into various pressure points around the head and the throat and can even be used to gouge out eyes it also has the effect of allowing you the thumb to hit even a hardened part of the body with out touch much damage and does not require some of the more long term ruinous contact conditioning that say training something like the Nukite or spear hand can cause. in this instance the contact point will still be a single digit just not a finger. [Answer] Other answers already suggested attacking the throat area, which indeed has a number of fatal vulnerabilities. However, even inexperienced duelist would know to keep his throat protected, and attacker would more likely just break his finger trying to push through defensive blocks. Martial arts like [Kyusho Jitsu](http://www.koryudojo.com/kyusho.html) can provide an idea on how finder-fighting duels can unfold. An attacker can strike a number of vulnerable points in the body, which would cause the defender to drop his defense, at least momentarily. More experienced defenders would try to break attacker's finger with powerful elbow or forehead blocks. [Answer] There are many places on the body where a single finger can produce fatal injuries and it is impossible to cover them all simultaneously. Everyone has already mentioned the throat, there are a number of sensitive spots there that are easily damaged. The solar plexus is a nerve cluster that can cause fatal paralysis of the diaphragm if struck with sufficient force. Near the solar plexus is the xiphoid process; a little tab of bone which, if broken off, often punctures the liver and results in fatal internal bleeding. The temple is another potential soft spot, being the thinnest point in the skull. Most techniques strike at it with an elbow, but a sufficiently sturdy finger could easily do the job as well. And finally, if he wants to go for maximal vomiting amongst the audience, just put an infectious agent under the fingernail and jab straight through the eye. There's a decent chance he can damage the blood vessels behind the eye and cause them to bleed into the brain causing eventual death, and if not the infection is likely to be fatal anyway unless their doctors are really good and have antibiotics. Even if he doesn't kill his opponent he will have permanently disfigured him. Additionally, a sufficiently skilled martial artist could make the killing blow look like an accident. Stumble, trip, everyone lands really hard and whoops, somehow there's a broken neck. What are the odds? [Answer] ## Sir Barrard uses his pinky finger. Considered as the weakest finger of all, using the pinky will surprise or even destabilize his opponent: Sir Barrard surely is strong to have confidence in this finger! But the trick is there: the pinky finger is in the direct continuity of the side palm of the hand, and if it is not a good thrusting weapon, it can reveal a great slashing weapon. [![enter image description here](https://i.stack.imgur.com/aXWLS.jpg)](https://i.stack.imgur.com/aXWLS.jpg) Now, with all his might, Sir Barrard must wait for an oppurtunity to deliver a slashing uppercut with his little finger upward the nose of his opponent, the idea being breaking his nose and sending pieces of the cartilage directly into the skull. [![Jab here to kill](https://i.stack.imgur.com/T0LLZ.png)](https://i.stack.imgur.com/T0LLZ.png) Source: [Quora](https://www.quora.com/Is-it-possible-to-strike-someone-in-the-nose-hard-enough-to-send-bone-into-the-brain-and-kill-them-instantly) Note that the blow must me delivered with a tremendous force, and this will likely result in Sir Barrard's finger and metacarpals being broken in the process. In real life, delivering such a blow and kill even with a clenched fist is hard to manage. But this is fiction, and you can use artistic license as long as it fits the plot in a spectacular way... [Answer] Death yoga. [![apan murda](https://i.stack.imgur.com/gHBRR.jpg)](https://i.stack.imgur.com/gHBRR.jpg) [source](http://carlawainwright.com/apan-mudra/) The chakras are yogic energy points within the body. The points govern and energize energy flows. One hears commonly about manipulating or otherwise focusing the various chakras, usually to achieve desired beneficial outcomes for the practitioner. Examples: <http://www.soulandspiritmagazine.com/13951-2/> > > Crown (Seventh) Chakra > > > Located on the top of the head, the crown chakra symbolises > spirituality and your connection to a higher power... > > > Tapping point: top of the head > > > Third Eye or Brow (Sixth) Chakra > > > This chakra is located directly between the eyebrows. It represents > intuition, imagination, reflection, and the ability to see things for > what or how they are. ... > > > Tapping point: between the eyebrows (be extra gentle with this point) > > > Sacral (Second) Chakra > > > The sacral chakra, also referred to as the womb chakra, is located in > the pelvis behind the navel. It relates to your creativity and > feelings and is also linked to childlike joy... > > > Tapping point: just below the belly button > > > Root (First) Chakra > > > The root chakra is located at the base of the spine. It represents > your feelings of safety and survival. It deals with issues of > abandonment, unworthiness, and insecurity. Its focus is safety, > security, and survival. > > > Tapping point: lower sacrum or top of your thighs. > > > There is more to these energies than this simple synopsis. The energy flows within the body can be and possibly must be connected to the larger world. Energy is power: neither good not bad. Energy that can be used to heal can be used to harm. Your fingerfights are offensive yoga - the goal being to destructively manipulate your opponents energies in the context of the larger energy of the world. Note:yogic manipulation of your opponents energy can kill, but it might not kill right away. The vibrations set in motion may take time to resolve into a pattern that causes death. Other things may be happening in your opponent over this time which he might be able to resolve on his own or with help - or which he might use to his own ends. I did not make this up. <https://en.wikipedia.org/wiki/Touch_of_Death> [Answer] If you are willing to bend the rules a bit, you could take inspiration from [Naruto vs Neji](http://narutochronicle.wikia.com/wiki/Naruto_Uzumaki_vs._Neji_Hyuga) fight. In the Naruto universe, every person has many Chakra/Pressure points throughout their body. The chakra points release chakra/energy that is essential for the body to function. If you close off a chakra point, then the corresponding body part stops functioning (or at least becomes much weaker). In this fight, Neji slowly closes off all of Naruto's chakra points, and as a result, Naruto's body becomes so weak that he can barely even stand. In your world: * Maybe the knowledge about pressure points is not common and Sir Barrard incapacitates his baffled opponent one pressure point at a time. * Or it is common knowledge in dueling circles, and it comes down to the skill of the fighters -- who can close off more/important pressure points first and incapacitate/weaken the other. Once the opponent is sufficiently incapacitated, and their defenses are weakened, a single powerful jab to the throat can be enough to finish them off. Plus, the second method makes the fights a lot more interesting to watch than fighters just trying to poke each other in the eyes/throat/groin. [Answer] Depending on how you define "unsportsmanlike" behaviour, I would say that the answer is probably a rabbit punch. As long as you are allowed to strike with the side of your finger and not just the tip, you can deliver a significant amount of force with a chop, either on the outer edge of the little finger or the edge of the thumb. A rabbit punch is a sharp strike to the back of the neck/base of the skull. It is called a rabbit punch not because it's small or ineffectual, but because it's a quick and clean way to kill a rabbit. It can separate the brain from the spinal cord, which is certainly fatal. ]
[Question] [ For the purposes of this question I want to look at Medieval-ish Fantasy environment, something in the classic vein of a Dungeons and Dragons setting, with humans, other races, (I don't have an exhaustive list but definitely Elves and Dwarves are in there), a little magic, and technology that does not post-date the late Renaissance. I want to understand whether, in such a setting, a precious metal based [commodity currency](https://en.wikipedia.org/wiki/Commodity_money) and a [fiat currency](https://en.wikipedia.org/wiki/Fiat_money), backed only by the long standing and well earned reputation for scrupulous dealing of the local merchant houses, could co-exist for long, multi-generational, periods. When I say co-exist I mean that the two currencies spend identically while not actually being formally pegged to each other; the idea is that one set of coins are made of bronze, silver, and gold and have traditionally derived their value from their metal content. In fact they still do in areas where the guilds don't have regular traffic. In civilised areas, a total zone no bigger than modern Europe, they're treated as equal to the Guild Merchant's denominational coins, which are made in a similar but different style and usually from cheap cast iron. For the "story" to work these currencies need to be able to have co-existed without major fluctuations for a couple of hundred years; is this realistic or are there either A. issues with the way the currencies will interact or B. basic differences in the way the two currencies will react to either external or internal economic pressure that would cause them to destabilise much quicker than that? To recap: * two coined currencies, one in precious metal, one in base metal backed by the promises of trusted institutions. * one-to-one exchange rate. * Medieval Fantasy setting with little magic. * how stable is the two currency system? [Answer] # I don't see why not Disclaimer: This answer heavily depends on the definition of `same economy`. This answer also does not claim that a fix 1-to-1 exchange can be maintained. --- You already mention that the classic coins derive their value from the actual value (usefulness) of the metal they're made of (similar to e.g. the likes of [hacksilver](https://en.wikipedia.org/wiki/Hacksilver)) - this is great, thus the coins are basically bullion to some extent. You also state that there are stretches of land where your merchants do not have much business, thus these areas have an active need for currency that they trust - this is pretty much a given with the coins that are traded by their material value. Now to your merchant-coins. As you say, they are backed by the guilds and merchants of the area. Wherever these factions are actively trading and doing other stuff their coinage will be used for currency. The stability of that currency comes A) from the fact that it is actively used and moving between people, and B) from the fact that guilds & merchants will insist on using it - to the point where some of them will not even accept the value-based currency (or only take it at a loss for the person buying wares from them). Cities will spawn districts where money-can be exchanged. While it is unlikely that the exchange-rate will be a stable one-to-one, there is nothing that should prevent the exchange-rate staying mostly stable over the time of decades up to a century - unless your guilds/merchants royally and coordinatedly screw things up. --- The important thing for those two currencies to co-exist is the size and relations of/in the area where they are used, yet even that is not really that much an issue. If you look back only some 500-1000 years you will find that most areas in medieval Europe had their own currencies or such, usually based on the next biggest city's markets (which also often decided upon the units of measurements used in the region and so forth) [Answer] Not only is it possible, it has actually happened at various times and places throughout history and on small scales continues to happen today. Probably the best studied example of the phenomenon is the era of free banking in Scotland, 1716-1845 [1]. During this time three major banks and a number of smaller banks in Scotland all issued currency. The notes were all denominated in pounds and all redeemable in specie (i.e., gold or silver), but only from the issuing bank. The key to the banks' profitability lay in getting the notes to circulate among the public for long periods of time before their eventual redemption. The system appears to have been relatively stable, without dramatic fluctuations in the convertibility of notes from different banks, and despite crises such as the Napoleonic Wars in the early 19th Century, right up until the system was ended by legislation in 1844-1845. Another example of multiple currencies existing simultaneously was the period known as the "Free Banking Era" in the United States, from 1837-1864. During this time, the regulation of banking in the United States was left to the states, which generally allowed banks to issue their own currency [2]. The system was in some ways less stable than the Scottish system, inasmuch as bank notes, though denominated in a common unit (the US dollar) often traded at a discount to their nominal value, depending on factor's like the bank's reputation and the distance from the bank's headquarters to the site of the transaction. Today we still see some instances of parallel currencies, mostly in the form of local currencies. Wikipedia has a list of examples, including the Calgary Dollar and BerkShares (which circulate in western Massachusetts) [3]. BerkShares are a particularly interesting case, as they are issued and redeemed at a discount to face value (95 cents on the dollar), but trade for full face value [4]. Unfortunately, there doesn't seem to be any information available on how many BerkShares are in circulation, nor any estimates of transaction volumes. So, to summarize, it is possible for multiple currencies to coexist. Historically, it often happened through competitive issue, while today it mostly occurs as local, limited-purpose exchange systems. I think it is significant that in both the Scottish and US cases the system was ultimately ended through legislation, not from any intrinsic lack of viability. To me, that suggests that banks (or perhaps guilds, in your case) will tend to issue currency if not prohibited from doing so, and that such systems tend to be robust over periods of several decades or longer. [1] [Free Banking: The Scottish Experience as a model for Emerging Economies](http://documents.worldbank.org/curated/en/719951468760530224/101501322_20041117150002/additional/multi-page.pdf), World Bank (1995) [2] [Wildcat Banking, Banking Panics, and Free Banking in the United States](https://www.frbatlanta.org/-/media/Documents/filelegacydocs/ACFCE.pdf), Federal Reserve Bank of Atlanta (1996) [3] <https://en.wikipedia.org/wiki/Complementary_currency#List_of_complementary_currencies> [4] <http://berkshares.org/how_to_spend> [Answer] ## Yes they can You won't be able to maintain the 1:1 exchange rate though. Modern economies run on the currency that governments issue. Governments will only accept payment for taxes in the currency they issue (ie, the US government is never going to accept payment in Russian Rubles.) It is this obligation to pay taxes (backed up by monopoly-on-violence) that makes fiat currency valuable at all. It's a tool for paying taxes. Medieval Europe had several governmental or governmental-ish bodies: The King, the Church and the Guilds. Clearly, the King is only going to accept payment of taxes in coinage that he issued. Why would he accept someone else's currency as that diminishes his claims to sovereignty. Everyone in the realm has access to this currency because it's the official currency. The Guilds can also issue currency in the form of coupons or stamps that represent some amount of services. This guild currency would be used internally for keeping track of debts and services. When tax time arrives, it can be traded for official government currency. For someone who doesn't belong to the guilds, the guild currency is still useful as it can be traded for a known quantity of services, say one guilder is enough to replace all four shoes on a horse. Over time, the exchange rate between guild currency and governmental currency will fluctuate as changes in national economics make currency more or less scarce; and as the services by the guilds grow more or less valuable to normal people. I don't see why this kind of arrangement couldn't last hundreds of years. Even new kings and governments won't matter as they issue new coinage to match their needs. As long as the guilds keep their internal currency sufficiently useful that everyone will use it alongside the official currency, then the guild currency can survive for long periods. ## Example A village has a method of exchange based on seashells except for the fisherman. He won't trade for seashells because he can't use them for anything. He will only take boar bones. (Who knows why, he's just weird.) Should this become a tradition that the fishermen are always paid in boar bones, then we have concurrent currencies. [Answer] Cuba does not only allow USD, but also (has/had) two local currencies. ([CUC](https://en.wikipedia.org/wiki/Cuban_convertible_peso) and [CUP](https://en.wikipedia.org/wiki/Cuban_peso)). It isn't one-to-one, but it is a fixed currency rate (currently 1:25). At least in this case the government has to regulate it to keep the rate "static" but you can do this obviously. Both currencies had coins and paper money. (CUC is being officially abandoned by 2013 but is still a valid currency) And were available at the same time without major issues. [Answer] This is a fundamentally unstable situation - you do not have two currencies here but four (gold, silver, copper/bronze, and the token of no inherent value). The implications of which are an entire area of academic study. The fundamental problem of a trimetallic currency is that the value of gold, silver, and copper coins change as the underlying values of the metals involved fluctuate relative to each other. This hasn't stopped real-world empires in the past from implementing it, but keep in mind that the relative values are inherently unstable. When copper becomes relatively scarce (from a copper mine being exhausted, an increased need for copper pots, improved daily trade activity among the peasants in a distant town driving up the demand for small change, or even if silver plates and bowls just go out of fashion) the exchange between copper and silver shifts, likewise when a new gold mine opens up or some neighboring kingdom makes a big tribute payment or some astoundingly rich guy from Mali decides to take a tour through your territory, it drops the relative value of gold. This is before we even get to unscrupulous people debasing the coins themselves. Stick to small silver pennies - lower value than gold so you're not trying to keep track of grains of dust, but most people can still use them for simple trade goods. For buying the small stuff, silver is soft enough to cut with a good knife - just put the knife across the coin and give it a whack to split the coin in half, or even do that a couple more times to split it into 8 pieces (history provides a great guide about what is truly workable). Trying to match different metals together in a fixed ratio is itself an exceedingly difficult problem, much less maintaining a fixed exchange rate with an inherently valueless token. Tokens need to be trusted to hold a value and be readily exchangeable for what people actually want to buy else they wouldn't accept it (or they would demand a significantly higher price in tokens to cover the risk). Why would people choose these tokens over a coin they know has an inherent value for trade? Forgery becomes a problem for the guild (and for people themselves as they don't want to risk accepting a token only to have the guild reject it). Individuals prefer payment in the best possible currency for them - if they cannot trust tokens, they will not accept them (without significant price adjustment). You will likely struggle to come up with a compelling reason for people to trade in tokens instead of metal coins or barter with other trade goods. Even if you manage to somehow establish a fiat currency as trusted by the population as much as an actual store of value, fixing its value in terms of a metal (without actively trying to fix an exchange rate - a difficult task which has bankrupted many countries) will likely prove impossible. [Answer] In theory it could... but it would be unlikely. over time one currency would win out over the other, both could still work, but it comes down to usefulness... For simplicity's sake and to suit the OP's demands i'm going to say a commodity currency is copper or silver coins and the fiat currency is a magical handshake, as apparently the word paper money is unacceptable, but these could be anything stone tablets, bronze axe heads (this is a real historic thing people!!!) or cookies... ok so maybe not cookies. Lets say an Apple is worth 1 Copper coin, and is also worth 1 magic handshake. and i need to go and buy 10 apples, then i could carry a purse (remember people in medieval times it was called a purse no matter the gender holding it!!!) with 10 copper coins, or maybe 1 silver or however the commodity would work, when i could carry 10 magical handshakes... one has weight and is obvious to thieves (big heavy purse) the other is light, is easily put in a pocket without lines or stretches in clothing... so why would i buy things with the coins? on the flip side, if it was raining anti magic then the magic handshake could disintegrate, i could pull my hand out my pocket and drop the magicalness and not notice. There are pros and cons to both systems, but eventually as time went on one would win out as the peoples preferred choice, one that they would carry instead of the other, but also have the other for when it was needed. (but would it be needed) now if you wanted the commodity system to be much more valuable then the fiat system, that might work, an Apples costs a magical handshake, but a copper coin could pay for a few bags of them. people would store their money in the commodity, but it would be impractical to pay for small items in so they would exchange some for the magicalness of the handshake so they can go down the market. Or flip it so that the metal coins would be far too heavy to pay for the big items or wagons full of goods so the fiat currency is used for that The only other thing i can give you to consider is that it is only in the last hundred years that pretty much the entire world truly gave up the commodity currency, previously all currencies were backed by gold. but it was too valueable to carry around so we used paper money (yes this is a drastic over simplifcation) So in short, both currencies being together and over roughly equal value, probably not, both exisiting together but of drastically different value, then yes is possible, as there are numerous countries around the world that accept dollars instead of their own currency, same with euros in the countries surrounding europe [Answer] Consider the [silver certificate](https://en.wikipedia.org/wiki/Silver_certificate_(United_States)#/media/File:US-$5-SC-1899-Fr.271.jpg), an early type of US fiat currency, [![silver certificate](https://i.stack.imgur.com/6JalL.jpg)](https://i.stack.imgur.com/6JalL.jpg) Facilitate commerce. These certificates could be turned in for silver money. It says at the top that the corresponding amount of silver was in the vault and this piece of paper represented ownership of that silver. If I live near the vault, and it has never failed to redeem these coupons for the silver, then I probably feel like the coupon is as good as the silver. If I am in Timbuktu, the locals there might not be comfortable with taking a coupon that can only be exchanged in the US, and might hold out for the actual silver. So too your systems. In the region where the merchant houses are a familiar presence, the fiat currency makes transactions easy - especially for larger sums where the metal is heavy. As one gets farther afield, people are less familiar with these merchants and so less eager to accept a certificate with their backing. In the region, travelers will show up with commodity currency and use it or exchange it for fiat money on entry (for their own convenience or by law). Persons leaving to trade abroad might change out some or all of their currency before leaving. Of course a small surcharge is levied on these exchanges. The merchant houses might charge more for a commodity currency transaction. --- Theft prevention. One might expect a commodity currency like pennies to be used by all persons for small transactions - a meal, paying a porter etc. Large transactions would be the province of fiat currency, and persons using fiat currency would be expected to be wealthy persons. In a medieval society your social class was obvious by your dress, manner and speech. I can imagine a society where such persons use fiat money among themselves. A middle class person like an innkeeper or animal trader would keep fiat currency because it is safer to keep gold and silver in the vaults of the house issuing the currency. Such a person would use fiat currency only for large transactions with wealthy persons. An underclass person attempting to use fiat money or redeem it for silver would be met with suspicion. On attempting to use or redeem such currency this persons might be made to account for the provenance of the fiat currency. I can imagine a scenario where I sign and put my seal on a high value bill that I have paid to a lower class person. I could imagine a scenario where such a person is detained as a "guest" at the merchant house where he went to redeem the fiat currency while a runner or pigeon is sent to the rich person who purportedly gave him this bill, to confirm the story. Such a system makes it more difficult for common robbers to rob rich persons. [Answer] The fundamental problem here is that there needs to be a reason for both to survive. This is touched upon in dot\_'s answer, but the reason behind it is not. If the two currencies are in direct competition then one will gradually grow in prominence and the other will fade from use. For example the fiat currency gradually replacing the commodity one is a common thing to happen. During that process both could well be used at the same time but it is not stable, eventually one will completely replace the other. That's because the two existing is not a stable system, in general people want their currency to be accepted as widely as possible so the most popular currency would over time become more popular. So there needs to be a reason why some people need one currency, but some people need the other currency. dot\_'s solution is to have each one used in different areas, and that is certainly one way forwards and could be effective. Other options though would be to have them used on different scales. For example merchants might use the fiat currency notes for huge transactions like purchasing ships and buildings. They aren't used for smaller transactions though where the precious metal coins are still used. Your average man on the street would never even see a paper note, it's worth more money than he sees in a year, but they would be frequently used by traders and speculators etc. In our world the dividing factor is often geopolitical. Different governments issue different currencies and in their country that coin is accepted. You could break that down further though and have different towns each issuing their own currency. Perhaps the fiat currency is the "legal" one and expenditure using it is tracked, but there is a strong black market economy which uses the coins. Those are just a few ideas off the top of my head but hopefully they illustrate what I mean. In order for two currencies to exist long-term in parallel all you need is a reason for both to exist. They each need a niche in the economic ecosystem where that one is favoured over the other. [Answer] In medieval Europe, international merchant banks created a currency they used among themselves, so they could settle interbank debts without depending on the (frequently-debased) coinage issued by local sovereigns. I highly recommend Felix Martin’s book Money: The Unauthorized Biography for the details of how this system worked (and how it fell apart). [Answer] # Bad Money Drives Out Good Economists call this Gresham’s Law. Historically, when a country’s money was theoretically a precious metal, and it tried to debase its coinage (such as mixing the silver with lead), people knew what was up. If the debased coins would buy just as much, but had less intrinsic value, they would spend those instead of the coins that contained more silver, the same way people don’t spend collectable coins or mail letters with collectable stamps, when there are more common ones with the same face value. Similarly, when countries tried to peg their currency to two precious metals at once, like when the United States tried to peg the dollar to both gold and silver until 1853, what happened was that one dollar’s worth of gold was worth a little more than one dollar’s worth of silver on the market, or vice versa, but the US government would trade you gold for your silver at a loss, with the taxpayer’s money. So people did that, and only silver would circulate as currency while gold was exported or melted down. All countries that tried bimetallism first abandoned either the gold or the silver standard in practice, then made that official, then abandoned the other. Today, countries either peg their currencies to a bigger currency that they do most of their international trade in, or to nothing at all. There were sincere arguments at the end of the 1800s for bimetallism, but modern economists would not find any of them convincing today. The people who supported that policy weren’t stupid, but they had different goals, assumptions and examples in mind than we do. ## Supply Shocks Happen A separate but related problem is that sometimes someone discovers a new gold mine, or a treasure fleet carrying silver from another continent sinks. Both of these things would put the supply and demand of gold and silver out of whack, and would normally lead to the same amount of gold being able to buy less silver. In fact, the only thing that could prevent that from happening is if someone bought the right amount of gold or sold the right amount of silver to maintain the exchange rate. # But What Could Make it Work? That’s what you really wanted to know. Here are some ideas that might help, only some of which involve magic: ### Immortal Speculators You know all those dragons or gnomes or what-have-you with their giant hoards of gold and silver? Whenever the market value of gold drops below sixteen times the market value of silver, they think that gold is a bargain, and sell some of their silver to buy gold. They don’t release all their gold coins into circulation, causing a vicious cycle where gold gets even less valuable, making even more people want to spend it instead of their silver, because so much of the gold and silver is in the hands of people who hoard it and speculate on it, rather than spend it. Maybe they used divinations to foresee what the future exchange rate of gold and silver would be, then bought whichever metal was currently cheaper than that, so it become a self-fulfilling prophecy. ### It’s a Drop in the Bucket Piddly little things like gold rushes and dragonslayings don’t have much effect on the market price, because the real markets are underground, where the Dwarves, Gnomes and Kobolds trade all the gold and silver they’ve mined over the centuries. If there’s some local fluctuation that makes your silver able to buy more gold than it could in the Hall of the Mountain King, some enterprising arbitrageur trades silver for gold, takes the gold up to the Gnomes, and trades it for more silver than they started with. The Gnomes don’t want to, or are unable to, or are not allowed to, buy things from the surface with all that gold and silver. So they don’t export their precious metals and they don’t cause inflation on the surface. The Gnomes have so much gold and silver relative to the surface that nothing that happens up there makes much of a dent in their stocks. ### Magic Gives the Currency a Natural Value If there are spells that create gold and silver, or spells that consume gold and silver, then that might establish their relative supply and demand. Perhaps gold is sixteen times more expensive than the same weight of silver because alchemists can create sixteen times as much silver for the same investment, or maybe silver is more valuable because it kills certain monsters. ### The Price is Fixed By Law The Great Pact of ancient times bound the Gnomes to buy from and sell to us at the same price in gold and silver, forever. If there were ever a surplus of gold and a shortage of silver in the land, we would choose to pay the Gnomes in gold and ask for silver. ### Why Would it Have Changed? That’s how it’s always been. A piece of gold has always been that size and always been worth sixteen pieces of silver. Everybody knows that. I guess people sometimes try to cheat and take advantage of the simple folk, but not enough to make a difference, thank the gods. Maybe it’s because gold is more rare, and always will be. Change the prices? Are you mad? ### Someone is Manipulating the Currency Okay, you got me, this wouldn’t really happen unless somebody were actively working to maintain the exchange rate of one gold piece to sixteen silver pieces. But who? And why? Maybe there’s one culture that uses gold for money, another that uses silver, and someone’s manipulating the economy to keep the exchange rate from rising or falling—think China or Norway. [Answer] Yes there is one way to fulfill all your criteria but only by violating one of two mutually exclusive premises, But what you describe already exists. The only way for the 1:1 exchange rate to be stable is for the merchant money to be fixed and based on the value of the common coin, in which case it is representative money not fiat. Whether or not the merchants have the the commodity money to back up their iron money is irrelevant, it is still representative. It is basically paper money without the advantages of paper (portability), which does make one wonder why it would arise but that is a different matter. As this has been used repeatedly for hundreds of years it is quite stable and was fairly common in countries without a state issued currency. In this case the merchant guild is acting as a bank, which was actually fairly common for merchant guilds and one of the main reason they formed. This guild needs to possess a LOT of power however because their currency offers no advantage and is far less easy to spend. A copper coin is worth its weight in copper everywhere and an iron coin is just as difficult to transport. But IF they are powerful it could be something they invented to help monopolize a particular type of trade. You can actually still see something almost exactly like this used today, they are called postage stamps. At one time postage had to be paid in postage stamps, and postage stamps were often exchanged as if currency and can be used as legal tender in several countries to this day (UK and US). All you need to do to make your system work is make the merchant guild only accept their coins for certain services. [![enter image description here](https://i.stack.imgur.com/18num.jpg)](https://i.stack.imgur.com/18num.jpg) [Answer] If you have a merchant guild large enough that buys and sells things important enough, and that always accepts either their fiat currency or bullion, and pays for things using a combination of the two, it could work. The merchant house would have to have lots of discipline and economic power. If the currency in circulation outstrips their ability to provide goods at a price people want to pay, then people will no longer want their currency and its price will fall relative to bullion. If they managed to pull this off over a century or more, use of their currency would spread within the lands where they hold economic power. If the economy grows faster than you can get ahold of bullion, this could be a huge benefit, preventing a economic choking of trade from lack of coinage. The problem I have is that this position is ridiculously powerful. They can, at an point, harvest a percentage of all of the wealth held by anyone with those coins by simply printing more (and devaluing the currency). Maintaining that level of power and never using it is going to be difficult to believe in anything short of a head of state of a secure superpower with a functioning internal tax network; such an organization already has the resources of the entire society available to them and no pressing need to expropriate them in the short term. [Answer] One way to keep it stable is if they are typically used for different things. To stop one currency from "overpowering" the other, they need some form of backing. Let's say, for example, Church and State. The Church of the major religion only use "natural" currency - they have metal coins whose value is based of the metal that makes up the coins. The State uses a Fiat currency, with paper or cloth notes. They have some metal coins for small denominations, but these contain far less metal than their worth. Now, Merchants tend to use the Fiat currency, because it makes large payments easier - and also because you have to pay your taxes with it. But farmers, lumberjacks, and other jobs that take place away from large cities or Government centres stick to the Church currency - for one thing, they can use it to pay for religious services, and for another it's simpler - this coin is worth this much, because that's what it's made of. There's no need to "trust" those poncy City-dwellers, or their disreputable Politicians. This means that different products are being produced in areas that use the different currencies: Lumber or Stone for construction, food from farms, and wool or cotton for clothing are all "ChurchCoin" products. Exotic spices, well crafted objects, furniture, and clothes - those are all "GovNote" products. There will be some places that do direct money-changing, but a lot of the "pegging" of the currency will be based at the "I can buy this for that price with these coins, and sell it at another price for those coins" layer. There will be fluctuations in price, but an inability for the different areas to create the items they are 'importing' at a comparible price (no fields in the cities, etc) along with minimal conflict between the currency backers (since you don't have 2 countries squaring up for a fight) should minimise this, and potentially lead to a convention of the exchange rate being treated as fixed. [Answer] There are many places in the world where more than one currency is in common circulation; for example in border areas it's common to have multiple currencies circulating. Before the US Revolutionary War the supply of cash was limited and people used anything they could get their hands on; Spanish doubloons were perhaps the most trusted and least discounted currency. There are even unofficial currencies widely honored; the example I'm most familiar with is Canadian Tire money in Canada, discount coupons issued by a ubiqitous department store which were often accepted as cash. However, the big stumbling block is exchange rates. In areas with government controls on currency it's common to see black market exchange rates swing widely afield of the official rate. (This gets much worse in authoritarian countries where there are official stores that only take official currency limited to foreigners, as the extreme example.) Here is the US the official exchange rate between gold-backed and silver-backed currency caused political strife in the 1890s as people had vested interest in a higher or lower exchange rate. [Answer] It can amongst the people as long as you can pay taxes in both currencies, that is key. The problem will be within the banks, and the control they have over the currency to adjust its value. Banks prefer one currency and over time will push for there to be only one. A really good example is pre independence America when they still used to pay taxes to the UK crown. America had started to develop it's own independent currency for trade (pre dollar) which the European banks did not like so to end its use they stated that taxes could only be paid in pounds. That killed the currency [Answer] Yes - It's possible Scarcity and Trust are the underpinnings of the Fiat Currency. The guild has the capacity to maintain a long-term, stable value by not flooding the market with currency or doing anything to shake the public trust. Keeping a one-to-one exchange rate with the Commodity Currency will be harder. A sudden fluctuation in the scarcity of the commodity could cause a major disruption (see [The Spanish Price Revolution](https://en.wikipedia.org/wiki/Price_revolution), caused by a rapid influx of New World Gold.) The easiest way would be if the guild controlled all of the mines and could regulate production of the commodity. Cartels aren't your thing? Then the guild needs to maintain a reserve; buying the commodity when it is plentiful, holding it off the market, and releasing it when it is rare. This could be achieved by issuing bonds. [Answer] Britain has had official coins for quite a while, and in previous centuries, these coins typically contained precious medals such as gold or silver. In the 17th and 18th centuries, there was also an unofficial promissory note system, where someone would give someone a piece of paper promising to pay X amount of money to whoever brought it to them. These notes would be transferred and used like currency, so if you have given friend X a note indicating that you owed them a pound, a complete stranger might come to you with the note a couple years later, expecting to be paid that pound. The value of these promissory notes were a bit like bonds, where the value of the note depended on how likely that the person who issued the note would actually honor the note. These notes were usually valued less than the official coins with precious medal because they were just promises, so a 1 pound note might be used to pay for something that was 80% of the value. This system slowly evolved into bank notes, where it was mainly banks who issued the promissory notes, with each bank printing their own notes. People used these bank notes along with coins, and the banks were usually reliable enough that the notes were valued equally with coins. That's where there was an economy with two equal currency types. Eventually, the government started issuing promissory notes as well that could be exchanged for precious metals and the non-governmental bank notes slowly fell out of favor. After those notes were trusted and valued, they eventually became fiat currency, where you could not exchange them for precious metals. As long as someone regards something as being valuable, and they are willing to trade goods or services for it with the expectation that someone else will accept the same thing in payment, it can be used for currency [Answer] We actually have this situation in switzerland. Our standard currency is CHF of course. This currency can be used every where and is the only swiss currency which is internationally acknowledged. Alternatively the canton of wallis just recently launched an own currency called ["Farinet"](http://www.lefarinet.ch/), which only can be used at certain places in wallis. The purpose of this currency is of course to strengthen to local economy. A much older parallel currency (1939) is ["Reka"](https://reka.ch/en/rekamoney/Seiten/reka-money.aspx?lang=en). As Farinet, Reka exists to strengthen the national tourism/economy. [Answer] Anytime that trade grows outside of local government you will have multiple currencies. Look at the Roman Empire. In what is now Israel, the temple tax had to be paid with silver sheckles, while roman taxes were paid with roman coins. Another example: When Spain started hauling gold and silver back from the new world by the ship load, much of it was minted into coins, triggering massive inflation in Spain. That money seeped across the borders (war is expensive) and you had lots of Spanish money circulating through Europe. At the borders both currencies will be in common use. You see that today on the Canada US border, where either currency is accepted at restaurants, ski-hills etc. Now a days most currency is electronic. Converting to the local currency is automatic. At one point I had a checking account that I could write US or Canadian denominated cheques by prefixing the amount with US$ or CAN$ But if it's supported by physical currency, especially coinage, which lasts a very long time, you can have both currencies circulating. In trade centres, you may have enough currencies that you end up weighing money. The stability depends on the governments involved. Having to weigh each coin is a pain, so for the purposes of trade, it's worth while to standardize currency. The easy way to do this is for the government to buy non-local currency, and issue local currency. This is a problem if the non-local one has a lower intrinsic value than it's nominal worth, but for silver and gold of reasonable purity it works well. Money is a matter of faith. I think you could introduce a new currency into your culture quite easily: * Pay people in some new coin. * Have stores where they can use the new coin easily to buy stuff. * Eventually, people will start using the coin for transactions between themselves. It helps if the coins are beautiful. Consider the effect of coins made of synthetic sapphire which can be made in a raft of colours, is much lighter than metal coins, and would outwear them by substantial factors. The stability of the exchange rate depends on the relative numbers of each currency's tokens in circulation. If one becomes less common, it's value is likely to increase, if it is required for certain transactions. This could be used as a means of subverting a country: Introduce a new currency, make it popular by creating stores or services that can only done with that currency, then either withdraw it from circulation, or flood the market with it. Coins usually cost more than their face value to make, at least the non silver and gold ones. My recollection that the nickel costs about 7 cents to make. But a nickel is used tens of thousands of times. During World War II, the price of copper got high enough that it was worth melting down pennies for their metal. For several years the US mint struck steel pennies. [Answer] Another historical example is that of Russia. In 17th century the government needed more money for their wars, so they started issuing copper money along with already existing silver coins. Their plan was "brilliant": copper coins were declared to be of equal value to silver coins, but only when they pay you for your work; you, however, have to pay your taxes with silver coins. So, eventually, all silver coins would be extracted from the population. Not surprisingly, it led to inflation, counterfeit copper coins, an even deeper financial crisis and, eventually, to the [Copper Riot](https://en.wikipedia.org/wiki/Copper_Riot). Later, in 18-19 centuries, there was the [assignation ruble](https://en.wikipedia.org/wiki/Assignation_ruble), which circulated in parallel with the silver ruble. There was no one-to-one exchange rate, the market value of the assignation ruble was lower than of the silver ruble. That system was sort of stable, existed for nearly a century, then it was reformed to something similar. There was also the golden ruble in circulation during all that time, but bimetallism was not uncommon in other countries as well. [Answer] You can do have a pegged currency. <https://en.wikipedia.org/wiki/Fixed_exchange-rate_system> Of course one currency will depend on the other in this situation. This is similar to how in some countries you can use the local currency, or the US dollar and both are acceptable. Often (but not always) this is because one currency is fixed to another. ]
[Question] [ For my story, I need there to be a planet close to the home world of my species (in the same star system) that the species could easily get to and easily colonize, but that does not have its own life already on it. Assume that this species is very similar to humans. I figured that the easiest way to do this would be to have a world in which intelligent life can survive easily (as in, humans could grow plants, walk around outside, breathe the air, etc. without any terraforming that can't be done in a few years) but on which life without intelligence will die out within a few thousand years if there is no intelligent life there to sustain it. Is there a way this can happen? If necessary, it need not technically be a planet but rather an equally sized body (maybe a planet-sized moon around a gas giant). [Answer] # No... Earth's environment has been shaped by the creatures that live on it. In particular, the oxygen in our atmosphere (and ocean) comes from and is maintained by photosynthetic life. If Earth had not developed life on it, for some reason, and humans came to visit it, it would have a nitrogen-carbon dioxide atmosphere, perhaps with some methane sprinkled in. Without breathable air, I doubt you would consider it habitable. # ...unless you are terraforming On the other hand, a lifeless planet in the habitable zone of a star would be pretty ideal for terraforming. Mars is in a pretty good condition to be made Earth-like, and it isn't even that close to Earth. An ideal planet for terraforming would have a strong magnetic field, like Earth, and a pre-existing dense atmosphere, preferably of nitrogen. If we found such a planet, terraforming would be easy (on the scale of terraforming). A way to make this terraforming scenario possible is having multiple moons of about the same size in the orbit of the same gas giant. For example, the four Galilean moons of Jupiter all have a surface gravity of 0.13-0.18g and masses within an order of magnitude. If only one developed life; then colonizing (and terraforming) the other three might be the scenario you are looking for. [Answer] If you're willing to have a world without complex life but the possibility to support it, a fairly easy way to do this would be to have the other planet be in its equivalent of the [Precambrian Supereon.](https://en.m.wikipedia.org/wiki/Precambrian) Have the evolution of life occur 500 million to 1 billion years after the planet from which your intelligent life originates, and there will be very little complex native life. Time it right, and you'll have explorers arriving on a world with little to no life on land, and simple multicellular organisms as the most complex form of life. Have your explorers only bring domesticated animals that would die out without their constant support, and you have a world where complex life only exists alongside intelligence. With water in the oceans, oxygen in the air, and no complex native life for another few hundred million years, you'll have exactly what you want! [Answer] The planet has a highly eccentric elliptical orbit. It's a paradise when it's far from the star, which is most of the time. But once a year (planet's year, not necessarily similar in length to Earth's year), it will pass close to the star and become hot enough to kill all life. Those passes will be very quick compared to the far sides of the orbit, that's how eccentric elliptical orbits work. But they will be long enough that no life can survive it. Unless a technological civilization runs an air-conditioned Noah's Dome for the duration. Optional: artificially hardened plants (genetically engineered perhaps) actually can survive outside the dome, but are not indefinitely viable without tending, due to some other biological limitation. Maybe they can't reproduce on their own, similarly to our consumer-grade bananas. [Answer] The only way I can come up with: habitable world used to have life, but it developed a sentient species that created a weapon as part of a war that killed off all of that life. When your species arrives, they have the technical chops to stop the life-killer, but without their constant vigilance, the killer comes back online. I'm thinking some sort of actively adapting mechanized system that your species cannot completely shut down (maybe they cannot find its automated manufacturing base). [Answer] Life doesn't just die without a reason. So maybe there's a rolling cataclysm that happens every couple of hundred years which wipes out most life on the planet. And the only thing stopping it might be your humans. But, as Ian Malcolm was wont to say "Life finds a way." For conditions to be right to sustain humans, there has to be the right mixture of oxygen in the air. Before life on this planet, the air was not breathable for us. Plant life is what changed things and made it sustainable. For a rock in space to have an atmosphere, the right mixture of oxygen and all that sort of thing...you really do need life, it doesn't spontaneously happen. If your colonists are growing things, there has to be, to put it bluntly, poop in the soil. And, if humans are living there, they will be contributing life and organisms to the planet. If they are raising animals, those animals will also be contributing to organisms on the planet on a microscopic level. That doesn't mean that conditions aren't harsh, and that there won't be very little life. Terraforming HAS to happen in your scenario, but life is not going to just give up and die, unless what they brought with them isn't enough to sustain a population. Even then, life will develop. It could look to the naked eye to be devoid of life, but...so did the dust bowl at one point... What you might do is look at the Precambrian era--there's life, but it isn't complicated, and will give settlers what they need in terms of oxygen. However, that life will not disappear once your settlers are dead or gone. It will continue to adapt and eventually become complex, but that will take...oh...billions of years. But, [happy news in this article](https://www.newscientist.com/article/2118088-complex-life-may-have-had-a-false-start-2-3-billion-years-ago/) you can make it earth. That's right. Earth. There's a little thing called The Lomagundi Event that happened here on earth. Prior to that the oxygen levels were pretty low, but suddenly, on a massive scale, they spiked. (Could it be your humans? Using a plankton soup in the oceans to push the oxygen levels up to a level they could use?) > > “The Lomagundi Event has recently been proposed as an interval of rather high oxygen levels, perhaps even nearing modern values,” says Michael Kipp at the University of Washington in Seattle. > > > There is no consensus on why our planet briefly gained and then lost > an oxygen-rich atmosphere. > > > And during this time, evolution may have been bumped a little, but it soon dipped back down again. Because so too did the oxygen level. And nobody really knows why. It's called an oxygen oasis in time. TLDR: Don't make your planet devoid of life, just make it uncomplex life, and the small population of animals the humans bring with will die off, leaving complex life to continue to evolve over billions of years, but certainly not present a thousand years after they leave, when the planet's artificially rizen oxygen levels plummet. Look into the The Lomagundi Event. [Answer] Life as we know it started in water. Since then it has adapted to all sorts of conditions, but in the beginning it was complete dependent on water to survive. So, make a planet that is much drier than ours. No oceans, few lakes. Life as we know it will not develop. We don't know if there are other forms of life that might appear in these circumstances, but you can easily say that "Well, it didn't happen here anyway." without anybody saying you are wrong. IMPORTANT: The rest of this answer is scientifically wrong. Leaving it here as a warning to others. See comments for details. As others have been saying, a life-less planet wouldn't have free oxygen, so you need some terraforming. Fortunately this is easy. Just spread plant seeds around! You will probably need to engineer a plant for the purpose, since the desert species we have don't grow very quickly. But hey, this is science fiction, your bio engineers will have know exactly how to sequence the perfect gene sequence for a plant that does the job. Of course, when the plants have done their job, they will have converted all the CO$\_2$ and they might starve and die. It is tempting at this point to assume that some of the plants would die and rot, releasing CO$\_2$ back into the atmosphere, creating a cycle. Unfortunately, things don't rot on their own. You need bacteria for that. So please remember to seed some of those too. Otherwise you might get fires, which will also release CO$\_2$ but will generally be nasty in other ways. Right, so you have oxygen. Time to add colonists! They are likely to establish their colony on the shore of one of the few lakes there is since humans are still pretty dependent on water. Time for you to make a decision: Is the original terraforming plant edible? If yes, people have landed in paradise. If no, they have a tough job ahead of them. The same properties that made the plant work quickly as a terraformer also makes it a bad weed. The colonists will curse the short-sighted engineers who were only looking at the short term. At this point somebody will suggest releasing a few herbivores, e.g. rabbits, to control the plants. Others will remember what rabbits did to Australia and say NO. [Answer] What you're asking for is a puzzle box. You want a planet which has some planet-wide problem which makes it inhospitable that can be solved by intelligence, and must be continuously solved by intelligence. The funny thing is, it's really hard to define what intelligence actually is. The harder you try to define it, the harder it is to create some naturally existing planet-wide issue which depends on it. One approach would be to have it be an artificial problem. Make the planet a quarantine planet with a dead-man's switch. Every few years, a console on the planet displays some difficult problem like a discrete logarithm. If there is no intelligence to punch in the answer within a time period (perhaps a year), the device activates and bathes the entire planet in unholy amounts of ionizing radiation to sterilize it. Such a planet might be highly useful for xenobiological engineering experients. Any violent species which seeks to leave the planet needs to reach a level of intelligence to solve such a math problem within a year, or the device wipes the experiment out. Another approach would be to have a planet that naturally wants to be in an inhospitable orbit, but may be nudged out of that orbit on a regular basis by the intelligent species operating the planet. This would be simpler, but comes with the issue that an intelligent species couldn't live "easily" on the planet. They'd need to first expend the energy to move it into a hospitable place first. [Answer] High amounts of UV will do it. Single celled organisms would be sterilized, whilst those with a dead skin layer would be relatively fine, though likely subject to higher amounts of mutations and thus skin cancer. You can adjust the dose to keep the whole planet sterile, but perfectly livable for any organism that has developed sunglasses and clothes, and they can grow plants within a greenhouse (if you have dosed your planet with very large amounts of UV continuously). If you need a mechanism to explain the UV, go with high amounts of X-rays hitting an earth type atmosphere, resulting in down-conversion by the atmosphere to UV radiation. If necessary, you can construct the history of your planet so that it develops complex life, that is then killed off by successive gamma ray bursts nearby. <https://en.wikipedia.org/wiki/Gamma-ray_burst>. You will need more than one, of course, because a single gamma ray burst will only effect one side of the planet. Additionally, how sterile do you need it? Your story may be able to function with most complex life killed off, and the only life on the planet are single celled organisms around a deep thermal vent. [Answer] You may be overthinking this. We currently do not know how life forms. There are theories but none have been proven. Since we do not have an accepted theory of how life originates we certainly cannot make any informed claims about how likely it is for life to come into existence generally, nor specifically how likely the formation of life would be in a given environment. Based on this there is no reason to believe that you are likely to find life on a planet just because it has the physical properties that we think are important to life (even it our assumptions about the conditions necessary for life turn out to be completely correct). Based on our current scientific understanding life can be extremely rare, extremely common, or anything in between. We still only know for sure that life originated once in our universe, and it may be incredibly unlikely regardless of the planetary environment. So for your story you could develop it that as science progressed it was discovered that life is incredibly unlikely to form in any environment. Or if you want the planet to be inhabited by things like plants but no sentient beings... then your problem is already solved. There is simply no scientific reason to suspect that intelligent life will evolve wherever life in general evolves. An astounding set of conditions must come in to play for intelligence to evolve (and we don't even know what all of them are yet), and there is no reason to assume that these conditions would be met on any or every planet with life. [Answer] To produce life, you have to produce a lot of thermodynamical processes. It is the result of the [second law of the thermodynamics](https://en.wikipedia.org/wiki/Second_law_of_thermodynamics). Life can't get energy from heat, it can get energy only from the heat difference. If the planet has no daily and yearly cycles, then it will be a still, silent, maybe warm planet - without weather, without anything. It will dead, even if there is water on it. Maybe the photons coming from the Sun could start some thermodynamical process, but the photosynthesis is a very complex process, plants won't develop on such a planet randomly. The first unicellular life on the Earth were [chemosynthetical](https://en.wikipedia.org/wiki/Chemosynthesis), it is the only method on which a life can start. To avoid the planet to have daily and yearly cycles, it should be a tidal locked planet orbiting on a very regular, circle-like trajectory around its star. It will result that the planets [terminator](https://en.wikipedia.org/wiki/Habitability_of_red_dwarf_systems) can be habitable, although its Sun-directed hemisphere will be hot, and the opposite will be cold. A little bit of weather will exist also there, because an little bit of atmosphere circulation will happen also there (although on different reasons as in our case). It can be the source of thermodynamical processes, if it is chaotic. Make it regular, ideally by a well-designed mountain system. Such planets can exist nearing red dwarfs, they may be even more as our Earth-like ones. [Answer] It sounds too easy, but one of the options is to make your planet inhabitable. Remove at least one of the [critical habitability factors](https://en.wikipedia.org/wiki/Planetary_habitability#Planetary_characteristics) and you'll end up with a planet that is unable to sustain life as we know it. If you don't go too far you'll end up with a planet where technological species can live with the help of life-supporting technology. The simplest example that comes to mind is an ice planet The planet that contains all the necessary elements and an abundance of water. Maybe even a breathable atmosphere. Intelligent life will just need to figure out how to heat it properly. They can live for an extended period under a heated dome, a cold planet still will get enough energy to support the limited population. But life will freeze as soon as they leave and/or their heating system shuts down. As far as we know, life can't develop on a planet without liquid water. [Answer] The lifeforms produce toxic substances which would accumulate and make life unsustainable if not counteracted. The only available means to neutralize the toxins involve transport mechanisms which are only performed by the more intelligent caretakers of the habitat. Would that fit your parameters? [Answer] An artificial "designer" planet (like Earth in Hitchhiker's Guide) could have been built by an advanced alien race, designed to support life but never populated for whatever reason. This could have been done as much as a billion years before your story begins, and life could still not have evolved naturally. After all, it took nearly a billion years for the first forms of life to appear on our planet, and even then it was primitive and microscopic for another 3 billion years. It might never evolve at all, especially if the planet was designed to lack all the conditions favorable for the spontaneous formation of primitive life. [Answer] A planet with a very short solar exposition caused by debris or giant planets. That would actually mean that you could still create life with artificial UV light. But with no intelligent life to maintain it all life would eventually die out. Of course life can also exist without light but there is also the possibility that life in this life never evolved in that way. There are a lot of explanations of why the planet now lacks sunlight you just had to pick one. [Answer] Maybe an scenario where a planet is constantly pelted by meteors having oxygen, nitrogen and other frozen gasses? the planet could have the ability to gain a hospitable environment over many millennia, and kill any life that may attempt to flourish. [Answer] ## You could have a planet with a [weak magnetic field](https://en.wikipedia.org/wiki/Earth%27s_magnetic_field#Importance). If it were just strong enough to stop the solar wind from stripping the atmosphere, but not strong enough to stop cosmic rays, then the constant bombardment would be devastating to life. If you combine that with some periodic source of ionizing radiation (e.g. a [astrophysical jet](https://en.wikipedia.org/wiki/Astrophysical_jet) passing through part of the planet's orbit) then you would really be wiping the slate clean on a regular basis. While even this inhospitable environment would have some life (e.g. around deep-sea thermal vents), it could be very minimal and primitive (e.g. single-cellular). Colonizing aliens could boost the magnetic field in just a few years by building a [super-conducting loop around the equator](https://en.wikipedia.org/wiki/Terraforming_of_Mars#Protecting_the_atmosphere). You could also add elements of [geomagnetic reversal](https://en.wikipedia.org/wiki/Geomagnetic_reversal) to make things more interesting. E.g. every few thousand years, a geomagnetic reversal happens while passing through the jet. All life is wiped out. [Answer] It seems to have happened on Mars according to [this](https://www.newscientist.com/article/2085604-first-direct-evidence-of-ancient-marss-oxygen-rich-atmosphere/) new scientist article. It did not get into details of how that happened. Oxygen would oxydze any pre-biotic molecule and life will not evolve. You still have to comment in your story how near is the atmospheric composition to that of their home world. Mars, having a weak magnetic field, may have its [water molecules dissociated](https://www.quora.com/Is-it-possible-for-a-planet-to-have-an-oxygen-rich-atmosphere-without-having-life-on-it) and broken down into oxygen and hydrogen. Hydrogen is stripped by solar wind and oxygen is left behind or stripped more slowly. Oxygen reacts with soil minerals to create the oxydes giving Mars its red colors, but over time soil minerals will be saturated with oxyen and it will build-up in the atmosphere. ]
