text
stringlengths 22
2.11M
|
|---|
[Question]
[
I am revisiting an older scenario I came up with, but I have been experiencing many of the same problems. I have a swampy, jungle world which flooded, causing a species of fire ant that made an ant raft to evolve a collective behavior, ditching anthills and becoming an ant-hill (I'm not sorry). Over thousands of years, the flood water receded and the clustering behavior of these ant-hills remained, creating a powerful, natural, biological army. Over many millions of years and some complicated evolutionary history, I don't have room to explain, These ant-hills evolved into a [collective consciousness](https://worldbuilding.stackexchange.com/questions/46962/what-would-a-collective-consciousness-look-like) complete with a military and hatred of local terraforming humans.
As they do not bleed and lack 'organs' so to speak, their species (Diluviumformica sapiens) consists of many smaller specimens, all working as a whole, communicating using touch and pheromones, the larger whole communicates with each other through much more powerful pheromones.
[Virtually immortal](https://worldbuilding.stackexchange.com/questions/45752/how-does-a-collective-consciousness-species-avoid-overpopulation) and destroying terraforming station, the Ant-hills must be stopped and we are ready to destroy them, but how?
The only option is a brutal ground war, as all solutions for space combat have been declared too risky to the safety of terraforming the world.
---
Given all of these restrictions, How do us humans effectively conquer this jungle planet and defeat the inhabitants? Modern guns would fail on these multiple bodied aliens as would most weapons, what kind of cheap fighting would be effective on these collective consciousness?
[Answer]
## Exploit their pheromone networks
Since each ant is a conglomerate of smaller individuals who cooperate by touch and pheromones, then design chemical weapons to disrupt this communication.
First, capture as many individuals as you can. Place them in a controlled environment with as sensitive a chemical sensor suite as you can muster. Put the ants through various scenarios and stress levels to see what the pheromones and pheromone levels look like. Depending on your findings, you may be able to make a pheromone suppressor or more interestingly, a pheromone(s) that signal disease and cause the ant to "dissolve" back to the sub-individuals.
Whatever findings made through experimentation will point you toward an approach for pheromone exploitation.
## Old Answer (It still works, it's just not as specific as the new answer)
## Take all the really bad things that humans aren't supposed to do each other anymore (basically, all the lovely weapons/weapons systems developed between 1917 and 1945, and are now forbidden) and use those against the ants
Let's go through them one by one:
## Flame or chemical weapons
Normal bullets and beam weapons won't work because they only affect a small number of targets at once. Area of effect weapons such as flame throwers or chemical weapons should affect large numbers of these ants at the same time. Also, assuming that they have physiology similar to Earth ants, they will be limited in size to the available oxygen levels. If these ants are large, it will mean very high atmospheric oxygen levels....the use of flame weapons is going to be spectacular!
Chemical weapons can be spread over wide areas. Even if they don't kill the ants, just slow them down or deny them access to an area, that will make the war significantly easier for the humans.
## Biological Attacks
Make a virus that only attacks these ants and let it loose. It's very difficult to make a virus that kills 100% of a population. Still, dealing with so much disease and degraded command/social structures should help along the human conquest.
Go one step nastier and target the ant's food supply. Make them starve to death. Or, don't kill the ants directly, infect them with a form of [Ophiocordyceps unilateralis](https://en.wikipedia.org/wiki/Ophiocordyceps_unilateralis), that turns them into zombies.
## Develop a debilitating parasite
Mother Nature is really good about making parasites that do terrible things to the host organism, so there is no shortage of approaches that can be taken when developing a parasite or host of parasites to attack and degrade the ant's war fighting ability. Really, there's no end of variation or combination here.
## X from Orbit
If any kind of orbital targeting, target acquisition or energy delivery is permitted (not sure why the resource wouldn't be available but whatever)
## X = Microwave
Built a huge microwave emitter in space. Point it at the ant hills. If the microwaves don't penetrate the ground, you've developed a wonderful area denial weapon that can be turned on or off at will. If it happens that the ants use a solvent other than water for their internal chemistry, change the microwave emitter to use that solvent's resonant frequency. In this case, the microwave emitter can be kept on even when humans are present (though do some very thorough testing to make sure).
Alternatively, change the frequency to good old IR and just melt the ant hills to slag.
## X = Large deorbiting objects
Throwing large rocks at the problem is a popular and time honor tradition.
[Answer]
Sun Tsu said: "Study the five factors of warfare: Way, Heaven, Ground, General, and Law. Calculate your strength in each and compare them to your enemy's strengths." While he may have been speaking from an age of human armies facing human armies, his advice is universal and can be applied in this case.
>
> The 'Way' is the strong bond your people have with you. Whether they face certain death or hope to come out alive, they never worry about danger or betrayal.
>
>
>
I am assuming your warriors are the kind that will stand behind you in this sort of fight. You've already indoctrinated them that this is a matter of life and death for the entire intelligent universe, so hopefully they won't betray you.
Your opponent has an advantage over you in terms of the Way. There is only one collective anthill, and its elements will die for their cause, not because they believe in it, but because they simply will. They lack the sapience to do otherwise.