[Question] [ I'm writing a science fiction novel set 100 million years in the future, but humanity is still the same basic form we have today, biologically speaking. Would 100 million years of evolution drastically change our biology or would scaling back the time frame to 50,000 years in the future be a better plan? [Answer] There is no way of telling what humans would have become after 100,000,000 years. None at all. Evolution doesn't have a plan or a set course. Natural selection leads all species towards being better-adapted to their environment, but in that vast period, there's no telling how the real world environment will change. As an author, you can decide that for your story, but the ways in which humanity would change in response to any specific environmental change are not obvious. The additional twist is that in the past few thousand years we've begun to modify our environment significantly, and now live in large numbers in many places that can't naturally support them (e.g., the water supply in California, or artificial heating in high northern latitudes). We don't really know how we'll change now that we can set aside many normal environmental factors, or if we'll be able to carry on doing so for thousands of years, let alone millions. The classic SF novel [Last and First Men](https://en.wikipedia.org/wiki/Last_and_First_Men) addresses these issues: over its span of two billion years, many human species rise and fall. It's well worth reading if you want to write on this scale. The 50,000 span is easier and safer, if less ambitious. Humanity will probably still be recognisably the same species over that span. [Answer] Let me put it this way; primates have been around for only 50 million years (give or take). Of this 50 million years, humans have been around for only 2 and recorded history has only been around for about 14000 years. It is extremely unlikely that human would look even remotely similar 100000000 years from now. Even 50000 is unlikely for human to be the same. Though there is a spark of hope; for the first time in human history humans are selecting mates based on love and not biological features, so it is possible for either of these goals to exists, however unlikely. [Answer] Organisms can exist largely unchanged for tens of millions of years if there is no real reason they should evolve. Evolution is a two-way street. So while humans have evolved very quickly up until now, there are plausible reasons why humanity could not further involve. I would suggest looking at Sharks and Crocodiles as examples. Both of these species have existed largely unchanged for tens of millions of years with primary differences being in size and other aesthetics. Humans will definitely change aesthetically, most likely larger eyes and less hair, but in the large part you could force them to be pretty much the same if they are so perfectly suited to their environment like a Crocodile is. You could even introduce this artificially through technology. [Answer] I would be shocked if homo sapiens exists 100My from now. Either we will have done ourselves in by then or we will have advanced far beyond what we are now. There are a bunch of very stupid things in our genes, I would be very surprised if we haven't cleaned up our genome by then even if we have done nothing else. Fixing the flaws will make an organism that can't breed with Mark 1 humanity and thus it will be a new species, not Homo Sapiens. In practice I think we would be many species by then as some groups decided to make changes that others didn't want to do. That's assuming we are even biological entities by then. [Answer] If there are no technological interventions, then humans will have long evolved away from their current form in just an eyeblink of time. Our remote hominid ancestors fist emerged about 5 million years ago, and distinctly hominid species can be traced back to @ 2 million years ago. Depending on how the environment changes, humans could evolve into almost anything (imagine a seal like creature evolved to hunt for food in the water). There were two books by Dougal Dixon which looked at this idea way back in the 1980's, the first was called "After Man", which supposed that the human race became extinct along with a lot of other species; creatures like rats evolved to fill multiple niches (deer like creatures to sabre toothed predators) as one example. "[Man after Man](http://www.sivatherium.narod.ru/library/Dixon_3/01_en.htm)" did the opposite, technology and civilization failed and human beings evolved to fill various niches, including some who became herbivores and others which evolved to prey on them (due to the damaged environment and genetic engineering, evolutionary pressure selected against general intelligence in favour of instinctive behaviours to ensure survival; an author's handwave). If any human creatures existed 100 MY from now, they would almost certainly be recreations done as a hobby or art project by very advanced post humans, AI, or aliens (see A.A. Attanasio, "The Last Legends of Earth", set a billion years in the future). [Answer] Is your novel set on Earth or on other planets too? If there are people on other planets, natural selection will be altering them to adapt to, say the low gravity of Tau Ceti IV or the high uv of Sirius B III. If they are stuck on Earth all that time, then there will be a few 'dinosaur killer' asteroids hitting, and mega volcanic stuff as continents drift around, along the size of the Yellowstone supervolcano blowing its top. Might be able to pack in a few ice ages too. All of those will potentially (unless your people have super high tech to prevent the disasters) cause periodic and massive population crashes. Whenever there is a population crash, there is potential for genetic diversity to be lost by accident. And for previously rare genes to become common by accident. Imagine, for instance, an asteroid hits tomorrow, and people only survive in large numbers in Australia. Future humanity would only have the genes and physical characteristics of the ethnic groups currently in Australia. Plus whatever new mutations arise and whatever they genetically engineer into themselves. [Answer] You might want to reign in your timescale. We're already tinkering with genetic engineering and mechanical enhancements 10,000 years after we first scratched runes into rock. "Humanity" could become a machine race in just a few hundred years if the transhumanists have their way. Imagine explaining the concept of a machine-borne infomorph - or even the internet - to a caveman. Now imagine how incomprehensible things will be to us when given 10,000 times the advancement. In 100My our descendants would be as far past us as we are past a protein chain. [Answer] There's a rather haunting story (Baxter?) which I read, following humanity pretty much unchanged from the survivors of the disaster which ends our civilisation, to the approaching death of the planet as the sun starts to expand. Actually, more a set of word-pictures scattered across a billion years, rather than a story with a plot. The underlying thesis, is that humans cannot regain a high-tech society because we have dug up and dissipated the key resources accessible to low tech. Future attempts, after millions of years of geological "recharging", will fail to reach our level due to scarcities, but only after again dissipating the key resources. On the other hand, evolution will do little to re-shape us, because humanity even in a primitive state, changes the environment to meet our needs, rather than being changed by the environment. We kill the predators. We protect weaker members of our tribes. We uproot the weeds. We plant our crops. We tend our flocks and herds. There are holes in the arguments. For example, evolution can be driven in unexpected ways by sexual preference. That's how the Peacock's tail and the Bower bird's bower happened: random accidents of the female bird's preferences spread over millions of years. Likewise, I think that a high-technology civilisation would eventually be re-attained by humanity, if we don't go extinct after the fall of this one. But equally, there has never before been a species that modifies its environment in the way that (even primitive) people do. So just maybe, recognisable humans will be around until Earth dies. [Answer] Food for thought: ## Evolution via natural selection has ended Survival of the fittest no longer applies. In fact, humanity has become extra conscious not to discriminate against any physical or mental disadvantage, but to make an effort to include and support them. This means any of those traits which may be genetic have a much better chance of remaining than in past scenarios. ## Evolution continues externally through technology In the past, if it got cold, the warmer/hairer beings survived and flourished. Now? Just put on a jacket. Not as fast as your fellow humans? Get a bike, or a car. Instead of forcing biological change, any difficulty in our environment now brings out technological improvements. So, now our "evolution" is voluntary and conscious, the question becomes: How do we want to change? And, when do we want to change? [Answer] Natural selection is the primary motivating force behind evolution. It is the mechanism by which a group of organisms is more likely to pass on traits beneficial to their survival as the individual members who pass them on are more likely to survive. For example, giraffes with longer necks are more likely to find food then their short-necked friends, and are thus more likely to survive and pass their genes on to the next generation, resulting in longer-necked giraffes. As all humans, without regard to their genetic traits, survive to pass on their genes to the next generation, and there are no traits which make you more likely to survive (and eventually procreate), humans do not evolve by natural selection. That said, recent research does show minor changes in humans over time such as smaller teeth, smaller brains and so on. Personally, I think these changes do not reflect much considering that technology changed our lives so much faster than evolution ever did. That means that research conducted, even with humans from hundreds of years in the past, cannot come to any real conclusions considering the technological changes made in this interval (such as nutritional changes, medical improvements, changed lifestyles, awareness to pollution problems and so on). I also think that as our technology improves we become more and more adept at adapting our environments to us (as opposed to natural evolution, which adapts the organism to the environment), and so lose the need to evolve, and thus, the mechanisms which drive it. Bottom line, I think that humans in 100 million years will be vastly superior to us mentally, but will probably look very similar to us. [Answer] If the time span is basically arbitrary and not relevant to the plot, then 50,000 years is much more believable, and still seems an incredibly long amount of time. Because I think the chances of humanity being biologically the same and still living on Earth after 100,000,000 years are very very slim. So slim that you would need a convincing explanation as to why humans have not changed. So really, I think the future is so open that you can predict whatever you want. Whether the reader finds it plausible is down to how good your plot and writing and backstory are. [Answer] The best way to understand how different the world might be in 100 million years' time is to consider how different it was the same length of time in the past. 100 million years ago, some of the first flowering plants were evolving, alongside the first bees. Some early mammal-like creatures did exist at this point, but without most of the features we would consider to make them true mammals. There were no snakes or ants. This is the age of the dinosaurs, but at this point even many of the most well-known dinos (T-Rex, Tricerotops, et al) have not yet appeared. Evolution is a slow process, but at this scale the world is a completely different place. Entire classes of species have risen and fallen multiple times in that space of time. You should read the [evolutionary timeline article on Wikipedia](https://en.wikipedia.org/wiki/Timeline_of_the_evolutionary_history_of_life), as it can give some good insights into the topic. Others have commented that "evolution has stopped for humans". They are basing this assertion on changes in our behaviour that have occurred in the last dozen or so generations or less. This is completely the wrong scale to think of evolution. Evolution hasn't stopped; it just isn't noticeable at that scale. In the absence of world-changing cataclysms, you'd need to be looking at tens or hundreds of thousands of years to see noticeable evolutionary changes. [Answer] In a 100,000,000 years I think the safest answer is : We'll be evolved beyond a level we can comprehend. If such an "entity" would be sent back to 2016, it would be seen as a divinity. Think about humans, 10,000,000 years ago we were tiny stupid monkeys living in trees, 100,000,000 years ago, we were some sort of hamster. Now from a hamster's point of view, we are gods, even beyond that. We can fly to space which is something a hamster's little brain can't comprehend. In a few centuries at most we will probably have completely mastered genetic engineering. We will be able to "control" our evolution. Then what we do from there will depend on our goals. Making ourselves healthier would be the first thing we ll do. By that I mean make our bodies naturally more resistant, increase our lifespan, have limbs that can regenerate etc... We ll also try to make ourselves "better". In such an advanced world, physical strength would be even less relevant than in our current world (where it's mostly for esthetics). I think we ll try to make ourselves smarter. Then there wil be some evolutions "just because we can". For example water breathing abilities, flyting abilities, all sort of skills from the animal world that can be applied to us. Then maybe milleniums after that when we reach a level of intelligence orders of magnitude above our current levels our goals would probably be different. Looking at the hamster vs us, look at 100,000,000 years of slow random evolution achived. Imagine what can happen in the same timespan if it s controlled by some super intelligent being... That s why I think that even the most imaginative sci-fi writers can't imagine how we ll decide to evolve and how we ll be in 100,000,000 years. ]
[Question] [ Imagine a world in which technology we would probably call "[technological singularity](http://en.wikipedia.org/wiki/Technological_singularity)" is possible and already happened on few places of the galaxy. By the singularity I do not mean that anything is possible, but rather that original biological species transform themselves into extremely highly intelligent computer programs with big amount of control of their environment, and they completely transcend their biological nature. The post-singularity societies might rebuild planets to giant computers or even create [Matrioshka brains](http://en.wikipedia.org/wiki/Matrioshka_brain), since the main scarce resources are computer time and memory. It would be relatively easy for such civilization to send spaceships that would transform all solar systems in our galaxy into computers and utilize them. It would be even easy for a small splinter faction inside such civilization, unless the "official forces" actively prevent it. The motivation is simply a lot of resources and freedom to gain. My question is: Are there plausible reasons that would prevent it and keep the civilizations bound to their home star systems? If there is such, the reason should be strong and valid for all such civilizations. If nine out of ten civilizations decide not to spread, and one does, the galaxy will still be transformed. [Answer] Very good question. Nothing can prevent a patient post-singularity civilization to spread all over the galaxy. Milky Way is around 100K LY across, so even at a slow 10% speed of light spreading (to allow rebuild/refuel spaceship at each new planet reached), most of the Galaxy should be visited in mere 1 million years. Compared with 4 billion years from the emergence of life to the present, one million years is nothing. So it should already have happened. Even at mere 1% of the speed of light, it takes a mere 10 million years. This is the real problem. Where is everybody? [Fermi paradox](https://en.wikipedia.org/wiki/Fermi_paradox). Even if most post-singularity "persons" were interested only in local entertainment, one out of million will be curious enough to leave the "hive". And will have enough resources to learn, travel, spread, and multiply. In few million years, a new race of "space explorers" would evolve, with curiosity and itch to take over the galaxy, even if they don't need the resources. Just do it for the heck of it. If it is possible to do it, someone will do it, given enough time. Why not? So there must be something preventing civilization like ours successfully transforming into the post-singularity phase. And that unknown danger is something we should worry about. There are plenty of planets compatible with life, old enough for life to emerge. Plenty of time to evolve all the way to Technological Singularity. Plenty of time for such singularity civilization to settle all over the galaxy. Time is not a problem - something else is. Most likely, advanced civilization (like ours) commit suicide before reaching singularity either by [grey goo](http://en.wikipedia.org/wiki/Grey_goo), green goo, or ecological catastrophe. (which is also one of possible answers to Fermi Paradox). After singularity, there is nothing to stop them. Few very good reasons to get out of your solar system: * In about 500-800 million years, our Sun will start growing to be a red giant, making Earth uninhabitable. * And even before that, some random asteroid or other calamity can damage our planet. The [Yellowstone super-volcano](http://en.wikipedia.org/wiki/Yellowstone_Caldera) erupts every some 600 KY. Asteroids able to extinguish dinosaurs may struck every 60 MY or so. * Even if you are able to defend your civilization from attack of another advanced civilization, basic strategy is "defense in depth", and you need sentry outposts far away from home planet, give advanced warning to have time for mobilization of the necessary resources. * Even if that another civilization is not inherently trying to eliminate "ours", you still need to have a defense in depth to have time to convey to them information that you exist and think. It is about 200 MY between ants and us. Imagine how hard would be to persuade younger partner (us like ants) some more advanced civilization to notice us and care enough to not extinguish our suns. The only answer is "defense in depth". For self-preservation, even post-singularity civilizations need to settle around other suns. Only reason to NOT settle around other suns (and eventually settle all over galaxy) is that some event prevented civilization to reach such advanced stage to be able to do it. And that should worry us. @Peter LeFanu Lumsdaine [answer](https://worldbuilding.stackexchange.com/questions/4918/what-could-restrain-post-singularity-societies-from-spreading-across-the-galaxy/4935#4935) has plausible suggestion of early singularity civilization imposing non-proliferation on any other later singularity civilizations. But even such "protector of wilderness" civilization would still be required to spread all over Galaxy and impose rules on other civilizations by "missionaries" and "park rangers". And it just escalates "defense in depth" over neighboring galaxies - because by this you voluntary limit your resources to just small part of your galaxy, and other competing civilizations from other galaxies might have more resources. Compared to that, @Mike Nichols [answer](https://worldbuilding.stackexchange.com/questions/4918/what-could-restrain-post-singularity-societies-from-spreading-across-the-galaxy/4930#4930) requires that every of the hundreds/thousands of civilizations reaching singularity will apply similar self-limits and will stop any spreading. That is just not plausible - even worse, that is naive. Why would any civilization take such risk on behavior of hundreds of unknown competitors? Why take chances, if you have resources to enforce the rules? See also: [Motivations for interstellar colonizations](https://worldbuilding.stackexchange.com/questions/4740/motivations-for-interstellar-colonizations) [Answer] If your beings have completely transcended all biological forms and are now incredibly powerful computers, why would they want to go to other systems? They don't need any more space, or energy, or materials. They are self-sufficient computers. There is no biological urge to reproduce or procreate. There is nothing to explore that they can't simply observe with telescopes and compute with their awesome minds. Yeah, they could turn the rest of the universe into machines like themselves, but what's the point? I think the best reason for the universe to not be consumed by uber-entities is that there is simply no good reason to them to do so. [Answer] Are there plausible reasons that would prevent it and keep the civilizations bound to their home star systems? Reason 1 Space is huge. Most humans, because of the way we are taught, don't properly perceive the size of space. If you have ever seen the earth and the sun depicted on the same page, you are seeing an exaggeration of the size of earth or the distance between earth and the sun. To properly represent our solar system with the sun the size of a grapefruit, Pluto would be a microscopic peiece of dust some 30 yards off in the distance. That we picture pluto in our diagrams on the same page as the sun, or even as a 3d model is a tribute to our distorted sense of space. So number 1 reason...space is HUGE! and we are badly incapable of envisioning how huge it truly is in our heads It would be relatively easy for such civilization to send spaceships that would transform all solar systems in our galaxy into computers and utilize them. I also think you are badly interpreting the size of the galaxy with this statement...even at light speed, these systems are far enough apart that it takes decades and millennium to travel between the two. Remember the light from the stars you are seeing is a distant vision into the past state of these stars. At light speed, it's a good 120'000 years to travel from one end of the system to the other, and we are talking of upwards of 300 billion stars in simply the milky way alone (billion being another concept that no human can rightly visualize). Lets say you drew the entire milky-way on a 10 meter by 10 meter map...our solar system will not be visible to the human eye on this map. And the milky way is a surprisingly small galaxy in the grand scheme of things. Reason 2 - different planets in different area's of the galaxy likely have a much different composition and bring with it a series of unexpected and near lethal challenges. In forming, the milky way likely has a compositional change from the center to the edges not unlike the solar system has. Who's to say rock worlds are even feasible in the inner bands of the milky-way? What challenges will each new system bring, and will it even be worth the invested resources to 'colonize' the new systems? Reason 3 - Interstellar travel might be far more complex than what we think. The Sun generates an amazing magnetic field that prevents solar winds from reaching it...these solar winds can hold protons flying at 99.99999999% the speed of light, striking objects with the force of a 70 mph baseball on an atomic scale. We get to see occasional glimpses of this as these protons will occasionally send neutrons flying at us at incredible speeds. This might make interstellar travel a much more arduous task than what it might seem currently. Who knows what effect dark matter may hold for interstellar travelers Reason 4 - why? I know that's a bit abstract, but in the end...why? What does anything truly have to gain by doing this? Is it that dies with the most toys syndrome? Is freedom of infinite expansion until the universe fades really meaningful? A philosophers dream question - but what if the reason another intelligent life form has never visited us is simply because a higher intelligence ultimately realizes the never will be an answer to the question 'why?' Reason 5 - eventual destruction. Suns die and are reborn, no planet is forever. The milky way is going to collide with the Andromeda galaxy eventually. And whatever that mass becomes will collide with another galaxy eventually. No matter what you colonize, it's going to change, it's going to be destroyed, and it's going to start anew. added: Reason 6 - Time distortion. It might not have been so many billions of years passing at different points of the galaxy and there may be places that have seen only hundred of millions of years next to ours. A bit more theoretical, but at what speed must something be moving in order to be frozen in time? added again: Reason 7 - Threat of splintering. In human history, games, and story lines there are many examples of the colonized turning upon those that created the colonies. The US vs Great Britain is the obvious example on Earth, but there are several fantasy story lines of Mars colonists revolting from Earth rule. There are also fictional story lines of entire races that revolted from their creators (Yor Singularity in Galactic Civ). With communication difficulties over large distances, what is to say newly colonized worlds do not try to conqueror those that colonized them? How does a singularity mitigate the risk of it's extended colonies becoming the primary threat of it's own existence? [Answer] [Mike Nichols’ answer](https://worldbuilding.stackexchange.com/a/4930/2676) suggests “lack of motivation”, or (differently viewed) “change of morality” as a possible reason. His version of the scenario seems a little bit of a stretch to me, since (as comments on the answer point out) it would require that all post-singularity civilisations would undergo this evolution of morality, with not a single dissenting exception. A variation of this seems perhaps more plausible. If one post-singularity culture — perhaps the first, or perhaps just a sufficiently powerful early one — happens to have the right set of ethics, they could set up and impose a moratorium on others, preventing anyone from spreading very far (while also choosing not to spread themselves). It could be because they particularly value diversity, or solitude, or some kind of wilderness conservationism ethic — any number of reasons. Of course, in some sense this would still be colonisation. They would have to distribute some representatives of themselves or their tech around the galaxy to enforce the “peace”. But the spreading they did could be much, much less obtrusive than any kind of full colonisation/expansion. Imagine them preserving most of the galaxy the way we preserve wilderness areas in national parks. There’s just enough ranger presence that if you try to build up too much yourself, they’ll notice you, come along, tell you the rules, and impress you with their power to (if necessary) enforce them. But most of the time, the presence is so distant and non-interventionist that you still are, to all intents and purposes, in a genuine empty wilderness. [Answer] > > Are there plausible reasons that would prevent it and keep the civilizations bound to their home star systems? > > > Maybe you are asking the wrong question. Other answers have mentioned the Fermi Paradox. That paradox comes from a different question. `Where is everybody?` Your question makes an assumption that you might not have realized. You assume that if they aren't "here" they must still be at "home". That isn't necessarily true. I'm going to making the assumption that you meant the question to be `Given a technological singularity that would let a civilization spread across the galaxy, where is everybody?` One thing to keep in mind, is that a singularity, by definition, is incomprehensible to us. The singularity uses super-human AIs to do things we literally cannot. A singularity is going to be more than just mind uploading. If, as you say, they've 'completely transcend their biological nature', perhaps that's why they haven't colonized the galaxy. In other words, the singularity causes them to leave and go somewhere else. Maybe they've ascended. Like the Ancients in Stargate, or the Q. They've lost their biological and corporeal nature and live in the quantum foam. They aren't going around and colonizing the galaxy for resources because mundane things like matter, anti-matter, and energy are below them. They don't even consider those things resources anymore. They've moved beyond that. Maybe the singularity occurs because they discover higher dimensional math. Instead of colonizing the galaxy, they are colonizing their home system an infinite amount of times in parallel universes. [Answer] I imagine most posters here will be familiar with the works of Iain M Banks, and his series of novels about 'The Culture', and the civilisation(s) he describes - extended post-singularity, post scarcity societies, where sentient beings co-exist with highly evolved AI (such that the AI has been almost transcended to become pure I). Several of the books address the issue of 'Why'/'Why not', morality, and motivation. The title 'Excession', particularly. [en.wikipedia.org/wiki/The\_Culture](http://en.wikipedia.org/wiki/The_Culture) [www.iain-banks.net/sciencefiction](http://www.iain-banks.net/sciencefiction) I regret I do not have sufficient rep to post this as a comment, rather than an answer. I don't feel it fulfils the criteria for an answer, but wanted to contribute. [Answer] I just finished reading Charles Stross' Accelerando (like, thirty minutes ago), and he does a great job exploring why post-singularity Matrioshka-brain civilizations might not tend to leave their home star. The scale of the book doesn't begin to touch what happens when the sun goes out, but his central premise (spoilers!) is that wide-scale conversion of "dumb" to "thinking" mass only begins in earnest once a significant portion of the population exists in mind-uploaded, rather than physical form: it's to solve a population crunch, not just for the raw computing power. By the time the solar system has been mostly computerized, with human or human-like intelligences doing their thing in cyberspace, proximity to the densest resources -- computer time and memory, as you mentioned, but especially one you didn't, bandwidth -- is most highly desired, and humanity as a whole is too unwieldy to move en masse. Even a wormhole-sized network connection isn't enough to squeeze the population through. These intelligent hunks of computerized matter cluster around their primary energy source, and, being able to simulate a whole host of realities, lose the adventurous spark (and most of the advantages) of going out to find new worlds. For plot purposes, the nail is driven into the coffin when the course of human cognitive augmentation turns them into something else entirely, and these ruthlessly efficient, market-driven nonhuman superintelligences succeed, then cannibalize their originators as a huge leap up on the food chain, and by then are stuck where they are for good. It's a good read. [Answer] Even if technically possible, space travel is expensive. In a post-singularity society, energy and mass can be highly efficiently used to generate their best approximation of computronium -- specialized states of matter that compute highly efficiently. To travel over interstellar distances, you need a lot of energy. Energy that would otherwise be sufficient to generate a rather huge amount of computation. Imagine if our solar system had 10^9 planets like Earth, all fully populated. And in order to send 3 people to a nearby star, we'd have to destroy 10% of them and kill all the people on them. In the long run, such a probe would result in a larger total "civilization". But with bandwidth restrictions of interstellar communications, those 3 people would be sent off, and would only arrive the equivalent of millions of years later (faster time scale from high clock speed), with the ability to send single bit of data every thousand years (again, scaled based on intelligence of us vs them, and how much they are used to communicating). So even once they are there, they are going to be sending messages back to a really alien society, and there isn't enough bandwidth to discuss what is going on (at the level the civilization is used to), let alone coordinate. So now you have a society that destroyed 10% of its population, and in exchange has created a colony that can not meaningfully interact back with them. The upside might be hard to see. Those 3 colonists arrive in a barren wasteland. Suppose they can manage 0.1% economic and population growth per year until they hit the equivalent of 10^20 people (they are building an economic system from scratch). So it takes them all of 50,000 years to reach the previous point of a civilized star system. At which point they could go and kill off 10% of their society (or prevent them from ever existing) and launch another star wisp. Repeated, this does colonize the galaxy (10 ly every 50k y times 100k ly is only half a billion years. If the trips take another 50k years, that only doubles things) (so long as your star wisp production per star wisp launch stays detectably greater than 1, the limit is distance: the wave of colonists ends up being limited by the geometry of the milky wa more than anything). So the capabilities of a post-singularity society might be great, but the other things they can do with those resources is equally great. And it might be the case that the post-singularity society can manage a greater growth rate locally in whatever they care about (computational efficiency, say) than they could by the (basically linear or quadratic) growth rate you'd gain from galactic colonization. --- Then there is the optimists case. A sufficiently advanced technology is indistinguishable from nature. Wrap stars in light-year deep computronium foam, and the surface temperature of the foam is... Sun outputs e26.5 J/second. A sphere of radius 2 light years has 50 square light year surface area. The sun emits about 1 degree kelvin over that radius. That is warmer than black body radiation: so a much smaller sphere can be used, which would place such a matryoshka sphere as being in homeostasis with the microwave background radiation. (The real problem is that it might also occlude other stars and thus be noticed) Move such systems out of the main part of the galaxy (the better to avoid super novas and the like). Wrap starlight around yourself to finish the invisibility job. And now you have invisible, massive civilization that looks a lot like dark matter. Leave some of the galaxy alone as a preserve. Noise is waste. Presume an efficient civilization, and you cannot hear them. --- Or, transcend. What if it is easier and more efficient to move computronium into more traditional dark matter than it is to visit another star? [Answer] The biggest preventative factor of a civilization such as the one you describe is motivation. If a post-singularity civilization is content with what they have, what their experiences are, etc. then there is no reason for them to seek anything else. They have nothing to drive them from their little bubble. Other factors could weigh in (lack of faster than light travel coupled with resource limitations, physical limits, risk, even cosmic radiation affecting hard drives), but the civilizations implied by your question would, effectively, have infinite time, which means time to mitigate or even eliminate any external limiting factor. Even political influences could eventually be waited out or gotten around eventually. There would have to be some variety of civilization wide contentment. Note, this would have to be quite different than stagnation. There would still have to be technological growth and evolution, they would just have to look internally ("I must protect my little slice of heaven) rather than externally ("I want their little slice of heaven). It would also imply a lack of scarcity. [Answer] lifespan, social structure, speed of reproduction, or lack of fast travel (even 10x light speed is slow when you're talking interstellar distances). [Answer] Like most things, what would be the driving force to spread across the cosmos, and what are the limiting factors preventing such a thing? If humanity figured out a way for a 'reasonable' price to travel to the nearest couple star systems in 3-6 months, we would do it just because we could. Humans are curious and get bored easily, so I would think that after a singularity that spreading across the solar system would be are first jump making a ring of settlements around the sun but that would only occupy us for a little while as we get better at it and use space construction techniques to build impressive interstellar ships. The more of this we have before the singularity the faster and more likely we would be to flee the solar system to explore strange new worlds to seek out new life and new civilizations... However, something that could certainly prevent that is if we enjoy very long life expediencies and we become a society that is more interested in our pleasures and entertainments, everyone is taken care of and no one needs. If everyone is satisfied they will have very little reason to want to risk their lives on long dangerous journeys with no guarantees of survival or return on investment. Need and ambition are the two driving forces of humanity and if we lose one or both we'll be more like the humans in Wall-E, or similar predicament. [Answer] We could restrain the absolute number of post-singularity beings by designing them to require a particular rare element to survive. Each time a being reproduces, that resource is split between it and its offspring. Over generations a point would be reached in which beings did not have enough of the element to reproduce with. Two caveats: 1. This would only limit the number of beings, not their geographic footprint. 2. Caches of the rare elements could be found in other places in the solar system, or the being could figure out a way to copy/conserve the resource. I'd love to hear any ideas that could solve the second caveat -- what could serve as the non-replenishable resource? [Answer] "Plausible technological singularity" is to me a contradiction in terms. The best my imagination can do with it, without throwing away what I think I know about computers, technology, brains and consciousness, is to imagine that a civilization deludes itself into thinking it makes sense to favor a giant self-sustaining computer/machine system over its own biological existence. The people would need to have dissociated from their embodied experience, or to have deluded themselves that it would persist in a machine, or otherwise that this would be a desirable move. They claim to transcend and incorporate all, but fail to incorporate much actual wisdom, and align with imperialist/industrial conquest ideas. I can imagine that happening, and conclude that the result would be a dangerous AI machine system which probably considered itself superior to other life forms, and would probably behave itself like the Borg, though probably without the powers given to the Borg by Star Trek fantasy technology. The main things I think would stop such a "singularity" system from expanding out of its own solar system, are practicality issues. * Travel to other stars requires more technological handwavium. * I also think that in reality, even if a society decided to die off in favor of such a machine system, I expect that such a system would begin to malfunction without any deluded biologicals to keep it on track with its perverted/wrong ideas about how it makes sense to build such a machine system. Without deluded biologicals, I think the "intelligent" computer system, which I would expect to have been programmed to "evolve" ideas and change its own programming, would sooner or later (probably sooner) get "interested" in logical computations which had less and less to do with the (ultimately illogical) delusions of their biological creators, and tend to do unpredictable odd things rather than trying to win some juvenile galactic conquest to maximize CPU cycles, because that is a fundamentally BS idea. * The idea of needing a star's (let alone a galaxy's) energy to harness as much power as possible because the singularity has so much to think about, seems very silly to me. I think the matrioshka brain is projection of Robert Bradbury's unconscious knowledge that there really would not be infinite interesting things for a giant AI to calculate about, or that it would be worthwhile to try. * That is, if you posit that it is possible to build an intelligent evolving computer intelligence, then I would expect it to deduce how silly and pointless the exercise of galactic conquest by itself would be, as well as the idea of manufacturing star-scale computing machines. If it doesn't deduce that, then I'd say it has a fundamental flaw. However, overall, I'd say it were quite possible to build a flawed machine system that would be programmed to go around replicating itself, and this system might well be programmed to try to take over the galaxy. But I don't think even if all of an entire galaxy were turned into a logical computer system, that it would ever conclude that a singularity transcending a biological species would make any real sense. [Answer] If speed of light is a real constraint, then the problem might be isolation. Leaving your civilization to explore, effectively means you will be cut-off from your civilization.... forever. It would be worse than choosing to use DOS, forever. Singularity civilization will be constantly accelerating, if you get off the train, you will never catch up to it. You would also be cutoff from communities (Goodbye, SE & wikipedia), help (who's out there doing tech support for DOS users?), family (who choose not to go Amish with you), celebrities & culture. That may be a tough pill to swallow. Especially if biological family (vs. self-chosen family - who will have less interest in coming with you, since divorce and ending of friendship is much more common) continues to break down as it currently is in Western Society. [Answer] Civilisation The answer is, in my view, in your premise - they're civilisations. Unless you presume FTL, separate worlds are really, really separated. Even lightspeed communication between solar systems is going to take years and will likely suffer from terrible bandwidth. The post-singularity AIs are going to stick around their home system because that's where the other AIs are and where they communicate and commerce and interact and whatever else they want. So while they may colonise a number of nearby star systems as their civilisation grows big enough to 'bud off' new large colonies in different star systems, the pull of remaining within a large, vibrant community will prevent them for spreading rapidly through the galaxy. [Answer] I disagree with those who claim that nothing could stop the spread. I could see many possibilities that would prevent it. First, motivation. There needs to be a reason for it to spread. The cost of spreading would have to be outweighed by the advantage of spreading. In a singularity situation, this may not be the case. While the capacity to spread may very well exist, that does not necessarily lead to that capacity being used. According to the Cosmological Principle, the universe is consistent over large scales. Once a machine based intelligence is able to learn everything it can (presuming acquiring new knowledge is a motivator for it) over a 'large scale', there would be very little benefit in spreading further. Second, fear... of a sort. There are no concrete indications that the limitations to understanding that we have discovered will be able to be overcome by a machine-based intelligence... in fact, there is pretty solid argument that they never could be. I am talking about the fundamental limits on mathematics from being capable of predicting systems with chaotic behavior. A conservative machine-based intelligence which puts avoiding threats to its own continued operation as its primary motivator would be hesitant to extend itself rapidly because it would quickly become incapable of predicting even its own actions. Assuming it has some level of 'acceptable risk', once it realizes this fundamental limitation to its ability to evaluate the consequences of its own actions, it will likely become very conservative. Third, time management. While machine-based intelligences would seem extremely fast to us, performing actions would still take time. Transfer of information within the organism would still be limited by the speed of light at the very least. This would slow it down the further it spreads itself. As it acquires new things to study, or new regions to gather data from, performing those tasks would take time and transferring the information throughout the system would also take time. In short, there are fundamental limitations on understanding and information processing that we've discovered and good reason to think that these limitations can not be overcome by a machine intelligence. Many of them could result in an intelligence restricting its own spread. [Answer] Perhaps we are simply projecting our own misunderstanding of the universe and our limited goals upon beings beyond our comprehension. Our grasp of the goals and means of action of entities many orders of magnitude beyond us is tenuous at best. Just like a hunter-gatherer asked about a terrible weapon would imagine a giant or very sharp axe, or a very precise arrow, but could not possibly even conceive of something like a nuclear explosive, so is our imagination limited by our technology and primitive culture. More appealing destinations. Perhaps a post-singularity society will simply find it easier to travel to parallel dimensions, tap into nearby universes, assault Heaven (or Hell), or Hal only knows what else. More subtle forms of colonization. Or perhaps they will simply transcend physical form, making the question pointless. Who knows what civilizations might be embedded into what we in our ignorance call the Higgs field, for example. Perhaps the Electroweak breakdown into electromagnetic and weak forces was an epochal and universe-wide civil war. [Answer] One of the primary goals of any form of life is that of continuing to exist. Perhaps post-singularity societies (or even pre-singularity) discover some sort of fundamental instability in our universe, and rather than waste time and resources spreading into something that will eventually be lost, they devote all resources to moving into a more stable universe. I'm sure this has been explored in science fiction already, I just can't remember where I've seen it. [Answer] There's been much discussion of the Great Filter already, but I don't think we can logically say the only answer is an impending apocalypse. We can accept that post-singularity (or whatever, really-really-advanced) societies are fragile- they can be whatever-color-goo'd, or destroyed by nuclear holocaust, or computer viruses, or who knows what else. So even if a society does make it to an interstellar-colonization phase, those colonies may themselves die out in time. We get a model more similar to the spread of disease than the spread of a fire. If a typical colonized solar system doesn't emit more than one group of colonists before it itself ceases to support life, then eventually (over cosmologically-short time periods, even) the interstellar civilization will die out, in much the same way as a virus will eventually die out in a well-kept human city. So we don't require all advanced societies to die out before they colonize other stars- only for interstellar colonization to be reasonably rare (for which there are good arguments) and for societies to die out eventually (good arguments for that, too.) Which makes the Great Filter idea a bit less terrifying (but not enough that I don't shiver every time they start up the LHC.) [Answer] I can't imagine there would be any constraints on such entities, and [Paul Davies thinks](http://www.dailygalaxy.com/my_weblog/2013/11/biological-intelligence-is-a-transitory-phenomenon-a-fleeting-phase-in-the-evolution-of-the-universe.html) post-biological sentients will be the the rule, not the exception. > > I think it very likely – in fact inevitable – that biological > intelligence is only a transitory phenomenon, a fleeting phase in the > evolution of the universe. If we ever encounter extraterrestrial intelligence, I believe it is > overwhelmingly likely to be post-biological in nature. > > > How would such entities breed or reproduce? A copy is just that, like playing chess in a mirror. Better to replicate the process from scratch, find or create a biological species and tweak them to sentience, then let them create their own SI (Synthetic Intellects). In this way you have a brand new SI unique and reflecting its biological progenitors. We may just be the factory workers, not the finished product ]
[Question] [ With a [Janka Hardness](https://en.wikipedia.org/wiki/Janka_hardness_test) of 5,060 lbf, the [Australian Buloke](https://en.wikipedia.org/wiki/Allocasuarina_luehmannii) is considered to be the hardest wood on Earth. Compared to other materials however, it still yields a weaker Compressive Strength and Modulus of Rupture than [Steel](http://www.azom.com/properties.aspx?ArticleID=863), and a significantly lower compressive strength than [Concrete](https://www.nrmca.org/aboutconcrete/cips/35p.pdf). While I could not find data for the Buloke, the [Quebracho](http://www.wood-database.com/quebracho/) species is almost as hard, and is only half as strong as steel by these measurements. Quebracho has around 12000 lb/in$^2$ compressive strength and 20000 lb/in$^2$ Modulus of Rupture, to steel's max of well over 100000 lb/in$^2$ for both. * What is the hardest breed of wood that can exist, either naturally or through intentional genetic modification or breeding? * Where in modern society would such a material be practical based on its physical properties? (Extra consideration for any situation in which it would be the best material for the job) Notes * Physical appearance is in no way a factor as far as this question is concerned. * "Hardness," for the purposes of this question, means highest Janka Hardness. * Even if the answer to the second part is that it isn't always effective, I'd still like the first part answered. [Answer] Why would someone ever use a 'worse' material to do a specific job? All engineering projects seek to minimize the use of various resources to achieve the desired results; 'worse' materials are frequently used because cost and availability far outweighs the effectiveness of pure material efficiency. For example, copper wiring is used in almost all electrical applications. Why? Because it is a good cheap conductor. Is it the best conductor? No; copper's electrical conductivity of $0.596 \cdot 10^6/\text{cm}\ Ω$ is only about 95% of silver's $0.63 \cdot 10^6/\text{cm}\ Ω$. What makes copper more desirable for more applications, its saving grace, is the fact that it costs around $\$2.7/\text{lb}$ (ranging 2-4 \$/lb over the last 5 years) compared to silver's $\$267.8/\text{lb}$ (ranging 200-500 \$/lb over the last 5 years) pricetag. In fact, a number of applications are attempting to convert over to aluminum wiring because aluminum's $0.377 \cdot 10^6/\text{cm}\ Ω$ is still quite reasonable for it's lower cost of $\$0.85/\text{lb}$ (ranging 0.65-1.20 \$/lb over the last 5 years). Concrete and steel are basically the coppers of compressive strength and tensile strength, respectively. They are used in most skyscrapers and other large construction projects because they are very good at doing their job efficiently at a reasonable price. Wood is typically used for smaller-scale jobs where pure material efficiency is less important than costs associated with greater availability and ease of construction. Where cost is not the limiting factor, other more specific design criteria may exist. Wood is a dielectric (i.e. non-metal) and so it may be more desireable in applications where radiofrequency reflections would be undesireable. Similarly it is non-magnetic and doesn't become magnetized the way a ferrous metal like steel does. Wood is also relatively lightweight compared to concrete and steel, it can be handy when hulking physical dimensions are of less concern than material density. --- What is the hardest breed of wood that can exist? This question is a little harder to answer outright with numbers, but the sky is the limit if you allow for ultra-futuristic levels of genetic modification. Wood is so strong relative to its weight because it is essentially a naturally-growing metamaterial. The plant's cells have walls composed of cellulose fibers and linked lignin polymers (which have high tensile and compressive strength, respectively) and form a matrix of repeating boxes which allows for a large amount of rigidity even after much of the cells interior water weight has been dried out. Bioengineering the organism to be stronger would only require designing better organic replacements for cellulose and lignin (and/or optimized versions). Carbon nanotubes or graphene sheets aren't completely out of the realm of possibility here. Additionally, designing more efficient metamaterial structures is another way to improve wood's bulk-material properties. The cellulose and lignin of wood forms a matrix of mostly-rectangluar building blocks, which is essentially a simple cubic crystal lattice formed of extra-cellular cell walls. Engineering plants to have more complex intra-cellular supportive structure could allow for these structures to more closely resemble diamond cubic lattice structures and increase strength by quite a bit. [Answer] Not to side step the "hardest wood" question, but as far as application... hardwoods are generally used in places where you want strength, but not weight. Things like tool handles, sports equipment (baseball bats, and hockey sticks for example), furniture, and so on. A cubic foot of steel is incredibly strong, but it's also incredibly heavy at 490 lbs (7900 kg/m3). A cubic foot of hardwood is usually closer to 50 lbs (800 kg/m3). As far as "the best material for the job" I've always had a preference for wood hockey sticks, but wood wrapped in Kevlar helps with wear and tear from... Well... Hockey. They're lightweight, slightly flexible, but still incredibly strong. My first stick is more than 20 years old and it's still usable despite some dings from rougher plays. As far as construction goes... Of course steel and concrete are stronger and in many cases more durable, but they're much heavier and they're also much more expensive. Also... The hardest wood possible really depends on the application and whether you're talking about a simple slab or a composite ply. [Answer] Are you asking for the hardest wood or the strongest? They are two different things. [Bubinga](http://www.wood-database.com/bubinga/) is the strongest wood I know of, with a Modulus of Rupture (bending) of 24,410 lb$\_\text{f}$/in$^2$ (168.3 MPa) but the crushing strength (compression) is only 10,990 lb$\_\text{f}$/in$^2$ (75.8 MPa), less than half the bending strength. Keep in mind that the crushing strength is very dependent on the orientation of the grain to the stress, the strength can be as much as ten times less when the stress is perpendicular to the grain. [Answer] [Lignum vitae](https://en.wikipedia.org/wiki/Lignum_vitae) has been used in engineering for centuries. As well as being dense and tough, it also has the unusual property of being self-lubricating. Many hydro-electric turbines are still made using lignum vitae for bearings, and plenty of older hydro schemes are still in service with lignum vitae bearings after decades. It was also widely used for lower-stress/lower-temperature bearings in cars and other vehicles. Track-rod/tie-rod ends in particular were always made of lignum vitae in pre-war cars, and this persisted well into the 1960s for some makes. [Answer] If you just look for the hardest wood, you may want to look at [petrified wood](https://en.wikipedia.org/wiki/Petrified_wood). It would resemble wood it in appearance, but it would offer stone-like solidity. Think of using it for making pillars in a building, you would have a pillar which looks like a tree, but behaves like a stone. Of couse you could hardly use it as a beam because of its poor resistance to traction. [Answer] In material science there is this picture of same force applied to different materials of the same dimensions. The first answer to "how to make it to not break so easily is "double the amount of material or put a support where the force is applied". So the real answer to your question is not where but why and how. For example the switch from wood ships to steel was dictated by the dimensions steel ship could have. On the other hand small ships were cheaper and lighter when made from fiberglass. Same with houses, if you want to build quick, not sophisticated building you use prefabricates. But wood is more plastic and freely available. So you could grub your plot and have material on site already. [Answer] Your questions are very broad, and have no definite answer. As mentioned in other answers, "hardness" doesn't have one single meaning. The Wikipedia Hardness article mentions 3 main "types" of hardness, but even using one style of measurement machine, quite different (and conflicting) rankings will be observed. A hard material, for example, is pretty much useless if it softens in the rain or upon exposure to sunlight or just as it ages. Of course, you can protect a surface from sun, and rain (to some extent), but there are a fairly large number of properties that a substance must have to be "useful". Also, and full disclosure here, I'm not a botanist, and have no knowledge of the Buloke, but Wikipedia says it's an Ironwood species. The same table that lists it at >5000 lists Ironwood at ~3000. You have to be very critical taking these numbers at face value. Ironwoods, I know a (very) little bit about. One of their properties is their high oil content. This is good for water (and bug) repellency but not good at all for painting or contact with other surfaces if they're prone to staining as (not if) the oil bleeds out. As previous answer says, don't confuse hardness with strength. My guess for the "hardest" wood we could breed/engineer would be that its just as hard as the hardest biomaterial known. I think (but am not sure) this is either calcite, aragonite, or the stuff our teeth enamel is made of, hydroxylapatite. It would be interesting to determine if silica-based biomaterials were any harder, I wouldn't be surprised. (Diatoms and Radiolaria make silica walls). Since biomaterials are nanocomposites, and can be 10 times "harder" than the inorganic mineral they derive from, it's not really possible (imho) to say what the upper limit is for hardness.( Diatomaceous Earth is used as an abrasive, so it's probably pretty hard.) For a material to be useful it not only needs a slew of properties to match a particular need, but the economics have to be favorable (meaning supply of the material good, and demand also strong). The test you mentioned was (probably) designed (at least it was selected) to be useful with wood in the applications wood is used in. Meaning other measures would probably be required before a particular wood is deemed hard enough to function in some unusual, atypical way. You ask two questions. The answer to the first is A. As far as what is now known, Wikipedia editors know more than I do, B. As far as what is possible, well, that's pretty much open-ended. Its certainly possible to make a plant develop a skin similar to the hard materials found in the animal (and microbiota) kingdoms. Find the hardest biomaterial known to man, and you can start there. If you want to speculate, increase its hardness by 10X. To answer the second. You didn't give us all of its properties. As I said, giving us a single property and asking where it "might" be useful isn't likely to garner many incisive answers, its just far too broad and vague a question. As they say, the devil's in the details. Hard materials, generally are used to protect other materials from damage, or just the opposite, they are used to damage other materials. So, use as surface layers or in abrasives would be my first inclination. [Answer] I think I'm going to change "Hardest" to "Tough and Versatile" because we don't have a use case as yet to narrow things down. However, an extremely tough and versatile wood in North America is the Osage Orange [Maclura pomifera](https://en.wikipedia.org/wiki/Maclura_pomifera). It's also known as the Hedge Tree. It is also the plague of anyone who has a need to cut one down in their own yard. 1. The Hedge Tree is pretty tough, the toughest in North America with a Janka Hardness of 2040 when green and it gets harder as it dries out, reportedly up to 2700. This is about 2 times as much as the hardest of Oaks. I have seen it recommended that you do any carving when the wood is still green because you won't be able to when it dries. 2. It is somewhat flexible. When combined with the hardness, it becomes a prized Bow makers wood. Native Americans would travel quite a long way to harvest limbs from an Osage Orange for bows. 3. It is very resistant to rot. It is frequently used for fence posts because it will last below grade (in the ground) for a long, long time. It doesn't get mildew or molds getting deep into the wood. Bugs also seem to avoid the wood. The fruit is often used as a natural insect repellent. 4. It's dense. This wood will eat chainsaws. I know this from having to cut one down in my yard. It was about 12 years old and it took 3 chainsaw chains to get through. Granted, I have a cheap chainsaw, but still. Incidently I still have a huge part of the trunk that is heavy as heck and I want to do something with it, but I don't know what yet. 5. it burns hot! When used as firewood it will put out about twice the eat in BTU's as most varieties of oak. It pops a lot, so not good in an open fireplace, but in a sealed wood stove I was able to keep my house at about 80 degrees f during a snowstorm where outside was 12 f. 6. It grows in a variety of climates and soils. It was used in the Midwest to create windbreaks and to help with soil erosion during the Dust Bowl. So for what is possibly the toughest and most versatile natural wood that actually exists, Osage Orange [Maclura pomifera](https://en.wikipedia.org/wiki/Maclura_pomifera) is your friend. It would also make a good basis for any sort of monkeying around you may want to do with it's genes. [Answer] As we're Worldbuilding, let's assume some development in genetic engineering, and the development of proteins to catalyse the assembly of carbon atoms in regular structures. Then it's conceivable that our modified tree could build a stable tetrahedral crystalline form of carbon, at least on a cellular scale - perhaps as cell walls or an internal spine. As it's still a tree, these small structures would probably be embedded in a cellulose matrix, which may have its own weaknesses. Nevertheless, their ultimate hardness would be that of their crystalline form - diamond. [Answer] Southern live oak Quercus virginiana has a Janka hardness of 2,680 lbf (12,920 N) see <http://www.wood-database.com/live-oak/> Not quite as 'strong' as some other species, but historically it was a very important component of American ship building because the long, curving limbs of the timbers could be made into ribs and other structural timbers without having to be carved. This gave great strength to the hull. Old Ironsides was an example of this kind of construction. Live oak was the secret weapon of American ship building. So part of the strength hardness question has to do with anticipated form. Aircraft spruce has one of the highest strength:weight ratios of any natural material--somewhat different example, but also noteworthy. [Answer] Supplementary answer. Wood is made of cellulose fibers. How strong is Cellulose? Very strong. There's lots of detail here: <https://www.extremetech.com/extreme/134910-nanocellulose-a-cheap-conductive-stronger-than-kevlar-wonder-material-made-from-wood-pulp> . Quote: "lightweight, flexible, stronger than steel, stiffer than Kevlar" ... It is, of course, produced by a tree in a structure honed by evolution (long term) and environment (during the tree's lifetime) to be of best use to the tree. We have to do a bit of work to re-form it into nanocellulose, rather than just sawing it into beams. Wood also contains a natural glue called lignin which bonds cellulose fibers together. Just as cellulose is at least as strong as our best plastics, lignin is at least as good as our best glues and resins. Until recently, it was an order of magnitude better, but our chemists have caught up, and now we can glue wood to wood as strongly as if the tree had grown the wood into the shape we wanted(\). Enter Glulam. (Horrid name: a contraction of glued laminate, I think). Anyway, google "glulam" and you'll find that people are now building small skyscrapers out of wood, and planning larger ones. It is, after all, weight for weight as strong as steel (and counter-intuitively, more* fire-resistant! ) Glulam is not the same thing as simple sawed timber, so architects are still feeling their way, and building experience and confidence with smaller structures first. This is world-building, so these references tell you what is possible (using cellulose). We may be able to re-program trees to grow wood more suited to our own needs, using genetic engineering. Or on a planet with higher gravity, evolution may have done the same (otherwise, there are no trees on that planet). And it's even possible that there's a better bio-polymer out there than cellulose. (\*) by the way, mediaeval builders used the shapes that the tree grew. They didn't hack the wood into arbitrarily straight but weaker timbers. They built arch-like roofs and ships containing naturally curved timber. Occasionally, they'd even tinker a bit with the shape that the tree was growing into while it was small and pliable, then wait a century to harvest timber with the curves they needed. We may now (or soon) have the biotechnology to steer the growth of a tree by more subtle means than tying a sapling to a framework. However, do we have the patience? [Answer] So not sure about which wood is hardest but here in Australia the ironwood species have historically been used for power poles. Their density and strength means that they are highly resistant to rotting (less of an issue in the outback) and termite attack (more importantly). Using steel is not that good an option as it conducts electricity. Decades ago the ironwoods were more accessible as you could cut them from the surrounding environment. Of course they have been over harvested and being a very slow growing tree are no longer a sustainable wood product. Also we're better at insulating steel poles and forming them out of cast concrete. ]
[Question] [ I'm building a setting in a fictional Latin American country which is under military rule. The junta starts a breeding program in the late 40's with help from unscrupulous escaped Nazi scientists. Assuming the breeding program starts with a population of 10,000 people with an average IQ of around 130, how much could could they raise the IQ in 5 generations? 45-60 => 1st, 60-75 => 2nd, 75-90=> 3rd, 90-05 => 4th, 06-? =>5th The constraints are as below: * There is a fund for keeping 10,000 people in the program only. * No genetic engineering or any other other biological experiments. * Children who don't fit the program's eugenic goals are given for adoption into selected couples of the general population. * Scientists running the program decide who will breed with who. For example they could keep 10% of the boys and 90% of the girls if that gives them best results. All the other children are given for adoption to selected couples. * The country has around 30 million people, the bred are very small part of it. Note: (story related; might not be relevant to the question) If it helps, my story happens in present age. The country finally democratizes and holds fair elections. The newly-elected president finds out about the secret breeding program. He also learns that the children given for adoption from the program are vastly over-represented among the country business & cognitive elite compared with their meager numbers. [Answer] Since as far as I know nobody bred humans, we can't tell for sure, so take below answer as pop scientific. It's using the [breeder equation](https://westhunt.wordpress.com/2013/06/07/the-breeders-equation/) and regression to the mean. Assuming that that average IQ of the population that outliers are drawn is 100 IQ, heritability is 50%, and that with each generation it gets 20% harder to become outlier. Also you are selecting top 1-2% of males, and 50% of the brightest females. In the first generation you started with equal number of 130IQ of males and females but in the next generation. You use top 50% of the females but only 1-2% of the males. In order to keep the population at 10,000 average number of children per women should be 4+ which is plausible. * Gen: 1 Avg 100 Growth: 0.30 50+ Female: 130 Top1-2% Male: 130 * Gen: 2 Avg 115 Growth: 0.24 50+ Female: 132 Top1-2% Male: 150 * Gen: 3 Avg 128 Growth: 0.19 50+ Female: 143 Top1-2% Male: 159 * Gen: 4 Avg 139 Growth: 0.15 50+ Female: 153 Top1-2% Male: 166 * Gen: 5 Avg 149 Growth: 0.13 50+ Female: 161 Top1-2% Male: 172 Tweak heritability (0.5) & decay (80%), and average IQ of your founding stock population for your story telling purposes needs. P.S. Given that 3rd Generation average has enough IQ to graduate at MIT, and outliers could become professors there, the IQ is not a problem anymore. Your country is constrained by other factors such as culture, lack of capital, research facilities, high-tech industry etc. So most likely majority of your bred geniuses would end up leaving your middle income country and emigrate to some rich western country. Read Garret Jones Hive Mind: How Your Nation's IQ Matters So Much More Than Your Own to see the issue. P.P.S. Since you are selecting only small percentage 1-2% of males you are vulnerable to the [founder effect](https://en.wikipedia.org/wiki/Founder_effect). If your outlier males have some kind of quirky disease it gonna spread like wildfire if you don't cull it from your population. Think something like Tay–Sachs. [Answer] ## Intelligence is not a singular trait There are many facets to intelligence. Let's start with some animal examples: ### Dogs. Everybody loves dogs and dogs love everybody. They have incredible social skills and are amazingly adapted to humans. They are the only domesticated animal that runs towards their "human" when frightened and not away. They can read human facial expression naturally. Even most apes have to learn that pointing towards something is not you just randomly raising your arms, but dogs instinctively look where you are pointing (if they trust you) as they understand the gesture. When it comes to technical/mechanical understanding dogs are incredibly bad. Dogs are barely capable of solving mechanical puzzles to get their treats. They can follow commands to solve it, but they lack the capabilities of solving it on their own. Dogs are very cooperative. They are very social amongst one another and with humans and can cooperate to achieve a common goal - like hunting. This is the main reason we bred dogs from wolves, originally. ### Birds Birds are the exact opposite of dogs regarding the two aspects I highlighted. Crows, for example, can solve mechanical puzzles of several steps to secure their prized treats, but they are absolutely incapable of cooperation. When two birds are sitting in front of a see-through box with treats and a lever they can pull connected to the box, they will quickly find out they can lift the box to reach the treats, but each bird realizes it can not reach the treats while it pulls the lever. So they stop. They could cooperate, one pulls the lever, the other one pulls out the treats, but they will not. Each bird is just thinking of "how can *I* get the treat?". Cooperation is not ingrained in their psychology. --- ## IQ Tests What we usually refer to as intelligence with humans is mathematical and geometrical understanding. That is what IQ tests are going for in most cases, too. "Here is a sketch of body X. Draw it rotated 90° to the right." Questions like this are aiming for a persons spatial understanding. IQ tests are just a rough estimation of a person's skills. They are everything but a precise measurement of intelligence. Intelligence is an abstract concept with many facets that can not be expressed in a singular number. Simply do a second IQ test right after your first and your score will be higher. Just because you know what to expect of the questions you will be quicker and more secure in your decisions. You will not have been getting more intelligent by doing a single IQ test. --- Now to the main question. ## Could intelligence be bred? Yes, basically any trait could be artificially selected for. It is more likely for two people with a very healthy and fit body to have children that are more prone to having healthy and fit body. (Same goes for unhealthy, btw.) If you have two people who are *strong exhibitors of any* trait it is likely that their offspring will be carrying that trait, too. Intelligence is not a singular trait. There are a many influencing factors, genetically speaking. People with genetic defects like Down-Syndrome can still be perfectly functional humans, but it is significantly less likely for them to be above average in most things they do. Other factors like high testosterone, estrogen and other hormone levels influence a person's tendencies and traits, too. Every hormone differently and there are always strong exceptions. Biochemistry is the most difficult thing to model precisely. ### Does it suffice to just start a colony of intelligent people? Not necessarily, no. Just because somebody is smart, does not mean they are a good parent. While many traits like physical prowess thrive on exercise, so does intelligence. It is extremely unlikely to grow up to be intelligent, when you have never had any nurturing of this skill. The human brain and body build what they need. When a child's mind is never given any intellectual input, why would it develop a skill to interpret such input? The intelligent parents' DNA just makes it more likely that the child is going to be good at building up intelligence. If it is never given an opportunity to build it up it will not use that potential. ## What you need ...is a program that selects compatible intelligent people and makes sure that they are raised well, including a healthy home environment and parental attention. Early education is important. Focus all of the education and attention on rewarding intellectual skill. This means lots of challenging games from a young age one in which the children can hone their skills. If you want them having a healthy psyche it should always be focusing on rewarding progress instead of demanding progress, the latter works to but comes with side effects I'll talk about below. ### An important side note While you could also create socially incapable, semi-autistic people with a very high IQ with less effort, by ignoring the "healthy" part I mentioned, I would personally advise against it as the people might have advanced skill sets, but their lack of social skills would make it more difficult for these skills to be applied in a productive context. Besides that, it would also be child abuse. Not too fond of that. [Answer] The question as posed can't be answered in a meaningful way. "Intelligence" isn't a smoothly defined, observable trait in the same way that, say, height might be. So any effort to breed "smarter" humans is going to be part and parcel a response to how your government is trying to assess "smartness". Additionally, even if we accept some effort to measure intelligence as meaningfully accurate, raw capacity alone isn't enough to get the results this government probably wants to see. Environmental factors are important in cognitive development as well (consider heavy exposure to lead, for example). So all of those need to be accounted for as well. Intelligence (variably defined) also seems to be a very complex trait (in the sense that there doesn't appear to be any single gene, or small set of collocated genes, that are associated with it), so breeding to enhance it might well need far more than 10,000 individuals in a rotating stock. And even in the wider population intelligence (as typically measured today) tends to revert to the mean (two unusually smart parents might produce children of more average intelligence-- that is, geniuses do not exclusively beget additional geniuses). Finally, there are serious ancillary matters that need to be considered. 10,000 is not a huge stock, and constantly breeding (and, presumably, inbreeding in this case) in pursuit of a single, complex trait is likely to cause unintended genetic issues as a function of that small population. These effects would be very difficult to predict in this abstract case. tl;dr** There is so much handwaving required for such a program to exist and "work", and intelligence so vaguely defined in operational terms, that your scenario can produce humans with any degree of intelligence you like. You could represent this with an arbitrary scale (like a deflated IQ score that can account for the constant re-normalization of IQ scores, or some measure that you just make up), or in a less-quantified but easily observable way (children from the program tend to end up in high positions, as your story setup already suggests). [Answer] > > [Marilyn vos] Savant was listed in the Guinness Book of World Records under "Highest IQ" from 1986 to 1989[9] and entered the Guinness Book of World Records Hall of Fame in 1988.[9][10] Guinness retired the "Highest IQ" category in 1990 after concluding IQ tests were too unreliable to designate a single record holder.[9] The listing drew nationwide attention.[11] > > Guinness cited vos Savant's performance on two intelligence tests, the Stanford-Binet and the Mega Test. She took the 1937 Stanford-Binet, Second Revision test at age ten.[5] She claims her first test was in September 1956 and measured her mental age at 22 years and 10 months, yielding a 228 score.[5] This figure was listed in the Guinness Book of World Records; it is also listed in her books' biographical sections and was given by her in interviews. > > > <https://en.wikipedia.org/wiki/Marilyn_vos_Savant> IQ is "supposed" to be normally distributed with mean 100 and sd 15. That puts an IQ of 228 as being 8.5 standard deviations from the mean. I tried to use Excel to calculate what percentile that would be, but it was so close to one that Excel rounded to exactly 1. Excel has 15 digits of accuracy, which corresponds to one quadrillion. So one should expect MvS levels of IQ in one in one quadrillion people. So it's understandable that Guinness has decided this is not a meaningful measure. At 130, IQ being normal would predict that we're already at the top 2.28%. That's about the limit at which IQ is valid. For a somewhat quantitative measure, I took the estimate of 80% heritability, and assumed this is constant across IQ levels (it's probably not, but I'm not sure how to account for that). I initialized a population with ``` genotypes = random.normal(loc=100,scale = 15,size=1000000) phenotypes = [.8genotype+.2 random.normal(loc=100,scale = 15) for genotype in genotypes] indices = [index for index in range(len(phenotypes)) if phenotypes[index]>125] genotypes = [genotypes[index] for index in indices] phenotypes = [phenotypes[index] for index in indices] ``` (Note that I took a minimum of 125 so that the average would be around 130) Next, I did: ``` for i in range(5): cutoff = sorted(phenotypes)[len(phenotypes)//2] genotypes = [genotypes[index] for index in range(len(genotypes)) if phenotypes[index]>cutoff ] 2 phenotypes = [.8genotype+.2* random.normal(loc=100,scale = 15) for genotype in genotypes] print(sum(phenotypes)/len(phenotypes)) ``` This simulates the top half of each generation having four kids per couple. I didn't bother modeling cross-breeding, assuming that it wouldn't affect the general trend much. The results I got were: 1. 130.78537880060884 2. 133.84842056079236 3. 136.4018939835269 4. 138.75734310708546 5. 140.9813744502485 What if you have eight kids per couple? For that, I got 1. 133.40673479773932 2. 138.49951120551688 3. 142.82479867356096 4. 146.75034206831734 5. 151.03096072228035 However, keep in mind that my numbers start after one generation of breeding. So, 133.4067 is the first generation to be bred. If "generation one" is just people taken from the general population with high IQ, then "generation five" corresponds to 146.75. Also, 15 years is rather short for a generation. You have some leeway in that the people running this are, as you say "unscrupulous", and thus not concerned with age of consent, but even so, the whole reason (or at least, one of the reasons) that we have age of consent is that 15-year-olds' judgment is not the same as 20-year-olds. Some analyses have put the age at which the brain stops developing as late as 25. While you can take the 15-year-olds that are smarter relative to other 15-year-olds, and this would give you some information about their final intelligence, it would be of [questionable validity](https://www.ncbi.nlm.nih.gov/pubmed/23919982). Furthermore, for a breeding program to work, you would have to have a lot of children; the more children you have, the more selective you can be. If each girl has four children by age 15, that puts the first conception at 12 at the latest, and that's only if they're continuously pregnant, which would be difficult to accomplish. [Answer] You can definitely train for ability to score highly in IQ tests, so you should be able to breed for it. That's not going to make anybody "smarter" - all it will do is increase the ability to score highly on IQ tests. Even Mensa agrees that IQ is only an indicator of intelligence or ability to problem solve\* As pointed out by @F1Krazy, your group's median IQ will remain 100, but you will be able to raise median IQ as compared with outside the group, as even with the inclusion of environments less conducive to IQ, the improvement over time has been positive (see [Flynn Effect](https://en.wikipedia.org/wiki/Flynn_effect)) so providing an environment conducive to learning, personal development and support and an improvement in health should all contribute. --- \I've been a member of Mensa for maybe 20 years and can categorically state that high IQ is not a consistent indicator of anything other than getting high scores in the Mensa test. Membership includes heads of business, unemployed plumbers, musicians, mathematicians... [Answer] ## Intelligence is heritable <https://www.scientificamerican.com/article/is-intelligence-hereditary/> > > Scientists have investigated this question for more than a century, and the answer is clear: the differences between people on intelligence tests are substantially the result of genetic differences. > > > But... > > We are talking about average differences among people* and not about individuals. > > > And... > > Any one person's intelligence might be blown off course from its genetic potential by, for example, an illness in childhood. > > > Still... > > we know, for example, that later in life, children adopted away from their biological parents at birth are just as similar to their biological parents as are children reared by their biological parents. > > > ## Bottom line You'll need to perform selective breeding, "just" as farmers breed plants, ranchers breed cattle, and rich people breed dogs. ## However we can't answer how much smarter they'd be. ## Caveat High intelligence correlates to higher rates of mental illness. <https://www.scientificamerican.com/article/bad-news-for-the-highly-intelligent/> > > The biggest differences between the Mensa group and the general population were seen for mood disorders and anxiety disorders. More than a quarter (26.7 percent) of the sample reported that they had been formally diagnosed with a mood disorder, while 20 percent reported an anxiety disorder—far higher than the national averages of around 10 percent for each. > > > [Answer] If instead of traditional breeding methods one were to use a method called iterated embryo selection [1][2], the potential IQ gain values could be much higher than the ones indicated by the other answers. In their paper [1], Shulman & Bostrom note that > > The effectiveness of embryo selection would be vastly increased if > multiple generations of selection could be compressed into less than a > human maturation period. This could be enabled by advances in an > important complementary technology: the derivation of viable sperm and > eggs from human embryonic stem cells. Such stem-cell derived gametes > would enable iterated embryo selection (henceforth, IES): > > > 1. Genotype and select a number of embryos that are higher in desired genetic characteristics; > 2. Extract stem cells from those embryos and convert them to sperm and ova, maturing within 6 months or less [3]; > 3. Cross the new sperm and ova to produce embryos; > 4. Repeat until large genetic changes have been accumulated. > > > Assuming a normal distribution of IQ scores with $\sigma = 7.5$, they [1] estimate the upper bound of the gain values from this method in a single generation as follows: ``` \| Selection \| Average IQ Gain \| \|-----------\|-----------------\| \| 1 in 2 \| 4.2 \| \| 1 in 10 \| 11.5 \| \| 1 in 100 \| 18.8 \| \| 1 in 1000 \| 24.3 \| ``` The predicted gain over 5 and 10 generations using the relatively modest 1-in-10 scheme have upper bounds of 65 and 130 points, respectively, after discounting the loss from diminishing returns, and the theoretical maximum gain over multiple generations has an upper bound in the interval between 30 and 40 standard deviations (225 and 300 points), likewise discounted. [1] [C. Shulman and N. Bostrom, 2014](https://nickbostrom.com/papers/embryo.pdf) [2] [G. Branwen, 2016](https://www.gwern.net/Embryo-selection) [3] [R. Sparrow, 2013](https://jme.bmj.com/content/40/11/725) ]
[Question] [ I had a dream that on my alien planet, there was a large desert that had naturally occurring glass marbles in the sand. My dream logic was that the sand was melted into glass and natural weathering turned the glass into a spherical shape. Obviously a habitable planet would not be able to harbor such extreme weather, and I realized that immediately when I woke up. So, my theory is the only way to do this on a habitable planet is through lightning strikes on sand + gritty wind and sand weathering to turn it into a sort of glass pebble. Is this feasible? What is another solution if not, while still leaving the planet habitable for large terrestrial lifeforms? (they don't live in the desert but the rest of the planet needs to be survivable) A few details about the planet: * It is larger than earth but composed of similar materials * The atmosphere has a higher percent composure of oxygen * The planet has larger oceans than earth and very few continents. (Think about a continent about twice the size of Australia. That is the largest landmass, and everything else is smaller islands) * The atmosphere is thicker than earth, so it is more insulating. * There is a very slight axial tilt, less than earth's. * Their moon is larger than Luna. A few details about the desert: * There is volcanic activity in the desert * There are lightning strikes * It is close to the coast * It harbors dunes and the weather that accompanies that * On the flat parts of the desert and by the coast and rivers, there is some plant life. What I want the marbles to look like: * Ultimately, I want them to be smooth but they don't need to be round. Ovular or flat are okay. The glass should be pretty thick as well, not incredibly brittle. It doesn't need to be transparent in it's natural state, but it should be able to be transparent when processed. [Answer] There are 3 types of natural glass: obsidian (volcanic glass), impactite (meteor glass), and fulgurite (lightning glass). Naturally round impactite is virtually unheard of. Impactite tends to have strong striations in the direction of impact that gives it more of a cleaved shape. It is also very rare for it to be transparent. Technically, a round transparent piece of impactite might be possible, but probably not a whole field of the stuff. Obsidian can be naturally round, but due to volcanic ash that is mixed into it as it's made, it's not transparent, even when polished. Fulgurite is normally the most transparent type of natural glass because it is formed just from the sand that the lightning hits without being mixed up with impurities from ash, meteorite, or granite below the sand. That said, it's also the least round because it takes the shape that the lightning moved through the sand. Any of the above could be made very round and polished in a river bed, but desert sand would erode them unevently. It's pretty unlikely that any of these forms of glass would match your description, but perhaps a gemstone would. Your dream reminds me of a documentary I saw on desert diamonds a few years back. Because diamond is harder than sand, they don't errod into weird shapes like natural glass would. [![enter image description here](https://i.stack.imgur.com/RlJZw.png)](https://i.stack.imgur.com/RlJZw.png) They are naturally round and just sit around on the surface in certain areas of the deserts in Africa and the Middle East. Like most natural glasses & gemstones, uncut diamonds are typically translucent enough to see light through, but need to be polished to become transparent like glass. That said, uncut diamonds can sometimes have a very good natural clarity to them; so, it may be possible to find a desert strewn with diamonds much like the more round ones in the picture below. [![enter image description here](https://i.stack.imgur.com/xlaLX.png)](https://i.stack.imgur.com/xlaLX.png) The richest and most obvious of these diamond deserts have already been picked through, but there are (or at least were) places right here on Earth that very closely resemble your dream. You probably don't need to change the alien world to make this plausible, you just need to be in the right desert on it. [Answer] Your desert glass pebbles are volcanic glass. In the US they are called Apache Tears. [![apache tears in a bucket](https://i.stack.imgur.com/uMql1.jpg)](https://i.stack.imgur.com/uMql1.jpg) [source](https://www.etsy.com/listing/655265321/rough-natural-apache-tears-stones-choose?gpla=1&gao=1&&utm_source=google&utm_medium=cpc&utm_campaign=shopping_us_ts1-e-home_and_living-home_decor-rocks_and_geodes&utm_custom1=a9ee2d7a-f808-4831-9fbf-c1b6c4567ff4&utm_content=go_1844177675_65111493530_346363826136_pla-302796601822_c__655265321&gclid=EAIaIQobChMI-uOHzKnx4wIVARgMCh30SQxeEAQYASABEgJzgvD_BwE) These are unpolished, as found in the desert. When polished they are a very beautiful deep black and suitable for use in jewelry. Some of the round ones in this image ones look pretty close to that without polishing. <https://en.wikipedia.org/wiki/Apache_tears> > > Apache tears" is the popular term for rounded pebbles of obsidian or > "obsidianites" composed of black or dark-colored natural volcanic > glass, usually of rhyolite composition and bearing conchoidal > fracture. Also known by the lithologic term "marekanite", this variety > of obsidian occurs as subrounded to subangular bodies up to about 2 > inches in diameter, often bearing indented surfaces... > > > Volcanic glass forms naturally and naturally breaks into these chunks, which are weathered into roundish shapes. Once you start with natural glass you could have them weathered and be polished to the end result you want - perhaps tumbled along a wadi by periodic floods? [Answer] Bring in a desert-dwelling animal or insect. There can be two ways to do this. One is have an animal/insect attracted to the glass itself. Depending on what it's made of, there could be minerals in it the animal needs, but the rest of the glass is useless or even poison. So the animal breaks off the glass and swallows it, leeching out the appropriate substances, then pukes up the rest. It comes out in a lovely glass marble shape, like a clam with it's pearl. It can come out the other end, too, but that's a little less...appealing. Insects are great for sheer number and being able to live practically anywhere, but animals can make larger or even variable sized ones. Though if you had several insects eating the glass chunks from the outside, they could leave behind "balls" of varying shapes and sizes. The other is an animal makes the glass. Same basic idea, but instead of being attracted to the glass itself, it's merely hunting for food. If the animal is something like a snake, it would have a hinged jaw that opens wide to grab it's prey. Since this is an alien world, we could posit that the prey is small, swift, and hides in the sand, and what's been best for this critter's survival (evolution-wise) is the hinge-jawed creature scooping up it's prey, sand and all. It then regurgitates the sand later, and what emerges are these beautiful glass (or glass-seeming but not true glass) balls. In either of these scenarios, over time glass balls would have built up enormously. Even if people now harvest them, these animals continue to burrow beneath the surface, leaving their balls there, and the winds that shift the sand around can also bury them, sometimes deeply, only to unearth them again later. Over the course of centuries you could have quite the motherlode. Either idea would need more hammering out, of course, but it could be a viable way to get the effect you want. [Answer] The glass balls are fossilized [honeydew](https://youtube.com/watch?v=1h7KV2sjUWY&t=197). The volcanoes in the desert were originally islands. The aphids that lived there were huge due to [insular gigantism](https://en.wikipedia.org/wiki/Island_gigantism). Now since they are insects, they don't fossilise as well. When tectonic activity cause the island to connect to the mainland, and then dried the ocean to one side of it, all that was left was the fossilised honeydew. Then the wind blew the fossilised balls and they spread through the desert. As to why this honeydew fossilised: a small part (~1%) of the giant aphids had a mutation that caused their honeydew to contain light activated resins, which caused it to harden and become inedible to the ants that tended them. The ants would still tend those aphids, but would leave their excrements alone. That is why you can find so much fossilised insect excrement from so many different ages around the desert. [Answer] If you don't insist they be glass, then sure. [Cave pearls](https://en.wikipedia.org/wiki/Cave_pearl) are little spheres of calcium salts that form due to successive periods of wet followed by drying. Each dry period deposits another layer. They can be quite regular shaped. The shape arises due to the regularity of growth, and due to the fact a sphere is the most mass per surface area you can get. So if, instead of glass, it was some sedimentary process, you could get many spheres. Conceivably there are materials that could be produced this way that are transparent or translucent. I don't happen to know one, but it's possible. [Answer] The following steps, inspired by the process used for manufacturing lead bullets in the past, can determine the formation of spheroidal glassy agglomerates: * take a sandy surface * let a meteor hit that surface * the impact will melt and splash material (sand) around * during its ballistic trajectory, the molten material will solidify in free fall * the solid shape will resemble that of a drop or o sphere * let the material impact a soft surface (i.e. water) * over geological times the water body can dry off, turning into a desert [Answer] Sorry no, at least not as a purely, earthbound, geological process, the environment doesn't allow for the amount of multi-directional rolling you would need to round glass into a ball. Glass yes, probably in the form of [fulgerites](https://en.wikipedia.org/wiki/Fulgurite) like the Mauritanian example shown below: [![enter image description here](https://i.stack.imgur.com/Gq4nL.jpg)](https://i.stack.imgur.com/Gq4nL.jpg) Smooth wind sculpted surfaces yes, the below is a purely wind polished piece of [desert glass](https://en.wikipedia.org/wiki/Libyan_desert_glass) from Libya: [![enter image description here](https://i.stack.imgur.com/FMz3A.jpg)](https://i.stack.imgur.com/FMz3A.jpg) But spherical or even near spherical no sorry. You might conceivably get away with a biological process, a creature that eats sand to extract surface nutrients/bacteria/algae on the grains and due to digestive deposition of waste silica cements the grains together in its dung. Given your newly stated goal the desert glass linked above is a good fit, it comes in quite large sections, it is however thought to be the result of a meteor impact rather than lightening strikes. [Answer] If temperature in the mantle of your planet is very high, one can have geysers erupting with quartz lava turned into vapor. It would then condensate in form of spherical droplets. [Answer] Impactite--desert glass, is actually not that rare or difficult to find, and they are quite transparent as well. For your desert, because the atmosphere were significantly denser, there could by significant past bolide impact above that desert, of which explode d in an airburst that is much larger than that of anything on earth. At a very high impact yield, the radiative heat from the fireball can melt the sand down, or if the sand were deep enough, shock melting from a large impact could send rapidly cooling molten debris flying out into a significant strewn field. Both process results in glass meteorites, or desert glass. And if there were a series of bolide events, or there is a significant large impact, you can have this glass literally scattered all across the desert. Now add in an animal that uses gastroliths for digestion: the animal will find the glass and swallow it, as the impactite were the only pieces of solid material small enough to be swallowed by an animal, yet large enough to grind up the animal's feed. The animal retain the glass for a while, using it to grind down the hard vegetation it eats, wearing them down until the glass pieces were too rounded for it's purpose. the animal will then pass the now rounded glass marble and poop them out, which are easily cleaned when the excrement decomposes. (Or the animals could retain the rounded balls until they dies and decomposes, leaving behind a pile of marbles) Now after a few thousand years, maybe all the glass were polished, maybe the herds of animals were still doing their jobs, but you now ends up with a desert full of perfectly transparent, rounded glass marbles. [Answer] I think natural marble balls could become possible by long term accumulation of sand in very desert areas over many hundreds of years. The strong winds of deserts could make the sand grams accumulate at different rates making marble balls to form and have different shapes and sizes. ]
[Question] [ Would a nuclear bomb surrounded by large amounts of separate shotgun-like slugs be a good anti-fleet weapon in space? If yes, how could you counter it? (If there is a better StackExchange for this question then please say so, I am new to this.) EDIT: Thank you very much for all of the quick answers and comments. I can now understand why this would be an,"usele... er, inefficient weapon," as it was put by Renan. Would it be possible to avoid the problem of guidance and range with sheer numbers of slugs (and power of bomb)? Would stacking layers of slugs on top of each other be more effective? (I am assuming that the slugs are made of some impossible material that is exactly like lead except for the melting and boiling points which are somehow not possible to achieve (like in JBH's answer))![diagram of multiple layers?](https://i.stack.imgur.com/jHSKQ.jpg) [Answer] People are having no fun with this question... Let's have fun... Let's make an outrageous but perfectly normal assumption in the world of SciFi: * Each 100 gram pellet is made of a remarkable alloy of Unobtainium and Adamantium, the result of which is completely indestructible when subjected to a thermonuclear explosion of 100 MT. They might glow a little, which would be cool to watch, but they're indestructible. So say we all. Our anti-fleet weapon (call it a doomsday bomb, 'cause it'll hurt everyone nearby, friend or foe) can release up to 417 PJ (yup, peta-joules) of energy in a single go. Admiral Humbug has that sucker packed with about 5,000 of our fancy pellets. That's about 83 TJ per pellet (we're going to completely ignore loses due to space between pellets, imperfections, blah, blah, blah. We're looking for ideal maximum velocity here). If I recall my math correctly... Joules = $\frac{1}{2}\times m\times v^2$ Which means our nasty little pellets are bookin' at 40.7 Km/s. Sucks to be my enemy! Problems * Outer space is big. The odds of ships being particularly close are low. That means you need a BIG boom with a LOT of pellets. Cluster bombs are generally only useful in close quarters. So, realistically, how close are the ships? If they're within mere kilometers (about touching by space standards), this will be effective. If they're separated by 10,000 klicks, this'll be just about useless. * Ships must be designed to take a beating while flying through space. There's dust and debris (asteroids come in sizes smaller than kilometers, we just don't generally care about the little guys) and your ship must have some way to take the pounding (shields or armor). Whatever that is, it will absorb some if not all of your pellet's energy. This is an issue only you can resolve... given the "cruising speed" of your ship and the equation above, how much mass can your ship withstand? Very simplistically (i.e., I'm assuming at "cruising speed" you can't be hurt by what you hit "normally") we calculate... cruising velocity squared $\times\frac{X}{2}$ = 83 TJ, solve for X. If X is greater than 50 grams, this is only partially effective. If it's greater than 100 grams, this bomb is just a party favor. * Remember, that bomb goes off in all three dimensions. There isn't a way to force the energy in just one direction. That means it's only useful as an "up yours!" bomb (e.g, you're going to lose the fight, so you're going to take your enemy with you). You could argue that you'll set it and run, but wouldn't your enemy follow? * Finally, remember that your energy is distributed among all the pellets. Adding more pellets means less energy per-pellet. It's a balancing game, because to get all the energy you need to completely surround the bomb. That means at least two "pellets" are required (two halves of a sphere). Don't get trapped in the idea of "what if I have 100,000 pellets! Then distance won't matter!" but they'd probably just bounce off the ships 'cause they each have 1/20th the energy. [Answer] This was a real weapons design considered in the 1980's, and projected to propel pellets in a fairly focused beam at up to 100km/sec. > > Up to 5 percent of the energy of a small nuclear device reportedly can be converted into kinetic energy of a plate, presumably by employing some combination of explosive wave-shaping and "gun-barrel" design, and produce velocities of 100 kilometers per second and beam angles of 10-3 radians\. (The Chamita test of 17 August 1985, reportedly accelerated a 1-kilogram tungsten/molybdenum plate to 70 kilometers per second.† ) If one chooses to power 10 beams by a single explosion, engaging targets at a range of 2,000 kilometers with a kill energy of 40 kilojoules per pellet (one pellet per square meter), then such a device would require an 8-kiloton explosive and could tolerate random accelerations in the target, such as a maneuvering RV or satellite, of up to 0.5 g (5 m/s2).‡ > > > The initial plate for each beam in this Casaba-like device would weigh only 32 kilograms but would have to fractionate into tiny particles to be an effective weapon—4 million evenly spaced pellets to produce one per square meter at 2,000 kilometers range. If such pellets could be created uniformly, which is highly questionable, then, at a velocity of 100 kilometers per second, they would each weigh 8 milligrams, carry 40 kilojoules of energy (the amount of energy in 10 grams of high explosive), and travel 2,000 kilometers in 20 seconds. Such hypervelocity fragments could easily punch through and vaporize a thin metal plate and could cause structural damage in large soft targets such as satellites and space-based sensors, but they would have little probability of striking a smaller RV, or even disabling it if a collision did occur.§ > > > <http://www.projectrho.com/public_html/rocket/spacegunconvent.php> A slightly more detailed description is here: > > "Up to 5 percent of the energy of a small nuclear device reportedly can be converted into kinetic energy of a plate, presumably by employing some combination of explosive wave-shaping and "gun-barrel" design, and produce velocities of 100 kilometers per second and beam angles of 10^-3 radians: (The Chamita test of 17 August 1985, reportedly accelerated a I-kilogram tungsten/molybdenum plate to 70 kilometers per second. t) If one chooses to power 10 beams by a single explosion, engaging targets at a range of 2,000 kilometers with a kill energy of 40 kilojoules per pellet (one pellet per square meter), then such a device would require an 8-kiloton explosive and could tolerate random accelerations in the target, such as a maneuvering RV or satellite, of up to 0.5 g (5 m/s2).\ > > > Third generation nuclear warheads could also be used as the drivers for extremely powerful HEAT or [Explosively Forged Projectile](http://toughsf.blogspot.com/2017/05/nuclear-efp-and-heat.html) (EFP) weapons, delivering a slug of metal or a high speed jet of liquid metal at the target (useful for smashing armoured targets or blasting moons and asteroids). The most advanced version of this idea was the "[Casaba Howitzer](http://toughsf.blogspot.com/2016/06/the-nuclear-spear-casaba-howitzer.html)", which ejected a star hot stream of plasma at a narrow angle, delivering laser like energy without the bulk and expense of all that laser machinery. The device would resemble the "Pulse unit" of an ORION nuclear pulse spacecraft, channeling much of the energy of the device through a small hole into a "filler channel" and using the energy to vapourize a plate of material to become the energetic plasma: [![enter image description here](https://i.stack.imgur.com/nnksn.jpg)](https://i.stack.imgur.com/nnksn.jpg) The ORION pulse unit. Nuclear devices to focus the energy of the blast would resemble this So using nuclear devices to "drive" materials or energy into a target allows you to use nuclear weapons at longer ranges in space (bypassing the inverse square law), and generate the target effects you desire, such as stripping away external fittings and damaging light components (a "nuclear shotgun"), cracking open hard targets (HEAT and EFP weapons) and even blasting targets with laser like energy (Casaba Howitzers). Choose your weapons. [Answer] A nuclear explosion is a poor choice for this application. In a nuclear explosion in the atmosphere, the energy largely goes into heating the gas of the atmosphere. The heated gas expands violently. This produces the shock wave and the mushroom cloud. It would definitely accelerate slugs in its path. But in space there is no gas to heat, only the materials adjacent to the explosion. Much of the energy is radiated off into space. The vaporized materials of the bomb casing makes a puny shock wave. Consider a regular shotgun slug coming out of the shotgun. It is propelled by expanding gas from the explosive in the shell. You could replicate this in space by using an explosive that itself turns into an expanding gas cloud, which then transfers its kinetic energy to the shells, accelerating them. For example, a keg of black powder. If you want to use a nuclear explosion you should surround your explosive device with something that will capture the energy of your explosion and turn it into kinetic energy, ideally expanding rapidly as a cloud of gas. That accelerating gas will then push on and accelerate your shells. A comet would work well to generate the needed rapidly expanding gas cloud.. [Answer] Following on JBH's line of thinking: When you said remember, that bomb goes off in all three dimensions, it strikes me that this is the real heart of the Problem of Space Warfare. Strategists think too low-dimensionally, too 21st century. No, the modern strategist will be thinking four dimensionally at least. So, how to apply a nuclear powered slug-bomb to space warfare? Well, everyone knows about time travel. You know, slingshot around the Sun: you pick up enough speed, you're in time warp. If you don't – you're fried. Well, Space Patrol battle strategists do this with fleet busting bombs. It's a bomb, so they don't care if one or two get fried! The long and short of it goes like this: long range sensor data coupled with data collected by Outer Rim fortification sensors alerts the High Command as to location, velocity, trajectory and flock arrangement of enemy vessels. Let the Battle Computer churn on that data for a while and launch the 4D Fleet Busters! These large missile systems, always in motion and awaiting orders, will now accelerate towards the Sun. Approaching the predetermined velocity, the missiles will slingshot around Sun & enter time warp! BAM!! They disappear from all enemy tracking sensors (which wouldn't know about their course changes for some 15 to 20 minutes anyway). At the appropriate time, according to van Wobbler's Equation, the missiles drop out of time warp and --- and this is the key to modern space warfare --- reenter normal time & space right smack dab in the middle of the enemy vessel!!! Imagine if you will: sublieutenant Skwlarklann of the Evil Space Empire is making her routine rounds of the IHD Panthera's engineering division, in keen and patriotic anticipation of the immanent surprise attack on the insignificant enemy's star system. She takes a well deserved sip of her latte macchiato, sets the cup down and looks up towards the Mysteriously Pulsating Crystal Warp Drive Actuator (TM) in the great arcade of the engineering division. Suddenly, there is a strong puff of air and a damp pfffffp! Momentarily suspended before the amazed sublieutenant's vision is an odd looking, dull metal device with a crude image of the Dear Leader painted in his union suit, making a rude gesture and a speech bubble saying Phuck the Empire!!! Before anyone can react, BBBBBBBBOOOOOOOOOOOOOOOOOOOOOMMMMMMMMMM!!!!!!!!!!!! The small nuclear powered FleetBuster Mark VII (Patent Pending) sends a couple tons of adamantium unobtanite shrapnel shards whizzing in every direction, completely crippling the engineering division, critically damaging the environmental systems, disabling the artificial gravity and attitude control of the poor beleaguered Panthera! Large shrapnel punches through deckplates and medium strength bulkheads alike. The ship's shields and heavy armour are useless against an attack from within. With all the capital ships and carriers destroyed or irreparably disabled, the Outer Rim Defense Force can easily mop all the smaller support vessels and fighters. So yeah, very effective anti-fleet weapon! Timing is key! How to defend against such an attack? That may not be such an easy thing to do! [Answer] With proper design your slugs would gain considerable velocity, but I doubt it would make an effective weapon. Think of the slugs as miniature Orion spacecraft, which is a concept that is very well-developed and highly likely to work. The trick would be to design the pusher plates optimally, and that would require some fairly high-quality engineering. Basically, you want the slugs to be as close as possibly to the nuke so that they accelerate as much as possible, but that costs you in numbers of slugs, and requires a more massive pusher plate. (The "pusher plate" is that part of the slug which is responsible for enduring the nuclear blast and absorbing its momentum.) It's hard to say where the optimal design is. My guess is that in a case like this you'd design something like an ablator plate where the face of the plate towards the nuke boils away and the gas released provides some of the push. You might do better with the nuke-pumped x-ray laser idea that was developed for the original Star Wars project. It's clearly [harder to do that the DoD thought](https://en.wikipedia.org/wiki/Project_Excalibur) in the 80s, but that's what R&D is for. [Answer] The shotgun bullets would be disintegrated by the nuke. The boiling point of [iron](https://en.wikipedia.org/wiki/Iron) is around 3,000K. The temperature of an area right next to a nuke blast center can easily outdo that [by two orders of magnitude](https://hypertextbook.com/facts/1999/SimonFung.shtml), probably more in space. At this point the slugs have probably ceased being a gas or maybe even plasma. This would make for the most usele... er, inefficient weapon ever in the history of space warfare. Even if the slugs were intact, any target would either be far enough to take the hint they should change direction (causing you to miss them completely), or close enough that the nuke will cause more damage than the slugs. Against a planet, the slug plasma would be the smallest concern. The nuke might cause damage, but the slugs won't. In space, projectiles only do for good weapons if they are guided. Otherwise even the slightest change in trajectory causes a projectile to miss. And you won't be able to guide those slugs. [Answer] One of the problems I see with a nuclear-kinetic shotgun, assuming that the engineers at Muppet Labs..., er, I mean R&D can make this, is that these things will keep going until they hit something. If they miss their primary target, they will keep going until eventually some sort of friction slows them down. I expect that after peace happens, there will still be pellets flying about. Long-term weapons that you don't have control of aren't a good idea in space. One weapon proposed is to set off a couple of fragmentation bombs (similar to what you've proposed) several places in Earth orbit. This would not only destroy most of our satellites, but prevent new ones from being put up. It might also prevent space travel from happening until the orbits are cleaned up of debris. [Answer] I want to build on [@JBH's answer](https://worldbuilding.stackexchange.com/a/110012/6807) a little. One of the key problems mentioned there and in the comments is that if you want the pellets to have a "shaped" direction (to focus their spread and energy more efficiently), they would need something of greater mass to push off of. Newton's buzzkill of a law means that in space, just as much energy would be transferred backwards (away from the shape you want) as forwards, so even a backplate of some sort would just fly directly back at you at enormous speed. So how could we avoid literally shooting ourselves in the face? Let's use some of our Unobtanium alloy to create a massive "core" for the warhead. It would be huge compared to the pellets, probably torpedo-shaped with an engine on the back to propel it towards the target. Then instead of a single spherical charge, it would have a ring of them around the core. The point is to make the core be the center of the explosion, which it would absorb nicely because that's what Unobtanium does. If the "backboard" for the explosions is balanced in the middle of them, the net force would cancel out and it would go nowhere. So what limitations would this have? Well it would be a bit more complicated design for one, and it would give you a ring of projectiles instead of a sphere, but that could be a good thing because then you don't have to worry about shooting yourself or your allies. Aiming/positioning it would be a little more complicated than just a dumb bomb, but it would still allow you to angle it such that it would hit a good amount of targets. The bonus is that you could also later recover the core, and prepare it with a new warhead (Unobtanium isn't cheap, after all, otherwise it would be called Affordium). Here's a terrible diagram of what I mean: [![enter image description here](https://i.stack.imgur.com/4IQ4d.png)](https://i.stack.imgur.com/4IQ4d.png) [Answer] ## This Could Work (If you change the design a bit) The device described by the OP is basically a nuclear space hand grenade. As others have pointed out, this is problematic, because space is large, and therefore a granade that is actually dangerous to the enemy will likely be very dangerous to your own fleet as well. ## So design a Nuclear Space Claymore The [Pascel-B](https://en.wikipedia.org/wiki/Operation_Plumbbob) nuclear test was an underground nuclear explosion that launched a one-ton manhole cover into the air at several times escape velocity. It would have been the first man-made object in space if drag forces hadn't vaporized it on the way up. In space the projectile would not experience those drag forces, and would instead travel in whatever direction you fired it with tremendous speed. So build a long, thick, hollow tube. Put a nuke at one end, and a large steel plate at the other. Insert impurities into your steel plate such that it shatters on impact, transforming into thousands of tiny, high velocity rounds. Much of the tube is converted into an expanding cloud of superheated gas, which slams into the steel cap with incredible energy. The cap breaks apart, and is propelled in whatever direction you pointed it. The fact that you can aim it makes it a viable weapon. Space Claymore. Has a nice ring to it. [Answer] Simply put, no. In a vacuum (space) there is no atmosphere. This means that, although the radiation dose would be higher, the blast (shockwave) would disappear, and the slugs wouldn't whip through space. You'd need to physically propel them. [Answer] We invent a capacitor that is charged like MAD by radiation. Now our missile flies into space and waits and listens for targets. When there are targets, it deploys a swarm of rail guns with enough velocity that they get a safe distance from the nuclear weapon. The rail guns have a capacitor on the back, ready to be charged. The rail guns orient. The nuke explodes, bathing the launchers in radiation. This charges the capacitors. They capacitor powers a rail gun which launches a bucket of projectiles at the target. [Answer] Never mind the material, it’s the quantity of fragments that will be the issue. In a typical bomb (anything from a hand-grenade to an air-dropped bomb), the mass of the fragmentation material is generally on the same order of magnitude as the mass of the explosive. That means that you’d be looking at a similar mass to the TNT equivalence of your nuclear device - eg for a megaton class weapon, you’d need a million tons of pellets. Think of it this way - if you had a bomb with a 10km blast radius, then you’d have a space in the order of 1,000km^3, or one trillion cubic metres. Put a million slugs (a pretty large number, giving you a weapon weighing several tons) and still only gives you only one small slug per 100m x 100m x 100m square. That’s not going to trouble a spaceship much. [Answer] There's some validity to this approach. It's called a fragmentation warhead. However, frag warheads are usually detonated near the target. You describe this as an "anti-fleet" weapon, which to me implies that you aren't targeting a single craft. You're targeting a fleet in general and trying to inflict multiple causalities. The problem is distances. A best case scenario says that these slugs spread out in a uniform disk that heads towards the target. The idea of a frag warhead is that the expected number of hits on your target (or targets) is equal to the number of fragments times the fraction of the area of the disk that your target covers. If you spread 50 fragments over a $10\text{m}^2$ disk and are trying to hit a $2\text{m}^2$ target, you expect that on average $50\times(\frac{2}{10})=10$ fragments will hit the craft. Now space is big. Really big. Really really really really really big. That spread is going to cause problems. Let's back up and take on a more terrestrial example. A modern [carrier battle group](https://en.wikipedia.org/wiki/U.S._Carrier_Group_tactics) will have an outer screen of ships to detect the enemy at up to $370\text{km}$ and an inner screen of ships within about $19\text{km}$ to dispatch them. Let's pretend our carrier group is all bunched up within $20\text{km}$. The exact makeup of a carrier group isn't very specific, but for our rules of thumb, let's say its 6 destroyers (like DDG-59), 2 AEGIS cruisers, and a supercarrier. According to wikipedia, this is not an unreasonable makeup for our example purposes. The surface areas of these ships are roughly destroyer: $3000\text{m}2$, AEGIS: $3111\text{m}2$ and Nimitz carrier: $25564\text{m}2$. Sum total, that's going to be somewhere on the order of $50000\text{m}2$, or $0.050\text{km}^2$ of surface area to hit. That carrier group is spread over roughly $300\text{km}^2$ of surface, yielding a ratio of $6000:1$. This means for every $1$ hit you want on this unusually bunched up carrier group, you need $6000$ pellets. Now practically speaking, you probably wont expect a single pellet to kill a ship. These are warships, after all. You will want to multiply that by some factor. Now let's get into space. Space is big. Really Big... Wait, I said that already. The distances between things are much larger. For the ISS, a "close approach" of debris to the space station is [defined](https://arstechnica.com/science/2013/07/how-nasa-steers-the-international-space-station-around-space-junk/) to be about $25\text{km}$ in radius. That means that the ISS seriously considers spending fuel to change course. In our seafaring example, we had all 9 of our ships bunched up to within a $10\text{km}$ radius ($20\text{km}$ diameter). If we assume the ISS was our supercarrier, with a surface area of $0.025\text{km}^2$ within this radius, we should expect to need roughly $80,000$ pellets in order to achieve a single pellet impact. Again, I would expect it to take a substantial number of hits to get a kill against a warship designed to take on not only these pellets, but the general debris in space. In interplanetary space, the distances get larger. We don't exactly have SOPs for interplanetary fleets, but distances of $1000\text{km}$ between ships would not be unreasonable at all. At those distances, such a shotgun approach becomes simply meaningless. So the next question is to find out how heavy your fragments are. Let's say you want to get $100$ hits on your target, with $100\text{g}$ fragments. That calls for $8$ million fragments at $0.1\text{kg}$ each, or $800,000\text{kg}$. The [ISS](https://en.wikipedia.org/wiki/International_Space_Station) is about $400,000\text{kg}$. Even if we drop our standards and use $10\text{g}$ fragments, it's still $80,000\text{kg}$, or $20\%$ of the mass of the space station. Which is going to lead to visibility. The larger a weapon, the easier it will be to detect. A warfleet is going to have a vested interest in detecting weapons approaching them. A weapon that's a good fraction of the size of the ISS is going to be relatively easy to spot as it approaches. Which brings up an interesting quirk of the weapon. You don't really need the nuke. In space, things move fast. Orbital velocities are on the order of $8\text{km/s} (8000\text{m/s}$) and interplanetary speeds are necessarily higher. At those speeds, you don't really need an explosive to impart additional velocity. Simply shoot at the craft from any direction other than from behind, and the relative velocities of the fleet vs the pellets will give you all the lethality you were going to get. A nuke would let you achieve the desired spread quickly, by giving each particle a larger cross-range velocity. This is helpful if you want to get in close, but getting in close with a weapon that's a fraction the size of the ISS isn't realistic. You might as well impart less velocity, with a smaller explosive, and do it earlier, giving the slugs more time to spread out. This would also give you the opportunity to make the slugs into precise shapes to improve lethality, and avoid the whole "nuclear bombs like to melt things" issue. [Answer] A design not too dissimilar to this is how real-world fission weapons actually work - but the effect is different to what you're imagining. Most of the mass of an early-design fission warhead is inert ballast. The highly enriched core is surrounded by a large mass of un-enriched material purely to provide containment, by way of inertia. The material is vaporised very rapidly by the initial electromagnetic products of the nuclear chain reaction, so it has no tensile strength, but the vapour still has mass, and delays the expansion of the rapidly heating fissile region such that the chain reaction can build and thus produce a more energetic detonation. The arrangement of (presumably) lead slugs you're envisioning would produce a similar effect, depending on how close they are to the fissionable components and how well shielded they are. They would need a kind of extremely heat-resistant 'wadding' similar to a conventional firearm in order to not be vaporised. [Answer] The heat radiation would likely be much more efficient than the slugs. In space there is no atmosphere so none of the blast energy gets lost to creating a shockwave. Instead you will have close to 100% of all the types of electromagnetic radiation in all directions unblocked by anything. It would heat the surface of a ship which would need to be built by a material that would either work as a mirror to reflect ( or at least not get vaporized ) by the intense irradiation. Now the radiation would decrease as the surface of a sphere around the blast center. We can maybe calculate how far away would be "safe" given some material the space ship is built by. But definitely it is the intense radiation and not any materia that would pose the threat of such a weapon. The slugs would have small total area that they could hit but the radiation hits anything in the line of sight with the speed of light. You would need a super duper efficient mirror material or absorber to protect against that. [Answer] I don't think slugs would work. If you are going to use nuclear weapons in space, wrapping the core with iron bars, wrapping that with a heavy duty solenoid, then to set off discharge a large capacitor through the coil, when the magnetic flux reaches peak, explode the bomb. The iron bars lase in the hard X-ray, soft gamma ray range. The magnetic field keeps the columns of iron vapour contained to lase a bit longer. If you can aim the thing with any precision, you transfer something like 10% of the energy of the weapon into his hull. You might make a shaped nuclear charge where some 80% of the energy is in a fairly small angle. So you are sending a jet of several million degree plasma. Don't how how coherent that would be. Again, if you can set it up so it carries a magnetic field with it, it may stay more coherent. Right now these are either not made, or not discussed where I can find reports. --- Overall space battles will likely be fought with missiles. They can respond to changes in vector of the target. Compare to Earth naval warfare. Even the primitive submarines of WWII put paid to battleships. They were recycled as sea to shore batteries. And in aircombat far more is done with missles than with guns. Space combat will be more like submarine warfare: Detection plays a huge role. Distances are large enough that the object isn't there by the time you get the signal. On the flip side it's like air combat in the absence of stuff to hide behind/under. No equivalent of thermoclines, or acoustic convergence zones. Not clear to me if space combat will be the equivalent of submarines (launch missiles from a big ship) or more like aircraft carriers. (Missiles are carried to a closer distance to be fired.) ]
[Question] [ There's this creature that swims over the surface of water and it's giant, almost the size of a whale and has thick scales as armor over its back. This creature almost never dives underwater so from afar it looks like a boat. Why would an animal only swim over the surface of the water like a boat and avoid going underwater as much as possible? [Answer] That's where its food source is. Most algae is found near the surface of the ocean, so if this creature has a semi long neck, it can swim gently along moving its head back and forth, up and down taking in the algae and anything else it finds. It stays at or near the surface as it's an air breather, so swimming under the water and then surfacing takes energy. This energy is much better spent floating on the surface, occasionally swimming, and mostly moving its neck to slurp up food. [Answer] Needs sunlight It could have a usage for sunlight. Maybe a system similar to how plants use sunlight in photosynthesis. Heck, it could be exactly that. Make it have cells with photosynthetic properties on its "back". That way, if it dives, it makes less food. It means that it can dive if you ever need that (for design reasons like mating; or for whatever story-line reason that might come), but overall it would be preferable for the creature to stay afloat. Symbiotic relationship Have another species live on your creature. Those are not sea-beings, and thus need air to breathe. Now you just need to find a mutual benefit in this relationship, which isn't hard (mainly because there are so many real examples to take inspiration from). Hypos for example have small animals pick traces of dirt from them. The small animals eat what they pick away. Hypos get free cleaning, small-ones get a tasty treat. This is a common thing with large not-so-mobile animals (elephants, sharks etc.). It needs air to breathe Quite a few sea-dwelling creatures need to raise above the sea and reach air to breathe. Usually they then return underwater, but maybe a creature the size you describe just conserves energy, and prefers to stay at air-level constantly. Moving up-and-down a large mass is a big waste of resources. Also, it might not bear the ability to "hold its breath" for long. [Answer] Buoyancy is a big deal for sea creatures. Pretty much everything living on or in water have a density that makes them naturally comfortable (i.e. energy efficient) only at certain depths, and changing depths without also changing their density (i.e. via lungs or air sacs) requires significant effort. Take ducks, for example. They're very buoyant; they can dive, but it takes significant energy to do so. Since that's also how they get their food, they naturally evolved to be very efficient divers, but since they're air-breathers they also naturally evolved to spend most of their time on the surface. Swans and geese, on the other hand, are also very buoyant but they don't dive. They eat mostly floating plant matter or seaweed they can reach just by stretching their long necks underwater while staying afloat. Just floating at your preferred depth (i.e. the top of the ocean) is the most energy efficient way of living, and for an air-breather anything that involves you staying where there's air is vastly preferable to the alternative. Natural selection wouldn't really promote any sort of diving instinct which goes against both of those without a compelling reason to do so (i.e. food or survival). If your large whaleboat is naturally buoyant and able to get food without diving (i.e. feeding on surface organisms, or using long appendages to grab food from depth), and is big and strong enough that it doesn't need to hide from predators, it seems likely that it just wouldn't evolve any sort of diving instinct at all. [Answer] Hmm. A boat would have a curved upwards shape. As for avoiding depth . . . 1. Avoiding predators. 2. It requires gaseous O2 to survive (lungs, booklungs, or tracheae instead of gills) And the most obvious one of all: Hunting. If there's a seafaring people, they'll jump for the chance to commandeer an abandoned boat. They climb in, the animal dives, surfaces again, and eats. This could also catch birds looking for a rest. If the scales are shiny, they might also mimic gold or jewels: another incentive for something (sentient) to climb on. [Answer] Terrestrial => Marine evolution To justify such a lack of deep water related adaptations, I guess the most logical explanation would be that this creature was terrestrial in the past, and was pushed towards the marine environment by biotic (or abiotic) factors such as competition or predation. Instead of developping diving adaptations, it developped buoyancy (which could be just as adaptative!) That also implies all of the feeding has to occur on the surface of the water. It could be: * Predatory: by luring underwater prey to the surface, or having underwater organs (arms, tentacles or jellyfish like structure like the portugese man-o-war). * Autotrophy: by symbiotic relations with some kind of vegetation or algae on it's back, feeding of sun radiation. * Filter feeding: feeding from the plankton on the surface. I guess the Autotrophy part would be almost mandatory, as a mean of protection against intense UV radiation. Other necessary adaptations would include the ability to process salt water. Exemple: using salt and Silica from sea water to create its scales (in a similar fashion to marine Diatoms) [Answer] # It's a flightless bird As others have pointed out, a creature would not dive if it was unable to do so due to being too buoyant, and if it had no reason to. As for reasons for diving, one is to get food and another is to avoid attack from aerial predators. The latter reason is taken care of by the armour, but we have to ask why a surface-dwelling organism would evolve armour instead of evolving the ability to dive, which is probably the easier solution for most organisms. This is where buoyancy comes in. If the animal is very lightweight it will be hard for it to evolve diving behaviour, and it might take the armour strategy instead. Buoyancy means low density, i.e. light weight for the size. But why would an animal be so light weight? One obvious reason is flight. So: we have to imagine that this organism's ancestors were birds, or pterodactyls or similar flying creatures. Think of something like a large sea bird, though not necessarily a whale-sized one. It eats something that lives near the surface, so it doesn't need to dive very deep (if at all), and it spends a lot of its time resting on the water surface, using its feet to paddle like a duck or a swan. If food is very plentiful and predators are few, then birds will often lose the ability to fly. We just have to imagine that this happens here, resulting in a bird-like animal that spends all of its time paddling in the water, never taking to the air. (One difficulty is that a bird would need to lay its eggs on dry ground, but if this is not an Earth species we can imagine that it has live young instead. Or it could evolve a special body cavity in which to incubate its eggs or something - you'll have to be inventive here.) After that, we just need it to evolve its large size and armoured back. Sea animals seem to evolve a large size quite often. The reasons for this are not completely understood (though see [here](https://www.wired.com/2017/05/whales-dang-big-science-may-finally-answer/)), but the same thing might well happen to a flightless sea bird. It would be easier for it to stay warm, it would have bigger fat reserves, and it would be so big that no predator could eat it. However, since it's sitting helpless in the water it could still be attacked by other aerial predators, who peck at its flesh without killing it. An armoured skin would be a sensible evolutionary response to this. [Answer] Maybe these are intelligent creatures with a society deep below the surface. The creature remains on the surface in order to receive something for performing the boat function as a service for another creature. It is intelligent enough to perform this action on purpose as a sort of employment for which it is given some sort of payment. Maybe the payment is something which can only be procured on land and is needed deep below the surface. Maybe instead of needing it the creatures just want this thing. Maybe they are collectors of rare dry land objects and this is the only way they can obtain these things. [Answer] > > Why would an animal only swim over the surface of the water like a boat and avoid going underwater as much as possible? > > > Because it is unable to do so. The density of this animal's body is so much less than water that whatever it does, it is unable to go deep inside water - the same reason why a boat remains at the surface. [Answer] This creature may be a giant, primitive fish that breathes air. Its lungs, due to lacking the adaptations of tetrapods, would likely only be adapted to provide the oxygen that the fish needs, and so the fish cannot hold its breathe and dive underwater [Answer] Because it's been bred to serve as a biological boat. It has a mouth like a manta ray, which allows it to eat and breathe as it moves. Six or eight oar-like flippers and a powerful tail with two flukes at the end provide superior maneuverability. Its armored back has a semi-flat, concave surface where the people go. Steering is possible because of a flexible protrusion on the top. This creature evolved as an extremely buoyant filter-feeding fish, the armor is to protect it from aerial predators and the protrusion allows it to sense wind speed and direction-when the wind bends the protrusion one way, that's where it's surface-dwelling food is going, so it goes in that direction. This allows for easy steering, and when the humans discovered this, they soon began breeding this species to serve as boats so they could reserve wood for other things (like construction). ]
[Question] [ There is this very weird species of bird that just can't get enough of delicious human flesh. But the bird has a problem - humans are big, smart, and social, so this little birdie has a unique skill: getting humans drugged up and brought into the forest. How the bird does it is the weird part: you see, these birds have a symbiotic relationship with fungus and they let it grow in their feathers and have the fungus release their psychedelic spores into the air so the human will breathe it in, and when in the human the spores trigger hallucinations. Then, according to vocalizations of the bird, the spores stimulate the reward center of the brain and lead the human into the bird groups where they tear the human's flesh off and eat most of it. They place more spores in the rest of the cadaver and let it grow into more fungus to use to hunt humans. So my question is: which bird would be the best candidate for a creature like this? What they will need is the brains to give off complex noises to trigger the fungus and a desire for human flesh. Also what fungus would would fit these qualifications, or could develop to fit them? [Answer] ## Vultures I chose vultures as a candidate simply because of their love for flesh. They also have quite alot of feathers, so I can imagine many places for a fungus to be tucked into. Also, listen to their sound. I can't imagine what it would do to those under some kind of hallucinatory effect. Vulture Sounds: <https://www.youtube.com/watch?v=uA5yGyB_z5U> ## Psilocybe semilanceata (liberty cap) - variation of it. There could be an explanation of a hybridization of Psilocybe semilanceata with some kind of mold. I say mold, because of it's fast growth rate. The way this could be done, picture the vultures in their nest. Perhaps they are resting, giving the perfect conditions for dampness mixed in with sitting on their excrement and rotting human remains from it's previous kill, getting in between their feathers. Perfect for this hybrid fungus to grow, and grow fast as mold doesn't take long at all. Now imagine they move around, exposing this fungus to the sunlight, drying it... and ruffling their feathers it turns into more powder like... so it can more easily be administered/distributed. Reference: Magic Mushrooms Around the World: A Scientific Journey Across Cultures and Time. By Jochen Gartz ## Edit: I'm aware that vultures would live in more arid climates. But perhaps this one could be in more of a grassland type area, near a forest. There's 23 different variations of vultures (according to Wikipedia). And seems to be at least a few that could live in that type of climate such as the slender-billed vulture. [Answer] # Ravens Ravens are basically crows on steroids; They're bigger, blacker, and more menacing. Even their beaks are stronger, larger, and more suited to eating meat. They too, have a diet including carrion, but unlike the crows, they fly often solo or in pairs; this makes them the perfect territorial human hunter. A murder of crows is a lot of crows to feed. A single human wouldn't last them very long. However, a single human could last a pair of Ravens much longer, allowing them to draw a lot less attention to themselves. They're also extremely smart (like crows), and have amongst the largest brain in those of avian species. And in terms of a noise to trigger the dispersion of spores, the Raven also has an advantage over the crow. The Raven has a much lower tone, whereas the crow is much more high pitched. Some Ravens can even create a "rattle". If you think about sound waves and how they affect objects, the two can be compared to the bass (lower pitched raven) and the "high" notes of sound (higher pitched crow). You can "feel" the bass when it's turned up high - what you're feeling are the vibrations. You can't really feel the high notes, it just kind of hurts. If you go high enough, then you eventually hit a resonant frequency with something and that will break (eg: glass). In terms of spore displacement, if the Raven could evolve to have a stronger voice, these vibrations could help disperse the spores or otherwise trigger the fungus to release the spores; at least, more so than the higher pitched cawing of the crows. ## Amanita muscaria variant For the fungi related section, I recommend a variant of Amanita muscaria - this mushroom already contains two compounds that cause hallucinations. Ibotenic Acid, and Muscimol. It's not too much of a stretch for a variant to evolve which is smaller, can grow on the bird, and has spores containing both those compounds. [Answer] # Tit is the best. It is small, nice looking, very curious and their small groups fly along the forest paths after you. It eats meat. If you want to feed them in winter, you should give meat and fat to them. And one more nice detail. Look in the movie how a tit kills a sleeping bat. Not for children! <https://www.newscientist.com/article/dn17749-killer-birds-bite-off-bats-heads/> God! They eat bats' living brains out! Really, you don't need to invent anything - really disgustful murderers pretending to be nice birds are around us! And they are intelligent. When I was 8, I had a tit in a cage. In a cage... It opened the cage closed by a hook at will and only slept and ate in it. During the day it mostly occupied the whole room. But it could be turned off by a dark cover over the cage - your heroes can win over the world evil using the darkness. [Answer] The best bird candidate would be the crow. It is both a carrion eater and a relatively intelligent species. It also has the ability to make many different vocalizations, including mimicrying other birds and even speaking some words. As for the fungus, you'd be tempted to go for those that produce psilocybin. But if you want humans being driven like crazy into a death trap, [cordyceps](https://en.m.wikipedia.org/wiki/Cordyceps) is a better match for the trope. [Answer] Owl Even though they have to get close enough to humans to shake spores on them, psychedelic death birds need to avoid being seen. Once the humans figure out what is going on, they will kill any of these birds they see and hunt the rest down. These birds need to live at a distance from the humans (and so be powerful enough to fly the commute) and they need to be camouflaged and nocturnal so they are difficult to spot. Owls want meat. Some also make amazing vocalizations. Barred owls can sound very creepy, like witches cackling. [Noisy pair of Barred Owls](https://youtu.be/rYH34K6cPX0?t=77) [Answer] I think the birds would have to be carrying the fungus with their talons, beaks. That works because birds already have that behavior (carrying, gathering). Birds spend a lot of time cleaning themselves and it's very important to their flight and to their health (especially because of parasites that can destroy a colony or habitat). Infections are easily spread to nests and chicks who are quite vulnerable; there wouldn't be a next generation of birds if they didn't keep their feathers clean. Nastiest bird that birders hate and wouldn't care how you misrepresent them (maybe) are European Starlings as they are an aggressive invasive species that harm local species, take over nests and regular feeding areas, real meanies that don't follow the social rules set for other birds. They are the ones you'll see doing massive swarming and usually travel in packs marauding all the neighborhood bird feeders. Since they swarm in massive packs (murmurations they're called, and that helps your story about the strange sounds) behaviors would be more easily transmitted to larger numbers in less time. [![murmuration of starlings](https://i.stack.imgur.com/YTmMc.jpg)](https://i.stack.imgur.com/YTmMc.jpg) [Answer] Don't focus on birds. Focus on the fungus. You can make the fungus that biologically needs a human cadaver to flourish, so it's the fungus who make the birds do the deed. Not the other way around. Learn about [Ophiocordyceps unilateralis](https://en.wikipedia.org/wiki/Ophiocordyceps_unilateralis), that forces zombie-ants to climb leafs and spread spores from there and (not fungus but worm) [Leucochloridium paradoxum](https://en.wikipedia.org/wiki/Leucochloridium_paradoxum) that infests snails, pretends to be a larva and makes the snail get eaten by a bird in order to continue reproduction in a bird. You can make both birds (intermediary hosts) and humans (definitive hosts) victims of the fungus. Any meat-eating bird will do. Even pigeons, for the added scare factor that in our world everything is set up, just waiting for the fungus to kill us all. [Answer] Ergo: Ergot. and Ravens Sorry, couldn't resist the pun. Ravens seem to me to be the best bird choice for a number of reasons. The key is that they are very smart. Like problem solving and tool using smart. They are often considered to be a bird of ill Omen. Finally, they are omnivorous, which is also important. Ravens will gladly eat berries and seeds without too much issue, but they prefer meat. That satisfies the feast on the human corpse side of the equation. Next we have [Ergot.](https://en.wikipedia.org/wiki/Ergot) Ergot has been a known hallucinogen for centuries. It also thrives on various grasses like rye and wheat kernels. with a bit of handwavium, you can create the following life cycle: Raven picks up the Ergot by eating some infected grasses that grow around the base of a tree or the outskirts of a forest. They get a little high on the spores and go to the outskirts of a nearby town. They flap in the faces of a human, dislodging spores into the face of the victim. This causes the hallucinations and maybe an aggressive response causing the poor sap chase after the Crow back to the edge of the forest. The toxins from the handwaved Ergot cause the victim to attack just about everything and then they will pass out and die from a heart attack or ramming their head into a tree. The raven caws his friends (sorry again for the pun). They feast on the corpse. The leftovers provide fertilizer for the plants. The Ravens distribute more of the spores which infect more grasses that will mature and attract more ravens. Repeat as necessary. This gives you a wonderfully logical source for tales of a dark forest, what with the Carrion Birds and villagers wandering off and getting killed. Make the fungus bio luminescent for bonus creepy points. [Answer] [Honeyguide](https://en.wikipedia.org/wiki/Honeyguide) Real honeyguides draw humans to wild beehives by making signals. A different species of honeyguide might have evolved to make signals to spores and then draw humans to the wood where it could eat them. Although the result is different - at least for the involved human - this behaviour is not so different from that of actual honeyguides. [Answer] Mockingbird They are small and agressive and can mimik other sounds which should cause a human on drugs to think that in the woods someone needs help or there is a party or whatever that he should join asap. The only modification needed seems to me are strong enough muscles and a razorsharp beak to tear flesh ]