>
> 'Heaven' is dark and light, cold and hot, and the seasonal constraints. 'Ground' is high and low, far and near, obstructed and easy, wide and narrow, and dangerous and safe.
>
>
>
The anthills have been here a long time. They understand the land far better than you do. Each anthill is going to be located in an easily defensible location.
However, we have space-faring travel. We can monitor the state of the planet across the world in real time. This gives us the advantage of the weather. Because we can move more weather-related data around, and move it faster, we can better predict the weather.
>
> 'General' is wise, trustworthy, benevolent, brave, and disciplined.
>
>
>
The anthill general may be a weakness. You mention that it is very expansionist, which means that, given a choice, it will choose to take territory rather than refining its control of the territory it has.
Your general I'm assuming is an excellent strategic mind, because that will make for the best story. I'm visualizing a Mazer Rackham for this scenario. If your general is less awesome than Mazer was, you may have to adjust this plan.
>
> 'Law' is organization, the chain of command, logistics, and the control of expenses.
>
>
>
I think this is where the battle gets interesting, because the command structure of a collective consciousness is so tremendously different from a normal army. A collective consciousness is going to have a loose hierarchy, rather than the rigid one we are used to. There will still be value in aggregating command decisions into a small number of elements of the anthill, but if those elements are disrupted, others will take over the job. This process will be as unconscious as you shifting your weight from one side to another to free up the muscles you need to pick something heavy up.
Our command and logistics will be far more brittle, but we have something they don't: electromagnetic devices. We can transmit information at nearly the speed of light with radios and cables and other similar devices. This means we have a tremendous logistic advantage in terms of information flow. Our soldiers will need to capitalize on this.
They may have radios also, depending on how advanced their society is. However, the mass high-bandwidth communication which makes a collective consciousness work would not be well supported by this medium. If you reduce them to radio, they are no longer one collective consciousness, but two, and they have less experience with that sort of situation than we do.
---
Okay, now lets use what we learned to combat these anthills. Our only real advantage is that we can transmit data far faster than they can. We can use this to develop a powerful tool to combat collective consciousness: [the speed of darkness.](https://www.youtube.com/watch?v=JTvcpdfGUtQ) If you can strike faster than information is transmitted, your opponent cannot prepare for it. The usual limit to this process is that the deeper you strike, the more cut off you are from your own general's orders. However, with the asymmetry of radio, you can strike faster than any of their intuitive high-bandwidth connections can respond to.
This gives you the ability to cut off a section of the anthill from the rest of its kind. At this point, it no longer has the brilliant tactical capabilities of the gestalt consciousness, it's much smaller. You can now wage a battle against the smaller piece. Repeat as necessary. The same logic works with the anthills themselves. Cut them off from the rest of the organism and take them on in isolation.
Along the way, you should be able to capture some of their dead ant bodies. You should be able to do research on them, and learn more about how they operate. This will be key knowledge about the enemy going forward.
The ideal goal would be to create a surgical strike that isolates a section of the anthill without raising any awareness. If you can move in subtly and quickly enough, you can interact with their information streams. This could be very powerful. As an example, it is obvious that once you strike, the larger side of the anthill is going to try to attack whatever forces you put in the way. It will have the goal of reattaching the lost group of ants to the greater whole. However, if you can strike swiftly and convince the segregated portion that the gestalt collective wants them to strike as fast as possible, and you can convince the gestalt that your segregated unit saw an opportunity and acted on it, then the enemy may not even realize that it is engaging in combat until it is too late.
Even if you can't interrupt their communications in such a subtle manner, you can let the weather do it for you. If you can predict the weather better than they can, you can predict how it is going to affect their communications. If you strike at the correct times and places, you can take advantage of mistakes in their weather prediction, so you know how they will respond better than they do.
[Answer]
Obviously, the place to start is "God Rods" -aka: hit them with an orbital bombardment. That doesn't mean destroying everything on the surface or wiping out all the other animals, it can even be pretty surgical, but you would definitely want to start with some "artillery" even if it is just in the form of some dense nickel asteroids redirected at their highest population centers.
Going down to the surface is going to be a very problematic issue, but there are ways around that. For one thing, if you have the technology to get to their planet, you probably have the technology to develop some pretty sophisticated ground combat drones. Large swarms of these could form your main offensive force. If you could develop self replicating ground combat drones, you are REALLY in business. Drones that work as a sort of technological "ecosystem" with nanobots that can break down mineral resources and build more drones on the fly. That kind of tech is exactly what you are going to need to keep the pressure on the endless swarm of ants.
Tactics should exploit the probable weaknesses of such a massmind. For example, I am willing to bet that the massmind would be better at focusing on large, major threats on a mass scale than on individual threats to single members of it's host colony. Similar to the way that you would be better at noticing and avoiding a bear than a virus. If you made the combat drones small, say 1/8th the size of the individual ants, and have the drones latch onto the ant bodies and kill them from inside their natural "defensive perimeter", the drones could spread out into large clouds and work their way through large numbers of ants without giving the massmind itself anything specific to focus on.