[Question] [ I’ve developed a concept for a plasma cannon, and I need it reality-checked. The cannon would gather ammunition by pumping air into the gun through an external fan. The air would gather inside a chamber, where it would be electrified and converted into high-energy plasma. The chamber would then open into the barrel, and the pressure produced by the plasma would be enough to propel it through the barrel. Would this concept work? Also, how would the plasma behave once it left the barrel? Would it be concentrated into a single centralized “bullet”, or would it form more of a stream? How far would it be able to go? [Answer] # Yes There are several devices in existence that work based on similar principles as yours (with one or two adjustments). While they're used for plasma research, rather than weapons, they could presumably be adapted for your purposes. If you were to make a plasma cannon from scratch, you should probably model it at least in part after one of them. The major issue remaining is containing the plasma once it leaves the barrel of the weapon; before then, it can be contained by magnetic fields applied by the weapon itself. After that, though, the plasma should expand in the atmosphere, where there's no significant residual field. The solution that seems to have been considered (at least by the US Air Force) is to simple rapidly increase the speed of the ejected plasma so that even if it dissipates quickly, it will still have traveled a significant distance. ## The plasma gun down the hall from me My physics department has the [SSX lab](http://plasma.physics.swarthmore.edu/SSX/index.html), a group that studies how plasma structures called spheromaks form and evolve. [Here's an image of the main part of their apparatus, the "gadget":](http://plasma.physics.swarthmore.edu/SSX/lab.html) [![Picture of the SSX lab](https://i.stack.imgur.com/02POw.jpg)](https://i.stack.imgur.com/02POw.jpg) Image credit: Michael Brown/Swarthmore College. The SSX group is interested in studying how magnetic reconnection in plasma works, and how particular structures (called Taylor states) form and evolve. They, too, have a plasma cannon of sorts, called a [magnetized coaxial plasma gun](http://plasma.physics.swarthmore.edu/brownpapers/plasmagun.pdf), which works as follows: 1. Hydrogen gas is "puffed" into a chamber (shown above in orange), which has to be extremely clean and must be at very low pressures - about one billionth the pressure at sea level on Earth. 2. A pair of powerful capacitors (one of which is in the image above, in green) are brought to voltages of 5-10 kilovolts each; this is what's needed to ionize the gas. 3. An electric current forms in the chamber and in the plasma itself; by interacting with magnetic fields, a [Lorentz force](https://en.wikipedia.org/wiki/Lorentz_force) arises and accelerates the plasma down the chamber of the gun. This is the major difference between their design and yours; pressure alone cannot bring plasma to these speeds. After this, other parts of the assembly create the precise plasma structures the SSX lab is trying to form, but those are irrelevant for your purposes. The important things we can learn from the above mechanisms are: * You can indeed turn normal (hydrogen) gas into plasma if you have strong enough capacitors, as you're trying to do. * Magnetic fields and electric currents are needed to accelerate the plasma to high speeds ([about 40 km/s](http://plasma.physics.swarthmore.edu/brownpapers/KaurJPPWhistler18.pdf)). * Instabilities can arise from impurities in the cannon or the chamber, as can leaks that let air in; because of this, the device needs to be regularly cleaned (with helium, I believe). This, I think, is the biggest issue with a portable plasma cannon; if you want to have an opening for the plasma to exit, you have to worry about stuff from outside coming inside. * Magnetic fields are also needed to confine the plasma; in their absence (i.e. in your case, after the plasma exits the gun), the plasma would expand and become diffuse, making it a less effective projectile. The whole assembly also fits in a normal-sized room (well, a pretty crowded and messy room), and should be transportable by a reasonably large vehicle. ## MARAUDER The main issue that would arise from just converting the SSX gadget to a weapon lies in confining the plasma after it leaves the barrel of your cannon. Inside, the hot plasma is confined by magnetic fields in a strong vacuum; outside, you have no magnetic fields (aside from ones arising from the plasma itself) and plenty of sources of turbulence in the atmosphere. This presents a problem, because it seems like it would be very easy for bursts of plasma to diffuse and lose compactness. This problem might have been solved, though, back in the 1990s, with the start of [MARAUDER](https://en.wikipedia.org/wiki/MARAUDER), a US Air Force project. Its device worked similarly to the SSX lab's machine, with two key differences: * Plasma acceleration happened via a slightly different design (a conducting probe inside the plasma, it seems). * The device was explicitly meant to be adaptable as a weapon, rather than a pure research experiment. After MARAUDER was classified in 1993, however, information about its development became unavailable. It was successful up to that point, and I assume they solved the problem of keeping the plasma projectile together (perhaps simply by shooting it at such high speeds - 3000 to 10000 km/s!). Given that, I think your plasma cannon could work. Even if the plasma dissipates over some characteristic timescales $\tau\simeq1\text{ ms}$ (this is an enormous guess), in that millisecond, it will have traveled 3-10 km. That's not insignificant. - and if $\tau$ is even less than that, well, you've still got a range of probably several hundred meters. Plus, you don't need to have phenomenal accuracy, as the electromagnetic pulse from when the plasma hits something should do a good job of knocking out electronics in the enemy's vicinity. At any rate, it appears that the Air Force considered the problem solved, considering that development went on for quite some time even before classified development began. . . . Just please don't take ours. We still need it. [Answer] Short answer: no, your design would not work. TL;DR: don't bother trying to make plasma weapons, especially not for use in an atmosphere. Longer answer: you can reasonably consider your plasma to be a dense cloud of very hot gas. Your gun doesn't use electromagnetism to propel the plasma, and most people don't hang around in places with particularly intense electrical or magnetic fields, so this is a reasonable simplification. What happens to a hot, dense gas in air? Well, it will expand rapidly and rise. The hotter and denser it is, the more rapidly and violently it will expand. This probably reminds you of an explosion. It should! What you're suggesting is effectively an explosion in a can that you're holding. The fact that your explosion is made of plasma doesn't mean it will be particularly special in terms of the fireball magically staying the same size and being projected forwards, it'll just go bang. If you use some other means to propel your plasma out of the gun, it'll travel a short distance but it'll expand and cool so quickly it just won't have any useful range. An analogy I've seen elsewhere is to compare a prospective plasma gun to a gun that fires steam. Sure, steam can be super hot and super high pressure, but even with the best engineering in the world, that jet isn't going to go very far in air. Have a look at this, for example. Looks awesome, but its only practical use as a weapon is that the hot gas can be used to propel a projectile. Your plasma gun might look this awesome (and possibly a nicer blue colour) but won't be any more devastating. [![Transparent potato cannon slomo](https://i.stack.imgur.com/dCSCo.png)](https://i.stack.imgur.com/dCSCo.png) <http://www.youtube.com/watch?v=_TNSUIsjdpY&t=114> If you want your plasma to go any distance, you'll probably have to look into forming plasmoids (which is basically what the device that HDE showed does). These aren't just blobs of hot ionised gas, but more interestingly structured things that can hold their shape to a certain extent thanks to their electrical and magnetic fields. Not for long mind you... they'll still expand very quickly, but at least you can shoot them out of a gun at a decent speed, so there's a small chance you can hit something before the plasmoid has expanded into nothingness. The US made an experimental device of this sort, but it was massive, surprisingly non-powerful and was intended to be used in space (away from all that pesky atmosphere). You can find more information here: [MARAUDER](https://en.wikipedia.org/wiki/MARAUDER). Plasma in a vacuum will expand at hundreds of kilometres per second, so it had to project the plasmoid at a good 1% of the speed of light to get any sort of useful range out of it, and that's without any air resistance holding the plasma back. Here's the capacitor bank that powered the it. You'll be wanting to work on miniaturising that, I suspect. [![Shiva Star capacitor bank](https://i.stack.imgur.com/PaS3c.jpg)](https://i.stack.imgur.com/PaS3c.jpg) [Answer] I see some problems in your concept: 1. fans do not build pressure. They just produce a flow of air. If you want to pressurize air, you need pumps. 2. The higher the pressure, the more difficult it is to produce a plasma: the gas molecule will travel a shorter distance before losing energy in an impact, therefore you will need higher energy input. 3. plasma won't move on its own. I have worked for quite some time with sputtering systems, the plasma cloud was not going anywhere in the sputtering chamber. If you want to move the plasma you need something which acts in the same way on the positive and on the negative charges. [Answer] It sounds like you have invented a plasma vortex cannon. [![vortex flame cannon](https://i.stack.imgur.com/rRNpS.jpg)](https://i.stack.imgur.com/rRNpS.jpg) The image is from the Backyard Scientist on Youtube. Here is a news clip about a plasma vortex cannon that hopes to be profitable. > > “Firefighters won’t go into a building unless they can see their way,” > Faulkner said. “So if they could fire a vortex ring of ionized air > into a space—down a hallway or up some stairs—and clear smoke rapidly, > it would really help...” > > > The gun forms vortex rings by forcing air or some other gas at high > velocity down the gun’s cylinder. The ring forms when the friction of > the cylinder wall causes a thin layer of the gas to roll forward on > itself like a donut. Imagine a tornado formed into a donut shape. The > ring revolves on itself while traveling out the cylinder and it can > maintain that stability for long distances. Depending on the size of > the gun, Battelle data confirms that a ring vortex can exit a > generator at 90 miles per hour and maintain a speed of at least 60 mph > for more than 50 yards. > > > <https://www.battelle.org/newsroom/press-releases/press-releases-detail/battelle-develops-vortex-ring-gun-for-firefighters-pesticide-delivery> So: 1: Low pressure gases -check 2: Fired under low pressure - check 3: Ionized gas / plasma - sure. Flame is a goo stand-in for plasma. The difference is that the vortex will confine your plasma into a shape that can traverse some distance and not expend itself in a hot cloud. If your tech can spin the vortex faster somehow it will probably stay together over a greater distance. [Answer] The guys above have already said it, so FRAME CHALLENGE! I had this idea in the back of my head for a while but was too busy trying to make dragons overpowered to actually say it. Patrick Star has already said that plasma is hot, ionized gas, which would rapidly expand in the atmosphere, i.e: an explosion. It's quite devastating, and could potentially damage electronic devices. So, the stuff isn't completely harmless. A device, that ionizes the gas in the server-side, is doomed to fail as the plasma would break up thanks to instabilities, a mother-booping facility-sized reactor can't completely nullify, and explode into your face like a wet fart. So, what if you create the explosion in the face of your target? Why not? A canister of hydrogen and som3 graphene supercapacitors, discharging their energy into it through an electro-laser, might let you strike goons down with the Hand of God. [Answer] Regular air is not a good feedstock to use for plasmas because Oxygen is electronegative. This means it has an affinity for free electrons. Oxygen squelches plasmas by capturing the free electrons that come near its orbital shell. I made my atmospheric plasma sources using Argon or Helium. For plasma generation, the higher the electric frequency the lower the breakdown voltage. At DC KVolts are needed, at 13.26 MHZ only 10s-100s of volts are required. Once the gas breaks down and forms a plasma, the electron temperature is ~1 eV at this point ( or 11000 K or Surface of the sun) but the ion temperatures are typically low -- near room temperature. The electron temperature isn't important for a weapon since it carries so little mass that it isn't an effective mechanism for energy transfer. As more watts are poured into the plasma the ion temperatures rise. And, ions contain the mass of an atom. This is where part of the destructive power of plasma is stored, the other being in the amperage of the free electrons circulating through the plasma. Now that you have a 'blob' of plasma, you need to accelerate it using something like a rail gun. Once the plasma hits the air, the leading ions will superheat the air causing its the pressure to drop, this allows the plasma to expand its energy punching through an atmosphere. From there, I agree with @HDE226868 descriptions of plasma behavior. [Answer] With some major adjustments, maybe. First, there is simply no way that a fan is going to ever give you the gas density you need. As someone else mentioned, you're going to need at least some sort of pump. Second, the stability of the traveling plasma is a big problem if you want something that will do more than just annoy your enemy. You can add stability by magnetizing the plasma. I would suggest that you do a google search on "plasmoids". EDIT: One more thing: If you could get a plasma with the density often obtained in real, present day containment devices, you might have something that would completely fry the electronics of some device of your enemy, which could be a useful thing. But if you want to, for instance, blast a hole in a wall, you would need much higher densities than are currently possible. [Answer] Basically you want ball lightning. It's poorly understood phenomena, and we don't know how to weaponize it. But it's rather unlikely the apparatus to create it would feature enclosed chamber and barrel. Antennae and coils would be much more prominent. ]
[Question] [ Closed. This question needs [details or clarity](/help/closed-questions). It is not currently accepting answers. --- Want to improve this question? Add details and clarify the problem by [editing this post](/posts/249203/edit). Closed 4 months ago. [Improve this question](/posts/249203/edit) Basically, giant crabs ridden by humans as cavalry, I just don't know if it's a good idea, and I could use some answers on how to make it work. The setting is medieval fantasy. The Giant Crabs won't really have a diverse diet, so ration problems, but then again they are giant crabs, with shells and claws, so I think this might be a good idea. Crabalry is a good name. [Answer] # Not realistically, but they would have other uses Before I proceed any further, remember the [Rule of Cool:](https://tvtropes.org/pmwiki/pmwiki.php/Main/RuleOfCool) > > The limit of the Willing Suspension of Disbelief for a given element is directly proportional to its awesomeness. Stated another way, all but the most pedantic of viewers will forgive liberties with reality as long as the result is wicked sweet or awesome. > > > So if you want a crabalry, have a crabalry. But if you want realism: * The square cube law ensures that no crab like those from our world would ever be big enough for a human to ride. Your crabs would have to be some other kind of creature that evolved differently, and carcinized (yes, this is a word and a thing) at some point. * Crabs need water. Even those who live on land need to be moist all the time. Horses can deal with dry conditions much better. This does not make a crabalry impossible, but makes it very limited to some areas. * Being cold-blooded, your crabs won't be of much use in snowy conditions. Sure, crabs can move around in arctic waters, but have you seen how slow they are? * Crabs need to molt every now and then. They will be useless while molting. * Crabs have a very... primitive nervous system. You might think that a big crab will have a big brain, but the truth is that [there are crabs larger than dogs](https://en.wikipedia.org/wiki/Japanese_spider_crab) (almost 4 meters/yards from foot to foot when stretched), yet they still have small brains. That's because a bigger brain wouldn't be helpful where they evolved. Your crabs might be smart though, since their evolution is up to you. But again: Rule of Cool. If you think it's cool, then lots of other people might think so too. Go for it. It would be cool to ride a beast that can run sideways and tear limbs from your foes with its pincers. Crab cavalry aside, giant crabs would be great mounts for uneven terrain due do the amount, shape and layout of their legs. They would also be like elephants in that besides serving as mounts, they can pick up heavy stuff from the ground on their own and place it somewhere else. So rather than direct combat use, they might be great for construction and as beasts of burden. This still has a place in the military, as well as being useful in a civillian way. [Answer] I’ll treat the Crabs like any medieval fantasy creature. There’s no point in watching something like LotR and then saying “wraiths don’t exist” or “those Trolls would collapse under their own weight”. These are big horse-sized or bigger crabs, people can ride them, they are domesticated enough to function as war animals. If you ask if Crabs could be Cavalry you run into the same problem as when people ask questions about mechs versus tanks. Of course it can’t compete or do the same things because they are different. So instead of asking if Crabs can be Cavalry, ask what function a Crab could have within an army! There are likely ways Crabalry can be its own thing! Crabs won’t have the speed of horse Cavalry, and that’s OK. Because unlike horses your Crabs would be far better protected against spear and pike formations. Whenever the horse Cavalry has to stop or risk running into a prepared formation, your Crabalry can move up. You wave a spear at them? They can bat them away, attempt to grab them relatively safely and have natural armor against it. Which any military mind would add some more armor on, reinforced leather most likely as club-like weapons would be the best against crabs. Crabalry would fill its own niche. It would likely function as heavy infantry that is highly resistant to Cavalry charges. It would also accelerate the evolution of Pike formations as the hammer/axe part would be one of the best tools against Crab shells that large. [Answer] # TOO SMALL Giant land crabs already exist. (Un)fortunately they are still too small. The largest crab is the coconut crab: [![enter image description here](https://i.stack.imgur.com/6I9EV.png)](https://i.stack.imgur.com/6I9EV.png) This is not only the largest crab. In fact this is the largest terrestrial arthropod. These things weigh about 5kg and are about a metre long. For comparison: [![enter image description here](https://i.stack.imgur.com/nOCJo.png)](https://i.stack.imgur.com/nOCJo.png) It seems the [largest known extinct land arthropod](https://en.wikipedia.org/wiki/Arthropleura) is a 2 metre long millipede that is estimated to weigh about 50kg. That's the weight of a St Bernard dog. Still too small to ride. At least if you're a human: [![enter image description here](https://i.stack.imgur.com/azQwI.png)](https://i.stack.imgur.com/azQwI.png) The crab is too small for Ripley to ride without smooshing it with her rock-hard butt. The crab is even too small for the little girl she rescues in that film. Since [everything eventually turns into a crab](https://en.wikipedia.org/wiki/Carcinisation) the assumption is that if a bigger crab was possible we would have seen one by now. So a crab big enough to ride is hard to believe. To solve this problem I suggest your giant crabs be normal crabs who had Enlarge Crab cast on them. This is the household name for modification II.a4 of Enlarge Monster designed specially to work on crabs. This spell is known to ignore such trivial considerations as whether the target would be too heavy to move after being scaled up. A wizard did it. [![enter image description here](https://i.stack.imgur.com/VwnGK.gif)](https://i.stack.imgur.com/VwnGK.gif) [Answer] ## Cry Havok! and let slip the crabs of war!!! [![enter image description here](https://i.stack.imgur.com/T2jXB.jpg)](https://i.stack.imgur.com/T2jXB.jpg) The question should not so much be "COULD" you ride a crab as "is this the best use of giant crabs on the battlefield?" There is one historical unit that giant crabs would replace much better than cavalry: war dogs. The point of a warhorse is to deliver a deadly warrior as fast as you can to (and from) the enemy lines. But giant crabs will be much slower than horses, and would be so well equipped with natural weapons and armor, that putting a knight on top of one would be a waste of a knight. War dogs were different. They were used to attack the enemy formation on their own using thier natural weapons. This created panic and disorder in the enemy ranks in preparation for an infantry or cavalry charge. War crabs would fill this role even better because crabs have a resemblance to spiders causing humans to have a natural fear of them. They also have thick armor and powerful claws that put dog fur and teeth to shame. So put those crabs on the front line and save your horsemen for what cavalry does best: Skirmishing, out-flanking, and chasing routs. [Answer] It would be a terrifying and effective mount if it was trainable. Which normal crabs aren't. The biggest drawback is how much room it would take. you couldn't have close formations, the legs would tangle and it just takes so much more room than a horse. And formations can be critical in medieval battles. I'd use them like tanks, stick a box on their backs with some archers or artillery and you have mobile, terrifying and self-defending troops which may well be invulnerable to heavy calvalry charges. [Answer] Yes and No. So - On the Yes side - a Giant Crab (able to be ridden by a Human and let's put aside the exoskeleton weight limit thing for a moment) is going to be big (duh!), is going to be armored and has 2 offensive weapons. This would mean that in the role of say Heavy Cavalry, they would fair pretty well - able to smash apart an enemy line, the terror factor of a giant pincer and being able to hoist a man up and cut them in half is not to be underestimated in terms of psychological impact. However... On the No side - What made Cavalry such an effective tool is speed a Galloping horse is faster than a Human. Even a nice steady canter is much faster than a mans Jog - and this is where Cavalry came into it's own - the ability to outflank and outmaneuver infantry. This also includes your scout cavalry - being able to go a great distance at speed and report what you saw and come back. Then you've also got the harassments of your enemies supply lines - There's some great examples of this in the Sharpe TV series that shows how that works - suddenly a light cavalry division comes around the corner, engages a slow moving supply train slash, Slash SLASH! then disengages before they can rally to a defense and return fire. In this area, even a Giant Crab, assuming the same speed of the fastest crab is only capable of 3-4 m/s, compares to a horses' 14 m/s. So this form of Cavalry a Crab wouldn't be effective. [Answer] [Crabs walk sideways](https://www.youtube.com/watch?v=qdRMHN2phkA). This will make it extremely inconvenient to attack enemy units directly in front of your formation. Either the crabs will need to turn to one side in order to approach the line of contact, causing each crab and rider to turn their backs to half the enemy, or the crabs will need to sidle across the battle line, greatly reducing their effectiveness as shock troops. On the other hand, no formation could be more exquisitely suited to a flanking attack then a company of lancers mounted on battle crabs. Lobsters, now... [Answer] I don't know what the naysayers are on about. This is awesome. Crabalry is a great idea. Terrifying. Pincers. They eat you while you're alive. Armored. Fast. Fearless. Hungry. Realism? If I wanted realism I'd work some unpaid overtime. How to "make" it work? Don't bother, just say it does. Or better yet, just show it working: "Sir Bob steered mighty Gorgonoplex to the left into the King's retainers. While Bob struck down a bodyguard, Gorgonoplex grabbed the Duke of Edinburgh in his mighty crushing claw. Tough break, that ain't gonna buff out!" Light Warcrabs (say, one metric ton, or about 2200 lbs) are saddled for an armored man wielding a flail. Medium Warcrabs can easily carry two men. One of them could be an archer. Heavy Warcrabs could weigh in at 5 metric tons and sport a tower of wood on their backs large enough to provide cover for 4 men. [Answer] ## Crabs Would Be Maneuverable I can’t really say much about the speed of the crabs, it would probably depend on lots of different factors, but they would definitely have one major advantage: the ability to sidestep and basically move in any direction. This added maneuverability could prove very helpful for evading projectiles, especially if this breed of war crab has fast reflexes. Also, the hide could be much tougher than that of a horse, possibly making them better equipped against anti-cavalry weapons such as lances. So in summary, yes, I think crab cavalry or “crabalry” would work. ]
[Question] [ Suppose King Midas learns to turn off his power to turn things into gold, and passes on that ability to his children. A few centuries later, King Midas has thousands of descendants, all of whom can turn things into gold by touching them, and all of whom can turn this power off when they want to. Specifically, when a descendant of Midas uses their power, the object they touch gains mass to become solid gold. (Air particles only turn into a thin, flaky golden film on the hand when the power is used, and they can't convert more than a few cubic meters in one shot. There is no danger of turning the entire earth to gold or similar disasters.) What happens to gold economically? Do people start building houses out of the stuff? how does this affect technological and economic development? What uses are there for gold when it becomes incredibly cheap? [Answer] Gold would then be completely unsuitable for use as the basis of any currency. It would just be another material with certain physical properties. Assuming the world society survived the screaming madness that occur in the years following the discovery that all their money is, well, not money... The good: * Gold is a very inert metal. It does not rust, it does not tarnish, it does not corrode even in the presence of some really nasty chemicals. You must concoct some really mean acids to even get it to admit that acids exist. This also means it simply does not form organic compounds, and is thus not at all a heavy-metal toxic danger, in any natural form. * Gold has very good electrical conductivity. Almost as good as copper. * Gold has a quite distinctive appearance. A very loud appearance, it positively screams "Gold is Here!" * Gold is ridiculously dense, almost twice as dense as lead. Being cheaper than lead, and immensely less toxic, it would be handy for counterweights, keels, barbells, etc. The bad: * Gold is ridiculously soft, and completely unsuitable for use as a construction metal without alloying it with something to beef it up. * Gold is ridiculously dense. Yes, this belongs in this column too! * Gold has a quite distinctive appearance. A very loud appearance, it positively screams "Gold is Here!". Yes, this to belongs in the 'bad' column too. So, everyone (or at least a great many people) can create gold at whim. None can UN-create the stuff. This positively designates it as a waste material. No matter what happens, eventually we will have too much of the stuff. It will be all over the place! And it has such a distinctive appearance! I can just see how property prices can be devalued by having too much gold contamination in the area. "Nice house, good access to schools, but the neighborhood is 7% gold. No thank you, we'll look elsewhere" It can be *dangerous! What if some insane Midas-person converts just the root of an airplane wing to gold? Or converts the steel support beam of a building, or bridge? Or how about just converting 1 cubic meter of that there nuclear reactor pressure vessel to gold? And are those realistic statues, or did the maniac really* convert a whole kindergarten full of kids into golden garden gnomes? I expect that the "Midas Wars" will be a brief and bitter fight to the death, leaving large tracts of the landscape littered with golden debris, before the Midas Curse becomes just another footnote in history. A cautionary tale of powers that mankind Should Not Have. Or possibly: Maybe the last few remaining Midas-persons will become valuable commodities, to be used under guard and operating under the strictest of supervision in a (already golden) prison-like environment. After all, it would be *handy* to have someone on hand that can instantly convert toxic waste, even radioactive waste, into harmless gold at a touch. And if the toxins and radioactivity harms them, so what. They are not real humans, they are just Midas-people. The same demons that tried (and very nearly succeeded) to destroy the world economy with their depraved ways. Billions starved before they were stopped, and they deserve whatever happens to them now. [Answer] For a start it stops being valuable. If we fast forward past the initial few generations (such that thanks to his descendants gold is now ubiquitous) & the economic upheaval of crashing the worlds gold economy & destroying its value as a medium of exchange you will simply find yourself with a world where it's used for everything lead was, non toxic gold water pipes, roofing material etc, You've set this in a pre-tech society & a few hundred years doesn't change that in the real world. So there are no new technology applications here it merely replaces lead. Which is good, a lot less lead poisoning all around because your using it in place of lead water pipes. But that's really about the only major difference I can see it making. That & silver is now the king of coins. [Answer] ## It could be like OPEC? If this actually happened, * the people with the "golden touch" would not be idiots... * obviously if you make too much, as everyone has mentioned the price of gold would simply plummet. But. Assume for a moment that every single person with the gold touch, keeps together in a tight, tightly controlled clique with NO splitters. As you can see - they are now SET. They would have an amazing amount of power and wealth. ## A rich vein (sorry! :) ) for plots... BUT. As you can also see, you immediately have a prisoner's dilemma game theory situation. What happens if one gets greedy and (somehow) escapes and makes gold freely for her own use? What happens if two competing sects - but, they have to diplomatically balance not producing too much. Surely, the gold-making sect (or sects) would build up massive military power to protect themselves. Surely, the gold-making sect (or sects) would build up tremendous "cultural traps" to keep members in line - just as with power-wielding sects in today's world - but more so! You're on a plot winner there! ## A great read ... Everyone should read [https://www.amazon.com/Evolution-Cooperation-Revised-Robert-Axelrod/dp/0465005640](https://rads.stackoverflow.com/amzn/click/com/0465005640) [Answer] I think you are grossly underestimating the amount of gold on Earth. According to this [source](https://www.bbc.com/news/magazine-21969100) > > Warren Buffett, one of the world's richest investors, says the total amount of gold in the world - the gold above ground, that is - could fit into a cube with sides of just 20m (67ft) > > > But not everyone agrees with the GFMS figures. > > > Estimates range from 155,244 tonnes, marginally less than the GFMS figure, to about 16 times that amount - 2.5 million tonnes. > > > That bigger figure would make a cube of sides 50m (166ft) long > > > According to those estimates we have something in the range of 8000 to 125000 cubic meters of gold. The fact that Midas and his descendants can stop the power at will makes no big difference. If "goldy training" a baby takes the same amount of times (and failures) it takes for potty training, I guess that any baby would accidentally produce a few hundreds of cubic meter of gold just in their young age. Plus all the amount willingly produced, it's easy to see that the use of gold as value storage would simply vanish. For a reference, look at aluminum: in the beginning it was so rare that rivaled with gold in term of preciousness, and statues were made out of it as a display of wealth (the one in Piccadilly Circus, for example), while nowadays we wrap food in it and throw it away. Probably it would happen the same with gold, with the added twist that gold can be eaten, so nobody would have to worry about unwrapping their bun. [Answer] Gold would lose it's value completely. Or not. If this family keeps its act together, they will hoard all of the gold they produce, releasing it slowly to control the supply to match the demand. The [De Beers group](https://en.wikipedia.org/wiki/De_Beers) has done this admirably with diamonds. These gems are really very plentiful. More than enough to go around. They are minded in huge operations. However, the De Beers empire has monopolized the entire process, and very carefully control how many gem-grade diamonds are released into circulation. > > From its inception in 1888 until the start of the 21st century, De > Beers controlled 80% to 85% of rough diamond distribution and was > considered a monopoly.[4] Competition has since dismantled the > complete monopoly, though the De Beers Group still sells approximately > 29.5% of the world's rough diamond production by value through its global sightholder and auction sales businesses, an effective > monopoly, as this still allows it to control prices, inflating them > dramatically. > > > I suspect the Midas monopoly would do much of the same, very carefully controlling the price of their source of wealth and power. Fort Knox, of course, would look like a miniscule operation compared to their storage vaults, however. [Answer] ## They are quite valuable. 9000 descendants making 3 cubic meters of gold every 5 seconds for a 10-hour shift gets you: $9000 uw \times \frac{3 \frac{m^2}{uw}}{5 s} \times \frac{60 s}{1 min} \times \frac{60 min}{1 hr} \times \frac{10 hr}{day}$ ...which is 194.4 million cubic meters per day, or, in gas mining terms, 6,865 [MMSCFD](https://en.wikipedia.org/wiki/Million_standard_cubic_feet_per_day). So this is somewhere around [Indonesia's current gas production](https://www.thejakartapost.com/news/2020/03/09/indonesia-aims-to-double-gas-production-by-2030-with-major-projects-in-pipeline.html) by volume, caveats being that it's a bit harder to move, you can't use it by burning it, and you can't release it to the stratosphere if you want to get rid of it. But it doesn't go boom or cause global warming. Gold is $19.30 \frac{g}{cm^3}$ or $19,300 \frac{kg}{m^3}$, so this is 3.75 trillion kilograms per day or 3.75 billion (metric) tonnes of metal output. That is actually [around double the global steel output for a year](https://en.wikipedia.org/wiki/List_of_countries_by_steel_production). True, the increased weight doesn't help very often (forklift counterweights, elevators, ballast) and more often the benefit will be half or less. Gold is, as some say, flimsier than steel. But it is still METAL. What would you do with it? Well, if gold can make thrones and crowns, it can make office furniture and computer casings. It replaces copper wire wherever copper wire is still used, and copper pipes, even PVC. Steel fences are replaced by weaker but heavier posts of gold. Shipbuilders deplore the flimsy metal but promote its corrosion resistance. Perhaps they keep a steel framework inside it. Wherever crummy screwdrivers and unreliable bolts are sold, the "white metal" made from zinc gives way to a gold and nickel blend. (At least it doesn't just snap - you can beat it back into shape) Rolled out into leaf, gold takes over for aluminum and even some plastics for food packaging. Cast into bricks, it makes for an attractive, durable paving stone wherever a brick road will do, though I think brick works out to be too cheap per cubic meter to take on directly. Steel was trading at \$711/tonne in a random web hit. Suppose gold is only worth a tenth of that, seven pennies per kilogram, taking on PVC and plastics and even upscale paving bricks. So that's $\frac{711}{10} \times 3752$ million tonnes daily, or \$266 billion a day. Talk about the wealth of Croesus! The present total gold value is reputedly \$9 trillion (random web site), so you can surpass that in a month or so. It is a pity that the Midas mutants are too dangerous to leave running around loose ... but they contribute mightily to the gross national product right where they are. [Answer] The accepted answer is provably false because the situation described in the question is exactly analogous to the current situation involving the role of central banks and quantitative easing. In short, economies around the world became dependent on private credit, which was directly synthesised by banks. When the system breaks down, the government steps in to replace the flow of new private credit with central bank and government money, through various mechanisms. They synthesise new money and drop into the economy through various channels, so the private sector can continue to borrow and pay off old debt. Once this state of affairs arises it is practically inescapable. Japan has been stuck in this pattern since their crash in the 90s and the West lives in a state managed economy since the financial crisis of 2007. In the Midas situation the same set of circumstances might have already arisen. And the growing abundance of gold would have simply allowed commercial banks to issue more paper money. It is not necessarily the case that would have caused inflation, it depends on economic circumstances. If we assume a free market economy where banks issue synthetic debt money, and where gold backing played no role in international settlement of trade imbalances, the inevitable economic outcome would be the same as in our world today. Gold synthesis is analogous to the eternal money synthesis central banks and governments are now compelled to fulfill. The difference is that digital money created in QE is generated in such vast quantities that gold production by a few thousand individuals would be insufficient. The relative value of gold as central bank money even when being created like that would be quite high. [Answer] The economy will crash. The situation is different from aluminium as back when aluminium was extremely expensive, it was not used for financial storage, i.e. it wasn't a part of our currency or financial property, whereas gold is a major contributor. But if they keep their production under control, the MIDAS Group could become THE richest and most powerful dynasty on Earth. Technological uses are aplenty. You could use gold in alloys, circuitry, contact electronics, conducting materials, special glasses etc. A major application would be gold leaf usage. Thin gold leaf production and gold plating could flourish providing huge scientific and economic applications. You could probably have a great time converting waste from dumpyards and processing plants and ... anywhere, really, into gold. Also, radioactive waste, and biohazardous material could be converted to gold too. A thing to ponder is if you could introduce a genetic condition, through which you did not convert an object to gold, but produced an equivalent weight in gold. For example you could convert 19.3 Kg of plastic to a cubic meter of gold, which would be really easy to transport. ]
[Question] [ In a sci-fi setting, suppose there is a species that has a very strong cybernetic enhancement, to the point where they can actually form a kind of pseudo-hive-mind, while still retaining their individuality and being able to disconnect from such a system at will. (Or form smaller, isolated clusters.) This way, they can access an enormous amount of brainpower and ideas, and they can quickly reach a joint consensus (or at the very least agree that they disagree very quickly), and they can rely on each other's wisdom at any time. Now, this would imply that members of this species are nearly-omniscient. How do you avoid this from becoming something that they can apply to every situation and completely overpower every challenge or other species that they face? [Answer] Being in a hive mind is not easy. There's a lot of brainpower that goes towards it. You have to structure your mind to leverage it. As a result, it is very easy to lose localized awareness, so it is more likely you will miss something you are seeing with your own two eyeballs. This effect could be crippling, especially if the technology is new enough that their society isn't helping them filter all that hivemind data. Take, for instance, our own hive mind. If you really look at it, the internet is really a hive mind. I mean, here I am sitting at my desk, helping StackExchange join a consensus about hive minds. (Turtles all the way down, I tell you). Now there is a definite difference in magnitude here. My ability to use my eyes and fingers to interact with you would be dwarfed by the bandwidth of a cybernetic enhancement, but the principles are similar enough that we can put forth some good theories on how the hive mind could work based on how the internet has affected us. One of the defining aspects of the internet's affect on us is just how much more data we have to process. Filtering becomes a major challenge. It used to be that your understanding of national affairs came to you filtered by your newspaper editors. It was short, conciseness, and fit on a few square meters of paper every day. Now we are inundated with information. The same event on a national scene now appears in 5 different newspapers, 4 trending articles, a facebook feed, and your twitter account blows up. And therin lies the rub. If you have more information coming in, you naturally have to process the data less. More importantly, that information is now very delocalized. Before the internet, most of the information you got was put in a frame of reference based on who or what is around you. We noticed things more. We simply weren't too busy trying to make sense of events on an extraordinary scale. Take police violence, and I'll do my very best to just stick to the facts and avoid opinions. According to [one website](http://mappingpoliceviolence.org/2015/), police killed 1,152 people. That includes both justified and unjustified homicides (aka murders). When numbers like that come across your desk, your brain has to process what to do with it. 1,152 is close to the mythical 1,500 people which is [supposedly](http://www.newyorker.com/science/maria-konnikova/social-media-affect-math-dunbar-number-friendships) the number of faces you can recognize and associate to a name. That's a lot of bodies! However, that number is on a large scale. The population of the US in 2015 was 321,442,019, per the [census bureau](http://www.census.gov/popclock/). That means 0.000358% of people died at the hands of police that year. That's a tiny fraction! What are we to do? One number is massive, one number is tiny. Which one do we want to pay attention to? Say we got one number from twitter and one from Facebook. They're actually the same fact, just phrased differently. Well, maybe we can phrase it in terms of "small towns." We're used to the idea that in a small town, everybody knows everybody, so our gut instincts regarding how bad things are in those small towns tends to be reasonable. Let's say a town of 10000 (the largest it can be by Alabama state law before it is renamed to be a "city"). Scaling these numbers for a town of 2000 people gives us 0.0358 deaths/year from police violence or one death every 28 years. So I just spent three paragraphs playing with just a single number. One result made it huge, one result made it small, and the other made it some murky number in the middle that would make you pay attention to who you elect as Sheriff of your town. I guarantee you that no matter how you work with those numbers, I can go cobble together a different form of the same number to throw your thinking back into dissonance. There's a reason that particular topic is an issue of national debate in the US at this very moment. Now, let's take a new scenario. I'm 15 feet away from you, and I'm tossing what appears to be a small heavy ball up and down. I then throw it at you. How long does it take you to forget this discussion of Sheriffs and national death rates and respond? How did you respond? Did you dodge? Did you try to catch it? Did you flinch? I said the ball appears to be heavy... what did that look like? It's impossible to tell the density of an object from its appearance. How'd you know how emphatically to respond to my actions? The answer is that you were subconsciously observing all of my body language while I was tossing the ball to myself. You might not have even been paying attention to me, but your subconscious was taking inventory of everything in the area. You would watch how I catch the ball, making estimates about how a human body bends and flexes under different loads. All of this was subconscious until I threw the ball and something woke you up and said "that incoming fast thing is heavy." You might not have even respond properly. We used to be better at such localized estimations. When we weren't busy preparing to deal with the cognitive dissonance of all of these national and global scale numbers, our brain was more geared towards dealing with local issues facing them day to day. It's simply a matter of training. We spend more time paying attention to the national scale numbers, so we develop that side of our capabilities more. To see that taken even further, consider the abilities of a tracker, especially a native one to the country. They can see things in the brush that we aren't even aware are there and use them to find what they are tracking. We've simply practiced that skill less and practiced the national level information filtering more. So as a result, I would expect these cyborgs to have much less of a situation awareness, because they have spent more of their time developing the ability to understand the larger scene. They would make up for this with things like sensor fusion. If two cyborgs can look at the same scene from different angles, they can fuse the data, and hide the fact that they weren't processing everything they could have. Which leads to an interesting twist to your original problem. Even if they can technically detach from the hivemind at any time they want, they may not want to. It may be humbling to see just how little you are capable of without access to the hive. They may even start developing excuses as to why they want to stay connected to hide the reality that they feel useless and helpless. In [Time's Eye](https://en.wikipedia.org/wiki/Time%27s_Eye_(novel)) by Clarke and Baxter, there was a group of people who were transported in time, and this problem reminded me of their plight. In that era, they carried around a small computer (smart phone?) which was always connected to a global grid. That small computer had an artificial intelligence that helped the humans work with this information overload. At one point after they were transported, now cut off from the grid, a human commented how frustrating it was, how helpless they felt without access to all the information from the grid. The AI's response: "How do you think I feel?" [Answer] You have quite a few options open to you. I'd take a mix of them. I'll assume that the species is human all but the cybernetic enhancement as a base point, and I'll also assume the brain is control of the cybernetics and not the other way around. ## Compatibility Ever wanted to get an app, but found out that it was for the other guy (Android or iOS), and you couldn't download it because it wasn't compatible with your phone's operating system? Now imagine if you have millions of brains, each with variations of the same patterns, being affected since birth. The way one person thinks, considers, or remembers something (even as overtly as if they use mnemonics or not) won't be the same as virtually everyone else; it'll always be different. So there's going to be overhead for every brain (or cybernetic implant) to try to sort out and adjust the input/output. ## Personal Bias Even if the information is adjusted so thoughts can be transmitted, on a more macro level people just process and think about the world differently. Political views, incorrect assumptions, personalities... the list goes on. ## Signal Noise and Resource Competition Sure, you might tap into the resources of my brain, but I'm currently trying to read a book, or impress this girl, or I'm dreaming of canine FBI agents interrogating me in my underwear in my childhood home. Unless the other people you're tapping into are brain dead, they're going to be using their own brains as well. This is both going to alter the path neurons take for your processing, but also bottleneck your performance when you tap into my brain. ## Insanity Well I don't suffer from insanity, I enjoy every minute of it! ...But those networked to my brain might not enjoy it. Insanity isn't an off-on thing, and it's shades of gray. How tight do you want the screening process to be to not provide "bad brains" in the mix? Can a screening process be tight enough? What do you even define as a "bad brain?" You're going to have less-than-optimal processing and altered memories... ## Overhead with routing You can't get something for nothing. Simply seeking out a brain at all is going to take processing overhead, and then finding the brain with the specific memory, skill or thought process you want is going to be another issue. Does the implant just wildly search around, trying to connect to brains and then performing a search on the gray matter for approximate hits? Do you have to dedicate people to being brain meta-data sources, so people have to connect to them as some sort of Google or phone book? "Hello, I need to know information on how to properly run a mile in a forest if I'm out of shape and barefoot. Where might I find this information?" ## Processing Time So I was considering what to eat this morning. Took me about five minutes to do so; I weighed my options, looked at what I had, tried to recall what time I'd be having lunch today... and so on. Even if a million brains could communicate at the speed of thought... the speed of thought isn't that fast. If a million brains are all trying to agree on a single breakfast to eat, they all need to sort through what options they all have access to and what all of their plans for the day are, compare and share... ...And not one of the brains can hold all of that information at once, so it becomes a logistical problem on how to store that thought process and share it on such a macro level. Obviously they won't be needing to agree on a singular breakfast, but the same concept carriers over to other topics. How about a trade agreement? Military action? There's too much for one brain to store, and even if one brain still could hold it, thinking just takes time, and you can't get around that. [Answer] Impose some limits on this ability. * The radio waves used for communication between members of the hivemind deteriorate beyond the allowed margin after 1AU (Due to the complexity and speed of the transmitted information the wave has been modulated very tightly and only allows for a small margin of error). This makes it unusable in interplanetary contexts. * The method of transimission is vulnerable to simple jamming by their enemies and can therefore not be used well in hostile situations. * Other species can use a man-in-the-middle attack to inject false information into the hivemind, which makes it unreliable. * The hivemind method is inefficient if used with multiple critical situations at once. If the species is attacked on three fronts at the same time the "discussions" regarding optimal actions get mixed up with one another and suddenly you find that fleet A, which is trying to defend the home planet, starts retreating instead of fleet B, which was attacking an enemy outpost and fleet C launches a suicidal attack against the well-defended enemy's home planet instead of fleet A which was only being attacked by a small contingent. * The method of transmission is subject to the speed of light: in interplanetary situations it takes minutes for any reaction to be broadcast to the rest of the hivemind, in that time the discussion has already moved along. In interplanetary situations it takes years, decades or millennia for the transmission to get broadcast, which is obviously not very convenient. Or compensate with other factors * This species lives in a part of the galaxy with very little [useful resource] and therefore is very limitated in the scope of what it can build. (e.g. Something used to power their reactors, which means their fleet of warships is limited to <100 ships) [Answer] * I'm basing my ideas on the following definition taken from Wikipedia. This means a hive mind is essentially one being in multiple bodies, while individuals using a mental internet like structure to communicate and exchange knowledge is not a hive mind. > > A group mind, hive mind, group ego, mind coalescence, or gestalt intelligence in science fiction is a single, collective consciousness or intelligence occupying many bodies or entities > > > * I'm considering humans, not an unnamed species. Most other answers do that too, only without admitting it. * I'm assuming the implant makes for a really hive-like connection in the sense that it's all or nothing - you share everything you think, or you stay offline and there are no filtering walls to keep secrets or ways to fake a personality - there is no way to lie to the hive, although of course you may believe untrue things. This may be technologically justified by saying that it's much easier to connect minds and to create new ones or really understand what is going on. * I did an evolutionary approach because I find them comparatively easy. * I assume the thoughts travel at the speed of light and the beings are close enough so that the delay isn't much more than 1ms (i.e. little compared to reaction time of the individuals). At the end I think a little about longer delays which could be caused by huge distances or by slower transmission speeds. Say one generation of adults gets those implants for the first time. Happy couples may use it, some even full time, others maybe during sex, or for calling home. Very close friends might also use it to communicate. Other than that, people mostly won't use it because it exposes too much of their thoughts. Certainly no one would connect to a world wide net because any malicious person could do them great harm. Those people who heavily use it (like said couples) will probably within a few years at most be incapable of separating from the system - it would be like amputating a large part of their brain, they would feel incredibly alone and might just die from loneliness and mourning. After this at the latest there would start to be regulations about minimum ages, maximum connection times and such. A hive police would be created which consists of police officers hooked up to public hives, listening for malicious thoughts. This would be absolutely necessary to protect those daring to connect to public hives, but would certainly also be used to enforce all other laws - no one could hook up to a public hive who committed any crime. This would probably cause widespread protests about some laws which are routinely broken, so those would sooner or later be abolished. Justice systems may force people to connect to find out whether they committed crimes, or offer the possibility to convicted people so they can prove their innocence if there was a mistake. Tyrannies may try to force their people to connect to a hive used for indoctrination and surveillance, but this would be more difficult to pull off than it seems at first - people might ask the dictators to connect too, and they couldn't because this would destroy their propaganda lies. But if done correctly, they could indoctrinate people in the old fashioned way first and use extremist honest followers as the base for their hive, to influence their people, but it would be difficult to steer. On top of this they couldn't abduct or torture anyone because they would just open their mind to the world and everyone would see the truth. I think in the long run it would bring about peace and tolerance - say in a war the civilians being killed could use their implants to broadcast their pain. This would absolutely poison any global hive and anyone connected to it would become as anti-war as possible. But on a smaller scale this would help society too: Nobody would dare hit or rape someone because the victim could broadcast their distress (just for a split second if they are hive-skeptical, as long as during that time they make sure to think about where they are and what is happening). On an even smaller scale, a bullying victim in school would sooner or later prove to some teacher what is happening (without risk of being called a liar or exaggerating or even having to make an effort). The friendlier society (that is, people with hive implants) became, the more people would be inclined to use their implants. For example I absolutely can't imagine first or even second generation users doing hive-speed-dating to find their soul mate. But sooner or later I could imagine people using this as the primary way to find partners - just connect to each other for an hour or two and they'll have a good idea whether they are for each other or not. I think the acceptance would slowly rise, society changing. Some extremist (or maybe call them brave and open minded) subgroups would form hive-minds from the beginning. From maybe three to five people up, I could imagine that they then could survive if a member died or left. Those real non individual hive groups would slowly grow and become more powerful, because essentially they would never die, they would just accumulate more and more experience, slowly phasing out old bodies and integrating new ones. Their growth rate would probably be limited though: Too many minds would surely overload the brains of the members. But after a couple of years of full time connection, those minds would merge and form a single hive-mind, which then probably could accommodate new members. But for those new members to connect not to other people but to, say, a 200 year old hive mind who already integrated 15 persons, would probably be a frightening or at least very strange experience, which would limit the amount of people wanting to do it. I think the proportion of hive mind integrated people versus people who still have individuality would slowly change to more hive minds (because those are advantaged) until the individualists are a tolerated (and quite possibly dependent) minority. Not all hive minds would merge to only one, because they might have philosophical differences too strong to overcome (say a christian hive mind versus an agnostic atheist one, or a fundamentally conservative one versus one in love of change, whatever). This may seem like an explosive combination, but unless the hive minds are extremist and refuse to connect to their opponents for discussion, they would probably still understand each other enough to avoid hurting each other. Such extremist or crazy hive minds would surely come into existence, but would sooner or later be killed or dissolved (if the latter is even possible) or incarcerated (and banned from integrating new people). This state, of maybe hundreds or thousands of hive minds and a couple of millions of individualists (who use hives, but limit their time in it enough to stay individuals) in billions of bodies seems stable to me. The in-between one of a majority of hive mind implants plus individuality not. So if I wanted to write a story in the between state, I would put it in the middle of the development, before the large true hives form a significant group of the population, but a couple of generations after the implants were invented. But even in the state of fully developed hive-society, they wouldn't be omniscient. The speed of reaction of the individual bodies wouldn't improve. They couldn't understand their environment much faster because this is limited by the sensory organs. If you want to limit them, don't give them sensory implants and maybe add a fantasy touch to the hive implants to make it more plausible that hive implants are possible but sensory improvements not. If a hive mind set 100 bodies to a task, they would be much more efficient at it than a 100 bodies communicating ordinarily, but every optimization has its limits, they wouldn't be stronger or faster or anything, just coordinated. Make the speed of thought transmission considerably slower than light and you seriously limit the maximum size of a hive. This would mean that the hives couldn't do too much space travel without becoming less powerful. With information exchange speeds too low (say speed of sound) a hive mind couldn't even encompass the whole Earth. They would have the same problem as a dinosaur where it takes like half a second for a command from the brain to reach the tail (I made that number up, but I know they had the problem and some had kind of independent movement systems and extended "reflexes" because of it). To illustrate: If the delay is 1ms, and an individual who has been integrated into a large hive speaks, then it's the whole hive who decides what is being said, who hears the reply and then speaks again. When the individual runs, all of their sensations reach the hive and the hive can control the running, improving the technique of the individual, drawing upon the experience of say an ultra runner who was absorbed. If the delay is an hour, then the individual may know how the ultra runner feels when running, but will have a different length of legs, less muscles, etc., which makes it considerably harder to integrate the experience and make it their own. And the process of integrating it would need to be done without immediate help from the hive because the hive only learns about it an hour later. With a delay of an hour, when an individual hears something, they will need to assimilate it on their own and when they answer it wouldn't be the answer of the hive but their own, because the hive wouldn't know about it yet. I don't think hives would even form under those circumstances, people would keep their individuality. With fixed, relatively low transmission speeds that means there would be some center of the hive, where many individuals would stay as close to each other as possible (so the delay is short and they can form a hive) and someone who walks away from it would develop individuality over time as delay increased. The hive may obligate all its members to regularly join the center of it for a while to update their mind with the current views of the hive (and integrate their views in exchange). Sending a member far away say on a space mission would carry the risk of losing them because the thoughts they receive would largely ignore them (because they are old and don't reflect the thoughts of the individual), they would probably feel more like something external, some video feed, rather than their own thoughts. A space traveller (or a group of them, kind of a sub hive) could learn that the hive is wrong about something (maybe even fundamentally wrong) and if they are far away it could take years for the hive to receive that information and then years again before the space faring hive would receive acknowledgment about it. During that time, the thoughts of the hive would certainly feel wrong. [Answer] ## Rebels Some members of this civilization hates the hive-mind, and forms their own system where they can live on their own. Time passes, and being the minority, being the ones that can't "rule" starts to bother them, but they move on and live with that. Until one day, two or three of them decides to attack the majority with both physical and psychological meanings, aiming to destroy the ability of forming hive-mind forever. During the war, the rebels realise that they can *scramble the comminucation* between members of hive, and *force disconnect individuals* from network by willpower. But they couldn't shutdown the network completely, since they don't have enough willpower to force disconnect every single individual from hive-mind. --- ## Jammer Technology Another civilization developed a technology that can *force disconnect* a targeted individual from the hive-mind, or all individuals in an area-of-impact when applied as a bomb. However, the technology wasn't powerful enough to shutdown the network completely, since individuals could reconnect to network after a certain amount of time. [Answer] Your assessment that they are "nearly-omniscient" is false. Omniscience is a theological concept that cannot be obtained in reality. Since you say each member is the species still has individual thought and therefore still makes their own decisions. Access and use of this powerful brain collective is no different than humans using supercomputers. The smartest human scientists, with the most powerful supercomputers at their disposal, still cannot agree on just about anything. Take the internet, most people on Earth can access a wealth of ideas and knowledge, yet there is always two or more polarizing views on everything. Liberals and conservatives, creationists and evolutionists, etc, etc. [Answer] When the Internet was first being conceived, it was a dream by many of the people involved that it would help to bring humanity closer together. In many ways that is true, but it also has served to deepen the divide between people. Since these beings will still possess some individuality, this network would most likely become very cliquey. There would be separate factions or cells which would have vastly differing opinions. It would be nearly impossible to know what kind of space politics they would be interested in, but rest assured that there will be many differing opinions. These beings would become cemented in their ideas, and would be quite idealistic. Individuals which refuse to drink the "kool-aid" would be separated from the herd and be culled. Expect there to be intense competition between different groups, as well as internal struggles. Assuming that there would be human contact, there would be some groups in support of us, while there would also be enemies. There would also be groups which are completely impartial to humans. The size and power of these groups can vary dramatically, and the organization between them can be vastly different as well. These factions would most likely try to isolate their signals from outside groups, but on occasion, they could meet to work out treaties, etc. Since there would be competition between these beings, it would greatly diminish the ability for one group to completely take power. [Answer] Thier enemies could have weapons designed to Target then maybe some form of computer virus that separates them from the collective. Or to maintain their connection to that collectively have to be within a certain range of each other. This would limit their movements as if they were too far away they lose their connection The Collective. Or Certain information is "classified" and withheld to all but certain specialist in the collective. Think of it like websites but it can't be accessed about a certain password. In the same way a certain information be closed off for most of the collective, only accessible to a few. Or maybe so dependent on the information stored in the collective that they have a hard time dealing with things that aren't stored there. For example if so used to knowing everything that they can't imagine that one of the enemies has a secret weapon that none of the rest of their Collective has can encounter and therefore will not be stored in their data banks. Because of their lack of imagination they are overconfident and are caught off guard by the new weapon. [Answer] I would hasten to add that a major drawback would be a dramatic loss of perspective. The individual would be rendered differently in time and space and existing outwith the hive might lead to anxiety and panic, as well as a huge psychological change in appreciation for co-existing in the moment - he/she(n/a) will likely find the passage of a second a huge waste of time. [Answer] How do you avoid this from becoming something that they can apply to every situation and completely overpower every challenge or other species that they face? Give then challenge good enough. Yes, we are not totally hivemind, and it's not so easy to imagine challenge or situation, without thinking about details of a potencial situation. But for our future and our future generations it's better and more fruitful not to nerf hivemind, but investigate their strength and weakness. They could be our future, or they could be our enemies - in both cases, it's good to know weaknesses to avoid or to exploit. Hivemind isn't god. If you see them as a perfect creature, it just means that your perception of how they work is wrong. Some are excited about it as some sort of personal immortality - they are wrong too. It's the same kind of immortality as to say you will live in your children, yes to some extent that's true. Or it is the same as to say, humanity is immortal, yes, at some extent per aspera ad astra. Investigate, and create them through challenges. It's not enough just to say they will do that easy because they are hivemind, but how they do that, how exactly they will do that. We can't think the same way and at the same speed as computers do, but we investigate code, we test code, we create code through testing, debug it etc - it takes time, huge time compared to execution but still we can understand that code. Information exchange speed limitation - 1c, is a pretty reasonable limitation. Less not needed, faster there are other challenges in terms of understanding how they may work (more pure algorithms stuff). You will find inspiration here [Swarm intelligence](https://en.wikipedia.org/wiki/Swarm_intelligence) - most examples do exactly what hive mind have to do, processing information bigger than they can fit in their individual brains, with a low(limited) bandwidth of data channel, and low(limited) speed of data transfer and processing. Also, databases algorithms about optimizing data storage and reduction of time access to data can be inspiring too. P2P decisions making and data storage's, as an example well-known bitcoins - they are working model of such system. The diversity of tasks is limited, but the vector of such systems and their fusion in one system could be applied to decision making and task solving in a more complex environment. Processing thoughts is also a matter of optimization. I'm not sure that entire internet hive mind should know that one's lip is itching right now, ups sorry hivemind, it's gone, false alarm. (a lot of people imagine HM as a mean to know any feeling of any person and that those persons exchange those feeling constantly all to all) So there have to be some arrangements, in this answer I wished to use another word instead lip, but some of the internet rules stopped me from doing that, especially because of possible reaction, which is not what I need to explain that HM idea. Obviously members will not transmit some stuff, not because they can't or because of rules, but because it's not needed, not reasonable etc - a just common sense of things. ## N.B. Engaging civilization isn't an easy task, especially if they are space civilization. Are Borgs a treat for those [My star will explode as a supernova. What can I do in order to ensure that my planet survives that?](https://worldbuilding.stackexchange.com/a/47982/20315) - no, they don't, they will be fed to BH and energy extracted will be by mass, not by how hiveminded they are. That's why we are friend with borgs, they are nice guys, each new year they send presents in form of energy, very deepminded collocutors. So yes, we have a nice time together, even when we are not hivemind like them. But yes, they are not perfect, they drink too much and forget sometimes that we are friends, so meeting them outside our home system isn't such a brilliant idea. Hmm, but maybe it's a game we have to understand ... In some situations it is not important how smart you are, lack of information, false information as examples. Hive mind might be better at filtering that bs information, IF it is interested enough in that particular time and place to do so, IF it has enough perception members here, which might or might not to represent information correctly and detailed enough to find some inconsistency. If projection of power of the hivemind in this place and time is weaker than those of their enemies, then they will lose in that place and time, no matter how efficient they are in using their hivemind (sure with optimal actions of their opponents, with can be replaced with more power) Their(HM) power not in fast decisions, but in long-term strategies, and in the coordination of actions of small and larger groups. Army also can coordinate their group's actions, maybe they need more people for that, so they are less efficient in terms of people, and yes less efficient in each particular individual case - but overall results will be comparable. On earth army of humans vs an army of hive-minded vampires, skipping the tactics and right to the battle - will vampire have super super advantage, from being hive minded. Yes some, but not really something which can't be counteracted with numbers of humans. Because the main task is engaging as individuals, as corpses, bodies, doing some actions. It is the same situation as with computing problems - some tasks are suitable for parallel processing, some are not, because of their consecutive nature. They do not use all their power for any task, it is impossible and impractical. So if one human threatens hive mind, it's not practical to overreact to the situation. 0.1-2 members of hive more than enough for to pay attention to the situation and handle it. As hivemind, they have the advantage to change those peoples each 5 minutes, so this booooring task will be not a burden for members, or by not allocating someone particular, just one of background subconsciousness processes. It is practical to allocate just right enough power for a task. They can fail and underestimate the threat, like a swarm of bees, might underestimate human - they do what they can each, but it's just not enough because of limitation of their hive mind. A hive mind is a system which has its limitations. If a hive mind has only gunpowder or nuclear weapon and has no acces to space, it can not do much against potential space invaders(that's another long story, but no handwavium, as usual), just because what they do have is not enough to create some resistance - they just can't concentrate enough of power in one place, because of physical limitation of weapon, which is nothing to do with Hivemind. Hivemind'ing does not make them automatically super explorers or researchers - they have to wish to be explorers and researchers or adventurers. If they do not, if as an example they say about the nuclear bomb - yes, it is powerful enough, so now we can chill and enjoy our selfs with the beauty of stars. They can be lazy, they can fall in a state of no doing. We as humans decided that space too hard and have not much profit or use of us - and where we are now? Not in space, each second we lose tonnes of energy (sun) because of those decisions. Hivemind's are different, they have individuality, face, manners, habits, patterns in solving problems (individual patterns like fingerprints), preferences, etc etc. Hivemind of ants will not care about members, a hivemind out of humans might care about members - this difference will lead to the difference in ways which are used to solve problems. Different solutions have different strengths and weaknesses. And not all hivemind's of same species(humans) will be the same in habits etc. Yes, sure it's probably another kind of difference then between humans as individuals or countries, but using them as examples is not the worst starting point to begin to think about differences in hiveminds. Different ancient goods are probably not the worst examples of representing of such hiveminds in human terms. Algorithms how information is filtered, redistributed between members, how it is processed, processing algorithms, organization - that's what is the essence of hive mind, subject of their evolution, source of their habits, strength's and weaknesses. That's kinda operating systems(OS). It took us at least 40 years to evolve our OS's for computers, but it still far beyond of ease of use and capabilities of those from the Iron man movies, that advanced CAD program or that OS from Mechsuit in District 9. Improving, changing - it is never ending jorney. [Answer] I would add a drawback to using the power. For example, headaches. Connecting to that hivemind would result in a huge influx of information very very quickly. Even for smaller clusters, two or three people talking all at once can quickly be overwhelming, especially if they're inside your head and you have no ability to tune them out. It seems like this would easily result in a headache, forcing the protagonist to choose between 'easy answer and excruciating pain', or 'harder answer but no pain'. Another option could be hardware limitations. Even an advanced cybernetic implant isn't perfect: it could only be good for a certain number of uses, or could do something to damage the user's brain if used too often. Another way of doing it would be adapting the situation that the protagonist (or antagonist) is in to create a benefit to not using the enhancement. Telepathic enemies, perhaps, that could deduce the location of important people by the path that their thoughts follow. Or an EMP to render the device temporarily or permanently useless. [Answer] Dungeons and dragons has Formians, who share their vision with all hive members. Star Trek has the Borg, which is almost exactly what you described but I'm not enough of a Trekkie to tell you the exact differences. The main limit with a collective mind is that it can still only see what the members of the hive see. Within their space, they all know everything that is going on, but if they don't have any units around, they can't do anything. I'd also consider how far the connection goes. In their ships they probably have repeaters to boost the signal strength, but outside of that maybe they have to be within 10 feet to share vision, 20 feet to share thoughts and 50 or 100 feet to vaguely know where the other is and if they're conscious/in pain/whatever. With today's technology, such a connection would require some kind of wireless signal. Producing enough interference on the band used for communication would cut members off from the others without their consent, likely resulting in some disorientation for at least a short while. If their enhancements are vulnerable to outside interference, you may be able to hack them. If some components aren't shielded, you may be able to knock them out with an EMP. If they're used to seeing and feeling through many sets of eyes/bodies, being disconnected from everyone else would likely cause them to become very uncomfortable, paranoid, alone, etc. Locking one in a room by itself for a day or two may cause it to mentally break down. ]
[Question] [ Imagine, if you will, an Earth-like planet orbiting a Sol-like star. Now imagine that, from somewhere outside the solar system, a rogue planet, rocky and of roughly the same size and mass of the first planet, enters the solar system on a trajectory that eventually takes it so close to the first planet that they end up touching one another. What happens? I was thinking that if both planets are spinning on their axes, they're going to rub against each other and potentially cancel each others' spin. Would their gravitational pulls eventually merge them into a larger rocky planet? How long would that take? If the Earth-like planet was inhabited, what would the inhabitants experience (after the panic subsided)? [Answer] # Your planet is screwed. As was mentioned in comments, the [Giant Impact Hypothesis](https://en.wikipedia.org/wiki/Giant_impact_hypothesis) details a very similar situation, as Earth collides with another body of slightly smaller size at some angle of roughly 45°, so neither of the two are totally destroyed. In a more direct impact, the centers of both bodies will collide and fuse, while excess material will be thrown off in one or more tails. [Eiland et al. (2013)](http://arxiv.org/ftp/arxiv/papers/1307/1307.7062.pdf) presented interesting models with one and two tails: [![enter image description here](https://i.stack.imgur.com/3UOXV.png)](https://i.stack.imgur.com/3UOXV.png) [![enter image description here](https://i.stack.imgur.com/aL629.png)](https://i.stack.imgur.com/aL629.png) Alternatively, if the planets collide at a more oblique angle, a disk may form: [![enter image description here](https://i.stack.imgur.com/IOcrq.png)](https://i.stack.imgur.com/IOcrq.png) These are simulations that result in material being ejected into orbit, thus forming a moon - the same thing that happened with Earth. In a completely direct impact, this may not happen; the two bodies could be destroyed. However, your scenario will most likely lead to a glancing blow and a disk. Note that in the first simulation only, each planet is spinning in the opposite direction as the other. See also [Stevenson (1987)](http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1987AREPS..15..271S&defaultprint=YES&filetype=.pdf) for a thorough theoretical treatment, which also explains how collision timescales differ based on different impactor masses: [![enter image description here](https://i.stack.imgur.com/iaFBo.png)](https://i.stack.imgur.com/iaFBo.png) That said, things might be different here. The incoming planet may be moving much quicker than the other body was in the Giant Impact Hypothesis, meaning that both bodies could be completely destroyed. More cool (colorful!) simulation images can be found in [Canup (2003)](http://lasp.colorado.edu/%7Eespoclass/ASTR_5835_2013_Files/2013_10_29_Canup.Moon.Icarus.2004.pdf), which should give you a better idea of the temperatures reached during such collisions (about $\sim10^4$ Kelvin is possible!). As I mentioned [here](https://worldbuilding.stackexchange.com/questions/34583/could-it-be-possible-for-two-planets-to-collide-and-not-kill-everything/34587#34587), death may come because of these high temperatures, which will heat even the deepest layers of both planets. Life can't run and hide underground. [Answer] # Everyone Dies I assume the planets are on a "gentle" (shallow) approach to one another, which seems to match your description of "eventually takes it so close [that] they end up touching". There will be panic as the planets draw nearer. Everyone will die; it's just a question of when and how. # Tidal forces As the planets approach, their mutual gravitational acceleration (doubled!) will pull them together and accelerate them to even higher relative speeds. The first problem is, the gravitational acceleration will not be uniform: the "near" pieces of the planets will feel a stronger pull than the "far" pieces, and this effect will be very pronounced. It will cause great earthquakes and incredible ocean tides (and tsunamis), which will obliterate anything within a few hundred kilometers of a coastline. It will also destroy [key infrastructure](https://en.wikipedia.org/wiki/Fukushima_Daiichi_nuclear_disaster). The atmospheres of both planets will be easily affected, causing weather patterns of a far greater magnitude than anything we know as both atmospheres will be pulled toward the center of mass of the two planets. # Roche Limit If anyone is still alive after all of the above, this last bit should do them in. Edit: Fixed math (and included steps!) Thanks to MadBender for the catch! The [Roche limit](https://en.wikipedia.org/wiki/Roche_limit) is the distance (radius) within which a celestial body (like a planet) can no longer hold itself together via its own gravity, and is then pulled apart by the gravitational tidal forces I introduced, above. The Roche limit (d) for rigid bodies1 $\, m$ and $M$ (your twin Earths), looks like this: $$d = R\_m \left( 2 \cdot \frac{\rho\_M}{\rho\_m} \right)^{1/3}$$ $\rho\_M / \rho\_m$ is the ratio of densities of both planets. Since they are identical, their density ratio will be 1/1, thus: $$d = R\_m \left( 2 \cdot \frac{1}{1} \right)^{1/3} \approx 1.26 R\_m$$ $$d \approx 1.26 \times 6\,371\text{ km} \approx 8\,027\text{ km}$$ As the two planets come within the Roche limit, the effects from the previous section will have already had catastrophic results, and started to elongate the planets. The difference is, that near the Roche boundary, gravity won't be enough to hold the planets together. The overall mass stays the same, but the planets are literally torn to pieces. The atmospheres and oceans more or less go without a fight (see previous section), but the solid pieces will come bit by bit, and the (now very chaotic) motions will result in more impacts, which will continually pulverize the pieces until there isn't much left but a ring of debris around the star, almost certainly with no survivors. What actually kills the remaining inhabitants is somewhat a matter of chance, but could be: * Direct impact or secondary impact forces * Suffocation/decompression as the atmosphere is pulled towards the center of mass but your tiny planetoid carries on a different trajectory. Or, the atmosphere simply gets thinner as the mass of your planetoid is too weak to retain it at sufficient density to support human life. # Other effects * The [magnetic fields](https://en.wikipedia.org/wiki/Earth's_magnetic_field) of both planets will combine, quite likely in a way that would reduce the effectiveness of the magnetosphere, allowing cosmic rays to bombard the inhabitants, causing an increase in radiation sickness and cancers, however I don't think anyone will live long enough for that. --- # Notes 1. Of course the Earth isn't completely rigid. However, all of the liquid and gases would already have been pulled and squeezed into the gnarliest surf anyone has ever seen. [Answer] Total destruction With the Earth's current orbit, the planet will have a [velocity at infinity](http://hopsblog-hop.blogspot.no/2013/03/what-heck-is-vinf.html) of between $12.5km/s$ and $72 km/s$, depending on the direction of which it hits. (It has an even higher velocity if it comes from outside of the solar system). Is this enough energy to destroy both planets into small pieces? Assuming the other planet is similar to the Earth too, we can use [gravitational binding energy](https://en.wikipedia.org/wiki/Gravitational_binding_energy) to answer that question. The combined energy required to totally destroy them is $4.5 · 10^{32}J$. The energy added from the slowest impact is $4.7 \cdot 10^{32}J$. So both planets will be turned into molten gravel. [Answer] Answer for less science savvy readers: If both planets are the same weight and size, and almost touch each other, it should be intuitive that at the point where they touch there is zero gravity, since the pull towards either planet cancels out each other. If it's not yet intuitive: imagine you are near where the 2 planets touch and you fall down - how can you tell towards which of the 2 planets you would fall? You can't. The circumference of the earth is about 40'000 kilometers, and it rotates about once every 24 hours. So at the equator the speed due to rotation is about 40'000/24=1'666 km/h, and the one thing holding the planet together was gravity. Imagine swinging a ball on a long string at 1666 km/h and letting go. Rocks (a.k.a. continents) and everything else, like air and water, will fall off of each planet, and either fly into space or bombard the other planet. For comparison, in an extremely strong tornado, air moves at 600 km/h and flattens buildings, now we have air, water, and mountains, moving at 1666 km/h and more. Once anything impacts the other planet, it becomes part of the other planet's surface. From there it will fly off again, for the same reasons it flew off from the first planet. No matter where you are, you either get squished or you get to see space - and probably get squished once you collide with other space rocks. Time to start colonizing mars, and hope the debris doesn't impact too hard there. Maybe it would be safer to colonize a moon of one of the gas giants instead, because they are further away. ]
[Question] [ The world is, as we all know, in a sad state: corrupt politicians constantly trying to diminish democracy to increase their own power; international corporations ignoring laws; mobsters taking over large parts of the economy because they can. Now, fortunately, I have discovered I have a superpower: I can shrink myself to a few mm in size and teleport anywhere, even inside another body! And I decided to become a superhero by using my power to kill the worst of those people. Only .. I need the deaths to look natural. The people I want to kill don't exist in a vacuum; they have friends and followers, and a death that looks unnatural might make the situation worse, not better. If the 75 year old president of Elbonia drops dead from a heart attack, people will mourn him, but if the 35 year old president dies from poisoning, the Elbonians will start a war with their neighbors because who else could have poisoned the president? Likewise, an obvious unnatural death of a drug boss will lead to a gang war, which I want to avoid. I'm a superhero, after all, not a supervillain! So, once inside their body, how can I kill people - under the assumption that a very competent pathologist or forensic investigator will examine the body, and I want them to be convinced the cause was natural? * Of course I could drop some toxic substance, from botulinum to an insulin overdose, but those will be detected. * I could drop some cancerogenic substance which might not be detected anymore when the victim develops cancer, but I want them to die within hours or days, not months or years. * Slitting open a main artery would work as well, but I'd be giving the pathologist a heck of a puzzle, and they probably wouldn't attest to a natural death. * I might be lucky and find an aneurysm that I'd just have to punch a few times to make it break, but most people wouldn't have one I could use to begin with. * Blocking an artery to cause a stroke would work as well, but again be puzzling at the autopsy if the victim's veins are generally in a good condition. I need a way to kill my victims and make the investigator say something like "this is uncommon in people that age, but it happens now and then. Bad luck, but no foul play". Actually I need many different ways. If one drug boss dies of a rare cause, it's bad luck. If ten of them die, it's already suspicious, but if ten of them die of the same rare cause, nobody will believe in chance any more. So, which ways do I have to kill those guys? (Please, take the science-based tag with a grain of salt. Of course the whole premise of the question has nothing to do with science at all. But I'd like the answers to be based in biology/medicine; real causes of death that could undetectably be caused by messing with the inside of a body). [Answer] I really like how Daniel B explained in details how to teleport into someone's body and make the person pass out biologically. I myself don't know much into the science part of this so I would like to extend from Daniel B's answer. ## Do the move to cause accidents. Much like how an example is given. Do it when the person is on the stairs, which will make them fall and can cause a lethal injury more or less. This is where the part I would like to extend. Do it on the street. Be it when the person is crossing the street, or while driving. Make the person suddenly pass out while driving in a dangerous rainy night could also be lethal. You don't have to make it crash into other people's car (because you want to be a hero, alright). You can just make the car out of control and hit something around there like trees or poles, or, even better, off the cliff. Do it when the person is doing something ordinary but potentially dangerous when unconscious. For example, when the person is climbing a ladder -- make them fall, when the person is swimming -- make them drown, or when the person is eating -- make them choke. [Answer] # Syncope on staircases Syncope, or fainting, happens when blood or oxygen stops getting to your brain. A very nasty time to get it is while walking down a staircase. If you pass out mid step, the physical consequences can be devastating. The easiest way to accomplish this is by teleporting into their carotid artery and directly applying pressure to their carotid baroreceptors. This will trigger their Baroreflex. > > The baroreflex provides a rapid negative feedback loop in which an elevated blood pressure causes the heart rate to decrease. Decreased blood pressure decreases baroreflex activation and causes heart rate to increase and to restore blood pressure levels. Their function is to sense pressure changes by responding to change in the tension of the arterial wall[1] The baroreflex can begin to act in less than the duration of a cardiac cycle (fractions of a second) > > > (From Wikipedia on baroreflex) In other words, by applying pressure to the baroreceptor directly, you convince the body that there has been a blood pressure spike. In response, the body creates a rapid decrease in blood pressure, leading to rapid unconsciousness. As a bonus, the heart won’t release any atrial natriuretic peptide to be detected in the post-mortem, so it’ll look like either an unfortunate trip and fall, or like a fainting spell. If you want to be more direct, just crawl up a bit higher and either slit the arterial wall near the brain stem, or use your little body to block the flow at a narrow channel. Brain hemorrhages and strokes ain’t nothing to fuck with. [Answer] Ingested, self-administered poisons. You can kill in any number of creative ways, but that takes effort. Why not use simple methods instead and simultaneously avoid the whole bloodpressure thing? Lets say your target has an event where alcohol is available. You pick an alcohol type of their menu and keep teleporting it into their stomach, preferably near the end of the event. They get roaring drunk and eventually die of alcohol poisoning. Since its initial start is public no one can say he was forced to drink it, there's no traces of injections and everything points to them having drunk it themselves. Best case scenario's: he's already showing drunkenness before he leaves, then dies in a car accident as he drives home. If he doesnt have an accident (say a taxi is called) they can die of alcohol poisoning as they get home. Besides alcohol you can use a number of oral drugs. If they are tripping their ass off as they are in a car they can easily kill themselves. Or in some cases you can fake an overdose of painkillers and alcohol, teleporting the offending remains in afterwards (it doesnt say you have to be 3mm tall so I assume a bottle and pill containers might be possible to teleport into a carseat or house). As a counter to just killing people, why not wreck their lives instead? "Politician showed up tripping balls and puking drunk at his adress to congress/whatever, claims he has no idea how he got drugged". Its not exactly a big leap that he may have done it himself, especially if there's more instances of him showing up drugged in other places with no trace as to how it happened other than "he ate it himself". You can break their credibility, have them be drugged while trying to make decisions so people think they are absolute idiots and should not have their power anymore. [Answer] There's a window now for heart attacks to be unremarkable So, normally, a 20-30 year old, in otherwise good health, dropping dead of a heart attack, would be weird. Fortunately for your main character, there's an explanation that covers for this at the moment! It's everyone's favourite disease, COVID-19! It turns out that getting covid seems to probably cause myocarditis, which is inflammation of the heart. This is generally a bad thing. There's also substantial arrhythmias seen in otherwise fit and healthy people, and we've seen a substantial increase in strokes and heart attacks in young men over the course of the pandemic. So, at the moment, your character can kill with impunity, as long as he makes it look like a heart attack - I'd suggest, perhaps, teleporting next to the heart and shocking some of the nerves directly. You could get away with pretty substantial damage, as well, assuming the person is going to receive CPR almost immediately, which causes massive bruising. If you have access to a biolab, I'd think about dumping some inflammation causing chemicals in the mix, just to give a nice, simple explanation. Citations Covid causes higher risk of arrhythmias and myocarditis <https://www.nature.com/articles/s41591-022-01689-3> Uptick in heart attacks track covid infections: <https://www.cedars-sinai.org/newsroom/covid-19-surges-linked-to-spike-in-heart-attacks/> [Answer] Cause them to choke! People choke all the time, and it’s very unlikely that someone could choke to death as a result of foul play. So, wait for your target to begin eating, teleport into their throat (I’m assuming you could survive inside the human body, even though it’s basically impossible to do such, but hey you’re a superhero!), and hold that chunk of food in place, blocking airflow. Soon, they die! The only problem is that others could do the Heimlich maneuver, so wait until they’re eating alone. Allergies! If this villain has an allergy, simply bring a butt-load of the allergen into their throat and let it go! They will probably die from ingesting it. Make sure, however, that you use a large number of trace amounts of the allergen (e.g. if they’re fatally allergic to eggplant like me, bring plenty of tiny chunks of eggplant). That way, it will seem like they ingested the allergen on accident. Take advantage of their bad habits! Do they smoke? Do they drink? Do they eat a lot? If they have any self-destructive habits, do your homework and figure out how this could kill them. Then do that exact thing! Cause the death that their habit would have eventually caused, and no one will be suspicious! No bad habits? Kill them with water! Some people, even if they’re evil, just don’t have bad habits. So you’re gonna have to kill them with one of the most essential substances ever: water. Get inside their system, and add lots of water until their blood salinity changes and they die. Unshrink, and add a bunch of empty, damp cups that look like they were full of water that got drank very fast, and place several ghost chili peppers near the body. It’ll look like they ate the peppers and drank too much water on accident. If all else fails, use cars! All these previous ideas take resources, but this last one just needs you and your superpowers! While they’re driving, get in their brain and mess around. They will crash. If you want, you can add alcohol in the car so they look like they were intoxicated. [Answer] Interfering with the sinus node will cause arhythmia and cardiac arrest. Almost anything with that size moving in the brain can trigger a transient ischemic event: after three or four episodes, dying of a larger event will yield a diagnosis of fatal idiopathic cerebral ischemia and be regarded as strange and unlikely, but "natural". And being well inside what, on that scale, amounts to a mountain of inertial armor will allow you to survive having caused any kind of fatal accident; basically, moving anywhere risky (the street, for example) or driving any kind of vehicle will be sure death. Moving substances from the inside to the immediate outside of the lower intestine will cause a peritonitis, and lesionating the lung tissue will cause an ab ingestis pulmonitis. Any of these will require hospitalization, and during hospitalization all sorts of complications may arise. The pathologists will wonder how someone could get a staphylococcus infection in the lungs or a never-before-seen endocarditis from E. Coli, but it's not very likely they'll be able to surmise what could have happened. Then, either judicious and repeated application of several substances, or just repeated multiple tissutal lesions, have a high probability of exiting in cancer; at that point, an incredibly quick metastatization would raise many eyebrows, but the resulting death would in all probability be deemed natural. Of course, just the fact that some specific group is dying at an unbelievable rate might attract attention. Prospective victims might employ advanced surveillance and all kinds of sensors to detect outside agencies; it is possible they'd think of micro-bots or engineered bugs being used for murder. Measures designed to catch those might well detect / capture you. [Answer] BECOME AN ACOUSTIC WEAPON, PUSH THE PERSON TO SUICIDE By settling in the auditory canal, and by hiding between the eardrum and a partition teleported at the same time as you, and which resembles the eardrum in order to fool the doctors. This place allows you to breathe too. Several choices are then offered, varying in intensity, going from the imitation of a tinnitus, to the infinite earworm song, up to, if necessary, becoming a small voice that makes the person crazy. [Answer] Imagining here that you, in 3mm form, have a way to avoid drowning in the blood stream, my vote would be for using yourself to mimic a clot reaching the brain, causing a vessel to rupture, bleed into the skull and, fairly rapidly, kill the person. Pro's to this method: * People sometimes do just keel over from a random clot getting stuck. It's not likely to be age related, and it's not something you can necessarily screen for like an aneurysm. It's just sheer bad luck. * It's quick, bleeding to the brain is Bad and if it happens fast enough and in enough quantity the damage to the autonomic functions will kill you before the blood loss does Con's to this method: * It's survivable. Look at stroke victims, the person might not be at their full force afterwards, but if there's quick intervention it's not 100% death inducing * you need to not drown in the blood yourself, are you somehow miniaturising a closed circuit rebreather set? I presume this is an option for handwavy science reasons, because getting into the blood stream is going to be half the battle. On the upside, again if you do it on the stairs or in traffic, the person is likely to fall and die. [Answer] Let's say that the physical component of a person is the biological machine (biomac); the meat, and what it does in order to remain meat. Let's also say that 'natural causes' and 'accident' (nca) is first and foremost defined as not sinister, not malevolent, not murder legally, not intentional morally. Let's further define nca as culturally acceptable, non-political, [credible](https://www.dictionary.com/browse/credible) despite being traumatising and presumptuous, indisputable despite being somewhat dubious. This gives us a framework of relevancy as there are many ways to remove a person, fatal and non-fatal. Ergo, i'm going to call these misadventures Each of your targets will have a motivation: Political, moral, personal. Random and senseless slaughter is vague and boring. Each of your targets has a significant presence: That might be global like a president of a powerful nation, local like a warlord in control of an annexed territory, others. Each target has influence: a descriptive power or measurable control over the presence; and, each of your targets has circumstance: age, fragility, environment, wanted status, hunted status, in hiding, in prison, etc etc. Each of these is going to have a noteworthy contribution to what is and is not an acceptable, plausible, believable misadventure. > > ie: a US pres. being shot is never ever going to look like an accident, while in the current light of the Ukraine and Russia situation, there is a real and daily risk of Ukraine's president being shot. Arguably not a "natural" cause, yet we've decided on a framework referred to as nca, and this is acceptable, believable nca. Context matters. > > > the biomac is unusually resilient, and can tolerate a lot of stresses and injury before expiration. Hollywood is not at all reflective of reality. However you have the ridiculous power to manifest yourself at will to the interior of a biomac where you could cause trauma without immediate detection. I am going to have to assume that '~3mm you' does not have the same mass as 'regular you', mostly because of the absolute confining limitations. If we're going to accept a 'magical' element, we might as well tweak it in favour of narrative. > > just touch on the notion of tiny size yet unchanged mass: Imagine any inanimate object that could reasonably have a mass of ~80kg (hello, USA! that's 177 lbs). I am thinking: a large piece of travel luggage; a large moving box filled with books; 20 gallons of water/milk; All four of the wheels of your car together with the tyre (or maybe just 3 of them, depending on the size); Yourself. > > Consider any object which is 2-3 mm in size. Looking around I see a tiny screw, a jumper-pin, a fragment of a broken magnet, a crumb from a cat food biscuit. > > Now imagine the combination of the two. The size of this, with the mass of that. Imagine having it placed into your open hand, or dropping on the floor. Imagine dropping it from a height onto a passing truck or bus. Imagine it manifested instantly and without warning, within your shoe, on top of your foot. Within the space of your gut > > > ### Methods of 'biomac' tampering which have both severe consequences and plausibility, and should result in misadventure within a respectable time-frame. ##### An in-exhaustive, unorthodox guide to malevolent leadership removal via oopsie-daisy. Written by Guntram Blohm. Introduction by littlegreenrock. Illustrated by \_\_\_\_\_. First edition. 2022. Badwolf press, CA. - Chapter 1: The brain is a complex ecosystem. * Intracerebral Hemorrhage * Ischaemic Stroke * Carotid artery disease * Encephalitis * Spontaneous Intracranial Hypotension - Chapter 2: Senses are kind of important. * The Inner Ear: • Acute Hearing Loss, • Vertigo, • Chronic Tinnitus, • Single-sided deafness, or Loss of Stereoscopic Sound. * Vision and the Eye: • Macular Degradation, • Chorioretinitis and Retinal Atrophy, • Optic Neuritis, - Chapter 3: Assassination of Character. * Broca's Aphasia * Fine Dexterity and Upper Motor Neuron Lesions * Facial Nerves * Incontinence - Chapter 4: Mobility and Locomotion. * Arms and Interaction * Legs and mobility * Hands & Fingers, Dexterity & Shaking * Toes, and Standing Without Assistance * Depth Perception, Throwing and Catching - Chapter 5: Heart and Lungs. * Practical Cardiopulmonary Overview * Heart Valves * Characteristics of Cardiac Muscle Tissue, and Introduction to the ECG * Pleurisy * Pneumonia - Chapter 6: The Other Vital Organs. * Kidneys * Liver - Chapter 7: Categories and Vectors of Infectious Disease - Chapter 8: Passive and Active Immune System. * Acute Auto Immune Disorders * Hyperactive Immune Response and Allergic Reactions [Answer] So you're going in with scuba equipment, eh? Easy! [Air embolism](https://en.wikipedia.org/wiki/Air_embolism) Just release most of the air from the tank in the right place. I have no idea if this is practical. [Answer] # Killing is ineffective and always noticeable Whatever you do, there are big flaws in the plan. First of all, regardless how they die, it'll be noticed. Everyone you deem too evil will die, making a recognisable pattern. Even if you use a different way to kill each of them. Second of all, killing people doesn't necessarily change things. You are hoping killing them will change anything, but it might actually bolster them. That is why I propose something different. What you want is change. Change comes best from within. Three examples. If you would want to get better female rights in Iran you can see that half the country on the street is needed to even consider change. If instead of people in the streets the people in charge die, nothing changes. Someone else will pick up where others left off. Or you have one or more people in charge say there need to be better female rights, then you're getting somewhere. ## A solution To truly reach a solution, not everyone needs to die. You 'just' need to get them to change. Just like the original question this can be done in many ways. An example: Leave a message to them that they will lose all sense of feeling in their genitals, unless they change their views at least for the public. The first threat is likely ignored, so you teleport in, sever the nerves on the lowest part of the spinal column and give the next message. Now you will have their attention and no one except the targeted person knows that it happened. It also helps that such defects are unlikely to be talked about by either the person, people close to the person or via the medical code of conduct. The next threat will threaten to make a limb useless. Continue until they comply, or if they refuse you kill them. Do the same with the next person until you get someone to comply. In this example I've immediately gone extreme, but you could start less bad. Making them drunk, cause indigestion, headaches, shortness of breath, stimulate a nerve that causes just the symptoms of a heart attack. The threat of something unseen that can do basically anything with their body, and if you really want to go there the bodies of loved ones, will be enough to persuade most people. The advantage here is that they will likely try to look strong to the public in the meantime. The chances that this becomes public knowledge is reduced. ## Conclusion Killing is in many cases ineffective or just a chance of improvement. Manipulation of the evildoers is where it's at. So long as they are useful they live unharmed. If they are not, they will suffer damage or death. Do this long enough and you will get change without committing to genocide. [Answer] ## Cardiac arrest Given that you're that small, an efficient way of killing somebody would be to teleport in their heart, and cause it to stop pulsing, thus causing a natural-seeming death. Of course, it looks suspect for a "young" person (20-30 years old) to die in such a way. > > corrupt politicians constantly trying to diminish democracy to increase their own power; international corporations ignoring laws; mobsters taking over large parts of the economy because they can > > > > > using my power to kill the worst of those people > > > However, most of the people you plan to kill are quite old, more like 50 or above, so it won't seem that suspect. [Answer] Lots of good options here (well... for some uses of the word "good" anyway). I'll add one more idea to complement them all: don't do it the same way with every victim. That will start to be suspicious. But as long as it's a different mechanism every time, you should evade notice for much longer. [Answer] Change the cause not the symptom Well despite your will for a better world with a "Judgedread" style, there is a definition issue in your hypothesis. Your are looking at the symptome of the problem. You are not looking at the cause. You will sooner or later die like any "judgedread". The cause here is the "power" not the politicians. Sh\\t calls for flies, and honey calls for bees. The answer to your cause is blindly easy : Kill the power not the people. Give it back to the people. Democracy is just a diverted way to make people believe they have their destiny in hand. It's easy to corrupt a single person, but a way much harder to corrupt the whole population. We do have the technology to vote, and discuss subjects without the use of delegates. Everyone should have her word to say. The final vote should be coming from the whole population, and even though those that disagree should still have the right to live on their own perception of reality. Free yourself from this false believe coming from before may '68 that everything must be in control of a pyramidal power. Read the book from George Orwell "The Animal Farm" and you will understand that forcing people to one way always lead to tyrany. With such "3mm power" you could, for instance, but not exclusively, like "antman" follow the supposed corrupted politicians secretly to find out their evil activities and reveal them to the world, and joined with advices for a new form of individual respectfull society without power hierarchy, therefore removing any interested for "flies" but only for "bees". The feather is stronger than the sword... ]
[Question] [ ## BACKGROUND I'm working on a medieval world in which homo sapiens [domesticated several other species of intelligent hominids](https://worldbuilding.stackexchange.com/questions/99806/how-long-would-it-take-to-domesticate-humans) during their prehistory, at first enslaving them to take advantage of specific desirable adaptions, and then breeding them to further specialize them for a social role. This combination of natural selection and breeding has, over a suitably vast time scale, produced a society of related but physically and mentally distinct species - a biological caste system.\* ## QUESTION I'd like one of these species to be ideal farmers. They would have probably evolved farming practices early in their evolutionary history, like certain real-world animals. Later, after inventing agriculture proper, they would have been conquered and bred into a herd of docile farmers and laborers for their human masters. By the end of this, they would need to be highly adapted to growing staple crops, petty labor, taking orders, and really not much else. Aesthetically, it would be a plus if these adaptions also led naturally to interesting visual differences, but I can already work cosmetic changes in pretty easily so that isn't my first priority. * What physical and mental adaptions could an intelligent hominid evolve that would make more ideally suited to farming grain staples? ## ADDED NOTES A very random hodge-podge of example ideas might include adaptions that allow them to sense the weather, better fertilize plants, do tiring and repetitive labor, cooperate peacefully in groups, adapt their own actions and biological rhythms to seasons of growth, somehow encourage plant growth or prevent disease, etc. etc. There are probably other interesting adaptions that I'm unaware of to be found in nature, and of course, I welcome any plausible original idea. As a final note, while I'd like to keep this hominid "human-ish", at least physically, site users should consider themselves welcome to push hard at the boundaries of that condition if it makes their answer more interesting. It's easier for me to scale an answer back than to scale it forward. [Answer] First and foremost you should breed for docility, this is a trait required for domestication. My answer is basically looking at existing primarily non-food farm animals (like horses) and breed for those traits (they may also be eaten so more edible varieties are also likely to be bred). * Strength, endurance, and size; if you are breeding a hominid for farm labor it should be able to replace a horse or other animal in terms of pulling a plow, turning soil, pulling a tree stump, lifting loads, or otherwise performing farm labor, hominids could be more useful than horses or other domestic animals as their tools could also potentially be used by regular people, requiring less specialized equipment. * The ability to digest cellulose or other plant fibers not digestible to humans: You don't want a work animal that consumes exactly the same food as you, this would make them competition for food, better for them to eat things people cannot. The ability to digest grass is a big part of why we domesticated ruminants; if your hominids can also do it or otherwise survive on farm scraps (catching mice?), it makes them even more useful. Some early [hominids](https://www.newscientist.com/blogs/shortsharpscience/2011/05/early-human-grazed-on-grass.html) likely did eat grass as a primary food source. * Non-upright postures; there's a reason farm work is called back breaking, it often requires bending over near to the ground, which is uncomfortable for our bipedal locomotion; an apes knuckle-dragging arm walk, may actually be a better posture for minding plants close to the ground. (this also makes them less human, reducing interspecies empathy) * Intelligence to a point. Nobody wants a dumb horse, but a smart one is just as likely to do what it wants instead of what you want it to. The ability to follow simple commands and perform repetitive tasks with minimal oversight are useful, but critical thinking leads to rebellion. You would only breed for intelligence to meet the minimum requirements, and this would likely not be the most important trait to breed for, and may actively be bred out of the species. As a side note, these creatures would likely be used for things other than farm labor. War horses are very distinct from a plow horse, expect weaponized versions of these hominids to be bred for war with very different attributes selected. [Answer] Farmer traits: 1. Fecundity. If you are a farmer you are more likely to have food than if you are a hunter/gatherer. If you have food it is less likely the kids will starve. If you have lots of kids who are not starving you have more people to help with the farm work. 2. Patience and focus. There is a theory that attention deficit disorder is an old behavioral set which was useful to our ancestors which was suppressed in many people during the transition from hunter/gatherer to farmer. Farmers must be patient and not compelled to switch away from something boring. <https://en.wikipedia.org/wiki/Hunter_vs._farmer_hypothesis> 3. Tolerance for high carbohydrate diet. Because that is where the calories are in staple crops. Supposedly our ancient hunter-gatherer ancestors struggled to digest starch. That is the case for chimps. In circumstances where the main calories were from starch, better starch digesting powers gave a survival advantage. <http://www.nature.com/news/2007/070903/full/news070903-21.html> 4. Lactose tolerance. All babies can drink milk. Northern Europeans retain the ability to digest milk into adulthood. That is useful if you have large domestic animals which supply milk. I thought that lactose tolerance was only in Europeans and did not understand why it was not also present in African people who have been keeping cattle for the past few thousand years. I was just ignorant - those people have evolved to be tolerant of lactose as adults also. <https://www.smithsonianmag.com/science-nature/africans-ability-digest-milk-came-livestock-agriculture-180950064/> 5. Endurance. Hunter gatherers get the credit for why [humans can outlast almost any other animals](http://www.slate.com/articles/sports/sports_nut/2012/06/long_distance_running_and_evolution_why_humans_can_outrun_horses_but_can_t_jump_higher_than_cats_.html). Supposedly long distance running is a good hunting strategy. I propose the phenomenal endurance of humans is also good for farming. Ultimately, I think many groups of humans already bred themselves to be master farmers over the past 5000 years. Your ideal farmer might be looking at you in the mirror, [Answer] Some of the traits that come to mind: • microscopic vision - to find out what pathogens affect their crops • night vision - to detect insects even if they are active only by night • photographic memory - to remember the various stages of the hundreds of pests affecting basic crops: life cycle of bacteria, fungi and insects to ensure they apply the correct/proper treatment; this trait is a double-blade sword because the ability to easily categorize and remember might pose the risk of the slaves becoming aware of their critical role in their masters' well-being • enhanced perception of the green colour - to determine the level of chlorophyll and the nitrogen deficiency • heightened sense of smell or taste - to asses the level of nitrogen, phosphorus and potassium in the soil, even better if it's extended to other elements like calcium, magnesium, iron, sulfur. [Answer] Stronger backs, knees and thighs for prolonged periods spent stooped or squatting (for planting, weeding, and harvesting) and a shorter stature in general would be advantageous. Farmers do not need bodies designed for running or endurance hunting, two things that had notable influence over our own development. Higher melanin levels and thicker skin would make working prolonged hours in the sun and among brambles and biting insects easier to endure. Thicker eye brows and longer eye lashes might evolve to cope with brow sweat and insects, respectively. Hairlessness in general might be expected as well, particularly if the dominant species controls their breeding as hair would be unlikely as an indicator of ability/desirability/personal expression. Stronger olfactory and taste reception would make detecting plant disease and soil fertility/composition easier. [Answer] I suppose that by "medieval" the question means "western European medieval"; the world is much larger than western Europe, and other cultures, such as the Indian, Chinese or Japanese cultures, had their own "medieval" periods; but few questions bother to specify what they mean by "medieval" world. Now, in western Europe, the medieval period lasted for about one thousand years, from about the 5th to about the 15th centuries. It was a dynamic period, which saw massive changes in social structure, culture, and technology. Medieval does not mean static. The question asks for physical and mental adaptions of a species of domesticated apes, making them into better farmers than humans. Which is a contradiction. See, they are slave labor; that's what "domesticated" means. Slaves do what their masters tell them to do; they have no agency. So what could make this Anthropoides agricola better field slaves than human field slaves? Be more docile? Hardly. In the entire history of the Roman empire the number of rebellions initiated by field slaves can be counted on the fingers of one hand, and only two of them, the [First](https://en.wikipedia.org/wiki/First_Servile_War) and [Second Servile War](https://en.wikipedia.org/wiki/Second_Servile_War), got any traction. Be better at working the fields? Hardly. Agricultural productivity is essentially a function of the technological level of the society, not of individual skill at ploughing or weeding. (Hint: consider agricultural output per hectare in the U.S.A. or Europe; it's at all-time high, yet very few people work in agriculture.) And then there is the problem that slaves are expensive and economically inefficient. Slavery in the Roman empire was abandoned without the need of a Roman Lincoln issuing an Emancipation Proclamation; by the beginning of the Medieval period there were very few slaves left, and they were mostly "luxury", urban slaves. During the Middle Ages slavery was theoretically still legal, but nobody had any slaves: because agriculture had been taken over by serfs, and domestic service by paid labor. Serfs have agency. They are not domesticated. The deal is, the lord lets the serfs work his lands and in exchange, he gets a part of the crops; or the lords leases some part of his lands to the serfs, and in exchange, the serfs work the rest of the lord's lands for free. This arrangement is a fundamental aspect of the European Middle Ages; some even consider it to be the fundamental aspect of the European Middle Ages. You cannot have a "medieval" world without this arrangement. Yet this arrangement presupposes that the serfs have agency: they are a party to a social contract, they are not "domesticated" animals. How could then the hypothetical Anthropoides agricola be a better serf than real human serfs? I don't see how. It's not as if agricultural output could have been made higher if only they had better serfs: the quality of labor was never a problem. The serfs worked as well as possible given the scientific and technological level of the society. The only way I can imagine would be to make them more subservient to the lords, but then serfs were very subservient anyway. Look up the [list of peasant revolts](https://en.wikipedia.org/wiki/List_of_peasant_revolts) on Wikipedia, and see how few uprisings happened in western Europe during the Middle Ages, and how limited they were. The few big peasants' uprisings during the Middle Ages were mostly due to changes in the society induced by its progress towards the modern world: the English [Pesants' Revolt](https://en.wikipedia.org/wiki/Peasants%27_Revolt) of the 14th century was caused mainly by the imposition of a poll tax and by the attempt of the lords to forbid the serfs to move into the economically booming cities; the terrible [German Pesant War](https://en.wikipedia.org/wiki/German_Peasants%27_War) of the 16th century was a convulsion caused by the complex changes experienced by a society transitioning from a medieval world to an early modern world. So the best agricultural ape is the one and only ape to have practiced agriculture. It's us. [Answer] As Will said in his answer, we are pretty much the ideal farmers. It was because we mastered farming that we became sedentary and got out of the stone age. The way to make humans even better farmers is not through intelligence - we have more than enough to do farming, even with medieval technologies. It is also not through the senses, we mastered the best times to sow and heap as we are (and without hearing aids nor lenses). The way to go is physiological. One way to go is to get this species guts to be more like that of herbivore mammals. Compared to cow manure, our feces are crap when it comes to enriching the soil with nutrients. So maybe a completely herbivorous hominid, naturally selected for its ability to farm, would be less dependent on having to raise other animals for their manure. Another adaptation would be the ability to be obese without the health hazards attached to it. If a specied is better at farming than h. sapiens it's probably because they have specialized more to farm, which probably makes it more dependent on farming... And if you have to wait for crops to grow before you can eat, without the possibility to eat game between harvests, you better be good at storing energy. If this species lives in places where it snows, it will probably be able to hibernate. In extremely hot places, it may estivate (same as hibernating, but triggered by extreme heat instead of cold). Finally, this species must be very good in combat. If fleeing from home will cause you to starve to death, then all defenses against invasions are fights to the death. These guys are fierce warriors. [Answer] Assuming a hominid race that is physically superior to humans with regards to farming, you could consider the following: * Instead of keeping your conquered agricultural hominid race enslaved (agri-nids?), you could allow them to keep their own land and society, but change it so that it benefits the humans. Make your agri-nids extremely superstitious/religious. This would help enormously with the initial domestication and subsequent control of the agri-nids. Humanity has plenty of examples of just how much you can get away with under the guise of religion/tradition For example, the 'cultural tradition' of 'giving thanks to our protectors' by donating half their harvest every quarter-year could be instated. After a few generations, who is going to question this? Particularly when the humans are providing their tools, repelling invaders, and building their houses for them! * Create specialized roles inside the already specialized society Most of the great thinkers and inventors of the medieval period were good at a lot of things - they were polymaths. Taking away education, and simply assigning groups of agri-nids to specialized roles should prevent these polymaths from emerging. It could also improve production of food, a la [division of labour](https://en.wikipedia.org/wiki/Division_of_labour) Other physical traits that would be useful could include: * More efficient digestive system - agri-nids need to eat less as they can extract more nutrients from the same amount of food * Ability to determine the pH of soil. This doesn't have to be accurate, perhaps their fingertips have sensors in that give an approximation? * Internal barometer - the ability to predict weather would be extremely useful * Some sort of biological pest control. This could be interesting - do they sweat an excessive amount of natural bug/slug repellent? Note: sorry this is a bit messy, if anyone can format it better for me feel free :) [Answer] If these other hominid species were selectively bred by humans then it is likely they would have been bred for low mental capabilities. They might also have been selected (by humans) for a trait similar to Autism and encouraged to develop compulsive/repetitive/ritualistic behaviours for the tasks involved in farming. If they could only function by routines then they would need a human supervisor to deal with unexpected occurrences. Which might not be a bad thing because it prevents them from taking initiative and wanting to have better lives. I don't know if it would be possible but maybe they might have been able to breed a hominid species that hibernates during winter when there are no fields to farm, thus reducing their food requirement in times when it was traditional for mediaeval human farmers to be subjected to starvation. [Answer] Many answers correctly point out that, for the type of traditional farming employed in Middle age, humanity has already "evolved" through the ages to do it efficiently. I believe you want the dominant species to be human-like, so the domesticated special should have some distinctive traits to tell them apart. My suggestion is: change the concept of farms, and have something completely different instead. The domesticated species should occupy some niche that is not occupied by humans. For example: * make domesticated apes much smaller and more agile than humans, very good at climbing trees and jumping from one tree to the other. Introduce big fruit trees that are more easily, and less dangerously for humans, climbed by domesticated apes. Perhaps when these trees are 'adults' they have some poisonous spines or poisonous excrescences that are deadly for us but not for domesticated apes who evolved to be resilient thanks to breeding. The fruit needs not be a fruit in the traditional sense of it. The tree should provide enough yield along the year to justify the effort, or maybe provide something special that would be very difficult to obtain otherwise and that enhances the diet of whoever eats it. The domesticated apes should have something in return: a shelter/food in winter because they lost capability to hibernate, or maybe some other food they are very greedy for (i.e. Sugar based one). * make domesticated apes that are much smaller and leaner than humans, very good at swimming and spending a lot time under water without breathing. They grow some crops out of some algae, and they get shelters/protection/whatever in return. Humans can also create artificial ponds through elaborated irrigation systems which they would also use for growing regular crops. Both domesticated apes should obviously taste good to eat, so make it more difficult for humans to empathise with them, i.e. their facial expressions should not reassemble ours too much. Also, you probably don't want your domesticated ape Bessy to die of depression because her pup was eaten at -insert festivity name here- day, so make them less affectionate than us and, most likely, our ancestors. Humans would still take over regular medieval farms, as they "evolved" for it, and employ these domesticated apes to enrich their diet pretty much as they did with cows, bees, sheeps, chickens and so on. That way, the presence of domesticated apes will not disrupt the look&feel of what we traditionally call Middle-age too much. [Answer] As farmers they would be bred for endurance and tolerance to an outdoor life of hard work if they were slaves. It depends a lot on the environment and crops. If they were on a tropical island farming root crops for a few weeks a year, they would evolve a lot different physically than if they were growing grain beside a river in a desert which is a lot more labour intensive. If you then managed to make them full time in the fields every day they would be very fit, strong workers, but probably no more so than a warrior who trains every day and hunts etc,. Mentally you would breed for docility and obedience and reinforce it with religion and military might. Over a long period of time this may change their psyche. Culturally and technologically would be their biggest evolution. Their material technology would all be geared towards farming and one of their kids would have a greater indepth knowledge of practical farming than an academic. Their culture values and status's would all be associated with farming and their intellectual innovations would come from that as well. But purely physically there is no reason for divergent evolution. We have had farming societies for the last 10,000+ years of all physical shapes and sizes. We have had slave societies with farm slaves for almost as long. I would say they are more shaped by their environs than their occupation. [Answer] Perhaps the most important part of growing crops, and certainly the starting point of growing them, is the soil composition and health. Soils can be very different even if they are fairly close geographically. Some of the most important parts of soil composition and health are: * Soil pH level-Some crops do better in a more acidic or more basic environment. A small pH change can have large impacts on which nutrients are available to the plant * Soil porosity- Soils need to have plenty of room for water and air to travel between the granules, but those pores must also be small enough to hold some water. Soil that is too compact will not let any water or air in, and plant roots will be unable to grow. Too porous and all the water will run straight through. * Soil nutrient content- Parts of the soil like organic material and minerals like Nitrogen are how plants get their required nutrients. Low organic matter or Nitrogen levels can severely stunt growth. To answer your question, in my mind one of the most useful adaptations a supspecies could grow would be fine finger like antennae, which could probe the soil up to a depth of say 6 inches. If we had an adaptation where we could sense things like nutrient content, soil porosity, pH, just by putting our hand in the dirt, it would be very beneficial. We could instantly tell where the best place for a plot of land is. Something as simple as planting on the right side of a hill can potentially double yield in row crops. It would also allow us to instantly tell when and where fertilizer was needed, meaning we could use less of it, and avoid lots of waste. ]
[Question] [ Basically my idea for a light speed travel concept (not faster than light) is the Zero Mass Field. I am aware that as far as we know this is impossible, but want to know if this makes logical sense and is believable as a fictional concept. My understanding is that anything with mass can't reach the speed of light because to do so would require infinite energy. I also believe anything with zero mass (e.g photons, gluons) HAVE to be moving at light speed. So my concept is the Zero Mass Field - a spaceship starts sublight travel in the desired direction before activating the field generator which creates a zero mass field making everything in it zero mass and speeds towards the interstellar target at the speed of light. The passengers and ship itself would perceive an instant arrival at the destination due to relativity. How you know when to stop is for another question. (I used the ftl tag as there doesn't seem to be an "exactly light speed" tag) [Answer] It is more than good enough for science fiction. [This is actually what the Mass Effect is all about in the videogame series that bears that name:](https://masseffect.fandom.com/wiki/Mass_Effect_Field) > > Mass effect fields are created through the use of element zero. Element zero can increase or decrease the mass content of space-time when subjected to an electrical current via dark energy. With a positive current, mass is increased. With a negative current, mass is decreased. The stronger the current, the greater the magnitude of the dark energy mass effect. > > > In space, low-mass fields allow FTL travel and inexpensive surface-to-orbit transit. > > > It is interesting that you are limiting your version to actual light speed ([and nothing else](https://www.awkwardzombie.com/comic/mass-explanation)). If you went any faster, you'd be fined by the [Auditors of Reality](https://discworld.fandom.com/wiki/Auditors_of_Reality) for [breaking causality](https://physics.stackexchange.com/q/52249/31264) :) [Answer] Here's how the first complete test would go (all the prototypes exploded violently, but it was hypothesized that was due to running the generator too deep in a gravity well). Test drone is launched by conventional rocket, and uses gravity assists from Earth, Venus, Earth, and Venus again to get to the orbit of Saturn in only seven years. All systems have passed multiple tests en route, so as soon as the Sun's space curvature is low enough (for the theorists), the unit is powered up. Because it's a much larger generator than the prototypes tested on Earth, the explosion is bright enough to see with the naked eye from Earth. The problem you have is that every particle in an object has its own particular velocity, and for any reasonably attainable inertial velocity (to use a term from E.E. Smith, who had the "free drive" aka "inertialess drive"), the thermal velocities of those particles will be several times that of the ship as a whole, and in literally random directions. Field powers up, and as soon as it reaches criticality, every particle is traveling at exactly lightspeed -- in whatever random direction it was before. The field will collapse in nanoseconds, of course -- but by then, each electron etc. will be several feet from the atom it used to be part of. Unbalanced charges will then complete disassembly the entire vessel at the atomic scale, and the rebinding of electrons will emit a pulse of EM radiation comparable to a small nuclear explosion. [Answer] Physicist here. Yes, your zero mass field does pass the handwave test for me. But. If you are comfortable approaching the hard science line of science fiction, note that according to current theory, it is the [Higgs field](https://en.wikipedia.org/wiki/Higgs_boson) providing mass to particles. Why not call it the negative (or anti-) Higgs field? "Scotty, engage the Higgs Quench!", "Damage report: our Higgs Choke needs repair." Next, zero mass particles travel at the speed of light. A direct consequence is that they don't experience the passage of time. There is no way they can intrinsically change. At all. So your zero mass space ship cannot, by principle, have a clock telling them when it's time to go to positive mass again. The cause must come from outside, i.e. something at the destination. This would be much easier if you only went to near light speed: enter neutrinos! They are so light (no pun intended), the most gentle of nudges accelerates them to near light speed. And you'd completely eliminate one of the deadliest risks of high speed travel: running into space dust, or rocks, or planets, or stars. Even stars are all but transparent for the neutrino ship (please manoeuvre around Black holes, though.) And since time passes for neutrinos (they could not [change type](https://en.wikipedia.org/wiki/Neutrino_oscillation) otherwise), you can carry a functioning clock aboard your ship to tell when it is time to become more massive again. [Answer] I fully agree with [The Square-Cube Law's answer](https://worldbuilding.stackexchange.com/a/191781/37815) that your concept is good enough for SciFi that does not aim to adhere particularly well to the physics we know. Nevertheless, here are some problems physicists may have with your concept: * [As Zeiss Ikon noted in their answer](https://worldbuilding.stackexchange.com/a/191785/37815), random particle movements will destroy your ship if the particles go light speed in the direction they have. * However, what exactly is the direction of movement? Are we looking at it from the perspective of earth? Or the perspective of the sun? Or the perspective of our galaxy? From the perspective of which galaxy, btw? You see, even special relativity says that there is no such thing as being at rest. You can only ever be at rest relative to something else, but you are are always moving in all sorts of direction, depending what you choose as your reference. And all these references are equally valid. As such, you cannot say: This ship switches to light speed in the direction it's currently moving. * For the ship, and thus for the field generator, time stops completely. The ship simply cannot switch off the field generator. It simply crashes into whatever is the first thing on its line of movement. At light speed. Do I need to say that the explosion would make the Tzar Bomba a fire cracker in comparison? Larry Niven made this exact same mistake with his Slaver Stasis field in his ringworld novel. (He made some more mistakes, but never mind.) * Energy and mass are equivalent, and the conservation of energy is the most fundamental rule in our universe. If you change the mass, you are changing the amount of energy, and physicists just won't buy this idea. They are quite particular about energy/mass conservation. Time and time again, whenever an experiment showed a discrepancy in energy, it led to the discovery of new physics, but the energy/mass conservation principle remained entirely untouched. Nothing of the weirdest physics we know today provides any indication that it might not hold in even the most extreme environment. * Space is not empty. Your massless particles will encounter stuff on their way. The collision may turn any grain of dust into a plasma, but the plasma cannot get out of the way of the following massless particles. As such, each grain of dust you encounter will punch a hole right through your ship. I would hate to look like a microscopic piece of Swiss cheese after a lightspeed voyage. It won't be healthy. I think, you best bet would be to say that the field generator is external to the ship, and that it sets the direction of travel. It basically converts the ship into its massless form. The destination is selected by setting up an anti field at the destination, which turns any incoming massless particles massive again. You could think of it like extreme distance beaming. I see no way of explaining the last point away, but I think that it would be safe to simply ignore this issue. [Answer] While you see zero mass fields often enough in Scifi to be believable to a general audience, the Higgs Mechanism pretty much disproves them as a possibility. The Higgs Mechanism is the prevailing theory right now about where mass comes from. It explains that mass is a function of the interactions between fundamental particles. For Electrons, it is caused by drag with the Higgs Boson Field, and for Protons and Neutrons, it is mostly caused by the much stronger interactions between Quarks and Gluons. So to eliminate Mass you would need to eliminate all of the interactions between all of the fundamental particles in your spaceship. This means there would be no forces left to hold you together... at least until the field generator comes apart and all of your matter has to find a way to reassemble. Best case scenario this will turn you into a sort of nuclear bomb. Worst case scenario, it will turn you into something much worse: a Quark Bomb. Quarks are bound together by the strong force which makes them really really hard to get apart, but if you eliminate the strong force for a while, all the quarks in your body will drift apart... but when your anti-mass field disappears, they will snap together with the strongest force known to man. Quark bombs are a lot of theory with only a tiny amount of observable data, but various models indicate that a quark explosion could be anywhere from 8 times as energetic as a same mass hydrogen bomb reaction to being even more powerful than a matter/anti-matter reaction. So let's say you have a spaceship the size of the Enterprise-D, and put it into an anti-mass field. The resulting Quark explosion would be anywhere from about 6 to 107 billion megatons assuming you cap your explosion as a pure matter to energy conversion. But as I said, a quark bomb might be even more powerful than antimatter. This may seem to violate the conservation of mass and energy, but the strong force becomes stronger as you move two bound quarks apart instead of weaker like electromagnetism or gravity. I don't know exactly how scientific this is, but some authors have taken this to mean that a single neutron can store infinite potential energy based on how far apart you pull its bound quarks. So, it is possible that your ship could even explode with all of the force of a supernova wiping out all life in the solar system. So, zero mass fields make for GREAT weapons and possibly some very interesting power reactors, but not so much good as a form of propulsion as described. ## Instead Use a Near Zero Mass Field One of the problems with math & physics is that it tends to fall apart when you start working with zero or infinite values. So, instead of a zero mass field, what happens if you just reduce your mass? The attraction between your fundamental particles will become weaker, but so will their inertia so an atom with 1 millionth of its normal mass will only be held together by 1 millionth of its normal binding forces, but it is also 1 million times as easy to manipulate; so, it could still (in theory at least) hold its normal shape and form acting totally normal within your local physics system. So lets say your ship is flying along at a humble 10 km/s, but you want to be moving at 0.9 c, you just reduce your mass to about .00000014% of normal. You are WAY less massive and have way less inertia, but still have a proportional amount of binding energy to inertia to maintain normal cohesion. This might also help protect you from relativistic collision problems. Inside your own field you are still only experiencing forces comparable to moving at 10kps; so, even if you run into some space dust at 270,000 km/s, the dust will become part of your local physics system and the impact will feel like a 10 km/s impact: which you can much more easily armor you ship against. Local physics fields of any sort are still pretty soft-science any way you add it up, but at least this should pass some basic believability checks as to why you don't just explode. ## ... and maybe use a Quark reactor to Power your Ship If you have the ability to just turn on and off the fundamental forces of the universe, then depending on what model you go with, you may also have a virtually infinite power supply. Your ship could have a reactor that simply takes a tiny amount of regular matter, lets it drift apart far enough, and then slam back together releasing more energy than your fuel has mass. Since your ship can now violate the conservation of mass and energy, you could in theory accelerate your ship past the speed of light. Or if you go with a model that says a Quark explosion maxes out as a 1:1 mass to energy conversion, then you still have something as efficient as an antimatter reactor, but much easier to control and use for practical purposes. [Answer] Its a good question and other answers brought up some good points, so I'll focus on what mass is (and isn't). The essence of the problem appears to breakdown to two fundamental questions: > > Is it true that anything with mass can't reach the speed of light? > (because to do so would require infinite energy.) > > > and > > Do all massless particles HAVE to be moving at light speed? > > > Which leads to the question: > > If we render massive particles massless to go the speed of light > and then return them to their massive state? > > > To get an understanding of the answer to these questions, we have to understand what mass is in the first place. Mass is quantity which describes the degree to which an interaction will change the energy of a particle. In a classical sense this is easy to understand, a force acts upon a mass, and the magnitude of mass directly (through inverse variation) determines how much energy that mass will gain. The energy gain is expressed as an increase in kinetic energy which is expressed through an increase in speed. This classical picture is not enough to describe phenomena near the speed of light however. This is because the phenomena known as the (Relativistic) Dispersion relation which mathematically is expressed as $E^2 = (p c)^2 + (m\_o c^2)^2$ and is invariant under space-time transformations. So in a classical sense we can think of a particle as "gaining" mass as its speed approaches that of the speed of light. This is because in the classical sense, for a force of F acting on a particle moving near the speed of light, the increase in kinetic energy will not be equal to the increase in kinetic energy from that same force at speeds well below the speed of light. For this reason we say that the particle gains "relativistic" mass. Since this relativistic mass is given by : $\gamma m\_o$ where $\gamma$ is the Lorentz factor $\frac{1}{\sqrt{1-(\frac{v}{c})^2}}$, we note that a singularity occurs when v = c. In other words, at the speed of light, relativistic mass would be infinite, and therefore an infinite force would be required to provide infinite energy to achieve this speed. The answer to the first question would be a yes. Now this is all well and good in the classical picture, but we have to consider the particles themselves. For example, this spaceship is composed of massive particles (electrons, neutrons and protons). A quantum picture view of mass is a little more complicated than the classical picture. This is because mass places more restrictions on the behavior of quantum particles than on classical particles. For example, massive particles can be described through wavefunctions. Wavefunctions describe "where" the particle is and how much energy the particle has and how that energy is tallied. If a particle is massless on the other hand, it cannot be described though a wavefunction, the best it can be described with is through a wave-packet. Without going into the mathematics of this, mass therefore fundamentally is connected with descriptions of localization and state. This brings us to the second question. In special relativity, a massless particle must propagate at the speed of light; because the rest mass is zero and the dispersion relation must hold true, we conclude that massless particles must move at exactly the speed of light. In the quantum picture, because massless particles cannot be described as localized states, propagation in free-space does not violate the uncertainty principle: we can know a photon's energy (from its wavelength) in free-space because we cannot know where it is at (no localized states). For this reason photons (and presumably gluons) cannot interact in a vacuum as long as mass is not involved. Thus this means that the second question is also answered in the affirmative. However, this extra layer of restriction means that massive particles cannot become massless particles without destroying all information on their states (this processes is known as annihilation). Thus the third question is answered in the negative. To conclude, current understanding of theoretical physics does not allow for massive particles to move at the speed of light, nor does it allow for massive particles to be converted to massless particles and then back again while retaining any information on the first states of the massive particles. [Answer] It might work, sort of (E. E. "Doc" Smith's Bergenholm inertialess drives did even better). The problem lies in the interaction with the rest of the Universe: moving at the speed of light, you will perceive every idrogen ion in vacuum as a sleet of hard cosmic rays, and the ship's prow will start to [photodisintegrate](https://en.wikipedia.org/wiki/Photodisintegration). The same would happen to the background radiation; that is why we [shouldn't be able](https://en.wikipedia.org/wiki/Greisen%E2%80%93Zatsepin%E2%80%93Kuzmin_limit) to detect protons with energy above a given range from other galaxies. The blueshifted-to-hard-gamma CMB gets them, and it would likely kill your ship too. You'd need a large beryllium-iron-lead shield in front to absorb the impact (it would be a good plot point, perhaps. Just like the ships of old, you'd need to stop every now and then for [careening](https://en.wikipedia.org/wiki/Careening) - removing the secondary radiation-activated plates from the hull, and replacing them with fresh ones). Also, outer space is relatively full of dust - and, worse, pebbles. Hit one of those when traveling at c, and it's just as if someone had hit you with a gigawatt gamma laser. You'd need to carefully evaluate the route. Possibly, you'd need a sensor probe to run ahead of the ship, and come back to report before you follow the same route; this would imply that even the apparent speed of the ship would decrease significantly, while still remaining very high (one lightyear "jump" every minute?). "Running blind" would be faster if you knew with very, very good confidence a dust-free route. Also, dispersing some thousand tons of metallic dust over a very large volume could be a way of stopping, and maybe destroying, a ship. In your universe, a stern chase would be a suicide chase. [Answer] There are many negative answers, and honestly I think that's a bit unfair. The main thing I want to say is yes, it does pass the handwave test. It makes far more scientific sense than warp drives or hyperdrives or most versions of wormholes. If we're not in the world of hard science I'd say this is definitely in the upper quartile of vaguely believable interstellar travel in science fiction. If you want to set the bar a bit higher for scientific accuracy then there are certainly ways to nit-pick. The first, which some have mentioned, is that it doesn't make sense to say it keeps moving in the same direction unless you specify an inertial reference frame. (That is, it moves in the same direction relative to what?) But that's easily handwaved, either by saying there's some kind of pervasive field that it moves relative to, or by saying that the drive behaves like a photon emitter, turning the ship into a massless particle travelling in a particular pre-specified direction. Perhaps it emits a single massive particle in the opposite direction, which is all it needs to in order to achieve that. The other potential nitpick is energy conservation. If you could Zero Mass your way out of a planet's gravitational well and then fall back in again, you'll have gained kinetic energy for free. That would break thermodynamics, so if you want to be realistic you'd have to make sure that's not possible. But this actually suggests an answer to the "how do you stop?" question: the ship turns back into normal matter if and when it has exactly the same kinetic and potential energy it had when it turned massless. To travel from one planet to another you have to set your trajectory very precisely so that you'll pass through the other planet's gravity well. Then (from your perspective) you'll jump straight from being in orbit around one planet to being in orbit around the other, so you never gained any gravitational potential. (Of course, space is very big and very empty, so if you miss you'll most likely end up travelling through space until the heat death of the universe, and then keep going for all eternity - none of which you'll experience due to the time dilation. So don't miss.) One could probably nitpick all of the above also, but I guess that's not the point. The main point is that if you're not going for absolute physical realism then I think it's fine, and you shouldn't let some of the other answers convince you otherwise. [Answer] The idea checks out at first. My biggest problem is that you don't talk about what the field does and how. You just say "everything in the field has zero mass", which like no. The problem is that mass is just a form of energy and saying the mass is zero thus is equal to saying the energy is zero. Which implies that nothing is in the field. So your current field is more like a "Energy Annihilation Field" which tbh is pretty cool. Your field would make more sense if you say it for example "converts all energy forms into a massless equivalent". That would imply that matter becomes some form of energy that has no mass. The energy is not zero, it is still there just in a different form. So yeah, change how you describe it and we are gucci. [Answer] How about using something to locally disrupt the Higgs field? The Higgs field gives mass to particles (not entirely true, but handwaving can make it so), so it is plausible enough that somehow shielding against it makes things mass-less. The Higgs boson is the latest great thing, so ought to be persuasive. [Answer] Let me suggest an alternative. There is a preferred rest frame but it just appears as if there isn't simply because the normal time dilation/length compression effects prevent us from noticing them (as the math requires) but you can raise that speed in a small volume. In other words the model here is that of a world with an infinite speed of light but with a background ether which slows it down to c (just like any dielectric) which normal physics can't detect because it's perfectly hidden by the math (you can derive SR just from assumption that all matter is in an equilibrium under inverse square laws with force carriers traveling at light speed…as it must for SR to be consistent) Now you just add some kind of effect which lets you push the either out of a nearby volume of space returning c to infinity This has a kinda interesting fun side-effect. If you apply this field to an object that's already moving very fast relative to the true rest-frame you get a huge release of energy that vaporizes that object. It's as if the object was squashed by the length contraction factor and then suddenly allowed to expand to its equilibrium state. Of course this model is totally classical but it is actually consistent though it has some issues in details (classical decay of electron orbits). ]
[Question] [ [The Black Sea](https://en.wikipedia.org/wiki/Black_Sea) is a brackish body of water, that [used to be separate from the Mediterranean](https://en.wikipedia.org/wiki/Black_Sea_deluge_hypothesis). Further back, it was likely [part of the Mediterranean](https://en.wikipedia.org/wiki/Eemian) before the [last ice age](https://en.wikipedia.org/wiki/Last_glacial_period). How long would it, or for a body of water similar to it, take to turn from brackish/saltwater to freshwater? [Answer] # It would overflow... As of right now, the Black sea is overflowing with water, leading it to push more water out to the Mediterranean than it receives. This was not necessarily the case during the last Ice Age, when it was a lake. But precipitation patterns have changed since then, so the Black Sea could not be a lake any more. The Bosporus has an unusual two way flow regime, where the upper layers of the water flow south, towards the Mediterranean, while the lower layers flow north into the Black Sea. According to [Gregg and Ozsoy, 2002](https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2000JC000485), the northward flow is roughly 11,000 m$^3$/2, while southward flow is 16,000 m$^3$/s. This means net flow in the Bosporus is a little less than the Ohio river in the US, or about twice the flow of the Rhine or Nile rivers. That is a not-insignificant amount of water. If you tried to seal up the Bosporus, the Black Sea would simply fill up and overflow elsewhere. # ...into a Mega Lake... On the other hand, suppose that you are Prometheus and you completely replace the Bosporus with a ~250 meter ridge of hills connecting mountainous Turkey and Bulgaria. With no southern exit, the Black Sea would overflow in the lowlands to the North and East. But nearby, there is a big patch of land that is below the level of the Black Sea. [![enter image description here](https://i.stack.imgur.com/PIRWo.gif)](https://i.stack.imgur.com/PIRWo.gif) The most likely path for overflow would be for the Black Sea to flood up the Don, across the [Manych Depression](https://en.wikipedia.org/wiki/Kuma%E2%80%93Manych_Depression), and into the Caspian Basin. In this case, the mega-lake would be expanded into particularly dry areas. The Caspian Sea does not overflow, because the eastern half of it is in desert, and it evaporates as much water as is poured in. At some point the Black Sea would become stable with inflowing water counterbalanced by evaporation. # ...but it will still be salty. The Caspian Sea is salty. Most endoheric seas, those that don't empty into the ocean, are salty. Without water leaving them, any dissolved salts taken into the lake will be concentrated there as evaporation removes the water the salts were formerly dissolved in. Taken to the extreme, with a lake isolated for a long time and a desert to evaporate the water quickly, you get the Great Salt Lake or Dead Sea, which are both saltier than the ocean. So the real answer to your question, is that if the black sea was disconnected from the Mediterranean, it would never become freshwater, it would only become saltier. [Answer] A model for this situation is nearly provided by the Baltic Sea. An alternative model is provided by the Dead Sea. Numerous rivers, accounting for most of the rain catchment areas of Eastern and Northern Europe, flow into the Baltic, while the only outflow is via the Skagerrak between Denmark and Sweden. Evaporation also occurs, but rather less than would occur further south, in warmer climates. The flow through the Skagerrak, though it's rather wider than the Bosporus, is almost entirely unidirectional, which is highly unusual for a sea connected to the world's oceans. About once per decade, a combination of spring tides with a storm surge causes a brief reversal of this flow, hence from the North Sea into the Baltic. As a result, the Baltic Sea's salinity is roughly 0.5-0.8% (actually about twice that in the depths), compared to 3.5% for ocean water in general and 3.8% for the Mediterranean. Baltic Sea water is thus sufficiently fresh that you could drink it without dehydrating yourself. Conversely, the Dead Sea lies significantly below sea level and has no outflow - except for evaporation. It is not directly connected to the world ocean system. Evaporated water leaves its salt content behind; this is the principle behind the distillation method of water purification. As a result, the Dead Sea has a salinity almost ten times that of ordinary seawater. Therefore, you can see that if the Black Sea were dammed so completely that it had no outflow at all, it would become more salty, not less - but if it were only dammed sufficiently to ensure it always flowed outward rather than inward, it might grow less salty. However, it is unlikely ever to reach zero salinity even in that case. [Answer] The answer is that this would never happen. If anything, water from the Black Sea would evaporate, thus concentrating the remaining water and make it more salty. By contrast, salt has no way to leave: it might be deposited by receding water but would redissolve if the water level rose again. Of course the Black Sea is fed by several freshwater rivers, which might indeed decrease the overall salt concentration, but that would never lead to the whole lake becoming freshwater: the original salt content would still be there. As mentioned in another answer, the only way of diluting that salt content indefinitely would lead the Black Sea to overflow, thus reconnecting with an ocean. [Answer] The answers above don't consider the possibility where the Black Sea is disconnected in the sense that it receives no water from the ocean, while still having outbound rivers flowing into it. In this case, the volume of incoming water flow I would be split between outgoing water flow O and evaporation E: ``` I = O + E ``` Now suppose the salinity of the incoming water is x and the salinity of the Black Sea itself is y. In the state of equilibrium, Black Sea would receive as much salt as it would lose. Evaporation doesn't carry any salt away, so ``` Ix = Oy y = (I/O)*x ``` So, for example, if half of the incoming water evaporates, the Black Sea would be twice as salty as river water in the long run. ]
[Question] [ I have a post-apocalyptic setting where the vast majority of humanity died off a few generations ago and the remnants were rounded up and placed on the island of Oahu, which has been made into a wildlife preserve. Packages of supplies and weapons are dropped off occasionally, to provide for basic needs, as well as entertainment and self-regulated population control. Given that several generations have passed since the mass die-off, the modern infrastructure of Oahu has likely deteriorated substantially. What would the cities on Oahu be like after a hundred years or so without maintenance, likely also subject to substantial scavenging? --- Regarding amount of maintenance from the remnant population, my current concept is that the population is quite small (maybe a few hundred people), so there's only so much time/labor to go around for repairs, even if everyone were inclined to cooperate. [Answer] A quick google search tells me that the size of the island is 597 sq miles. That makes it a large island. Now let us concentrate on your question. The first thing that would happen after the apocalypse is that the service stations would cease working. That is to say, the electric power station(s) and phone system would stop working within a few weeks of the disaster. Scavenging for foodstuffs and other supplies would mean that the malls and stores would be the first to suffer. Humans have an inexplicable urge to stock up on supplies even when there is no need for them. Considering that the small population of few hundred people cannot maintain the sewerage and drainage system of whole cities, the drainage pipes and sewers would get clogged within a decade and become dysfunctional. This means that during and after the rainy season, the streets would have knee-deep water in them for weeks. The standing water will also gradually weaken the base of buildings through moisture. Moss and lichen would start growing on the walls within a few years and creepers would take root wherever any hint of soil is present within wall creeks and roofs. Grasses will start growing on the edges of roads and pavements within a few years, followed by small shrubs. The grasses and shrubs, combined with annual heavy rains and lack of repair, will gradually begin to damage the roads. The tarmac will begin to tear off, exposing the filling below. As the tarmac tears off, more grasses and shrubs will take hold, accelerating the process. Unattended wooden houses would be the first to break apart and be ruined. Considering the warm, moist climate, I think most houses will start getting soggy within a few years and be ruined within a decade. Concrete buildings and skyscrapers, with their very sturdy metallic skeletons and weather proof paints, will resist the longest. Initially, the paint layer would peel off (in a decade) and then the cement and building blocks would start falling here and there. After about seven decades or so, mostly the metallic structure would be left standing, with parts of concrete and building blocks attached here and there. Note that this would happen to the outside walls of the skyscrapers. The roofs would begin caving in after about five or six decades (a guess, based on the composition of materials used in roof construction and climatic conditions of the island). So after a decade, you would find the exterior of most multi-storey buildings softened up with metal core showing here and there. The inner parts would be mostly intact, but with fungi and mushrooms growing in all moist places. While the electric and phone services would have long since stopped, the poles and cables would still be present at places, even after 100 years. They will be extremely rusty and weak, but it will take somewhat more than a century to completely rust away the rust-resistant poles and cables. If zoo cages are opened after the apocalypse, you would find many types of animals thriving on the island. This would include herbivores like deer, rabbits and small bison/buffalo herds and carnivores like leopards, wolves and alligators. [Answer] There have been television programs on that which provide a better answer than we could, in most regards, e.g. [Life After People](https://en.wikipedia.org/wiki/Life_After_People). The exception is the scavenging angle. * The survivors would be interested in maintaining buildings. Perhaps they scavenge materials from some to repair others. A house can last quite a long time if the roof is patched from time to time. * Oahu means not much worry about heating, and people can live without air conditioning. So they'd stay in the cities even without power. [Answer] [Gunkanjima](https://en.wikipedia.org/wiki/Hashima_Island) is a city-island that has been abandoned for 43 years. It is exposed to severe weather, which "accelerates" degradation time, so this island is very similar to the island you describe in your question. It was built with very modern techniques for the time, in particular Japan's first large reinforced concrete building was built there in 1916. That means Gunkanjima is not so different from today's cities. It also has everything a city would have: apartments, schools, water and electricity system, public baths, industry, etc. I visited the island, and here are some findings: * Some buildings are in ruins, but others are well-preserved. * As far as there are no holes in the roof, it seems like building do not deteriorate much even after a long time. You get mold, and wall papers fall off, but no plants start growing inside, even in the humid climate. In particular, the 1916 building still seems almost livable after 100 years. * External elements like entrance stairs are devastated, probably due to being in the rain often. Steel cores are rust and concrete is broken. * Electricity machinery (like transformers) are totally rusted. Almost all electricity poles are bent. Expect balls of electricity cables here and there. * Vegetation is found at ground levels, but not that much on concrete areas. Think of how vegetation often does not grow on wide rocks depending on wind and sun exposure. Multi-storey buildings are certainly not "overgrown" by vegetation. * Obviously, there are no public services. You can have a look by yourself using Google Street View, they even have the inside of some buildings. The bigger buildings with solid roofs will probably offer the best living conditions for your survivors, and will most probably remain semi-livable (but without public services) for more than a century. [![enter image description here](https://i.stack.imgur.com/gW4GR.jpg)](https://i.stack.imgur.com/gW4GR.jpg) [![enter image description here](https://i.stack.imgur.com/bZkDu.jpg)](https://i.stack.imgur.com/bZkDu.jpg) [![enter image description here](https://i.stack.imgur.com/gxeHB.jpg)](https://i.stack.imgur.com/gxeHB.jpg) [Answer] The interesting thing about doing this on Oahu is that preindustrial people lived there for centuries. Today, the methods those people used to build their structures and farm the land have been preserved out of cultural pride as well as tourist attractions. I think it would be a lot easier for postapocalyptic Hawaiians to revert back to stone age ways than it would be for, say, the Swiss. 100 years later in Oahu people will be living like the old Hawaiians did, probably in the same places and with the same sort of building and agriculture. One of the nicer post-apocalyptic scenarios I have ever heard of! The other thing about the cities - Hawaii has a big storm every few decades and after the second one Honolulu would be toast. By 100 years it would be a mixed forest of native and nonnative species like the rest of Hawaii. Low hills would mark the sites of former buildings, like the Maya sites in the Yucatan. Escaped panda bears and gorillas would be nice additions to this land. There is plenty of bamboo for the pandas and lots of wild fruit for the gorillas. [Answer] There are different types of neglect. What we should consider is the size of remaining population, its ability to perform the maintenance and location. Your population (few hundred people) is way too small to maintain infrastructure on the entire island of Oahu. They can, however, live nicely in one of the smaller villages. The ability to do the maintenance is not very clear. What kind of supplies will be dropped? Scavenging can only go so far, and without fresh supply of appropriate materials, keeping even a few buildings and roads up do date would be problematic. Your people would have to improvise, like, "What can we do when we run out of bags of fresh cement?" Overall, they should be able to manufacture suitable replacements for most building materials, if they have a will to do it. Location of your site will determine the speed of deterioration (or natural restoration, if we like to call it so). Hawaii would be a very intense place for man-built structures to last. While in some dry climates I would expect buildings to last for centuries, on Oahu natural erosion and plant growth should consume Honolulu within decades. After two centuries, some skyscrapers would still stand, some would collapse, and ruins would be overgrown with plants. I don't think this is where your people would like to live. Additional factor that concerns me is social organization of your colony. You have mentioned that among the dropped supplies there will be weapons. Why would a small community on Oahu need any weapons? I imagine there would be perpetual infighting, which would keep the population down from what it could be and affect the amount of maintenance that could be done otherwise. [Answer] Well this all depends on HOW much lack of maintenance you are referring to. Roadways would more than likely be chewed up within 10-20 years. Concrete highways have a potential life span of 30 years before needing to be repaved. Alternative means for transportation would revert to either walking, biking, or a carriage/animal of some form. Assuming an extreme lack of maintenance, the island wouldn't be getting any gas. If they do, it is in very small quantities that will need to be rationed off and used for generators and other more critical life support features than vehicles. Buildings will more likely than not be overgrown by plantation and depending on how poorly they were built, may even have parts of it collapsed at this point. While the pipes underground may be able to last 100 years (assuming they were freshly placed shortly before the catastrophe) they won't be in good enough conditions to trust them for water. This again assuming that the generators and pressure systems that governs the pipes stop working. Water will have to be drawn from rivers, lakes, oceans just like we did without plumbing or create basic irrigation canals that can use gravity to transport water. It would be unlivable in the way we know current life. Electricity would be minimal and spotty. Cell phone service will be non existent. TV would be gone. MAYBE radio but it would be doubtful. Walkie talkies would probably be the most common form of communication (assuming batteries are a part of the care package). Essentially, you would have to revert life back to life without any modern comforts. The buildings would be livable enough but everything would virtually have to be done by hand. Cleaning of clothing, getting water, food. Candle light for night time unless provided solar powered flashlights (which there is such a thing, I have 2 myself). Again, I am imagining an extreme example of neglect as I am not sure how much neglect you are referring to but I would imagine that things would be super run down and life would be reduced to that of the pre-industrial era. You also asked about looting which yes, stores and valuable goods would be cleaned within a year or 2. [Answer] You can look at photos of places like Chernobyl, Fukushima etc for a sense of how nature would take over (though not quite 100 years, and not Oahu). Chernobyl: [Chernobyl & Pripyat](https://imgur.com/a/trm7p?grid) Fukushima: [Guy Sneaks Into The Fukushima Exclusion Zone, Posts Never-Before-Seen Pics Of Town Untouched Since 2011](http://www.boredpanda.com/man-sneaks-into-fukushima-exlusion-zone-today/) Other abandoned places: [21 Photos Of Nature Winning The Battle Against Civilization](http://www.boredpanda.com/nature-reclaiming-civilization/) [Answer] I'm surprised no one has mentioned the challenges/consequences of fire. Even if no electrical fires were started before power failed, and most accelerants were pillaged, they'd struggle to identify and contain fires. Hawaii does possibly benefit from possibly [reduced lightning levels](https://www.fs.fed.us/database/feis/fire_regimes/Hawaii/all.html) and from being fairly moist. But any urban fire that got going would still be a challenge to put out with limited fire-fighting understanding and resources given the decay of structures within the city. You did well in choosing Oahu rather than the Big Island, as there's no active volcanoes. Human sources could be very problematic, but let's assume those are carefully controlled too. But even so, it could still be precarious, as this [US Forest Service paper](https://www.fs.fed.us/database/feis/fire_regimes/Hawaii/all.html) indicates that there has been a significant increase in flora fires in Hawaii in the last century due in large part to the introduction of non-native grasses. So while you may not be in the worst location scenario, there's still probably a fair chance of at least pockets of fire damage. The citizens may be able to detect and put out fires around a small village, but protecting the big cities like Honolulu would seem very difficult. So it's likely that some parts of any areas they don't focus on would be damaged by fires. And even within their active cities, there's a fair chance of significant damage, or perhaps even a scenario where the entire population is decimated by wildfire, unless they received good knowledge or assistance for dealing with this. ]
[Question] [ I understand that the U.S. has accidentally dropped bombs on ourselves many times without actually detonating the bombs. These accidents have caused craters, but no radiation (or in a couple cases, just a 'little radiation' that leaked into soil, etc). An easy google search will tell you more. We've also accidentally transported armed nuclear warheads without realizing they were armed (see R. Maddow's book 'Drift') But for my specific question... is it remotely possible that after a nuclear bomb has been dropped by accident, it could then detonate? That is, create a mushroom cloud? If so, how? How would the failsafes fail? WHY THIS IS WORLDBUILDING (because there have been complaints) I'm literally building a world in which such a thing could happen. I'm writing a novel where we have a different president, a slightly different governing system, and more or less the same military, but slightly more incompetent than it currently is. This world will reflect on our current world a good bit, but it differs a lot. In the novel there is a nuclear detonation in the U.S. that is basically the U.S.'s own fault... want to figure out a way that it could believably happen) [Answer] Yes, it is theoretically possible. (nuclear) bombs do not look at flags or landmarks, they don't know if they are exploding in a friendly territory or not. They are just given some coordinates, their computer follows the trajectory from the launch point until the target point and then, KABOOOM, they explode. If somebody, accidentally or willingly, would insert the coordinate of a friendly location and nobody should realize the error until the explosion, the blast would surely happen. (the same can happen if instead of giving the coordinates to a computer, one gives the coordinates to a plane carrying the bomb) That's why there are several redundant security layers in such systems, to reduce the chances of human failures. [Answer] Honestly, nuclear weapons (or American nuclear weapons, at least), have robust and effective safeguards to prevent a nuke from accidentally going off for technical reasons (like an electrical short in the triggering mechanism or being hit by gunfire or an explosion, or being set on fire, etc.), and are designed to be exceedingly hard to detonate anyway. The general design type in use is an implosion-type device that requires [special, high performance trigger devices](https://en.wikipedia.org/wiki/Krytron) to initiate a [spherical implosion that compresses the fissionable core to "critical mass" (density, really)](https://en.wikipedia.org/wiki/Nuclear_weapon_design#Implosion-type_weapon). As a result, it's not really possible for an accident to detonate a nuclear weapon, from a technical standpoint. In fact, it's extremely difficult to deliberately detonate a nuke without all the required components and authorization codes, so the "terrorists steal a nuke and set it off" trope is pretty implausible, too. Having said that, nuclear weapons are tools, which do what the human operating them tell them to do, not what the human operating them meant to tell them to do, which has resulted in dozens of "near misses" over the decades, and that's how you would plausibly detonate a nuke by accident - human error. While there are layers of safeguards in place there, they've been bypassed or failed frequently over the years, and many of those have made it into the press. [Nuclear launch codes set to 00000000 for 20 years](https://arstechnica.com/tech-policy/2013/12/launch-code-for-us-nukes-was-00000000-for-20-years/). [Nuclear silo doors left open while the nuclear officer slept](https://www.cnn.com/2013/10/23/us/air-force-nuclear-silo-doors-opened/index.html). [Six nuclear cruise missiles accidentally loaded onto a B-52 were missing for 36 hours](https://en.wikipedia.org/wiki/2007_United_States_Air_Force_nuclear_weapons_incident). ... And there are scores more, going back to the 50's, [including a frightening list of instances](https://en.wikipedia.org/wiki/List_of_nuclear_close_calls) where nuclear powers were close to deliberately launching nuclear weapons at each other under mistaken pretenses. It's not hard to imagine how coupling one of these incidents (or something similar) with a poorly timed drill or training exercise or weapons test could result in a live nuke being launched and detonated, and I think that's your most plausible approach here. Known, documented examples of human error with our nuclear weapons, coupled with some bad timing turns a training exercise into a nuclear detonation. [Answer] There was an extremely close call in the 60s. the US Air Force came close to detonating a 4 megaton bomb over North Carolina. According to one engineer, "one simple, dynamo-technology, low voltage switch stood between the United States and a major catastrophe". [More about that here](https://www.theguardian.com/world/2013/sep/20/usaf-atomic-bomb-north-carolina-1961) Human error is a major factor in all of the close calls we've had and therefore I feel it's perfectly reasonable for a nuclear accident to occur. [Answer] The "best" failure mode resulting in an accidental detonation would be if you dropped a semi-decommissioned first generation atom bomb, one with a "[golden gun](https://en.wikipedia.org/wiki/Gun-type_fission_weapon)". In theory if a golden gun weapon hit the ground, very hard, at the wrong angle it could go off. That is it could if all the safeties had been pulled and the bomb casing had been removed so it hit the ground parallel to the axis of the firing mechanism. This is because golden gun bombs consisted, operationally, of a simple guide barrel and two subcritical lumps of fissile material that fit together when one of them is fired into the other. If the mechanical safeties had been pulled out the extremely rapid deceleration of hitting the ground could do the work normally reserved for the trigger charge. In actual bombs the golden gun was oriented perpendicular to the designed impact line so that accidental drops couldn't set them off even without the safety rods across the barrel. Modern bombs are a whole lot more complex and require a finely tuned detonation sequence to go nuclear so setting one off accidentally would be nearly impossible. It should be impossible for a modern weapon to be detonated accidentally or through negligent handling but if a real bomb and a real arming code was slipped into a training exercise for nuclear deployment then you could get a deliberate mushroom cloud incident from a modern weapon. FYI the highest nominal yield for a Gun-type Nuclear munition is for the W33 nuclear artillery warhead which was only retired in 1992 and had a tested nominal yield on 40kilotons. [Answer] Not our bomb Upset over Russian territorial grabs, Ukraine discloses that it still has nuclear weapons left over from Soviet days and is ready to use them. Frenzied diplomacy ensues, and ultimately the Ukranians agree to give up their nukes - but to the Americans. The US agrees to take them back for safe disposal. These bombs are of ancient Soviet make, and the angry Russians refuse to provide information which might be of help dismantling them. Worse, in getting ready to use them the Ukranians have jerry-rigged these bombs to bypass the missing Soviet safety protocols. On trying to disassemble and inactivate one, it is detonated. [Answer] Oh dear oh dear oh dear. Where do I start? I highly recommend Command and Control by Eric Schlosser. It's an account of American nuclear safety and policy through the Cold War. It's an excellent, if somewhat alarming read. There was a lot that could and nearly did cause a nuclear disaster, especially when they were being flown around by bombers, at least until saner, safety minded people finally prevailed and forced better safety standards. What precisely could have gone wrong? * The X-Unit (a kind of power discharge device used to detonate the explosive 'lens' that set off the bomb) could accidentally be charged by a short circuit or old cabling. From there only a minor additional issue of any kind could have caused discharge and detonation. * An error in (manual!) assembly could have easily triggered the detonator in older nuclear weapons * Dummy 'training' nukes were stored right next to real nukes. Pre-assembled nukes of course had real atomic cores integrated into them. * Nuclear weapons were designed in such a way that a fire could cause safety features to be bypassed because of wires being close together. Now it's our good fortune that this hasn't caused a nuclear accident to date but of the 32 broken arrow incidents to date any one of them could have ended in nuclear fire - many over US territory! So yes, it's entirely realistic and it wouldn't be all too distant a world in which we look back and ask 'is there a world where we never had a nuclear accident' Today's nuclear weapons are much safer by design, of course - a product of a great deal of hard work by many people - but it's not too hard to see how we could be back to that level of (hidden) risk. In 2011, some technicians at the Los Alamos nuclear laboratory decided it would be neat to pose 8 plutonium rods for a photo op. They were close enough that reporters clustering around to take photos would have caused a criticality incident (from their bodies reflecting neutrons), killing everyone in the room. As it was it was realised and carefully defused in time. The safety team walked off the job in disgust afterwards, and to this day the lab still hasn't been able to satisfy safety checks and remains closed. It's no effort at all to imagine a world not too far from now where growing political pressures and global instability have led to the development of new weapons. Where concerns about the ability to guarantee their detonation overrides concerns over how to prevent it. A new missile, built without the hard-won lessons of the nuclear age, 24/7 alertness drills, a miscommunication to an operator in Hawaii... It would be all too easy. [Answer] My favorite story demonstrating that this is possible is the [1980 accident in Damascus, Arkansas](https://en.wikipedia.org/wiki/1980_Damascus_Titan_missile_explosion). A maintenance accident led to the explosion of a Titan missile (it's fuel, not its warhead of course). The warhead itself was blown outside of the base's perimeter. If its safeties had failed, there'd be a big hole in Arkansas. [Answer] During the cold war, this was actually a scenario which was not at all unlikely. Both the USSR and the United States were prepared to launch their arsenal as quickly as possible in case the other side showed any signs of aggression. Launching nukes quickly requires loose safeguards. Accidentally triggered world war III was a very common topic. Some cult movies from that era about that topic are [War Games](http://www.imdb.com/title/tt0086567/), [Dr. Strangelove](http://www.imdb.com/title/tt0057012/) and various James Bond movies. But there are many more examples. Common triggers are: * Miscommunication in the chain of command * Human error while handling the nuclear launch systems * Crazy supervillain tricking superpowers into nuking each other by staging a nuclear attack However, if you want your story to take place after the Cold War, then all these scenarios will feel outdated and unlikely. The United States no longer face a threat of mutually assured nuclear destruction (no, North Korea is not a serious nuclear threat to the US mainland), so they no longer need a hair-trigger on their nuclear arsenal. If you want to revive the cold war era fear of the world constantly being at the brink of nuclear annihilation, you might have to introduce a new nuclear arms race which would again warrant a way to quickly fire (and misfire) nuclear missiles. [Answer] I'll quote an anecdote from the other side of the pond. A Soviet ICBM firing drill does wrong in the 60s. Well, the ICBM is loaded with a mock-up of the bomb, but it does not land in the area anticipated. Meanwhile, in a town, like 9000 km from the designated goal area, a strange meteorite falls down and digs 3 meter down the street. After an investigation, following turned out. The ICBM was set up by entring the fire distance and orienting the rocket to the correct azimuth of the destination. Some poor soul oriented the rocked correctly, but 180 degrees in reverse. The missile shooting and maintenance team got into deep trouble with military court. --- What would you need: * The 60s technology. I bet that nowadays the coordinates of the destination are entered via a computer link. There would be failsafes to prevent typos, wouldn't they? Really? Really? So I'd speculate that one rather needs to choose "New York" or "Moscow" from the list than entering coordinates directly. * That was a bulk head. You'd need another mishap to mount the real warhead on the rocket. This makes it two very, very unpropable mishaps. * You might want to add an evil will of a second (or third) party to organise these mishaps. [Answer] You mentioned that you've looked into previous broken arrow incidents; I'm curious, did you come across the B-52 crash in Goldsboro, NC (1961)? Long story short: the plane lost control, crew ejected, and the two Mark 39s -- 4 MT Hydrogen bombs -- it was carrying were somehow loosed during the descent. One hit nose first and buried itself 20'+ in a field. The other, known as the Faro bomb, opened its parachute and ran through all of its safety switches except the arm/safe switch physically controlled by the pilot. * <https://nsarchive2.gwu.edu//news/predelegation/pd15_02.htm> * <https://www.theguardian.com/world/interactive/2013/sep/20/goldsboro-revisited-declassified-document> * <https://www.theatlantic.com/technology/archive/2013/09/the-single-switch-that-saved-the-east-coast-from-nuclear-disaster/279916/> * <https://www.ocregister.com/2012/12/31/orange-resident-recalls-holding-future-in-his-hands/> Other terrible nuclear ideas we've had that may fit your plot line include the M-29 Davy Crockett Weapon System, because we needed a small portable nuke launcher that can be operated and carried by a three man team or mounted to a jeep. (up to two mile range and ~10-20 T yield) GAR-11 Falcon Air-to-Air missiles, because dog fights are not interesting until you start throwing 250 T warheads at each other. 27 Oct 1962 they were deployed on F-102As to help Charles Maultsby's U-2 escape Soviet Air space and MiG interceptors; the pilots had individual control over the missiles. [Answer] If you're willing to get into gray areas there are rumors that the US and Russia had 'backpack nukes' (or 'demolition nukes'). They were designed for two-man special ops teams who were dropped off some distance from the target and traveled overland to the target. Think of something that you would place at the base of a major bridge - a special ops team carrying conventional explosives couldn't take down the Golden Gate bridge but a team with a small nuke (Davy Crokett size) could. Ditto a team that "accidently" drove a van off the bridge over a major dam. Conventional explosives won't do much but a small nuke, detonated under 1000 feet of water, should be able to screw up the internal gear (e.g., the power turbines) even if it doesn't punch a hole in the dam. There are also theoretical 'briefcase bombs' that could be carried by an individual. I think that's less likely since you would either need so much shielding that it would be obvious (try looking casual as you carry around an 80 pound briefcase in one hand) or they would set off the radiation detectors that you don't realize are around. But that's pure conjecture on my part... Anyway if you assume that the rumors were true then you can also assume that they're designed to be easily set off by special ops teams - there may not be the usual safeguards. Given what we know happened with real weapons it's not hard to imagine something similar with one of these rumored nukes. [Answer] Other contributors have noted several indirect safegoards (physical keys, electronic keypads). However there are other safeguards in the detonation sequence itself. A carefully choreographed set of events must take place in some designs. For instance, the crush bombs achieve critical mass by taking a hollow uranium soccerball and detonating explosives on each panel. The safeguard in this case is that the triggering explosives must detonate at nearly the same time to cause a nuclear explosion. The implication is that whatever set of mistakes / actions that lead to a nuclear detonation would have to avoid interfering with these carefully choreographed events. From my example: If the wires to the explosives on the soccer ball were cut, you couldn't just sodder them back together. Changing their length or their conductance "may" be enough to keep the explosives from detonating at just the right time (resulting in a bunch of broken uranium plates or the fizzle described above). [Answer] Yes. Can you accidentally shoot yourself in the foot with a pistol? There isn't really a difference except for scale. You are already accepting a guidance/engine failure as a real world scenario, you are only needing the arming sequence also fail simultaneously. It is a system, systems fail. It may be extremely unlikely that all the moving parts fail simultaneously, but the "is it possible" question is most assuredly yes. The "how" is as easy to find as opening a browser and searching for weird stories about how things break... * Targetting GPS failure: the system thinks it is in the right place, so it arms. * Structural Failure: The physical impact of the failing rocket. * Government Contractors: The failsafes never worked, but no one ever noticed. * Human Error: Like the Russian rocket from years back... someone installed the failsafe hardware upside down, and by some ridiculous but real-world miracle of ineptitude, it worked inversely. * Act of God: Lightning strikes as the misfiring missile is about to crash otherwise harmlessly, and triggers the reaction. ]
[Question] [ Closed. This question is [opinion-based](/help/closed-questions). It is not currently accepting answers. --- Want to improve this question? Update the question so it can be answered with facts and citations by [editing this post](/posts/146891/edit). Closed 4 years ago. [Improve this question](/posts/146891/edit) Some purple person, somewhere, collected the Eternity Baubles, clicked their heels and suddenly, half of all living beings in the universe just go poof.1 The effect isn't restricted to sentient beings, but to literally every living being: half of the plants producing oxygen just vanish, theoretically. Barring the potentially grim effect of that (which would be hard to analyze), let's use the premise that half as many consumers can survive on half as many living resources (probably not correct, but no need to over-complicate). So tomorrow, half of the humans vanish. We assume equiprobability for everyone, since our purple giant thought it would be only fair. On average, half of farmers die. Half of politicians die. Half of airline pilots (including those in flight) die. Half of nuclear plant workers die. We assume the distribution roughly even out in the end, given the scale. I'm really curious to know if, theoretically, assuming we suddenly lose half of the workforce, society itself can survive the aftermath and adapt to function roughly as it does now? (Of course, half as many people doesn't mean half as much work, because handling the half-pocalyspe will require a fair bit of extra-hours. Firefighters will probably have some busy days) Do we have enough redundancy to keep society going, or do we just mostly die as a species, with only a fraction of the surviving 50% making it into the wild? 1: Any resemblance to a current blockbuster movie is incidental --- EDIT (META DISCLAIMER): There is currently a [meta debate regarding questions overlapping with third party world](https://worldbuilding.meta.stackexchange.com/questions/7334/policy-clarification-asking-about-commercial-or-third-party-worlds). While this one has obviously been sparked by the viewing of a recent movie, I'd like to ask from a high-concept question point of view, which is in accordance to WB.SE rules. The question use no mechanisms from the MCU, nor do the answers. No super-heroes, no space civilization visiting us, just plain old Earth humans and their society. The premise is only easier to explain with a visual example at hand. I suppose the VTC come from the legal debate currently on meta. I'd appreciate if the close-voters could clarify why they do so, if their reason is different from the one counter-argumented above. [Answer] Alright, let's start with a basic premise; if half the humans disappear, more than half the population dies. Like you said, some people are in charge of planes, you only have half the firefighters on duty when half the food being cooked catches fire because there's no-one to take it out... You get the idea. Just to be clear, the first week is going to be pure hell. You're going through massive emotional trauma because you're missing your son Mike and your Aunt Mabel, but on top of that stores are shut, supplies are running low and everyone around you is freaking out. The hospitals are packed, ambulances and fire brigades are under immense pressure and generally speaking you're not turning up to work either because with everyone freaking out around you it's easier to just go with the flow. The second week is worse, especially now the looting has started, the radio stations and TV channels are down leaving so many idle and desperate hands to be the devil's playground... But, things get better. I'm not saying it won't be tough, especially for the cities. We've dealt with those apocalyptic questions like zombie outbreak before and I'm the first to tell you the cities are gone in those scenarios, but this is a little different. There still are police, emergency services, government officials, businesses, etc. Also, we're not dealing with something contagious. It's a one-off event that's going to cause massive emotional trauma and then some definite emergency and supply issues, to be sure. No-one's going to be happy for a very long time. But, if you survive the first month and have a good government response happening around you, society survives. Some people will do it tougher than others and to be sure, there will be a lot of suicides and the like due to the people who just can't cope. But, with the exception of some perishable goods, there's literally now double all the stuff just lying around. So, there's a very good chance you'll survive even if you raid the neighbour's pantry to do it. Eventually, you'll get back into work as well (the government will really want you to do that) and society will survive. It'll be a bit dysfunctional at first and to be blunt, economies don't like the kind of sudden change it's going to experience - expect a flat couple of years first up, but given the even distribution, we won't lose any really critical knowledge and experience will be gathered by all the 'next in lines' that have been gathering experience already beside their mentors. They just won't have the buffer they'd relied on in previous years is all. In the country, it will be tough but then so is drought, cyclone season and many other issues faced in agricultural lands. People will get through it with little disruption past the initial shock. The cities will fare far worse in the short term and to be sure, there'll be some looting and violent activities, but there is still authority in place, and hopefully they'll rise to the occasion. But society will survive and will adapt to the new conditions. [Answer] ## What does history teach us? * During the [Thirty Years' War](https://en.wikipedia.org/wiki/Thirty_Years%27_War#Casualties_and_disease) the Germanies lost almost half of their population in the 17th century. As we all know, the Germanies eventually recovered and became mighty Germany. * [Justinian's Plague](https://en.wikipedia.org/wiki/Plague_of_Justinian#Virulence_and_mortality_rate) killed almost half of the people living in the (Eastern) Roman Empire in the 6th century. As we all know, the countries of the eastern Mediterranean eventually recovered. In both cases, after recovery the countries were profoundly different from what they were before the disaster struck. So the conclusion is that yes, we can and will keep the society going; but what will emerge will be a new society. [Answer] There is absolutely no problem for the society to survive in your scenario. Killing half of plants and animals will barely be noticed. We kill more than that all the time. Most species will recover within a generation or two. It may take a while for long living species like Oaktree or Blue Whale, but that's not a serious concern. As for human, yes, there will be no problem either. Relatively speaking. According to different estimates, [between 20 and 80% of jobs are unnecessary anyway](https://www.theguardian.com/books/2018/may/25/bullshit-jobs-a-theory-by-david-graeber-review). Many companies will struggle in the new situation and may collapse when their services are no longer a priority (e.g. producer of reality TV?), but their more productive employees will find jobs in essential businesses. Fewer people means lower demand for services as well. [Population has doubled in last 50 years](https://www.worldometers.info/world-population/#milestones). As you may imagine there was a society 50 years ago. As in the other answer, we had large scale depopulating events before. It's not unheard of for a country to lose 20% population in a war, even in recent times, for example [Poland in World war 2](https://en.wikipedia.org/wiki/World_War_II_casualties). They not only lost a fifth of their population, including most of the educated elites, but were also physically devastated by war. Warsaw was nearly obliterated with around 90% of buildings destroyed. After the war they were trapped behind the iron curtain and cut off from international trade or cultural exchange and yet managed to survive as civilized societies and rebuild from ruins. In your scenario most of infrastructure is intact, at least initially, so your society can absorb much higher loses. The sudden drop will be drastic but will not destroy our civilization. The old, inefficient power plants will just be closed as the demand for electricity halves. The good nuclear plants that lose half of their staff will halve the holidays for the survivors for few years and recruit some staff from closed plants and recent graduates to fill the gaps. At the moment [half of STEM graduates work in unrelated jobs](https://dera.ioe.ac.uk/2664/). Instead of joining investment banks they will get productive and fulfilling jobs in their field. No problem at all. TL,DR Apart from initial panic, there won't be a long term danger to the society if half of the population disappear. On the contrary, if you're one of the survivors and don't die in some riots in the immediate result of the event you may even be better off than before. [Answer] Microbe populations will bounce back within days, fungi at a similar rate and plants over the course of weeks to years depending on the size of the organism. That's assuming that their ecosystem still exists and they still have a viable population. Some species will go extinct because the 50% of their population that dies happens to be disproportionately either male or female and they lose too much genetic material. When it comes to societies though we're talking about human causalities and social complexity becomes a major issue. > > "As little as a 2% lose in critical infrastructure workers could cause the collapse of any first world nation you care to name." - Scientific American on the impact of epidemics on complex societies. > > > The biggest issue isn't actually the people themselves being off sick, or in this case dying, it's the lose of institutional memory that those people represent. The biggest problems occur where you have a small group, possibly even single people, who know things about their workplace that no-one else knows, and they happen to work in power plants, oil refineries, chemical plants, water pumping stations, and transport hubs. Nuclear plants may be a major threat to their immediate surroundings and the wider world, [some](https://en.wikipedia.org/wiki/Guy_McPherson) have suggested that in the event of human extinction they could in fact sterilise the whole planet in the end. But even small plants making [fertiliser](https://en.wikipedia.org/wiki/West_Fertilizer_Company_explosion), [pesticide](https://en.wikipedia.org/wiki/Bhopal_disaster) or [refining crude oil](https://en.wikipedia.org/wiki/Texas_City_Refinery_explosion) are a threat to the people around them if they lose key staff who know how everything works. Even if the farms weren't effected by the die-off, costing at least half the year's harvest, if you don't have truckers and enough diesel to keep their vehicles moving people are going to starve en masse in cities all over the world. That will happen even before the short harvest, failure to adequately distribute the existing food stocks in storage could kill millions. Subsistence farmers are better off since they live off the land they live on but even they buy in some of their goods so they're still going to suffer some damage. Also lets be very clear that an initial 50% kill is going to cause massive secondary casualties given the proportion of critical staff in certain environments: * Cruise ships, and super cargoes, are likely to end up adrift with no surviving bridge crew. * Trains are likely to crash all over the world without drivers, or with drivers but no remote switching staff realigning tracks. * Planes may fall from the sky with no pilots at the controls, some cities will be burned to the ground due to multiple near simultaneous airliner crashes. Firefighters may be further hampered by lack of staff at pumping stations etc... leading to a breakdown in water supply. * Some isolated communities that lose medical or infrastructure staff, are eventually going to die off due to some normally small defect, or a breakdown that wouldn't have happened with someone watching the dials. * Some isolated farming families will lose both parents and the kids will burn down the house or starve before anyone thinks to check on them. Odds are that a lot of farms will suffer catastrophic damage due to neglected chemicals or livestock in the weeks and months after the disaster. [Answer] The actual losses will be much higher than 50%. Equiprobable distribution of losses means that some passenger planes won't loose either pilot but some will loose both. Planes falling out of the sky not only kill off their passengers but also any unlucky ground dwellers under them. High speed Freeways are going to be deathtraps! Critical tasks such as surgeries, which are going on at the moment of the disappearance will probably go bad, not because key people will disappear, but just because having anyone in the surgical room disappear will leave the survivors so distracted and disturbed that mistakes are bound to happen. There is a 50/50 chance that the secret service agent holding the football will disappear, taking the nuclear trigger with them. Does that thing have a deadman switch wired up to it? I don't know but it might. If the trigger survives, what are the chances that someone will use it, mistaking the disappearances as a foreign attack? Half of the passwords in the world will be gone, so half of the securely stored information is gone forever. Complex computer systems often have only one or two people who understand their most critical parts, so expect a lot of service failures. Half of the money in the world will be out of circulation for a while. The government departments which issue death certificates and handle probate are going to be under staffed and a little busy for a while. If one of the deceased was your boss and she was the only one who could sign paychecks... Now factor in the emotional responses of the survivors. Without warning or explanation, many will have lost their reasons to live in the form of fallen partners and children. Under-informed, bereaved and armed is a really bad mix. The WTF-Killings rate will skyrocket. With half the police and military gone, and economic chaos, expect the crime rates to rise as well. My point is that the actual losses could nearly match the initial losses, so our society's ability to survive is uncertain. At the very least, expect our modern society to perish. Our tower of technology is very brittle and would definitely not survive losses of that level. So ultimately, it depends on your definition of "Society". If by that you mean your ability to use your phone to pre-order a starbucks coffee which you will pay for with plastic using money you haven't earned yet... then "no". If you mean some surviving humans working together to feed themselves using manual farming techniques which they mostly have to re-invent the hard way... then "yes". Given what would be coming afterwards, the lucky ones would be those who died in the snap. [Answer] # Society where? Blue whale society might struggle. If you kill off one krill in every two, you're significantly reducing the density of the food supply. It takes so much energy for a blue whale to feed that they don't bother opening their mouths unless the krill achieves a certain minimum density. Though this has as much to do with krill behaviour patterns, so they could be ok in the long run. Unstable governments might go either way. You're tossing a coin about some governments, one could estimate that 50% of dictators would go. If the country is based on a solid chain of command and social order then they'll simply be replaced. If they're strongman types then it's time for a good old fashioned revolution. However if there's a country under pressure from something simpler, like a shortage of water, you've suddenly reduced the pressure on the limiting factor by a significant percentage. You could bring an unstable country back from the brink. In summary, countries with good infrastructure and a solid social order will suffer, but they will survive. Unstable nations could go either way, but then they were unstable in the first place. [Answer] A lot of folks have covered a lot of great ground by treating each country as a closed system. However, we also need to consider that warfare at a distance is a relatively new phenomenon and historical precedence doesn't tell us a lot about this. I would expect a number of countries to take advantage of the situation and perform some sort of first strike against neighboring countries or distant enemies. There are many simmering tensions in the global landscape and a drastic shift like this could be enough to tip them over into full-on boiling. Your question was phrased: > > Do we have enough redundancy to keep society going, or do we just mostly die as a species, with only a fraction of the surviving 50% making it into the wild? > > > While societies may keep going, the instability caused by opportunistic nations (or, indeed, rogue elements within nations) may be enough to destroy our species as they wage war to gain dominance. [Answer] The Black Death killed 25% of the population of Europe (approximate). This is only twice that, the conclusion is obvious. Initial confusion and dislocation, followed by rapid promotion to fill the gaps, and eventually everything will go on as normal. Conclusion: society will survive. [Answer] Many other answers have addressed the immediate issues around losing half of all living things at once...mass chaos and conflict followed by something of a equalizing period whereby life gets on with the business of...well...living. I'd like to offer that life would actually THRIVE under this circumstance. Plant life: The red in tooth or claw can also be categorized as green in root and stem.... [plant life is as competitive, if not more, than animal life](https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/1365-2435.12081). The sudden loss of half of the vegetation would cause an eruption of competition from the surrounding plants. Unlike areas where the forests have been cross-cut and ALL mature life removed we would have plants of various stages of life ready to consume the space that is now suddenly available to them. Plants that might have been struggling can expand and thrive in the new environment. Additionally they will be competing less with human and animal competition (if only for a little while) allowing greater ability to spread unmolested. Animal life: The sudden shock to the food chain would cause distress in a number of species. However, with less competition from humans and fewer competitors for resources in general, many animals could experience a sudden surge, or resurgence in their populations. The sudden void would allow for many species to reclaim spaces they once might have inhabited. This can have an [incredible impact](https://www.yellowstonepark.com/things-to-do/wolf-reintroduction-changes-ecosystem), not only on those species but the landscape itself. Humans: The most adaptable of all species would be forced, as we have at other times in our history, to adapt to a sudden change. While our forebears were forced to cultivate fire, adapt bronze, iron, and steam to survive, we would be given an opportunity to also adapt to an entirely new set of mores. We saw this after the plague ravaged Europe. The (more or less) sudden loss of life during this period gave way to worker shortages among the worker strata. This coupled with the greater availability of land allowed for a greater capability of upward mobility among the lower class which in turn sewed many of the seeds for the Renaissance. The new period of stress post "Purple Man Heel Click" coupled with the relative abundance of resources would create the crucible for expansion and change once again. [Answer] Going "poof", i.e. complete removal without corpses, will take away a lot of [biomass](https://en.wikipedia.org/wiki/Biomass_(ecology)) from the Earth's ecosystems. This will deplete the sources of nutrients, even bacteria will have difficulties to recover, not counting plants and animals. Since the soil consists to a great part of living organisms, the surface of the soil will lower (depending on the amount of biomass inside). The survivors will find themselves in harsh and degraded environment with the need of refertilisation, not counting the social and economic effects of the half-pocalypse. [Answer] So from a food perspective, it shouldn't worry. Generally, apex predators represent 1/10 of the biomass of it's prey species. If it takes 10 sheep to feed one wolf, and Purple dude uses the Eternity Baubles and the Unlimited Oven-Mitt and claps his hands, you now have 10 sheep for every wolf. There are less wolves on earth than sheep, but the ratio still holds (5 sheep feed 0.5 wolves). There was a documentary on either National Geographic or Discovery Channel called "Life After Humans" which assumed the tragedy was much higher... all human life was wiped out of existence. The first thing they cover was Nuclear Power plants, however, Nuclear Power will go into an emergency scram (read shut down) mode without direct input from humans within a fixed time period, so assuming the Clap doesn't cause infrastructure damage, there shouldn't be any significant accidents. It also won't trigger an accidental firing of missiles because of unattended launch equipment. (The Nuclear Football and the President have been separated before without incident. As discussed on Mythbusters, it's entirely possible for an untrained passenger on the plane to land a plane with guidance from a ground control... though in a pinch, you can land at an airport by an autopilot like system on most modern planes. For those of you who recall 9/11, all airliners in the United States were landed safely without any losses in an emergency shutdown of airspace. There are no procedures for this, which actually allows for more flexibility in achieving this goal. Given the case of nearly all emergencies declared and the weakening of on duty personnel, there will probably be some additional loss of life, but not nearly as many... and some planes will lose no pilots but some stewards. International flights would be the hardest hit as well as planes in take off and landing at the time of the incident. Most militaries, police forces, and government leaderships have redundancies built in so that if one person cannot perform duties, the next in the chain of command will be able to. ]
[Question] [ Say you've gone back in time Terminator-style (no possessions, no clothes, nothing but you and your cells) to roughly 6,000 BC to the ancient near east. You meet a farmer and his family who take you in, assuming you to be a vagrant who has been robbed (you are naked and confused in the middle of the desert after all). You figure it's the time and place it is because you recognise certain elements of the landscape and basic architecture of the buildings you can see. Now, you don't know the language he speaks, you have no way of translating other than pointing, and the only language you speak won't be around for another few thousand years. You can communicate basic things like food and water by pointing at examples of them, and let's also assume the next day you walk out to see the farmer farming away and gesture to help him, so assuming he's willing you have secured food, water, and way of paying for it. Over your time working and living with your foster farmer family your main goal is to learn to communicate verbally so you can start making sense of the world around you. [This article](http://fourhourworkweek.com/2014/03/21/how-to-learn-a-foreign-language-2/) says it is possible to learn a new language in 3 months, but that is with translations available in your own language, plus a wealth of other resources. Is it therefore realistic to say in this situation you could communicate effectively after a year of living and working with someone who only spoke the ancient language? [Answer] It doesn't really matter if it is an ancient language or a contemporary one. Throwing someone into an environment where there is no common tongue will end up being the same. In this case you are likely going to be motivated to learn the language just to be able to communicate. So most of the basic things will come quickly. Objects are easy to learn and many common actions as well. Apple, cow, tree, eat, sleep, etc. Now one thing you talked about both an ancient language and one spoken by a farmer. In this case it should be pretty easy to have a 'normal' conversation with the farmer in a few months. You won't be discussing philosophy or maximizing crop yields partly because many of these concepts are going to be beyond the knowledge and learning of the individual. If you were found and cared for by a priest or other learned man of the time, you have the ability to learn a lot more, and the priest likely would be able to teach you speeding up your learning process. But in general I'd say full immersion with no option to use your native tongue, a few months and you'd be a decent speaker. [Full immersion](https://en.wikipedia.org/wiki/Language_immersion) just for the 1 or 2 hours a day in classes makes a huge difference. A full 24 hours a day, 7 days a week, 365 days a year you are going to learn a lot. I can't find it but I've seen stuff for how long it reasonably takes. [Answer] You don't need to be able to identify the language in order to learn it. [This study](http://www.livescience.com/46938-why-adults-struggle-with-new-languages.html) shows that adults are capable of discerning nouns, verbs, and sentence structure in an entirely made up language. Two different forms of memory help us learn a language. [Declarative memory](http://www.livescience.com/43153-declarative-memory.html) allows us to learn nouns, verbs, subjects, etc. [Procedural memory](http://www.livescience.com/43595-procedural-memory.html) is less exact, and allows us to learn and remember rules of grammar and context. Adults have a far superior declarative memory than children, however they struggle to use their procedural memory without distraction. That said, this means that your time traveler will be able to learn words very quickly in the new language, if his hosts are amenable to teaching him the words for things he points at. Within a few months he should be able to identify all objects on the farm. He should also know basic verbs, enough to say things like "sleep, eat, wash, etc". He may know subjects, enough to say "I/me" and he will likely be able to identify more abstract concepts like "night/day" and perhaps even religious ideas if the farmer is interested in this sort of thing. The host itself is probably the most limiting factor in learning the language fluently. As an uneducated worker, your farmer has a limited vocabulary and is likely illiterate. [The average vocabulary of an illiterate language is only 3-5000 words](https://books.google.com/books?id=oore9h_L48EC&pg=PA110&lpg=PA110&dq=average%20size%20of%20vocabulary%20of%20illiterate&source=bl&ots=bZSt4U78DF&sig=J07qauEA9K-ucDgE5-J4D52oPS4&hl=en&sa=X&ved=0CCMQ6AEwAWoVChMIxYiuga7gyAIVhFcmCh0DRQDs#v=onepage&q=average%20size%20of%20vocabulary%20of%20illiterate&f=false), which doesn't sound that small, until you realize that most European languages with written lexicons today have upwards of 50,000 or more. If all you want to do is "communicate effectively" then you should be able to do that within the first six months. Granted, you will probably be saying things like "Me work dirt" or "Eat meat now" or "Give water", but the message will be clear to the native speaker. Depending on the language, the time, and the speakers that you encounter, you may never reach true fluency in the language. But it shouldn't take as long as you think it will take to be able to communicate with other native speakers. [Answer] Year might be enough, or not. It strongly depends on which language you are learning, how different is it from the language(s) you already know, and what kind of proficiency level you want. And process of learning language will be very different from the way we learn new language now. Big problem you will have when learning new language is that pencils and notebooks and dictionaries were not invented yet. You have to remember it all, cannot write any notes which you can conveniently take along and consult/review. Which will be a problem if you are visual learner - prefer visual input over audio. Just take audio language course, like Pimsleur, and check how many times you would prefer to read what was said to see the differences. Even if Pimsleur translates it all for you. Some [tonal languages](https://en.wikipedia.org/wiki/Tone_%28linguistics%29) have up to 8 tones for every syllable - and different tones have different meaning (syllable "ma" repeated 5 times in different pitch means "crazy horse run though village"). So unless you have a musical ear (experience of playing instrument, like piano), and expect that, you will have hard time distinguishing differences. Some [click languages](https://en.wikipedia.org/wiki/Click_consonant) have up to 100 consonants you may have hard time to reproduce. Some mental concepts can be completely different. I recall that some Australian tribe has no concept of "left" and "right", but only "north" and "south" - like "there is ant next to your north leg". So you may need to change your mental model what language is about. Child's brain has advantage of [neuroplasticity](https://en.wikipedia.org/wiki/Neuroplasticity). Adult brain is substantially less flexible, and has harder time to adapt to new grammar. According to some research, by 12 is too late to start learning second language - you will never become like native. Also, nouns are easy, you can point and ask. Verbs are much harder. Verb persons and tenses and moods are even more complicated. Some verb tenses might not be present in your mother language. If you know Spanish - imagine if most verbs were irregular. You would have hard time even to see they are related. It's not like in English, where all persons are the same (or adds 's). Spanish and English are similar languages from [Indo-European languages family](https://en.wikipedia.org/wiki/Indo-European_languages). Learning Spanish in few months says very little about how much time you need to learn some more obscure Chinese dialect, or click language like [Xhosa](https://en.wikipedia.org/wiki/Xhosa_language). In example, even experienced Japanese learners of English have problem distinguishing R from L - because that difference does not exist in their mother language. In many languages, there is gender in verbs. Your (male) explorer will make fun of himself if will be using female form of verbs, learned from farmer's wife and daughters (which might be assigned to help him, because he will be able to do only simple works to earn his food). If the only language you know is English, and the only other one you tried to learn is Spanish, you have no idea how more complex are other more different languages. Especially if neighbor of your farmer is speaking different dialect, or if you have a bad luck and spend a year to learn some obscure language spoken in a few mountain villages. Summary: If you are lucky and new language is similar enough to yours, you may be able to function in your new community in a year. If not, you will struggle, be able to speak very limited language (and be handled/helped like a child, and not considered equal or competent ). And likely, you will always speak with an accent. And because you are considered incompetent (dim-witted: cannot even speak properly), you will ave hard time to "sell" your ideas about more advanced technologies you know are possible, but unable to explain with your limited vocabulary. Or you break some tabu, commit some crime and they decide to abandon you, as not worth taking care of. How I know it: I am fluent in two more languages beyond my mother language (which is not English), and have basic understanding of few more. Even after 20 years of "full immersion" into English I do have accent and make mistakes. And as far as languages go, English is rather easy. [Answer] There isn't any difference between learning an ancient foreign language and a modern foreign language since the process is exactly the same. A language is a set of ordered symbols and sounds that represent ideas. Learning a primitive language means internalizing the sounds and the ideas they convey. From a practical standpoint, learning this language is a life-or-death problem. If you can't communicate then you're probably going to die. You'll learn pretty quickly. You'll have valuable skills to trade for survival. Math, any kind of hygiene knowledge, accounting, season, astronomy, advanced tool making (if you can make copper or bronze you'll be hugely popular). Six thousand years ago means that practically no one will be literate so you don't have to worry about writing or reading, just talking. [Answer] In addition to other answers, I think you can easily find some similar situations happening in real world. One that I can cite without research is [Nicholas Miklouho-Maclay](https://en.wikipedia.org/wiki/Nicholas_Miklouho-Maclay), a XIX-th century > > ...Russian explorer, ethnologist, anthropologist and biologist who > became famous as the first scientist to settle among and study people > who had never seen a European. > > > He has lived (with two servants) for several years among New Guinea native tribes, apparently without any prior knowledge of their language. As Russian Wikipedia states (I did not find any detailed English source, though I did not search much), after one year he knew about 350 words of one of many local languages; sometimes to find the meaning of even the most common words he had to spend months. This all was despite the fact that he had a lot of things that XIX-th century could have provided to him: notebook, food supply, medicine (apparently very helpful for negotiations with natives), etc. At the same time, natives initially were rather suspicious to him, which makes the setting more difficult than you have described. [Answer] I agree in principle with bowlturner. The first priority would be to establish a primitive nonverbal communication to get the basics; food, water, shelter, and a means to continue to receive those things (if you go back in time with nothing but your own skin, all you have to give initially is sweat). Once you're in a rhythm with these, which might take a week or so, you might try to communicate your willingness to learn the language in some way. You might point at something and then put a hand to your ear, indicating you want to hear the word. Once your host gets it, you'll get a flood of noun vocabulary; anything you can point to and get a symbol-word is yours for the learning. As your vocabulary grows, you'll start hearing these words in context and conversation, and this will be the last real quantum leap required to be able to communicate verbally with a degree of fluency; you are going to have to recognize the boundaries between words, and the parts of speech, well enough to mimic them and put together simple sentences. Once you can ask more complex questions, you can get more complex answers, and your fluency and language education will get another big boost. It's not impossible in the slightest. Our own children become semi-fluent in their native language (or even two or three) by following exactly this process. There's only one problem; they get this far on a time scale of about 5 or 6 years, during which time a human's brain is adapted specifically to learn the society the child lives in including its language, and for the majority of that time they really have nothing to do but learn the language. By already being fully ambulatory and knowing what language is, you might skim off the first year or maybe two of the average child's life, but if you follow the same process I think it would still take you about 3 or 4 years to become fluent in a language you are immersed in, given no inherent commonality with your native tongue. [Answer] I lived virtually this same scenario in present day Quebec, working and learning French on farms and if you're doing it every day and have no other choice, you'll be fluent in well under a year. And I don't agree with this idea that somehow a farmer is less intelligent than a priest! ]
[Question] [ Nowadays there are warning labels on most everything: this is flammable, that will cause injury because it's sharp, this substance is poisonous, and that canister is under pressure, but what types of warning labels would you need for items designed to be used in a weightless environment? [Answer] There is a very large set of possibilities. For real-world examples do some research on what NASA, Roscosmos, JAXA, ESA, CNSA do. The list below is just off the top of my head. ## Gravity/Acceleration Cannot be used in microgravity. Must be used in gravity field greater than X% of earth. Must be used in gravity field less than X% of earth. Cannot withstand acceleration greater than Y. Must be aligned along a certain axis for acceleration. ## Pressure/Atmosphere Must be used at an atmospheric pressure greater than X. Must be used at an atmospheric pressure less than X. Cannot be used in Heliox atmosphere. ## Outgassing Must only be unwrapped/used in an environment with a scrubber that can handle a particular chemical. Must be decontaminated via (some method) when moving from atmospheric composition X to composition Y. Must be exposed to hard vacuum for X hours before being brought into atmosphere. ## Electrical/Magnetic/Cosmic Ray Environment Requires shielding in a certain EM range. Requires grounding. Requires shielding from certain cosmic rays. Cannot be used during a solar flare of greater than X intensity. ## Biological Cannot be used if organism X is present. Can only be used if organism X is present. Cannot be taken to an uncontaminated planetary environment. Can be injected into a person only if they have a certain symbiote/implant/genetic marker. ## Temperature Can only be used in temperature range X to Y. Can only be stored in temperature range X to Y. Do not change temperature at a rate greater than Z/sec. [Answer] The already existing answer is great, but besides the sciency bits, a lot of the warnings will probably be the same, just more important, as outer space is significantly less hospitable than Earth's surface. Fire warnings, for example, will still be very important, as a fire within a spaceship would be catastrophic. In fact, flammable materials should be very rare in a spaceship for that very reason. As for things that are unique to outer space, there are plenty of dangers to warn about in a spaceship. Glaring red warnings on airlock doors, and above anything that might affect the life-support systems. The air, water and temperature systems are essential, so anything that might affect the power supply should be fraught with warning labels. Hazards in zero gravity... you need warnings about whether or not something attached to a wall can easily come detached if you tug on it, so you don't accidentally fling it across the room, or so you don't use something unsuitable for a handhold. You need to be particularly careful about spilling liquids in zero gravity, as they'd be particularly hard to clean up. For accelerations and decelerations, there will be all manner of fancy seat belts, and little decals on the walls showing cartooned explanations of how to put them on. Think of the safety cards you see in airplanes- you'll want an equivalent of those, too. [Answer] Many Earth products have ridiculous labels, like "don't put anything living in this microwave oven", "Caution: the coffee in this cup can be hot", "do not point loaded guns directly at your face", "warning: this ice cream melts in the sun", labels that sound stupid to put on objects because they seem so obvious. However, each of these labels has been put on there because someone, somewhere, at some point, did exactly what the label said not to do, was injured or lost the product this warning pertained to, sued the company and won. I see no reason why space products would be any differently. "Warning: do not fly this space ship too close to celestial objects". "Warning, do not stick any appendages in the automatic food generator while it is active." stuff like that. [Answer] The thing about silly warnings on earth is that most of them were added because someone, somewhere actually did it and did try to sue the manufacturer. Whether the warning can be followed in practice is irrelevant, as the only purpose is to try to give the manufacturer more leverage in case of a legal claim. So considering the actual incidents and accidents that have occurred in spaceflight, we can color things up a bit and warn: * On fecal disposal bags: "Ensure bag is securely closed" ([Apollo 10](http://mentalfloss.com/article/64345/nasas-46-year-old-floating-poop-mystery)) * On hotplates: "Do not use in oxygen atmosphere" (Valentin Bondarenko's death) * In ocean landing capsule: "Astronauts need adult supervision while in water." (Sergei Vozovikov's drowning) * On spaceplane braking system: "Observe caution when deploying while vehicle is in motion." ([SpaceShipTwo](http://spaceflightnow.com/2014-10-31/virgin-galactics-spaceshiptwo-suffers-anomaly-during-test-flight/)) * In ocean landing capsule: "Do not use capsule if door seal is damaged." ([Libery Bell 7](https://en.wikipedia.org/wiki/Mercury-Redstone_4#Liberty_Bell_7)) * In airlock: "Manufacturer is not responsible for difficulties in re-entering the spacecraft that are caused by physical size of the astronaut." ([Voskhod 2](https://en.wikipedia.org/wiki/Voskhod_2)) * On fuel oxidizer canister: "Hazardous - Do not breathe!" ([Apollo-Soyuz Test Project](https://en.wikipedia.org/wiki/Apollo_Soyuz_Test_Project)) * On exercise equipment: "Use eye protection!" (Norman E. Thagard eye injury) * On space suit: "Discontinue use if you feel like drowning." ([ISS Expedition 36](https://en.wikipedia.org/wiki/Expedition_36)) [Answer] Not for use in artificial gravity. The artificial gravity systems that exist on spacecraft sometimes have weird effects on items. Symptoms include: * Repulsion instead of attraction * Wrong gravity factor * Random Annihilation of atoms in item * Sporadic nuclear decay * Possible corruption of the computer running the universe [Answer] "CAUTION: Small carcinogenic particulate matter; do not inhale; open only in gravity or well-ventilated area. In case of accidental release into atmosphere evacuate room and call your Life Support Administrator." As far as typical consumer goods go (i.e., not guns, don't generate EMP, not infectious, etc) the relevant difference about space is that you're in microgravity a lot of the time. And as ISS astronauts have told us, keeping things neat in microgravity is tough; dust and liquids will often just float about indefinitely. This gives them a much better opportunity to get inside of you and cause trouble. So, while on Earth a "do not inhale" warning on a, say, box of dishwasher soap likely isn't necessary, in space it would be a necessary legal disclaimer. [Answer] There are some collections of such signs on the net already. [Here](http://www.schlockmercenary.com/2000-06-25) is a short (comical) selection, and [here](http://www.aleph.se/andart/archives/2006/10/warning_signs_for_tomorrow.html) and in the linked Flickr page is a huge collection of warnings signs for the world of tomorrow, though not exclusively for space. So depending on how serious and futuristic you want the signs to be, here are some candidates: * autonomous vehicles in operation (make sure you are recognizable as human) * malicious autonomous vehicles in operation (enter at own risk) * nanobot contamination zone (life-long quarantine required if they touch you) * AI experimentation zone (don't give them any ideas, or any unsupervised input at all) * holodeck ahead (anything you see here may be an illusion, [including any exit signs](http://rickandmorty.wikia.com/wiki/M._Night_Shaym-Aliens!)) * antimatter (don't interfere with the containment fields) * very-high-density matter (read the "Neutron bullet" chapter from [What-If book](https://whatif.xkcd.com/book/) for details) * steep gravitic gradients (gravity has different orientation and force all over the place, so watch the floor markings and keep vomit bags ready) * distorted space-time (stay away from anyone who looks like your grandpa) * area without network/internet connectivity + serious version: if you have an accident in this area, no one can hear you scream, so have someone else watch you + non-serious version: staying in here may cause feelings of loneliness + other non-serious version: staying in here may cause your brain implant to become unsynchronized with the rest of the hive mind (or maybe it just misses the latest security updates and you get a malware uploaded to your brain next time you go online) * alien overlord area (if they notice you they'll wipe you away like the bacteria you are) ]
[Question] [ Let us say that the humans, with our era of technology plus 5 to 10 years, are contacted by an intergalactic alien union. They want us to join them, and we gladly do. As it is common when several countries with non-military purposes invade each other, they participate in competitions together. Let us say that there is a Miss Universe: The QUESTION: How would the evaluation process be like? In Miss Universe here, we value: * Intelligence * Shapes * Oratory * etc What would a Miss Universe be asked? We have several species there, which we can assume that there are at least one species reptilian, one amphibious, and other types, each completely different from each other? What would the evaluation look like? PS: No intergalactic wars, no bitter rivalries, the judges aren't biased in any way, we are there, the candidate from our world is there. Only one candidate per species. [Answer] Sir? Mr? Ma'am? Miss? In a universe as large as ours (infinitely large, possibly) you're going to have a lot of species with [more than two genders](https://worldbuilding.stackexchange.com/questions/579/is-it-possible-for-a-species-to-have-more-than-two-sexes). So we can scrap the "Miss". I'm going to assume that there are two possibilities to solve this problem: 1. Segregate by gender. Just make separate categories: Male, female, etc. 2. Everyone together. The above only works if the species all generally have male and female gender. This may not be the case for all species. In that case, simply throw everyone together and hope for the best. --- > > What would a miss Universe be asked? > > > Here are some (possibly humorous) suggestions: * "How many languages do you speak?" [Insert question about correct usage of the progressive-future-past-intelligible-participle in the Kalingathrizan language.] * "Are your familiar with the [obscure and likely insignificant] War? What lessons can we learn from it to apply to today's wars and other conflicts?" * "Have you read The Hitchhiker's Guide to the Galaxy? Do you think it actively represents the social and economic issues in our universe today?" * "Can you play $n$ instruments (where $n$ is the number of mouths of the being) at the same time?" * "Do you think you are smarter than the average being (accounting for different brain sizes and complexities)?" * "Is that a real [insert body part], or an implant? Is that normal in your species?" * "If you could have world peace on one world, which one would it be?" [Answer] That's pretty much impossible. A pageant rates the contestants on different criteria, each one of them very subjective. One important criteria is physical attractiveness. Different species would have a completely different idea of what's physically attractive or not. There would simply no way to compare them. Say, you would be a judge in a beauty pageant for animals. You have a dog, a cat, a python, a parrot and a jellyfish. You have to judge which animal is the most beautiful. How could you make a fair and objective judgement? They are just too different. Now imagine the same thing with lifeforms which didn't even evolve in the same ecosystem and are thus even more different. Another is personality. But different species would consider different personality traits to be favorable in a female. A contestant threatening to eat the jury alive might terrify one species, while another might find it a beautiful display of strength and dominance. Also, what about species which don't even have a concept of male and female? They could be asexual, hermaphrodite or have more than two sexes. Who would they send to the pageant and who would they vote for? [Answer] In a competition that has a significant emphasis on physical beauty, I would anticipate that that portion of the competition would become rather less subjective than it currently is. To rely upon the judgement of biological judges would almost certainly impose species-based bias on the proceedings. It is possible in the case of humans - and should be so for any alien species for whom there are standards of physical attractiveness and who might want to participate in such a competition - to define an algorithm that can determine how closely an individual is to an ideal example of that species. Once such algorithms have been defined, the beauty portion of the competition could be judged by full body scans with the result for each competitor being obtained by mathematically deriving the individual's divergence from the ideal model. The lower the divergence, the greater the individual's score. The scores for each contestant, regardless of differences in species, could then be realistically compared. It might be interesting to note that some species, such as humans, may prefer not to appear in public without clothing. However, it may also be practical for the machinery performing the judging of the beauty to scan the unclothed bodies of the contestants without revealing images of the contestants, and only outputting the contestant's numerical score. This would be a fairer method, since - in human society at least - it can be shown that standards of beauty in clothing are highly subjective and subject to change over time, and hence much harder to derive a mathematical standard of beauty. As to other portions of the competition, these could be judged by biological judges of all species involved with the assistance of translators. It would probably be necessary to not allow the judges to know what contestant was asked what question, and only provide them the translated answer. As for the Miss part of Miss Universe, I would say that this would limit entry to those members of each species that play the greatest role in reproduction, as well as those who have not yet reproduced (This isn't Mrs. Universe, after all). Where all members of a species play an equal role, all would be eligible for entry, but where some individuals have less time/energy investment into the act of reproduction than others, only members of the gender investing the greatest amount would be eligible for entry. [Answer] Interesting, since our Miss Universe is a Beauty Pageant. Meaning it is meant for beautiful specimens. The rest of the competitions is to 'show' those that have more than just beauty, brains and other talents since they are all good looking, they need someway to shift out the 'best'. In all honesty, I would expect such an intergalactic competition to either look more like a pet show, with 'best of breed' and what not, each one highlighting their species skills etc. or a more likely scenario might be more of an Olympics style competitions, a way to brag up the abilities of each species, male, female, and other. [Answer] I don't have enough rep to comment, but you could look at things like dog judging contests. Each breed has certain traits and they're all judged on things like which dog is the most healthy, shows those traits the best, and so on. While different alien races will have different opinions on "beauty", there are definitely traits that each species treats as more desirable (like in humans we like certain nose shapes, cheek bones, shoulder/hip widths, breast shape, etc) and you could judge them on that. It'd definitely be tricky being a judge though! [Answer] In fact this situation reminds one of the Eurovision Song festival. Candidates from different countries come there, and sing a song. Afterwards each participating country can distribute score points amongst the other countries. Of course this has the disadvantage that countries with similar languages (think species with similar appearances) tend to distribute more points to eachother, but it is probably as close as it can get to a fair and practical scoring system. [Answer] One way of looking at it would be beauty would be defined as a sort of "average", with a bias towards the most powerful or dominant race. There are many studies that show this sort of "averaging" of faces results in something most would consider beautiful, even if the constituent parts might be considered ugly on their own. As for the dominant race element, this is sort of accepting that completely unbiased judgement is an impossibility, and that these sorts of events have an ideological/political element, just as they do on Earth. Just as "cute" animals are one that couldn't possibly harm humans (or survive on their own without human intervention in many cases) I believe judgement of aliens would be similarly a mixture of how different races perceive the threat-levels of others. I imagine the most beautiful would probably a "harmless" organism, kind of banal on a universal scale. [Answer] Assuming the contest is still a beauty contest, it certainly does raise the question of how you would compare the beauty of different species. Frankly I think the problem is difficult enough when considering only human women. How, exactly, do you define beauty? Can you really arrange all women on a scale from most ugly to most beautiful, with no ambiguities? I think not. I've occasionally seen female body builders held up as ideals of beauty, i.e. women who are very big and muscular, and personally I don't find them attractive at all. That said, one can overstate the problem. Suppose you showed me a wolf and a lion and asked me which was more attractive. I might have a preference for wolves versus lions. But if one was obviously mangy and poorly kept while the other was sleek and well-groomed, there would be grounds for a comparison. I could imagine judging an inter-species beauty contest on the basic of grooming, presentation, and the like. Of course that assumes that the alien race has similar concepts. When you start talking about hypothetical aliens, who knows what they would be like? Maybe the aliens' idea of "true beauty" is the ability to recite the alphabet really quickly. Or to shriek loudly while hurling feces. As we've never met any aliens -- discounting UFO reports -- we don't even know if they exist, much less what they are like if they do. Maybe we'll find that aliens are very much like us, and maybe we'll find that they are so different that they are incomprehensible. [Answer] I like trying to think outside the box when I see lists of answers that seem split between two aspects of the question, so here goes. Some previous answers get hung up on beauty being primarily "physical" and write off other attributes as mere 'tie-breakers', while other answers go to the other extreme by taking any definition of 'beauty' and implying that differences in species/races/etc. will be too different to compare with said definition. I think some sort of compromise on both of these concepts would work well in this type of competition. First, while we humans certainly weight physical appearance heavily when determining "beauty", even among humans this is not the only criteria. I find it hard to believe any human, without total hearing loss from birth, would fail to acknowledge that music can be beautiful upon hearing a selection that appeals to their personal tastes. At the same time, blind humans will still have a concept of "beauty" that does not include what would traditionally be called 'appearance'. Humans also find beauty in skills and talents (beyond their use as tie-breakers, just ask a sports fan about a 'beautiful play' made by a player of their favorite team). Next, since the definition of beauty will certainly vary among the participant races/species, so use that. Maybe have each participating world submit their single most important criteria (or a select few criteria, 2-5?) for "beauty" to be used as judging criteria in the competition. This ensures that all participants are evaluated (within the limits of any subjective competition like this) on even footing with all others. So there could very well be a "physical appearance" portion of the competition, proposed by us humans, and we may even fare relatively well in that portion (who knows?), but how would we do in the part of the competition dedicated to making noises audible in the widest range of frequencies at the same time, without the aid of external instruments, proposed by the species that has no eyes, and who's primary form of "beauty" is their version of singing through their 4 mouths? If a human were to actually WIN this competition, it would almost certainly NOT be the same human that would win a more traditional beauty pageant here on Earth, but instead one that is "good enough" by our own physical appearance standards, while also appealing to as many other varieties of "beauty" presented by the other races. Maybe an attractive(appearance category) astrophysicist(intelligence category) singer(talent category) that can hold their breath for a long time (category submitted by an amphibious race, and singing talent just happens to help with lung capacity) and was born with 6 fingers on their right hand (from a race with 6 arms and 8-12 fingers on each "hand" that defines beauty based on the total number of fingers) [Answer] Futurama answered this sufficiently in 2000. Bob Barker's head would host it on Tova 9, while the winner would get a bouquet of flowers and and atomic tiara. A giant paramecium would win it. The Miss Parallel Universe pageant would be held the day beforehand. <https://theinfosphere.org/Miss_Universe_Pageant_3001> [![enter image description here](https://i.stack.imgur.com/xv04y.jpg)](https://i.stack.imgur.com/xv04y.jpg) [![enter image description here](https://i.stack.imgur.com/b1cLo.png)](https://i.stack.imgur.com/b1cLo.png) ]
[Question] [ One of the most popular types of superheroes breaks down to the "highly skilled, highly intelligent, (sometimes well funded) martial artist," with the most well known example of this superhero trope being Batman. So what is Batman like? Batman specifically exhibits physical prowess across the board the equal of Olympians, mastery of a variety of martial arts, gymnastic and acrobatic mastery, impressive engineering and craftsmanship skills, hacker/programmer/general computer genius-level capabilities, and ability to buy a wide array of impressive and often military gadgets on a billionaire's budget. He also manages to pull all of this off, fighting crime and supervillians (for the purpose of this question, we'll say "crime, terrorists, and similar threats to American society"). He has a long history of fighting these threats, and has survived the various possibly lethal encounters. And the icing on this cake is that he's accomplished all of this without drawing suspicion from either law enforcement or the public. Impressive, but unfortunately unrealistically so. Within the bounds of: * Human capabilities (mental and physical) * Physics * Economics/Logistics * Criminology * Modern public media * Etc. And given the constraints/options of: * Our Batman cannot be any richer (liquid and other wealth combined) than any private citizen of the real Earth * Our Batman may be the owner (CEO, President, and primary stockholder) of any one fictitious private business that has a real-life parallel (publicly traded or private). * Our Batman may have mental capabilities of any description as long as there is historic justification for such capabilities * As long as he remains 100% human and bound by biology (or historic examples), his genetics can be whatever makes him best suited for this role * Our Batman works alone or with <5 people (who fulfill secondary or support roles). These people have absolute loyalty, and may hold upto similar physical/mental capabilities as our Batman. * Our Batman must be based out of any one major metropolitan region in the USA. * Our Batman can be of any age that would best fit this role ...How would could such a figure reach the previous listed accomplishments? How far would we have to dial back our caped crusader to return to the realm of reality? [Answer] Perhaps not that far at all. Consider in the real world we have seen terrorists like "[Carlos the Jackel](https://en.wikipedia.org/wiki/Carlos_the_Jackal)" capable of committing terrorist attacks against some pretty heavy hitters (like breaking into an OPEC meeting) across the planet without being stopped by police or security services. On the other side, the Mossad sent teams around the world looking for the "[Black September](https://en.wikipedia.org/wiki/Black_September_Organization)" terrorists responsible for planning the 1972 Munich Olympic massacre and were largely successful, also eluding law enforcement and Western security for the most part (Read George Jonas' book "Vengeance" for the account of one of these teams). Now these people are/were not Olympians, mad scientists, expert computer hackers etc. (Avner, the protagonist and team leader in the book Vengeance describes himself and his team members as presenting like a pretty ordinary bunch of guys). Where they and their opponents are different lies in their mental preparation. In order to work undetected, they need to develop acute powers of observation and memory, have the ability to integrate large quantities of information and make and execute rapid decisions. The fact they are/were spies and terrorists means they do have effectively unlimited resources (Spies largely funded by state sponsors. In that period, the USSR, Lybia and other Arab states were sponsors of Terrorism, today we see nations like Iran funnelling billions of dollars to Hezbollah and other proxies, while ISIS was initially funded by the Gulf States as a means of countering Iranian adventurism). The Israelis going after Black September and Carlos the Jackal are very dated examples, going back to the 1970's. While I have no first hand knowledge, it is quite easy to believe that the training and support that terrorists and spies receive has increased by orders of magnitude since then, and of course the individuals who do these jobs are going to be rated in the sorts of cultures they come from (no spy in the 1970's would be a computer hacker in the sense we understand, since personal computers and the Internet did not exist. Today, however, it would be a rare individual who did not have some knowledge and understanding of computers and the internet). [Answer] This reminds me of my inspiration for my protagonist in my novel The Crusader. In the real world, I once worked for a company called Blackwater USA. They were a large government contractor that were responsible for providing security to the State Department and CIA. There was a lot of hype and pandemonium about how Blackwater was a "private army" which was mostly hyperbolic BS, but there is a certain bit of truth at the core. The founder of Blackwater is a former Navy SEAL who in the early 2000s ran a significant government contractor which employed a large number of highly trained military vets, owned its own mini "air force", and controlled a pretty respectable arsenal (by corporate, NOT government standards). If you think about this in terms of "real world Batman". Prince was a guy who had some interesting skillsets, would have been capable of self-deploying to pretty much any corner of the world and surviving, had access to a lot of gear and weapons that might be useful, and (had he been so inclined) potentially could have done a lot of the things you would expect of a "real world batman". In my novel, I altered some of the background for my protagonist. I went with Delta rather than the SEALs for his background because I felt that the Army SF teams emphasis on counterinsurgency, languages, "force multiplication", and survival training would make him more flexible. Obviously, since I was writing a novel and not a comic book, I gave him some flaws and limitations to make things interesting, but in this case, you could presume that your "batman" is a top-notch specimen probably ex SF or SAS or whatever, who has had some major country spend a few million dollars to train him, and who now controls some sizable corporation. To handle the "how does he hide" aspect, I would probably make him a Federal contractor (maybe FBI). That gives him some access to contacts, information, and a certain degree of free movement that would facilitate his vigilantism. Obviously, it goes without saying that any "real world batman" would be always one small step away from a MAJOR prison sentence! Such is the cost of being a superhero though. [Answer] If you dialed back Batman to his original appearances, he would easily be a possibility in our world. As he is today, it's still possible, but there are some areas that would need tweaking. Human capabilities: This one is easy. Simply look at the peek examples in any given area. Starting with mental capabilities, the easiest place to start is IQ. The highest known IQ is around 230, with at least one individual suspected to be in the 250-300 range. So, let's be generous and give Bruce a 300 IQ. That's not the whole picture of a person's mental skills, but it's a quantifiable start. This gives a baseline indicator of verbal, mathematical, spatial and symbolic reasoning, as well as mental processing speed. For someone like Batman, we would probably want to weight the last two categories heavier than the first two, since the ability to identify symbols and patterns, and the general speed of thought would be the most useful to him. Beyond that, you have his deductive reasoning, his vast knowledge, his ability to think strategically, and his inventiveness. Again, you can point to real world examples that, when taken together, combine to give a good approximation of Batman's capabilities. Dr. Joseph Bell (the inspiration for Sherlock Holmes) had amazing deductive skills. There are plenty of examples of people with extremely powerful memories. It's a skill that can be learned and practiced. Again, you can point to plenty of examples of master strategists throughout history. I would say this most often comes down to a knowledge (innate or learned) of human behavior, but that's my opinion. Regardless, there are many historical examples of people who were able to defy the odds. And finally, inventiveness. Again, you only need to look at someone like da Vinci to see examples of how creative someone can be. So far, I don't see anything in Batman's mental capabilities that would need to be dialed back. Physical capabilities again, it's easy to find examples of the peek limits of the human form. Just look at the Guinness Book of World Records. People lifting up to a thousand pounds, breaking several slabs of concrete at once with just their fist, surviving extreme physical trauma, and so on. This might be one area where we would need to dial it down. Not so much in what he can do, but in how much punishment he can take. There are certain laws of physics, and no matter who you are, some of the more comic book-y injuries would simply kill or severely injure you. For example, you can build bone and muscle, but your brain is still a soft mass floating in a small amount of liquid, and a strong enough force is going to cause it to go slamming into your skull with enough force to injure it, no matter who you are. Economics: This one is tough. In terms of pure numbers, it's easy. Plenty of places have tried to calculate the real world net worth of various rich superheroes, and Bruce usually comes in at around 10 billion, which is entirely realistic. What is less so is his ability to make that money work as far as building his bat gadgets. Nolan did probably the best job of realistically showing how this could work, but it would still be hard to hide the fact that he's using his money to fund his alter ego. Eventually his shareholders are going to want answers about why they've sunk money into inventing a bunch of prototypes that would have been very successful in military and law enforcement, which went nowhere. Social Media: This combined with the technology we have today, would make for the least believable scenario. Cell phone cameras, combined with facial recognition software, and the fact that he's one of the most famous people in the world, would mean someone would put it together sooner or later. Plus there's the fact that few people would have the time and money necessary to put in the training he has and build the gadgets he has. The best way he could accomplish this is with a double - someone close enough in build and features that no one would notice the difference, but they could do the antithesis of the popular shirt "I'm not saying I'm Batman, I'm just saying no one's ever seen me and Batman in the same room together." There, you've seen them in the same room, and you couldn't have two Batmans (Batmen?), so our hero couldn't be Batman. Most likely though, people would still suspect there was at least some connection. The best option for this is not to be the playboy millionaire, but to be boring. There are enough multi-billionaires that, if he didn't stick out in some way, he could get lost in the crowd. Also, not owning the company that could produce his gear directly would help. If he could figure out some way of getting what he needed covertly from someone else, preferably if they weren't aware, that would further distance himself from a chance to be the Bat. Shell companies, funded through offshore accounts, things like that. [Answer] A realistic Batman wouldn't be one man. No one man could be the Batman, the physical toll on body and mind would be too great, but a team of skilled martial artists, escapologists, and persons with special forces training could do the job. They would be part of a team or a succession of Batmen. The Batman operation would be funded by a CEO billionaire, who we may call Bruce Wayne, and probably aided and abetted by a cabal of like-minded billionaires, businessmen, and public officials. Quite, possibly, the Batman's rogues gallery could be staffed by persons run by the same operation. Their activities would exist to justify the vigilantism of Team Batman. This would also explain how the Joker, Penguin, Catwoman, the Scarecrow and other criminals are soon free to commit more crimes. Again these criminals who not be the one individual, but a series of persons filling their roles. Doubtless the real target of Team Batman and its vigilantism would be uppity malcontents with misguided ideas about ending the plutocratic dominance of the deserving wealthy, ensuring there was justice for all, upholding democratic ideals and generally thwarting the social, political and economic elites from running society to suit themselves. A celebrity crime-fighter would be perfect cover for the powers that be to keep the lower classes in their places. Most especially when that celebrity crime-fighter was the mask for many highly skilled operatives to do what was needed to be done. This model of the Batman does adhere to the culturally fashionable opinion that Batman is a fascist thug, and, therefore, an instrument of wealth and power. Anyone who deduced that the author of this answer was a Superman fan would be right. [Answer] Don't get me wrong, but I think with right circumstances, Batman can be realistic. Look, you have vigilante who since he was kid, was driven by vengeance who killed his parents. He is rich, so he have proper resources to get best experts in each field to teach him all what he needs to know to be Batman. As he has a goal and his mission, he will not side track and waste his time on fun with his friends. During the day, he could hide behind mask of eccentric billionaire, who is always sitting as his home, and afraid to come out, and die like his parents. As long as he pays all his bills, nobody will ask many questions. Real version of Batman would be bit darker than original one, and It will have shorter life span than one from comic books. So let's fix that. Let's create Batman not as individual, but as team of people. Who do we need to meet given requirements. 1. Multimillionaire who wants to throw some money away on Batman Initiative. He is financial expert, he knows how to make a money, and how to hide them. So BI funds can be untraceable. 2. Two highly trained soldiers. It will be best if they got training from special forces SAS, Delta Force, etc. One of them is guy who wears the suit. We need two in case of emergency: if one of them got injured, then we can quickly replace him by another one. 3. Operator, highly educated individual. He is the brain, using small cameras and various sensors he sees all what batman sees and even more. Together with his knowledge and analytical skills and internet access, he can solve any mystery and find almost right away where to send Batman to get more baddies. But, if we can go slightly beyond constrains, BI could be government covered agency, created to deal with very dangerous criminals who can't be dealt in normal circumstances. Because they corrupted local law enforcement, have influences in high places or have extremely good lawyers. If we go with this route, BI team could be slightly bigger, access to some data could be simplified and would be easier to cover some tracks. [Answer] The idea of a single person being able to meet all the requirements of Batman is absolutely impossible without massive scale backs. The biggest issue would be the time required to maintain his high level of performance in that many fields. Considering that Olympic level athletes train up to 6 hours a day, leading minds in engineering work over 10 hours a day, leading minds in computer science work over 10 hours a day, the standard corporate work day takes up 9 hours, and humans need around 8 hours of sleep to perform at their peak. Add these up and he would need around 43 hours a day to maintain the ability to fight crime the way he does, not including the time he actually spends investigating and fighting crime. Now the idea of a team of 1 sponsor and 5 support people being "Batman" is much more feasible. With one Martial Artist (wear the suit), one Engineer (design the gadgets), one Computer Hacker (bury/dig up evidence), one Computer Programmer (keep the batcave online), one Detective/Forensic Scientist (solve the crimes), and one Businessman (supply funds) they could all be advanced specialists in their field and complete the duties of "Batman". The hardest thing to overcome would be satellite/drone/radar surveillance. If they drew too much attention then the government would put eyes on the area "Batman" showed up the most and would find the batcave. They would have to maintain an MO that did not grab the attention of anyone higher than the local PD, while squashing "Superhero" rumors and replacing them with something less enticing to the public. [Answer] It is possible to be Batman...sorta. As long as you discount "peak human physical ability" and some of the stated limits of Batman's abilities as just the writers not quite understanding how the human body works and what that means. For example, lifting 1000lbs is possible, but doing so while running as fast as Usain Bolt is not. Batman can do both in the comics, but this is because it is said that he is at peak human ability which is translated to the ultimate that individuals can achieve in a given category, when I think it is best to intepret it as what a human that is in overall peak condition can do. Which means he's slower than Bolt and weaker than the strongest man in the world, but he is at the highest level possible in those categories in balanced with each other. Edit: I want to point out that my interpretation of peak fitness, which is never an actual thing but just a description, is more in line with what is stated in the comics. Bruce points out somewhere that Dick is better than he in areas, Jason in others, and Tim in others. This is because how they've been raised, were trained up, and their natural physical characteristics. Tim and Bruce can never match the level of acrobatic ability of Dick, but Dick and Bruce can never match the hacking and detective skills of Tim. (Yes. Batman is literally like 4th in line for the top detective in DC canon despite being considered the top by most people). This being the case it's obvious that Bruce isn't "peak" in every individual category, but "peak" overall. The best answer though for how possible this is can be found [Here](https://www.youtube.com/watch?v=Cj0wGKQILfg). I would state all the info, but he references many things in the video and explains it quite well. The gist of it though is that to do it you have to do a very specific sleep schedule, education program, diet, etc that are all shown to work, but you'd pretty much have to be insane and rich to be able to do it, but not extremely so. A few million probably would get you to be able to do it. You also likely would have to start as a child so you'd have to have someone force you into it more or less to get to that level. So you can "possibly" build a human that is Batman... however we don't know the long term strain of such a regimen and as a result, even though it "seems" possible, it could be that if someone lived like this they'd have an extremely shortened life... [Answer] > > He has a long history of fighting these threats, and has survived the various possibly lethal encounters. > > > That alone sounds very implausible. If you routinely go through fights in each of which you have a 5% possibility of dying, statistically speaking you are dead. In real life, you cannot dodge every bullet. The Batman and James Bond-style hero simply cannot exist. The only possibility to have a long and successful career is being very careful, avoiding fights and risks, relying on henchmen, not exposing oneself, not engaging in a fight unless one has overwhelming advantage. Though this doesn't make for a good story to tell on TV, I am afraid. [Answer] Assuming Batman is a single human individual with access to, for simplicity's sake, the resources of a powerful multinational defense corporation, we can analyze the limiting factors within Human capabilities (mental and physical). Human mental capability is often mistakenly thought to be measured with an IQ, or Intelligence Quotient, test. While it is fairly agreed upon in scientific circles that intelligence and IQ have a non-weak correlation, the causation is still a rather open question. That is to say that a high IQ is no doubt indicative of strong pattern recognition but, may say little with regards to the speed and ability of an individual to assess and take appropriate action in a high risk combative environment. Hence the different forms of "intelligence," the word itself being very ambiguous. For example, a highly selected military operative (think Delta force or SEAL) is highly adept at modern combat skills in a wide range of situations, however, there is little to suggest that a high IQ would imply better performance in this case. The average Ph.D candidate on the other hand, is significantly above the average high school graduate on most standardized IQ tests, at the same time it is quite apparent that the average Ph.D candidate makes much more use of pattern recognition, memorization, and data analyzing skills than does the average high school graduate. Thus, we conclude that Batman most likely would have a higher than normal IQ. After all our Batman is proficient in the use of computers and gadgets, both of which give a moderate advantage to those who are quicker at pattern recognition. However, there is not much to suggest that a "genius" level IQ would give Batman much of an advantage to crime fighting. The most important mental function would be tied to that of physical processes, namely procedural memory. Batman undoubtedly is proficient in acrobatics, martial arts, and preforming repeated tasks with gadgets, vehicles and (non-lethal) weapon systems. Some individuals have been shown to be more adapt at retaining and improving procedural (or sometimes called 'muscle') memory of which it must be noted there are different types. Having the ability to preform tasks repeatedly, while maintaining accuracy and functionality would be crucial for Batman to have the edge in both combat and non-combat operations. Whether in fighting a gang of thugs or solving a crime case, Batman is demonstrated to use a large selection of skills and tools at his disposal to accomplish the job, rather than relying on any powers of mental deduction or pattern recognition. Thus we conclude that Batman would be an individual with a moderately higher than normal IQ, but with extremely fast reaction time, very adaptable procedural memory, and a lot hands on training. In other words Batman would most likely have a strong back ground as an athlete and military or paramilitary, spending most of his time in the gym and on field ops, rather than in a business office or lab. [Answer] I don't think it is possible to be Batman. Let's say you are a high rank officer in Wayne Enterprises and you have regular meetings with the CEO who is Bruce Wayne. One day you read the news saying that Batman helped the police catching a criminal at night and your boss does not come to the meeting next day. Some time later you read that Batman rescued someone from a mob leader and the next day your boss comes to the meeting very tired(like he didn't sleep the night before). You soon realize that every time Batman does something in the night , the next day your boss acts strange. By the way your boss is a muscled man and has no family. You suspect. Next time when there is a live footage of a car chase including Batman(like in the third movie) you call your boss and he doesn't answer your phone, but normally he always answers his phone. You find out that he is Batman. > > It took Hermione(15 years old student) to find out ,that Lupin was Werewolf, only 1 month. She deducts it from the days that Lupin is not in class and full-moon cycles. > > > [Answer] My vote is for maybe realistic, with some tweaking (either of abilities or expectations). Physically, his abilities would have to be top notch, equivalent to Olympic-level athletes - although not actually an Olympic athlete, since that requires a lot more specialization to the point it might be counterproductive, but the raw abilities of one. If we want to be specific, perhaps the abilities of an Olympic-level acrobat or gymnast, since the flexibility, control, and body-awareness will be very useful (physically specializing towards, say, strength or sprinting-speed might not be versatile enough). There will be people faster, and stronger, and people with more specialized training in a single area, but if he has a decent level of native skill and takes his training seriously, he can maneuver better, fight where he can and out-think, plan traps, or manipulate the situation where he can't. As for age, physical fitness tends to peak in from the 20s to early 30s. If he starts his 'career' at 20, or maybe even a little younger, say 18, he has at least a decade and a bit with which to pick up the experience and skill he will need to be able to compensate for the effects of aging and also the accumulating injuries form fighting, and keep his career going a little longer. Even so, his age will be a limiting factor - there will be no 60-years in this career no matter what the comics say, 3-5 years is reasonable career length for sports (given chance of injury) and most athletic careers are over by age 33. Even if he can use experience and skill to compensate - by stacking the deck, choosing fights wisely, being sneaky and underhanded, and not directly competing where he doesn't have an advantage, at some point he will no longer be effective in direct fights against younger, stronger foes even if they are less skilled. At that point, he might be able to train a successor and/or serve in a support capacity if he would like the name to continue longer, but his career is all but over. He probably won't be a "master" of all martial arts, that seems a little too much - especially since they will be specialized and mastery of each will require different strengths and weaknesses. But basically familiar with many types, sure - and a master (or nearly so) of two or perhaps three different styles might pull of the fighting quite well. The muscular control and body-awareness that comes with mastering a style or two might let him fight quite effectively even if not in his chosen style, if a specific style (that he still has to be familiar with) happens to be the best match for an opponent's style. And given the raw, Olympic level abilities, and starting training young and with a lot of motivation, being somewhere from fairly good to master-level in perhaps two martial arts might be reasonable when just starting out. Picking up the basics of other styles (and maybe mastering a third, depending) would be less critical, and could happen at any point along the way. That is, they would help with versatility and flexibility, but they would also take extra time and effort. As for wounds and injuries, this will need some lowered expectations. He can be skilled, and careful, and have the best in body armor and gear - but injuries will still happen, and will not be magically healed. Stories are usually pretty bad at this, since they want shock value without actual consequences. So, every time he gets injured, he will need time off to heal, and he will need time off for bullet wounds, for broken bones, and also for strains and sprains, burns and cuts, and even significant bruising, since he needs to be in fighting condition. He will need periodic time off anyway, recover from strain, stress, lack of sleep, to catch up on all the littler healing (scratches and bruises and and whatnot) since that will interfere with him fighting...and also to basically keep his life balanced and livable. It is possible that this time happens, but "off-screen" in the media version, and he could do non-physical work in the meantime (perhaps also "off-screen" extra time investigating). But in general, he will probably not be out nightly but maybe have appearances spaced over a month, or even a year. If his costumed appearances are tightly correlated to injuries, it will also make it much easier to track his identity - anyone injured during relevant time periods, over time, will probably give a fairly short list, with the added bonus of going out while injured/recovering might also let people figure out and track injuries quite specifically (still favoring that knee, something with the shoulder, etc). On the other hand, if his appearances are irregular to begin with, that might mask healing time between regular investigation-time and non-costumed activities. Mentally, he might not need quite so impressive abilities to be quite effective. He will need to be highly intelligent, yes, and have a good memory, a decent problem-solving ability, deductive reasoning, and the ability to think unconventionally and look for out-of-the-box solutions. He will need a decent level of ability to figure out things on the go, while they're happening, and to change his plans to changing circumstances. And obviously the more native abilities he has, the easier all that will be. But really, he doesn't need to have abilities or training out of reach for a very good detective or investigator. And, studying and practicing can improve native abilities quite a bit - not to mention, he can lean on artificial help, in terms of computers, gadgets, and programs, to achieve quite a bit more. So, for the rest - he doesn't need to memorize tons of details with access to a computer with which to look them up, maybe just things he expects to need on a day-to-day basis, or what he needs for a single outing. If he's got a decent connection to that computer on the go (I think I recall a glove-computer or the like), he can look things up if he has even a few minutes to stop and check. Or a (good) voice system so he can ask the computer to look stuff up for him if he hasn't got his hands free. Or a single accomplice, who can just access the computer and do a search if it turns out he needs more information between going out and coming back in. If he has a little camera on his suit, or audio recording, he only need a decent memory, not a perfect one - he can look over recordings after the fact to pick up details he might have missed. With money comes the potential to buy or access copies of the best investigation programs, from pattern analysis to forensics to tracking programs. But wait, if he has the mental abilities, and resources, of most pretty good detectives or investigators, how does he continuously out-perform, for example, the police? Well, he can pick and choose which cases to investigate, while actual police (and so on) are investigating many cases at the same time, since they are responsible for all of them. If he has too much going on to deal with some crime, he can drop off tips and information to the cops instead of investigating everything himself. Also, between having lots of money and only needing enough resources for himself, he can always have the best equipment and most cutting edge programs, while police and so on will settle for the most cost-effective and still pretty good resources, and will have to share them among many people and cases. So not only can he focus in on just whatever he happens to be working on, he can also spend a long time going back to a case until it's solved to his satisfaction, without the outside pressures (the media, the higher-ups, the politicians) that the police might have to deal with on any given case. The more realistic version will probably need to spend more time analyzing and researching the crimes, compared to the media version whose investigation time would be truncated or "off-screen", but with a tighter focus and the best of resources, he could still be very impressive. And again, the more time between appearances will let his healing and recovery time drop to a more realistic level. Hacking and programming, hm. I think he would need to be quite good, to make it work - but again, while the better his skills the easier, he doesn't have to be genius level to make it work. He can augment his actual skills with access to the best programs and tools for the purpose, including those used by police (for breaking into digital systems) or computer repair places (for data recovery and such), but he will want to be fairly good in his own right for situations where he is without the regular tools. It would be easier if his company hired really good computer people and did some work in the relevant areas, had some division for developing such programs for law enforcement, (which will also give him a cover for procuring his own copy of the latest). Or at the very least his company should be pretty careful about cyber-security and he keeps himself up-to-date on what they were looking out for, borrowing their expertise to figure out exactly what he needed to learn and what he could get around other cyber-security systems. He would need to know enough to take what they were doing and apply it elsewhere, but he could piggyback off of their results instead of having to be a genius about it himself. Having even one trustworthy computer-person in the know would help a lot, but it might be worked around. It also might be helpful, in a different way, if his company was doing work on computers instead, and thus he could (sneakily) have some back door installed (for legitimate, um, data-recovery purposes!) that would let him have a shortcut if whatever computer he needed to break into happened to be of his company's make. And speaking of which, logistics. Obviously, if he spends company resources on developing the gadgets (and/or producing them) and then doesn't sell them, his company will want to know what the heck is going on with R&D. On the other hand, it might not be a bad idea to produce and sell some of the gadgets for use, the gadgets that are more useful than dangerous, anyway. The gadgets being sold might be larger or less efficient or less tricked out versions anyway (due to pricing or ease of use, or deliberate choice). Perhaps the "best" version would sometimes still be sold for military/police use, as well - it gives a reason for still making them, and if they are available to buy, it is harder to point fingers at who might have them than if they are actually restricted. He should probably "buy" them from the company, though, at least replace enough of the cost from his personal fortune, to not run up red flags about someone skimming profits. For anything he reasonably can, he should be buying the best products available (by proxy, if possible), and maybe modifying them as needed for his specific use... the fewer things he has that aren't widely available, the harder it is to track him down using them. Other gadgets, ones more specific and less hide-able, he might want to make or acquire equipment for making himself. Most rarely, he might develop or partially develop a gadget through the company, and never put it into production - something which will cause questions if he does it too much, but might work if really needed. For batarangs, or whatever, a machine to produce specific shapes from metal might be a good investment (since he needs a lot of them, and I think they're visually distinct), and also producing solid metal cutouts might not be too complicated of a process. Or at the least, he can acquire such machinery for (or from) his company, if he can just hide the specific mold or equivalent that is needed to actually make them. For other gadgets, he might be able to acquire needed parts from piecemeal from other companies and spend time assembling or modifying them - at the cost of time and for the value of secrecy. If he's careful with the equipment, and doesn't loose it all over the place, he might be able to get away with a few gadgets not market-available without people knowing enough about them to try and track back to the source. As for economics, a billionaire's budget should cover most of what I've mentioned (programs, really good computer system for one, some gadgets), as long as the billions are his personal fortune, not his company's - although, if he doesn't want to be known as openly funding, well, himself, he might want to combine frugal personal spending habits and a public image of a spendthrift, so people don't wonder where his money is going. If he has more money tied up in his company, it will be trickier - since budgeting, or auditing or internal checks (for tax purposes, for internal budgeting, to prevent corruption) might turn up cash flow discrepancies, that may look like anything from embezzlement to money laundering to financing something underhanded (which I guess this is). If at all possible it will be better to keep the business as clean as possible, paying the company for raw materials or damages and keeping the cash flow clean. Lastly, social media. This will be trickiest, and the least plausible answer. Social media is everywhere, and between camera-phones and tracking software and people, oh, people everywhere, keeping something like this secret is going to be very difficult. To start with, he will need a body double in the know, or several who may have different levels from being in-the-know to being ignorant. Because people will ask questions if he needs to drop out of sight, and announces (say) a trip, and there's no reports back of sightings in the areas he was "going to". If one person covers too many of these trips, they will likely get suspicious very quickly, so they must be somehow in the know. On the other hand, if there are several, using them at different times, each with some semi-plausible excuse for missing a single event or trip and not wanting to admit it, may cover longer stretches with no single one getting suspicious about the accumulated time - as long as they are somehow prevented from comparing stories. Beyond that, any visible injuries will be dangerous, since they will likely be recorded (and available for comparison) long after they have healed. They can build up a case over time, especially if compared against injuries known to be suffered while in costume - because once or twice may be coincidence, but over time people will get more and more suspicious. And they may also reveal the body-double scheme if not handled carefully. Also, he will need a lot of really good stories for the injuries and scars, because not only will they accumulate very quickly, and leave distinctive marks (wait, how many bullet wounds?), they are likely to be continually renewed, from very old to barely healed - so can't be attributed to a single, or even a few, larger events instead of continual injuries. It will be hard to explain why he doesn't stop such activities that dangerous or beyond his skill level even long enough to heal, and there won't be official backup for any such story (police or hospital records, or reports of similar accidents or injuries) when people do get curious, and look for answers. They might assume scandals, they might assume criminal activity (either towards him, like abuse, or from him - which vigilantism kinda is) - but once people start investigating, those discrepancies will stand out. So, to make it work... his daylight persona also can't be out and about every day, and will need to be able to drop out of sight sometimes with little notice. He might be able to be out more during the day if he goes out at night less (when injured, or when still investigating, or during down-times or such), but since going out when injured is not a great idea unless the injuries can be very well hidden or attributed, less exposure is better. He will need body-doubles, and fair reasons for them to believe that he wants to duck out of whatever and not tell why (which might involve "fake" secrets, but whatever). He will need his doctor to be in on the secret (and also capable from primary care to serious patching-up), and willing to spread misinformation on his behalf when people come questioning. For his helpers and those in the know, take your pick of who is in the "five or less" the question asks for - at least one general helper for computer access while out, basic patching up, organization, and giving excuses about him; his doctor, for larger injuries and also primary care; some accomplice in his accounting or business who knows what is really going on with the cash flow and why, to misdirect others; helpfully but not required - a really good computer person who can check on the computer work, help with programs and such; helpfully but not required - at least one body double so they aren't asking questions about why he needs to be out of sight so very often; and probably (depending on circumstance), whoever trained him might have some idea of what he was doing with that training even if they aren't "actively" helping, especially investigation training and martial arts - the former has few other uses, especially to be good, and the latter might identify him from familiarity with fighting style and/or seeing a fight in costume. So, to sum up - the more realistic version will go out much less often, and spend extra time being his cover persona, researching, healing injuries, and acquiring, customizing, upgrading and fixing the gadgets and programs he uses. However, his ability to focus in and spend the time and effort beforehand means he will be quite effective on those occasions where he is out and about, and irregular appearances will let his reputation have time to grow in the telling. He needs to be decently wealthy, and his company should at minimum have a division doing R&D for law enforcement or military tech - including programs, tools, and forensics, so that he can legitimately acquire and develop the things he needs and even profit from it, though much of what he uses (or is seen to use) should be commercially available, so it is harder to track him that way. He needs to openly claim to practice/enjoy something dangerous enough to justify the continual injuries, and also need to be personally unreliable, and have enough reasons to be that way, to justify body-doubles. He has three to five accomplices, and possibly two or three other people who might guess, given the right circumstances (but who also might listen to the reasons why and be silent). He probably should start late teens to early twenties, he can count on his physical prowess for no longer than ten years from that, and he might stretch his career a little further through experience, underhanded tactics and stacking the deck - though perhaps not much further, before he has to find a successor if he wants the name to continue. At which point he can be one of the five support people for the next one. I think that's most of it, really. [Answer] This is a pretty unrealistic question because the nature, abilities and restraints on almost all of these characters is dependent from story to story and author to author. When a character spans 60 years of ass kicking and more writers manipulating his life story than jesus, the variety of versions of the character are astounding. The fact that they were able to justify batman enough to ask this question means the creators of the character were successful. If you take the 'Movie Version' of batman from the Christopher Nolan series, I see no reason why he couldn't exist. In fact most of the Live action film versions are pretty plausible (although no real batman would put nipples on the batsuit) Delve into the realm of comic books where batman is simultaneously fighting his entire Rogues gallery whilst simultaneously leading the justice league into outer space to fight aliens whilst also being stuck in a hole in Uzbekistan with gonorrhea and it becomes a pretty silly ideal... \\Unless there are cloned batmans. Or he's secretly super triplets... Maybe christian Bale acted in "The Prestige" as a hint Within the greater realm of comic book fiction we don't really have the expectation for realistic justifications because fiction by nature is not realistic. There is, however, an expectation for some form of justification from the story teller as to why their characters exist. If you had a dude running around in a bat suit beating up on random citizens without justification nobody would care about the story. Justifying and explaining who and why the character is who he is gives the characters depth and opens up new realms for story tellers to dig into. A property such as batman spans to wide a reach to say 'could he be real?' and the character owners aren't about to confine him to one version. Could you ask the same question for similar characters in a one-shot or limited series title like watchmen? Absolutely. Except for Dr. Manhattan, almost all those characters could effectively exist within our own real world. Night owl is much like the Batman Archetype, Rorschach is almost his dark reflection, and Ozymandias is pretty unrealistic, but not impossible... So it all depends on the context of the character. Batmans 'skill sets' could all be learned effectively in a short space of time. Anybody with an IQ over 100 should be able to learn just about any skill within a month of intense training with experts in the field to guide you. People today are either too busy working/ surviving/ partying or dealing with some other bullsheizen to worry about saving the world from super criminals. Ol' Pareto figures you only need to know 20% of a subject to be 80% effective at it. Couple that with wealth and the fact that you can train yourself to learn faster and you're the golden goose. Learning to be a computer hacker could honestly be a day of playing with backtrack. It also stands to reason the wider your fields of expertise the better you will be as a detective... Even the worlds greatest detective. ]
[Question] [ This question already has answers here: [Why might dwarves be black skinned in a medieval fantasy world?](/questions/53006/why-might-dwarves-be-black-skinned-in-a-medieval-fantasy-world) (19 answers) Closed 5 years ago. The Drow from Dungeons and Dragons are a race of elves with dark skin and pale hair that live mainly underground. How could these elves develop such a coloration when they live underground, away from sunlight, and by all means should be pale like many other creatures that live entirely in caves? [Answer] Radiotrophic melanin. Underground there is more ambient hard radiation. Radon gas is a prime example and a major source for radiation exposure in subterranean spaces. The Drow use this radiation to supplement their metabolic activity in the same manner as radiotrophic fungi. <http://large.stanford.edu/courses/2017/ph241/white-t2/> > > . Robertson et al. studied black yeast (Wangiella dermatitidis) > subjected to low-dose ionizing radiation. [5] They wanted to deduce > the impacts of chronic radiation on the melanin-containing yeast > (recall that melanin is the pigment that results in human skin color), > as well as melanin-lacking yeast. They discovered that radiation led > to increased survivability in the melanin-containing fungi, as they > were able to absorb more nutrients and export more toxic metabolites > from their cellular systems. The scientists even found that fungi were > able to safeguard their DNA and utilize ionizing radiation as energy > for DNA repair in some extreme cases. [5] Dadachova et al. also noted > that while melanin-lacking fungi grew better in non-irradiated > environments, this observation quickly reversed in the presence of > radiation, with melanin saturated fungi actually increasing rapidly in > dry weight in the presence of continual radiation. > > > This growth can be at least partially explained by melanin's ability > to catalyze an oxidative-reduction reaction typical of cell > metabolism. According to Dadachova et al., the electron transfer > properties of melanin in the NADH oxidation/reduction reaction > sequence necessary to supply cellular energy increased 4-fold after > prolonged exposure to radiation. Furthermore, even melanin-containing > fungi cells subjected to limited nutrient conditions responded by > growth when exposed to radiation as compared to their non-melanized > cell counterparts. > > > Maybe the Drow use this for energy. Better would be for the melanin catalyzed oxidation /reduction to serve the same role UV light does on the surface - UV hitting the skin makes vitamin D for humans. In circumstances where UV light on the skin is scarce (people wear a lot of clothes, or days are short) humans evolved paler skin to maximize the ability to capture what UV there was. Assuming human-type vitamin D metabolism in the Drow, they get essentially no UV light. They instead use melanin pigment (the only human pigment) to capture hard radiation to make vitamin D. The Drow are actually cave adapted albinos who secondarily acquired the ability to capture hard radiation energy via pigment, which is why they have white hair and pink eyes but skin that is nearly coal black. --- Thinking more about what phenotype would result from this use of melanin, it would not look like humans exposed to UV. UV stops at skin, but hard radiation penetrates tissues. The drow would therefore have melanin through and through - not just on skin but also interior tissues and organs, blood, sclera and everywhere. Their sclera would be black and their blood would be black. This could happen if there were an organ that secreted melanin into the blood stream - occasionally this sort of global pigmentation can happen to people with widely metastatic melanoma - depicted. [![melanosis with metastatic melanoma](https://i.stack.imgur.com/75H3t.jpg)](https://i.stack.imgur.com/75H3t.jpg) [Diffuse cutaneous melanosis in metastatic melanoma](https://escholarship.org/uc/item/7rf1s96t) Hair does not have a blood supply and so would stay white. Apparently irises are unaffected too so they would stay albino red. [Answer] The Drow were dark skinned before they migrated to the Underdark. They migrated a long time ago by human standards - possibly enough time for humans to start speciation (we have only a vague idea how long it takes in humans), but elves reproduce very slowly. An elvish generation can be 40-500 years. Add to that that their population is very small to begin with - The largest drow city has only 20,000 people. There might not be a million drow in the world. There is not a lot of opportunity for a mutant, pale skinned drow to be born. When a mutant drow is born, it is often killed at birth. For example, Drizzt was almost killed as a babe for having a different eye color. Additionally, species tend to be much slower to lose traits with no benefit than they are to gain traits which provide one. For example, in giraffe necks, the nerves for their vocal cords travel down into their chest, around their heart and back up to their voice box. Why? Because it never stopped a giraffe from reproducing. Intelligent species are even less likely to fail to reproduce due to some vestigial trait. Animals with culture and the ability to pass on knowledge are more likely to adapt their culture or their education than to adapt genetically. [Answer] From [this question/answer](https://biology.stackexchange.com/questions/39157/does-melanin-protect-humans-from-gamma-radiation), we see that melanin can slightly protect against radiation - but only slightly. So, if you lived somwhere surrounded by [radioactive rocks](https://en.wikipedia.org/wiki/Granite#Natural_radiation) - such as in underground caves - an extremely high level of melanin (leaving your skin nigh-on completely black rather than a deep brown) might provide just enough protection that you and your progeny do not suffer the DNA damage present in your paler bretheren, granting your descendants an evolutionary advantage. [Answer] The reason for having an advantage from Dark skin is that the pigment melanine blocks UV from the sun light. A possible explanation for drows' dark skin could be a natural source of UV radiation in the underground caves where they live as constant exposure would lead to fair skinned creatures dying of cancer most likely before reaching adulthood. [Answer] Though I couldn't find a real-world equivalent for the things I'm going to list, a few possibilities come to mind: * Symbiotic relationship with a fungus/lichen that protects the Drow skin from excess moisture or cave-dwelling parasites. This would require the fungus/lichen to be darkly pigmented. * Hyperpigmentation caused by a melanin disorder that (somehow) improved their ability to reproduce (the darker skin seems more attractive or allows them to evade predators more easily). Evolutionary pressure would eventually crowd out the non-pigmented Drow. * A mineral or other substance found primarily in a food essentially only the Drow eat. This substance would need to collect in the skin of the Drow to darken it, similar to how bilirubin collects to cause [jaundice](https://en.wikipedia.org/wiki/Jaundice) or how [silver](https://en.wikipedia.org/wiki/Argyria) can collect in humans. I hope this helps! [Answer] According to the D&D lore, the Drow once used to populate the (sub)tropical region of [Ilythiir](http://realmofadventure.wikia.com/wiki/Ilythiir), from which they were [driven underground](http://baldursgate.wikia.com/wiki/History_of_the_Drow_I) by other races: > > We know very little of the Ilythiiri, or "Elves of the South," before > this crucial event[the Descent]. Even then they were known as "Dark Elves" for the > hue of their skins. They dwelt in the jungles and hot forests of the > South. A proud, warlike, culturally advanced (some sages of other > elven people say "decadent") folk, the Ilythiiri attacked all > neighbors, including other elven tribes. Their cruel raids and > depredations, ordered by warlike nobility and the clergy of their two > cruel deities, Ghaunadaur and Lolth, forced elves, humans, dwarves and > others to ally against them. > > > Considering the above, their skin color could have been an [evolutionary defense](https://en.wikipedia.org/wiki/Dark_skin#Advantages_of_dark_skin_pigmentation_in_high_sunlight_environments) against the harmful ultrawizard radiation. [Answer] A simple answer would be that elves use something other than melanin to protect themselves from sunlight. And something other than melanin to make their skin dark. So extrapolating from humans and other animals similar to humans is a mistake. In humans, dark skin is caused by melanin, which protects the skin from sunlight. In elves, dark skin is a natural color, as easily maintainable if not more than white skin. Perhaps drow are albinos. It's just that in elves, the equivalent of albinos have dark skin. [Answer] In the forgotten realms (the main D&D universe), drows have for ancestors dark elves, who lived in the surface and had brown skin. However, it's clearly stated that drows have not only brown, but ebony-black skin. Their ancestors also probably didn't have the distinctive white hair of the drows, but black one. During the Descent, however, divine magic was used by the elves main god to turn them into drows. > > Corellon Larethian’s magic, channeled through his clerics, turned all > dark elves into drow. By that point some dark elves modified their > bodies, and were thus not changed. The entire subrace of dark elves > was turned into drow, including the survivors from Miyeritar. Elves > believed it was done as collateral damage due to the elves not > properly understanding elven high magic. > > > Source : <http://forgottenrealms.wikia.com/wiki/Drow> It's to note that drows, due to their link to their goddess Lolth, and possibly from demonic blood ([see Wendonai](http://forgottenrealms.wikia.com/wiki/Wendonai)), are inherently magical creatures, and have many innate magical abilities, as well as a strong resistance to magic. So as disappointing as it is, at least in this D&D universe, the answer would probably be simply magic / divine curse. [Answer] Periods of Drow history were desperate and violent, with both civil warfare and outside invasion. Darker skin was selected for because it helps both a predator and prey to hide. ]
[Question] [ I'm writing about a world that predates most modern forensic techniques, and I am looking for some old-fashioned methods of sleuthing that would have been available at around the 1850-1900. In one scene, there is a massive explosion that results in a lot of blood and dead bodies. I'm looking for a plausible explanation for how my protagonist, who was present (and bleeding) at the scene of the crime, was tracked back to her home a day after the fact after no one knew she had been there and no one saw her leaving. I need a reality check on whether dogs could have possibly been used to do this back then, specifically: * Could a dog follow the trail of a person who had some of their own blood on the bottom of their shoes, even if it was a day old? * Could a dog pick out the scent of a single person in the rubble of a collapsed building with ~30 bleeding/dead people around, or would so many scents confuse it? In other words, could a dog deduce the scent of a single person even if it were mixed with so many others, or would it have to have smelled them all separately? * What about if it already knew their smell, say by smelling something they touched? Would it be able to tell that the scent of a certain human corresponded to the scent of that person's blood? (i.e. Does your blood smell like "you"?) * If not, is there maybe something other than blood that a dog might be able to track better? Something that could have been available (but not too common) roughly around Victorian England? The solution needn't necessarily be dog related--it's just all I can think of at the moment that wouldn't be anachronistic! Non-canine solutions from that time period equally welcome. Edit: Dogs are way more impressive than I thought they were! Now I'm glad I picked my username. [Answer] I saw a documentary where they were training a young, rescued bloodhound as a tracker. One of the tests was where the subject (to be tracked) went to a baseball game (in a stadium). So their scent was mingled with thousands of other people. The subject walked into the stadium, past the hot-dog stands and so on, and sat and watched the game. The next day, after the game, after everyone had gone and the stadium was empty, the dog came in and tracked the subject's route, through the crowd: and found which seat in the stadium they sat in. I'm not saying that the game was a scene of carnage but this example matches many of your other criteria: * tracked a day after the fact * a single person distinguished in a crowd * didn't even need a trail of blood There might something unusual/ideal about a stadium: a lack of wind and other weather, for example, and/or a relatively odourless (concrete) floor. Tacking might (I don't know) be harder if it had rained overnight. [Answer] # Very well indeed. I recall watching a Mythbusters episode where the team attempted to evade a bloodhound using many different techniques (water, pepper, cologne, changing clothes, etc.). They got hunted down every single time. [Mythbusters](http://www.discovery.com/tv-shows/mythbusters/mythbusters-database/trick-bloodhounds-sense-of-smell/) (Even though the link is on the official Discovery channel website, they get their advert feeds from some dodgy places - use care in looking at the linked website here). > > A bloodhound's olfactory sense is said to be about 1,000 times better than a human's, which is why the canine is so good at sniffing out our odor-emitting skin cells. In fact, that personal perfume is strong enough that none of Jamie's bloodhound-busting tactics worked. He zigzagged and doubled back on his trail, ran through a river, washed and changed clothes, doused himself in coffee and cologne, and even covered his tracks in ground pepper — all to no avail. Each time, the bloodhound sniffed right through the ruse and found the hiding Hyneman. > > > Up against centuries of top-notch breeding, the busted myth was no match for the bloodhound's superior schnoz. > > > So for your fiction, what you're proposing is absolutely believable. [Answer] When the person leaves the scene, it is basically creating a trail from an high noise area (many odours) to a more silent area (fewer odours). What the dog has to do is simply explore the area while knowing what to sniff for. Going roughly in circles and outwards from the center of the area, the dog will sooner or later find the trail, and then follow it. [Answer] Sure. [Toby](https://en.m.wikipedia.org/wiki/Minor_Sherlock_Holmes_characters#Toby) could do that, and it was written in the time range you specify (1890). I'm not saying it is actually possible, but readers found it believable, and people were familiar with tracking dogs in the present when it was published. [Answer] From standard dog scent training: Dogs will usually scent on the skin flakes and perspiration (since that's what's leaking or flaking off people normally, you don't normally have blood to work with). Training in rubble and around lots of people is standard. The dog will normally be trained to lock onto a single person and ignore bystanders. Training on scent objects is normal. A common example is a wood object and a metal object - someone handles one of them and then mixes it up with other objects. The dog then picks out what you handled. The other thing that you commonly see is to use a clothing object to indicate to the dog exactly who to track. As previously stated, you normally don't use blood as the track target, it is more commonly clothing - so perspiration and skin flakes... [Answer] ## Absolutely! We (my wife and I) have a trained tracking rescue dog and what a dog can do is nothing short of amazing. This web page [Only the NOSE really KNOWS Part 1](http://www.schutzhundvillage.com/nose1.html) has some great information. In our experience a dog could do as follows, 1. Could a dog follow the trail of a person who had some of their own blood on the bottom of their shoes, even if it was a day old? Answer: Absolutely, blood having a strong scent (blood that has mixed with skin scents, via bleeding from a wound) would be very easy for a dog to do what you ask. 2. Could a dog pick out the scent of a single person in the rubble of a collapsed building with ~30 bleeding/dead people around, or would so many scents confuse it? In other words, could a dog deduce the scent of a single person even if it were mixed with so many others, or would it have to have smelled them all separately? Answer: Firstly, when getting a dog to track someone it would be very rare to use blood, everyone has a different odor and you would have the dog try to find the odor of that individual, so no, hundreds of bleeding people grouped together would not have an affect on the dog distinguishing between scents. It would be very easy for a dog to find the person you were after 3. What about if it already knew their smell, say by smelling something they touched? Would it be able to tell that the scent of a certain human corresponded to the scent of that person's blood? (i.e. Does your blood smell like "you"?) Answer: Again, rarely would you use blood, as I stated earlier, the primary way to find someone or something is to track something they have touched. But, to answer your question, yes the dog would be able to tell who's blood it was. One caveat, how they do it I don't know and I have never tried to do it from two different peoples blood that was drawn from a syringe, as odors from that persons body usually mixes with blood when bleeding, drawing blood would minimize that. I also want to point out, that if the dog did not know what the persons odor smelled like , it would not be able to find them. You would need something that they have touched previously. 4. If not, is there maybe something other than blood that a dog might be able to track better? Something that could have been available (but not too common) roughly around Victorian England? Answer: Like I have said many times, blood is not a typical item used to track people, a piece cothing or something similar. The dog is able to distigush between peoples odors in a different way that we do. This web page has some great info, [Human Scent and Its Detection](https://www.cia.gov/library/center-for-the-study-of-intelligence/kent-csi/vol5no2/html/v05i2a04p_0001.htm) > > With practice, the men could distinguish among cloths which had been > on different parts of the body, but they could not distinguish one > individual from another. Lohner apparently didn't get dogs to sniff > these cloths, but he pointed out that trailing dogs can take a scent > from clothing off any part of the body, and he concluded that whereas > humans differentiate among odors from different regions of the body, > dogs recognize some common component which identifies the individual. > > > I could go on, but a lot of great information on the two web pages that I linked. ]
[Question] [ Meet Henry, he is a sharp and quick-witted rich young adult from the High Medieval Ages(1000-1347). He can be described as someone with decent adaptability skills, though not much He found a time-machine that another time traveler accidentally left behind. He inadvertently starts the machine and time-travels to this year in an advanced city like Singapore, Tokyo or London. The time machine only works once, there is no option of going back. He obviously will not be used to the world that we have now and will be extremely befuddled. Fortunately, you know that he was going to come and you are ready to help him here. Question: How will he or how long will it take for him to adapt to our current world? Or is it even possible for him to fully adapt and blend in as a modern human like us? Important thing to note (citation from quora): > > The first error would be to assume that medieval Europe was in any way a primitive society. It was not; it was as sophisticated as today’s society in art, philosophy, and literature, and many aspects of modern technology date back to the Middle Ages > > > The first problem you will face is communicating with him, the English language used in the medieval ages are different from modern English. But lets just say you are already prepared for this and already learned the English that Henry used. The very first huge difference he will notice is obviously the environment around him, flashing neon lights and colorful skyscrapers everywhere, horseless carts zooming at lighting speed, weird looking humans wearing suits with wires in their ears while staring at a weird brick on their hands \| Medieval city \| Modern advanced city \| \| --- \| --- \| \| [enter image description here](https://i.stack.imgur.com/5vrAC.png) \| [enter image description here](https://i.stack.imgur.com/P29FG.png) \| How long would it take to convince him that all these techs are not some sort of black magic sorcery?, If its even possible before he goes crazy To measure the technology level in the high middle ages, here are some inventions and technologies they used: * [Astrolabes](https://en.wikipedia.org/wiki/Astrolabe) were used * Invention of the [Movable Type](https://en.wikipedia.org/wiki/Movable_type) system * Invention of [Glasses](https://en.wikipedia.org/wiki/Glasses#Invention) * Invention of [mechanical clocks](https://en.wikipedia.org/wiki/Clock#Fully_mechanical) * Invention of [Windmills](https://en.wikipedia.org/wiki/Windmill) * Development of a [three-field rotation system](https://en.wikipedia.org/wiki/Crop_rotation#Three-field_systems) * Development of [heavy ploughs](https://en.wikipedia.org/wiki/Plough#Heavy_ploughs) * Communication ways: > > [Messengers](https://medievalbritain.com/type/medieval-life/occupations/medieval-messenger/) were often used in the medieval era. They would travel across the land to communicate the messages of the king or queen to others. Medieval people often used particular clothing, designs, badges or banners to visually communicate information to other people. > In many cases, someone wanting to send a letter from one place to another would need to know or find someone who was traveling there anyway. > > > Oh and one important thing: he also needs to learn our modern language and learn to communicate with today's people, fortunately he is a smart guy so teaching him a new language shouldn't take too long Lets take a look at some other factors: Henry wears [tunics](https://en.wikipedia.org/wiki/Tunic#Medieval_tunic) or jackets with stockings, leggings and [breeches](https://en.wikipedia.org/wiki/Breeches) just like every other rich nobleman there. Women in his era wore long gowns with sleeveless tunics and [wimples](https://en.wikipedia.org/wiki/Wimple) to cover their hair. Our clothings will be considered very unvirtuous by Henry, you will also have to help him use and learn the clothings we use today. The food types that he ate aren't so different from the food we eat now(cereals, rice, meat, etc). We have colored drinks and packaged instant foods which medieval ages don't have but adapting to these food types wont be a big problem. The eating etiquette for rich medievals are different from ours but i also don't think it will be that big of a problem. Okay after some time, you finally managed to teach him the logic behind these new technologies and how they work. Here comes another problem. Adjusting to our social life will be a huge problem for Henry. In his era, the rich and noblemen are very [privileged](https://en.wikipedia.org/wiki/Nobility#Noble_privileges), [![enter image description here](https://i.stack.imgur.com/f1kxKm.png)](https://i.stack.imgur.com/f1kxKm.png) Now feudalism does not exist anymore, he is no longer rich here and has to try living as a normal modern human and follow our society rules here. This will be a drastic change for him. Some other things we need to teach him: Witches do not exist here, we have doctors and scientists instead. We have a cure for common diseases now, a fever will not kill you. All genders have equal rights. Beating and abusing children randomly is not allowed. We don't really have arranged marriages anymore. And loads more... Another thing i forgot to mention: he will lose all his family members, love partner, kids(if he had any), friends and everybody he knows which will cause severe depression and will require a ton of psychological treatments. Better act fast before he gets eaten up with suicidal thoughts :/ [Answer] I'd say in less than 2 months he will learn how the base system works and manage to fend for himself, and in less than 2 years he will be indistinguishable from a normal future person. Humans usually learn vital things pretty fast. A rich CEO in another country might never learn the local language, they don't need to. There are plenty of rich foreigners in China, who never learned the language even after decades there. The average guy thrown in another country will learn the language to a basic level in a few weeks, because otherwise they will literally starve, and will become fluent after a few years of total immersion. I studied French for 5 years and I hardly understand when french people speak and I can't formulate an answer, but I learned Italian in 1 month by living there, Russian in about the same amount of time and English in the last 7 months by nerding on videogames and youtube. 7 months ago I couldn't even count to 10 in english. Tribal people adapt perfectly when thrown into modern cities, I used to live in a village for example. Therefore a rich noble guy would have it even easier than me. And this is only my opinion but I suppose the richest guy in the medieval era would sacrifice an eye and an arm to live in our era, things they could buy with bars of gold at the time they can now buy for a few cents. To listen to your favourite song all you need is to press the play button, no need to organize a theather. If you get injured today, that's just a cool story to tell your friends. If that happened then, you'd be praying for your soul as you ache and wish to die sooner. And even the most indoctrinated people can change their mind if you aproach to their level. My mother was a flat earther, antivax and believed blood donations were a form of satanic vampirism...my father believed jesus was an alien and we were created from monkeys having sex with angels... Just needed to let them talk first and explain their viewpoints and suggest to pay more attention to their own logical holes. They are "normal" now. So I'd immagine a noble guy would probably be mentally capable of maintaining a "noble discussion etiquette" and thus could easily be reasoned with. Edit All he needs to do is something taboo and get the police called on him, he might get either directly sent to a homeless shelter or if he did something bad, sent to a jail for a few days or weeks. (If we ignore police corruption and abuse of power, he will be fine) The moment he gets into a homeless or refugee shelter he will be taken care of and get free modern clothes and food. The food is usually paid by the government or private non-profit agencies, the clothes are donated by the average people. A lot of countries have boxes where you can throw your old clothes and they will be sent to shelters were people may need them. Now he is fed, dressed and all he needs is to socialize a little to understand the language, what comes next is up to you storyteller. [Answer] I like this question. Thanks for posting it. This does not seem like an unusual situation. Refugees arrive every day from lands that are culturally different, organized on different social principles, and may be not as technologically advanced. These situations are addressed by social services groups (formal or volunteer organizations). Note that your question is "how long to adapt" not "how long to succeed". The former can be rapid if the visitor is to meet their primary needs: health, food, shelter. The latter might be fast (go on talk shows, get an agent, get paid to be interviewed by historians and scholars) or slow (it might be difficult to make a living as a feudal aristocrat or pursue legal claims on properties they might have owned a thousand years ago). Sticking with the 'refugee' model of adaption, there are plenty of examples of physicians and engineers from abroad moving to a new country and only being able to get jobs as drivers, cooks, or laborers. Is this success? To some, it might be if they can survive and their children can be free and someday be successful. [Answer] ## He will ignore a lot. I've been friends with multiple immigrants from foreign countries who came as adults, including some from places that lacked modern technology. A lot of things won't be an issue. Bright lights? Their hometowns are often brighter, because there's less of a constant haze of pollution, and people could use paint. Weird fashion? Whatever, you don't care what people wear. That's what they do mostly. They ignore weird modern things. ## He needs to learn to move. What is a big issue is the constant gate keeping humans do. There's a weird flashing light, and if you enter the road when it's one colour you die. There's a complex mess of arcane signs, and if you ignore them you die. There's a series of buttons you press inside vehicles and if you press the wrong one you go to a random place you can't easily escape from, a hidden hell inside a concrete shell. You need to navigate an artificial mind to use a moving carriage and bypass checks and barriers. That would require a lot of effort to adapt them to, so they could move freely through the world without attracting attention. ## How to help them. An apple smart phone would help. People from foreign countries generally get very good at using apple smart phones to help them navigate problems, because they are made to be very intuitive even for old people. [From personal experience, and the news, this is a common reaction of illiterate in English people.](https://www.reuters.com/article/mobile-global-idUSL1E8N77BL20121213) > > “I just taught my Persian grandmother how to use her new iPhone. She’s 77 and speaks no English,” said Soheil Arzang, a 27-year-old law student in Palo Alto, California. “With a Windows PC there are so many buttons, it’s confusing. I converted my parents officially to Apple iPhones, Macs and iPads.” > > > What they basically need is to be able to call and text you if there's a problem, google basic problems, follow a map, take pictures and see pictures, and read their emails. That's all. Simple is best, because more complicated devices take a lot of effort to understand. ## Social changes. It wouldn't be that hard to explain the differences. [![enter image description here](https://i.stack.imgur.com/HisBA.jpg)](https://i.stack.imgur.com/HisBA.jpg) The upper levels of the image are a bit suspect, but most of those aspects you don't interact with. It should give them a basic idea of who not to mess with. Most of your other ideas they'll likely ignore. > > Some other things we need to teach him: Witches do not exist here > > > "They were a big problem in my day. What happened, did your scientists kill all your witches? They were riding around with snakes in their tunic in my day. People online claim they're witches. I guess your scientists didn't get them all." > > we have doctors and scientists instead. > > > "Sure, lets trust some random rich people." > > We have a cure for common diseases now > > > "Sure, cure me." > > All genders have equal rights. > > > "Everything I googled said otherwise. Both the feminists and the MRAs agreed we lack equal rights." > > Beating and abusing children randomly is not allowed. > > > "In public, sure." > > We don't really have arranged marriages anymore. > > > "I get that, but why would you want to marry someone terrible your elders hated? You'd bring shame to your family." They're not gonna believe all your random assertions about reality, especially since so many people on the internet will validate them. [Answer] It's going to be very difficult (if at all possible), particularly the social aspects. Personally, I don't think the technological changes would be that big an issue. Sure, phones and cars would probably seem like witchcraft at first, but ultimately "window dressing". The social changes, and particularly entering a non-feudal society would be... tough to put it mildly. Specifically, let's take a look at the life that he presumably had beforehand: * Birthright Lands: His father presumably owns an estate and, by extension, a county or other large chunk of land which he manages. Every day when he wakes up, he knows his future is generally safe. One day, his father will die and all the land and duties associated will become his. This will happen not because he is skilled or hardworking, it will happen because he was born. The (effective) loss of these lands and a future will be devastating to his psyche. * Human Help: Does he know how to cook? Does he know how to dress himself? One of the biggest things that's changed in wealthy modern cities over the last couple hundred years is that the price of people has gotten astronomically higher. As a rich young lordling, he has had, since his birth, people waiting on him hand and foot, who, when he says "jump", they only ask, "how high, mi'lord?". Even if our lives are luxurious in terms of conveniences even low-class people can afford, the lack of human help is going to need serious readjustment. * No marketable skills: As a rich young lordling, he was presumably training to fill his father's boots eventually. This involves becoming literate, learning mathematics (accounting specifically), physical combat, and a whole slew of social skills that are needed to manage both peasantry and nobility alike. Unfortunately, basically all these skills are useless to him in modern times. The language will need to be relearned and any accounting knowledge he has will be pathetic compared to today's standards. Even the social skills are shaped by his feudal mindset, and wouldn't get him very far outside of certain scenarios (notably, he might have the most luck in Japan where tradition still holds strongly in the workplace and "honor" or "face" is taken very seriously). * Feudalism Fundamentals: This is hard to describe, but I think it's a big one. Back then, people (peasantry and nobility alike) believed in it, and genuinely just thought that nobles were just born better. He's been getting a non-stop stream of "you're special" for his entire life since birth, and transitioning into a world where this isn't the case could cause a psychological disconnect. It's commonly said that "it's never to late to learn a skill", but for your protagonist, it will be difficult. Compared to his age group, he's over a decade behind. I mean, our modern youth is ridiculously educated: by the time they graduate high-school equivalent, they've had a whopping 12 years of 5-days-a-week full-time learning. Sure, an older person can learn faster and at a higher level than a kid because they presumably have more discipline, but it's going to be extremely disheartening to be a person who is uneducated while people his age could've casually run circles around most "highly educated" people of his time. Personally, I don't think that this person could ever adapt completely and become a productive member of society, because unless they have an iron-will and/or someone willing to essentially baby-sit him for years, they're probably going to get stuck in a self-reinforcing depressive spiral. [Answer] ## Bring him to an Amish Community There is no reason to leave him in a major city. Amish communities have standards of living and culture that are very similar to the medieval period which would all be very familiar to him. The one big difference would be that he would have to adapt to the life of a lowly peasant, but this was not an uncommon occurrence in the medieval period. Members of the nobility were often exiled for various reasons and forced to live below thier station. Being a stranger in a strange land, the noble would be devastated, but fully understand that he was living in a state of exile. While a noble would not have a lot of transferable skills to the modern world, he would know (at least in theory) a lot about how to live an Amish life style, and may even be able to bring certain wisdom about primitive living that has since been lost. Because his entire life revolves around understanding how to organize a primitive economy, he could even eventually elevate his status and prosper knowing only what he already knows. What's more is that the Amish know of the outside world pretty well. So, if he decides he wants to leave, they know how to prepare him for what to expect. [Answer] Dropped down town in Singapore or London, you say ? Well the first weeks will be the most difficult. After his arrival, his clothing would get noticed immediately. Children follow him and gaze at him and make a fool of him. There is no means of communication yet, so he would probably have to undergo humiliations passively. To get a roof over his head, he'll need some means, like gold. He is a rich man, but how much gold did he have on him, when he accidentally started the time machine ? When he took too much gold, he will get robbed and may be killed in the city. When he did not take any gold with him, he would need to resort to begging for money and help, to stay alive. This must be quite difficult and inconvenient for a young man who was used to superiority and abundance in his time. Now suppose our medieval bloke copes with the situation, and he is good looking. He'll get noticed for that, his clothing may even help to be regarded as some kind of artist. There's mystery around him, many people will be interested to know more about him. Supposing he is able to build some social life, have friends.. In a few months, he will have picked up the language. Journalists get a hold of his incredible story and he will be news item #1 on a lot of media. It depends on his personality and his friends, what happens. A cult could arise around him, a cultural revival of medieval times, with our guest as the hero, and a source of thruth. At some point, scientists will pay attention too: this guy arrived in a time machine. Where is that device and how does it work.. When the hype is over, he'd probably end up like some world famous autist savants do: researched by science, safely encapsulated in some "institute" where they can develop their talents, among people who are interested and able to understand and connect. It could also be a little more dynamic. My 2021 Catweazle novel would probably spend some time on a wild goose chase, involving alledged offspring of ancient ancestors related to this noble young man, claiming they suddenly lost family members when he arrived, because he did not have children in medieval times, changing his future and our present time. Of course, this is all regarded conspiracy, but our poor noble man has no answers to that. They would demand he returns to the middle ages immediately. Meanwhile, some genious scientist found out how the time machine works.. and on the last page he returns to his own time. [Answer] Henry will take a little longer than he lives to fully adapt. How many people do you know who grew up ten years too soon who never really adapt to modern life? My own parents were born just as the Great Depression segued into the lead-up to World War II -- Hitler consolidating his power, Stalin pushing Lenin out of the way, airplanes switching from biplanes with fabric covering to all-metal speed demons (and the promise, if you had access to the right publications, of airplanes that didn't even need propellers!). Now, in their mid-80s, they don't even use modern smart phones, and the only reason they have a computer is because my mother learned to use them on the job when they were new enough only big businesses and government agencies had them. I know people my age (born after Sputnik but before Gagarin's orbit) and even a little younger who aren't really comfortable with this stuff. My father would be more comfortable sleeping on the ground alongside a trout stream (at 85!) than living in a city like New York, Tokyo, London, or Singapore -- even if he didn't have to learn a new language to do it. Now, picture someone who didn't have the advantage of living through the last five or six decades when all this stuff was invented more or less gradually. Henry will learn his way around; he'll learn the language, and to read (as long as it's not Chinese or Japanese), not to walk against the light, make and take calls on a smart phone, he might even learn to drive (not where I live, please) -- but he'll never be "adapted" to the level of comfort even a city dwelling immigrant in his sixties or eighties today has, never mind that of someone his own durational age who grew up where he lands. He'll be a "stranger in a strange land" for all of his days -- and he won't have Mike Smith's fictional ability to adjust to the alien. [Answer] It depends on what you mean by "adapt". And it may well depend on individual differences. For instance "The very first huge difference he will notice is obviously the environment around him, flashing neon lights and colorful skyscrapers everywhere..." Now I am a product of the modern world: indeed, I've made a good living at working pretty close to the bleeding edge of tech. Yet I can't adapt to life in an urban environment. (I've tried.) I can just about survive long enough to make my way out, but I'm miserable and on the verge of sensory overload most of the time. So if you really want to help your time traveller (and you have significant resources), you get him out of the city as fast as you can. Find a nice rural research campus/think tank, where he can be interviewed by historians, and learn to handle the useful parts of tech, without having to deal with sensory overload. "Or is it even possible for him to fully adapt and blend in as a modern human like us?" Is it even necessary to fully blend in? There are lots of people who eschew various parts of the modern world, yet manage to live fairly happy & productive lives despite that. "How long would it take to convince him that all these techs are not some sort of black magic sorcery?" Is it even necessary to convince him that it's not sorcery? (Of the "white magic" sort, of course.) To maybe 95% of modern 1st world people, that's exactly what it is: magic. They've just learned the spells ("Hey, Siri", for instance) needed to use their magic devices. [Answer] What an interesting question. I've often thought about what it would be like to be transported to a different time. I think it would be much like moving to a new country and having to learn the language and adapt to strange customs. I know from personal experience that it is not an easy process to go through, although there are many rewards. The answer to how long it takes to adapt is that like all learning experiences, adaptation to a new culture is a long and complex process, and it is different for everyone. People have very different levels of resourcefulness, and different attitudes toward change. I would think that examining Henry's assets and deficits in this regard would make an interesting story. A Couple of Ways to Think About It: You might want to research the "stages of culture shock", which is a construct developed by anthropologist Kalervo Oberg for understanding the process Henry would likely be faced with in adapting to a new culture and language. Wikipedia has an in-depth definition & description of the problem. According to Wikipedia, there are four stages one would go through to adapt to a new culture: Honeymoon Negotiation Adjustment Adaptation You might also want to look at stages of grief. In a sense, Henry has lost all his family, friends and everything he knows, BY ACCIDENT. It is reasonable to assume that he would experience grief as it becomes clear to him that he can never return. Elizabeth Kübler-Ross, a psychiatrist and author of the book “On Death and Dying,” identified five stages of grief, leading to acceptance of loss. Denial Anger Bargaining Depression Acceptance Henry will be undergoing both of these processes, while having much to learn simultaneously. Using familiar constructs that describe these processes will help you outline a logical trajectory for Henry's behavior & reactions to things. While he will have many wonders to explore, he will also experience disorientation, along with feelings of isolation and loss. He will need to be resourceful, and have a capacity for forming new & trusting relationships or he may suffer from depression that undermines his ability to adapt. One of his strengths may be that he has a good education, since he is from a rich family, and may already have some experience learning another language. Maybe he studied Latin. And maybe he has some practice using his noggin. But also, coming from a privileged background, he may be hampered by a sense of entitlement that would make arriving with only the clothes on his back, and no modern work skills quite a hardship. What other character traits does he possess that would either help or hinder him in adjusting to his new life? I look forward to hearing more about Henry. He certainly has an adventure before him. [Answer] It depends if there is any part of the new world that he finds to be traumatic or in direct conflict with his personal values and principles. If you look at survivors of totalitarian churches, it takes about two years to adjust emotionally to the idea that everything they ever believed was false, alongside building up skills. But dealing with grief, trauma, loss, confusion, and the fallout of being lied to typically takes ten years or more. Particularly if he sees that people -- loved ones -- from his own time were suffering unnecessarily from preventable diseases and distorted thought processes. Yet he might also feel alienated by destructive choices of today that would never happen in his own time. If you're asking how long before he feels like he is a valued member of contemporary society and is totally accepting of current society, the answer is probably never. [Answer] He already has a framework for coping with a totally strange world: he might think he has died and gone to heaven/hell; or maybe taken to fairyland. > > In the tale, Oisín (a human hero) and Niamh (a woman of the Otherworld) fall in love. She brings him to [Tír na nÓg](https://en.wikipedia.org/wiki/T%C3%ADr_na_n%C3%93g#Ois%C3%ADn_and_Niamh) on a magical horse that can travel over water. After spending what seems to be three years there, Oisín becomes homesick and wants to return to Ireland. Niamh reluctantly lets him return on the magical horse, but warns him never to touch the ground. When he returns, he finds that 300 years have passed in Ireland. Oisín falls from the horse. He instantly becomes elderly, as the years catch up with him, and he quickly dies of old age. > > > The problem is whether this model will help Henry survive, or make life more difficult. [Answer] Unless time travel machines are public knowledge at the destination time your traveler could easily end up in a mental institution or in holding for deportation. During the initial culture shock your traveller is very much at risk a running afoul of the law as they would be completely unfamiliar with many of our laws, customs and even etiquette. Once the traveller is detained the police would very likely attempt to verify their identity. This would be a drawn out process since the person doesn't have papers and communication would be very difficult - especially when it comes to advanced concepts like "nationality" and "passport" which are things a medival person would not be familiar with. If you want to get an idea of the linguistic difficulties Icelandic is a pretty good analogue as its relatively unchanged from old norse while Norwegian has evolved significantly. Both languages have many words in cognate but Icelandic is barely intelligable to the average Norwegian as the pronouciation and meaning is significantly different. If you then threw that person into Tokyo it would be extemely difficult to find someone who even knows what langauge they are speaking and who can translate it. If Henry even manages to communicate that he is a medival lord and that he entered a strange contraption and ended up there its very likely that it would be concluded that he has a dissociative disorder and it would be extemely difficult for him to prove otherwise. That said if he was extremely adaptive and lucky and manages to fly under the radar long enough to learn the langauge, technology and customs and overcome the difficulties of not having a documented identity, lack of any useful and documented education I would seriously doubt that he would ever get above the lowest rungs in modern society. [Answer] > > How long will it take for a medieval human to adapt to our current world? > > > Never! Period! > > How long will it take for a XXI century human to adapt to medieval world? > > > Same thing, but worst! Today we have antidepressant medicine to give your from past traveler. In the middle Ages they could make a trepanation into your head, that simple. How to explain your travel visitor that we are in the future and not being part of a medieval vision of hell? How to explain that his religious views are wrong and that Earth is not the center of the universe or that the Pope is not infallible and people seriously believe that all in the Bible is fake? We are living in one much better world than people of the middle ages. Much better. But we are far from a paradise. We have exchanged some evils for others. It is amazing some answers placed a real time period that at - the end - a past traveler could be adjusted to our time. Of course I forgot to mention he/she could drop dead on the spot of our "brave new world". Also forgot to mention he/she was not vaccinated for any kind of virus disease. A simple case of flu will kill he/she before you could take any action. This guy could have to take antidepressant medicine for the rest of his/her life. > > Or is it even possible for him to fully adapt and blend in as a modern human like us? > > > Of course, the possibility do exist. In 2007 giant pandas do produced offspring. <https://www.giantpandaglobal.com/zoo/tiergarten-schonbrunn/yang-yang-long-hui-mated-2/> May be your time traveler does not kill him/her self. ]
[Question] [ "Congratulations, you're hired!" Is usually something everyone is happy to hear. Except, the job... You're the local vampire lord's publicist. Well, congratulations. Your job is quite literally to give a villain undeserved good publicity. Failure? No problem, if you want your new boss to kill you, your friends, family, and that guy you buy those yummy croissants from at the market. And not just any death, no... we're talking about someone that enjoys inflicting suffering on his 'meals', before drinking them dry. Again, congrats? There's an upside, though! Your boss likes keeping his... meals and lifestyle as low key as is possible, provided it makes keeping the sheeple tame and compliant. And you can even request a budget to make your job easier(ish). There are three target audiences you need to deal with: high class, mid class, and low class. Simple enough. Doubly so, given all the inter-class fighting. High class 'nobles' like being on top, so they're likely to keep the mid class beneath them by any means necessary. Mid class 'citizens' want the high life, and will do anything to get it. Low class... well, they're just trying to survive. They're usually too tired from working 12-14 hours a day just to be broke, so there's little risk of them caring so long as they and their family/friends aren't directly affected. As well, slavery is a thing. So it'll make 'arranging meals' far simpler. Even though... it also doesn't. Your boss has a bad habit of killing the 'blood bag', and he needs to have fresh blood (fresh from the vein, naturally) every three days, at most. This isn't too bad given the population density (the city has in excess of 200 million registered (non-slave) citizens. So. How are you going to keep your employer alive so you'll get paid? Things to keep in mind: (this is a late edit, so I'm not going to hold this against already offered answers) * Vampires need to eat regular food, to have calories to burn. * Your boss has no real preference for blood bags, and he has AB-positive blood, so the bloodtype of the blood bags is not relevant. * You cannot choose your boss's meals, and 'helpfully suggesting' might upset him. (read: make him want to kill you on principle alone) * You have contacts with local writers, so influencing what is being written (newspapers and the like) is plausible, but difficult. * Getting your employer involved will create the exact problems you are trying to avoid. (Though he is more than willing to feed on the 'haters', it's the kind of publicity you want to avoid.) * People already know about vampires in general, but no one has had any substantial interaction with them. However, the general consensus is that vampires are evil and vindictive (which you confirm with one meeting with your boss). * People go missing all the time, and there are thousands of homeless people. So a few hundred going missing per year won't even be noticed. [Answer] The first big decision will be if the vampire wants to come out as a vampire. If the vampire doesn't want that, there are two interesting options: * Deny that vampires exist. Try to destroy the reputation of anybody who believes in them. Vampires? Do you believe in Santa Claus and Trickle-Down Economics, too? Get real. * Claim that vampires do exist, but ascribe the wrong characteristics to them. Vampires only come out of their coffins on the full moon. Everybody knows that. Anybody who is seen on other nights is no vampire, no matter she is never seen in daylight. Hire some good novelists, a few TV producers, and a game designer or two to promote your definition of vampires. If the vampire does want to come out, things get tricky. * Try and promote the idea that vampires are stylish and sexy. Hire those novelists etc. mentioned previously. Try to make sure that your boss only goes into public well groomed. * Try and promote the idea that vampires fight another supernatural evil. Sure, they suck blood, but they're keeping the city safe from the werewolves. Can you recall any outbreak of lycanthropism since we have vampires in town? See? Not a single one. * If nothing else helps, there are good vampires and bad vampires. Good vampires help against the bad vampires. You might notice some parallels between my suggestions and the vampire novels and [movies in recent decades](http://tvtropes.org/pmwiki/pmwiki.php/Film/Underworld). * Try and make sure that your boss never, ever eats the upper classes. Can he restrain his impulses? If not, you have a problem, and the sane vampires will have to take action against the insane vampires. If your boss is on the wrong side, perhaps you should try and talk with a (more) sane vampire. If you're lucky, you will still be alive when the dust settles. If you're very lucky, your new boss will be a very sexy vampire who doesn't [bite too much](http://tvtropes.org/pmwiki/pmwiki.php/Main/FriendlyNeighborhoodVampire). * Try and make sure that your boss doesn't eat in public. Same reasoning, same consequences. Unless a little bite is quite survivable. Then you need to find dozens of "victims" who live long lives thereafter, with a thick wad of money as a token of gratitude. It would still be possible that the boss is a more messy eater in private, but that's behind closed curtains. * Try and discourage systematic looks at serial killers and cold cases, especially if the victims were from the lower classes. [Answer] Cult-Worship/ Tit for Tat Your main problem is convincing the wealthy/masses of the worth of these Vampires.I don't know what criteria yours follow but I'll assume they have generic Dracula prowess. *1)* For the Wealthy, there are many reasons why a less than scrupulous noble would want a Vampire as a friend. As long as the Vampire limits his feedings to slaves, the nobleman would be more than happy to have such a powerful ally. Vampires are excellent spies, saboteurs, and agents of the night - a thing that makes them useful for political espionage, assassination or other things. They could even serve as bodyguards/advisors to the very wealthy Lords, advising them on magical things and world events in general due to their longevity. 2) The Masses,as the primary prey of a Vampire don't see any direct benefit from a Vampire, but could be rallied against them by some populist. In order to counteract this, a veneration system around Vampires could be in place. The public instead of treating them as predators, treats them as the vengeful manifestation of God coming to punish sinners. If your noble is a 'divine right of kings'-type leader, he would be head over heels for this. Not only does the Vampire's service to him (as the chosen of God vindicate his decision to employ one), but it also means that his political enemies are condemned by a higher power when he sets the Vampire on them. This is absolutely brilliant for control of the masses. [Answer] You might play up the living-history angle Your vampire has seen the ages, human history and innovation (and drama, oh the drama). Ok, well those in power, and interested in getting into power, may be interested in legitimizing their status this way (especially if your vampire can be persuaded to nudge their familial histories in the correct directions). After all, nothing like a good, upstanding history, or an appropriately dramatic one, to serve as leverage and fodder in status games. As for those lower down on the social ladder, well, it can be about entertainment, or appeal to the exoticism or nostalgia of the past, giving life to stories of the exiting, romanticized periods of history - if your vampire has any skill, of course. Depending on their scholarly inclination and personality, they might also like to play with the idea of the wisdom of past ages, playing up their very long lives and experiences to suggest they are wiser or more knowledgeable than most people. This can play into PR, again, with a good storytelling value. It can also (depending on personality and skill), also play into more substantial power struggles - advisors to the rich and titled, dispensing their hard-earned knowledge for a cost, or for the "betterment of humankind" (this is thee kind of thing a PR person has to spin). They can be chess-masters of human politics, and have people pay for the privilege - since a vampiric advisor might legitimize their social or political status. Your vampire might wish to cultivate a reputation as an artist, or a patron of the arts - long lives means lots of time for hobbies and interests. And even if they don't happen to want to create artworks, well, some of those disposable people might have talent - give them materials and time, and keep their actual creations for a while after the maker has gone for lunch, and the overall collection might look like the collection of a serial dabbler in art, with plenty of room for artistic eccentricity, and even a source of income if they sell off older works. And in the other direction, long lives might mean kindnesses or favors get paid forward, too - a favor done now to better their children's lives, or grandchildren's, after the favor-givers are gone. After all, if your vampire forgets, or reneges, the favor's already given, and the person to whom they were promised, already dead. But, your PR person plays up your vampire's "honor" and "loyalty", and occasionally give or seem to give favors, based on "ancestral debts", and people will be willing to offer much for the idea that they might improve their family's lot later on. As for meals, keep it low key, offer stories about any moral alternatives (like blood donations or such), whether your vampire uses them or not, and work to give an impression that the donors survive - maybe hold blood drives (and advertise, and pay those donors handsomely), and that blood can go to a hospital or down the drain, so people aren't asking if the blood your vampire needs is related to the disappearance rate. [Answer] If the vampire's lifestyle is really low key, it means there is not much proof about what he's really doing. If you have to provide him good publicity, it might mean he is known to be a vampire, but not known what he is doing, so we have to embellish that. Start by claiming that killing people and sucking their blood is just a myth. Then go from the myth to stereotype. It's just an evil stereotype made up by some evil supremacists who can't tolerate if someone is different from them. Draw parallels about how some groups were accused of doing evil things in the past, and claim all such cases were just pretexts for oppressing them. "We all live in the 21st century, so can you please stop being prejudicial! We should accept everyone as they are!" - this will go very well with the ideological position of most of today's media. If you have significant funds, you can start smear campaigns against anyone who tries to bring proof about the vampire's evil deeds. There will still be a small and loud community who will hold strong anti-vampire sentiments, but you can even turn it to your own advantage: you could even post exaggerated and obviously falsifiable stories in their media, which they will eagerly believe and share, but will make them look foolish in the eyes of the rest of the world. They will be reduced to being just a fringe hate group, so no matter what proof they will come up with, they will not be believed. [Answer] FOR IMMEDIATE PUBLIC RELEASE: > > Today, Dr. I. Ping Feng, at a press conference at City Hall, has > renewed his call for the Mayor to take action against the scourge of > untamed, rabid, infectious werewolves. These beasts are not human, > but an uncontrolled danger to society. They have no control over when > they change, what damage they cause to the city, nor who they bite and > doom to a similar bestial life. Further, their hairy and sweaty nature > is a blight on public transportation, and discourages tourists. > > > In response to questions, Dr. Feng indicated that the Mayor casting > aspersions on vampires was understandable but misguided. Vampires, > Feng noted, are in complete control of their actions, are wildly > popular at night clubs, boost the economic fortunes of the city with > their investments from centuries-old wealth reserves. They have the > best interests of the city at heart, unlike werewolves who'd rather > the whole thing be burned to the ground and reclaimed by the forest. > > > He closed by suggesting that a modest redistribution of city funds > towards wolfsbane would go a long way to cleaning up the werewolf > threat, which has in particular been a threat to teens since 1985. "We > must think of the children." Feng said. "The worst thing a vampire has > done to a teenager is granted them youthful immortality, but > werewolves have a tendency to rip them limb from limb - even werewolf > survivors are cursed with hairy face acne and unstoppable rage. Can we > look at the next generation in the eye if we have done nothing to stop > these terrible, awful animals?" > > > In other news, 9 out of 10 dentists surveyed indicated they would not > treat werewolves, citing difficulty and accident-insurance concerns. > > > [Answer] Assuming that vampires have already come out of the coffin in this world, get a vampire assigned to every emergency response vehicle in the city. They are there to provide optional death avoidance to any accident victims who cannot be saved any other way. Bringing over the injured and saving them from death, not only fills a vampire's stomach, it turns that vampire into a hero. It should only take a short time until one of your assigned vamps gets lucky and saves a child or wife of one of the upper class. Now the power brokering can begin; slowly infiltrating the upper class and educating them to your needs either by persuasion or conversion. In no time, you will have new vampires (who share your needs and point of view) or vampire sympathizer (who just wants to stay alive), sitting in every seat of power in the city. From there, your problems are solved. The upper class won't be talking about you because they are you. The middle class won't be trying to become upper class any more because they don't want to be dead. The lower class is still so busy working that they haven't yet noticed that a change of management has occurred. Let the feast begin! [Answer] It depends on if your vampire has come out of the coffin, as it were. From the question, it appears that the public at large does know of the existence of vampires, even if they may not know exactly who it is. In that case, I would suggest Batman. Your vampire acts as a vigilante targeting violent crime in the streets, feeding on the perpetrators. The lower classes will love him, provided he doesn't cause collateral damage, since the police aren't going to make much effort on crimes in slums or among street people. The middle class looks down on the lower class and envy the upper class: a couple of thugs getting killed while committing a crime? Well, they had it coming. You only need to ensure the proper spin on each story as soon as it comes out, and they'll stay quiet. The upper class will be the biggest threat. These are the people with money to burn, if they want to go after something or someone they dislike. One socialite, whose dog was drained dry a few years ago; one right-wing born-again, religious nut, who believes it his God-given duty to slay the demon, even if he kills more people in the process than the vampire would; a mobster/bureaucrat/Jack D. Ripper type who feels threatened Re: his precious bodily fluids; any one will be a threat to your vampire, especially, as they have the contacts and the money to actually do harm. These are the people you have to neutralize, without your boss paying them a visit. To counter these people, your vampire needs to project himself as one of them--shouldn't be too hard. Market him as "an eternal champion of the city" maintaining order throughout the ages at personal risk, even though he could live a comfortable (after)life without the effort (and keeping the unwashed masses in their place through the direct application of violence ;)). In any interaction with this class, have him present himself, as a sophisticated, well-read individual, somewhat eccentric but with a proper wardrobe. Think golden age or Batman '66, rather than Burton. Conversely, when interacting with a lower class, the vampire needs to present himself as the protector of the powerless from those with power. Here, you can go for the scary, unapproachable look, within limits, of course; no reason to terrify the people you're claiming to protect. Like a good politician, he must be all things to all people. Honestly though, he'd find it a lot easier if he were a she and good looking. People forgive a pretty face more than a monstrous (or even average) one. If your boss is a bit on the negative photogenic side, being a vampire and all, get him a mask. Use the fact that he doesn't show on a mirror (and so, presumably, a camera) to add to his mystique. A touch of [the Shadow](https://en.wikipedia.org/wiki/The_Shadow) would probably help, and appeal to your boss' sense of drama at the same time. [Answer] Teach him to play guitar... Seriously, he doesn't even need to play particularly well, just enough to give a convincing stage performance. Hire a really talented band to back him up and do the studio recording. Pay off a few radio DJs and promoters and your problem is solved. In a few easy steps you've taken your boss from monster to rock star. People expect rock stars to be a little dark and eccentric. They put up with their excesses and expect wild behavior. Not to mention that your boss also gets a steady stream of juvenile delinquent groupies to feed on... "Angsty teenage rock fans run away from home all the time, nothing to worry about, I'm sure they'll turn up." And a constant touring lifestyle keeps the bodies from piling up in one place. If anyone gets too suspicious convince him to do a few public service announcements about the "growing problem of teen suicide, pregnancy, drug abuse, or whatever" just a little something to keep the moral outrage directed somewhere else. [Answer] There is no need to imagine because that already happened. [Stephenie Meyer](https://en.wikipedia.org/wiki/Stephenie_Meyer) was hired some time before 2005 to write a series of novels portraying vampires in good light, and even several films were produced after those novels. Undoubtedly, it worked and it's clear that vampires reputation is a lot better than it had been after [Nosferatu](https://en.wikipedia.org/wiki/Nosferatu). [Answer] # Vampires as humanity's protectors Vampires are the one type of supernatural that needs to protect humanity. Without humans vampires can't survive. If vampires are already known to exist, make it well known that any threat to humanity as a whole is a threat to vampires. This is a two way publicity job. While producing articles about threats to humanity that could wipe out humanity for the humans, make sure they are presented to the vampires as well. If they weren't long term thinkers, they probably wouldn't still be around. Once the vampires start working on solutions and prevention methods, publicize that. Is some idiot in New England trying to summon an Old One again? Get a film crew there to watch the vampires end that threat with enthusiasm. Is there a possible pandemic out there? Show what the vampires are doing to detect and stop it. Is there an asteroid out there with Earth's name on it? Show how the vampires plan prevent the extinction of humanity. Once you get vampires to see that it is in there best interest to be on top of these things, they will take it from there. Then it is just a matter of getting press coverage. # Vampirism as an Achievable Goal You to can become immortal if you qualify! You have to set some high standards because every vampire created is a burden on the population as a whole. This can be done using the cult method; the "inner, inner, inner circle" get the bite. Have hoops to jump through and training and tests that people have to pass to reach higher ranks. Only those who are hand picked will, of course, reach that innermost circle. Look at Scientology for a good model of this. Another method that is a bit more open is to have a truly merit based system. Set it up so that 1 out of 100 nobles can qualify, 1 out of 100,000 middle class people can qualify and 1 out of 1,000,000 lower class people can qualify. The criteria for each class can be different. # Do Vampires need to Kill to feed? If the answer is yes, my second option will take much more spin to implement. However, there are always people who allow bad things to happen to other people (NAZI Germany, anyone?). So it still might work. If the answer is no, the first option or a combination of the two becomes really easy. You can probably even get people to compete to become donors. ]

Subsets and Splits

No community queries yet

The top public SQL queries from the community will appear here once available.