Another idea is to latch onto the ants and inject them with a DNA altering virus that would turn that ant into a walking poison factory for the rest of it's "hill". Some clever bioengineering could do wonders.
Bottom line: try to avoid "Starship Troopers" type scenarios where you have boots on the ground as much as possible.
[Answer]
Chemical warfare. Ants typically use a pheromone based form of communication. Unless you are postulating a quantum linkage for every ant, using false chemical signaling could enable local dominance in a small area and communication difficulties across regions.Taking out the Queens becomes a priority as they tend to host the primary decision processing. Clean up might be a pain, though.
Climatic shift. You're already terraforming, and you have the high ground. Increase or decrease the temperature enough to turn the environment against the ants, but not enough to kill off the environment.
Genetic warfare. Assuming you can contain the results, introduce alterations to the ants via food and water supplies. Reduce fertility. The Queens and the males are the weak links. As an alternative, find or introduce predators and/or parasites and give them a leg up.
Sensory overload. Test the limits of the input capacities. Saturate the processing capability of the hive mind. Try sonics. Certain frequencies affect insects.
Orbital mind control lasers. Precise, fast, environmentally friendly lobotomy. Target queens if possible. Build or drop fake facilities as lures, then have at them.
[Answer]
Breed you own ants. Sterilize them. And let them take over the planet. Wait a few generations and your intelligent ants will be destroyed by cheap immigrant labor.
Ether that or they'll elect an orange ant with bad hair, in which case they're doomed anyway.
[Answer]
Find a chemical compound that inhibites the collective consiousness, the ants needs someway to communicate, you could disrupt that signal (wich I assume be a electromagnetic signal or some kind of pheromone).
If the consciousness is more like "innate decision making" (so not a real collectivity but just a behaviour that favours the collectivity) then your best bet is guerrilla against small groups of ants.
**Culprits:**
If that species is very similiar to ants, then they keeps their extreme physical strenght (being able to lift small cars should be easy for them, also eradicating trees is very feasible). These are extremely dangerous creatures on melee combat, and are favoured by any kind of ground (they can move everywhere).
Assuming they have evolved technology, they would favour equipment that is much heavier than those of humans, for them carrying heavy weapons is a trick.
**Possible weak points:** sensible to chemical compounds, they possibly are very sensible to smells making more viable chemical weapons even weapons that could be totally harmless to humans. If thye behave like a collective they will problably send solitaire scouts, the scouts are free kills for any incursion team, by they time they send reinforcements the team can be taken off the surface.
**Strong points:** possibly they have a deep underground network, they need no excavation machinery afterall, are very strong on melee combat and everything happens can be seen by other beings (afterall they are a collective). They can probably smell anything, so you have to prefer snipers, soldiers in full bio-suit (prevent smells), or aircrafts.
**So possible tactics:** sniping on open rocky grounds (the only ground you can see them coming and they cannot come from underground because of rocks bed). Bombarding their food reserves and cities. Earthquake bombs to destroy their tunnels. You could probably kill some of them and go unnoticed if you are able to create "accidents" (like falling rocks from a cliff, if you assume a falling rock could kill one of them). As weapons you should prefer highly disruptive weapons (so the kind of weapons that generate much heath, like U238 bullets, RPG missiles, napalm)
**Never colonize the planet:** unless you find a virus that destroy all of them, they are very capable of hide for years thanks to their strenght, so even after you colonize the planet they will be able to kill lot of your people. (unless you create cities that have steel basements and very high walls).
[Answer]
I’d like to point out the analogy with the brain: any one brain cell is not intelligent, but the collection of interconnected cells is.
Diseases like meningitis can kill people. Sometimes the “collective” can fight back successfully, sometimes it can’t.
How fragile is the anthill mind? Consider what a stab to the brain would do: killing only a few cells, but *disrupting much more*, it can cause specific disabilities based on the region affected. Imagine the difference between killing random brain cells and targeting the [hippocampus](https://en.wikipedia.org/wiki/Hippocampus)!
Now the mobile anthill has some innate tolerance to being disturbed. But that can be pushed to the limit, and attackers can target specific features and disrupt the logistics of the distributed intelligence.
As far as simply killing ants, the colony doesn’t have an infinite supply. Killing workers is equivalent to a siege, and will keep resources from the central hive. With real-world bees you have *colony collapse disorder* when workers are killed at a higher rate than they can be replaced, and the hive’s only pre-programmed reaction is to prioritize resource gathering and send out other individuals from other jobs (individuals progress from job to job and gathering is last), and loses those *too*. A smarter hive capable of planning would keep them instead, but would be “under seige”.
[Answer]
+1 to the flame/chemicals/virus answer, those were my first thoughts too.
But here is a question: How do the ants communicate as this shared intelligence? Do they use electromagnetic waves? Using an [EMP](https://en.wikipedia.org/wiki/Electromagnetic_pulse) weapon would disrupt their means of communication, turning the highly organized swarms into scattered messes, unable to coordinate with their comrades. The disorganization will cause them to lose their effectiveness very quickly, buying time for the other methods to work more effectively, as well as minimizing damage. The humans would be damaging their own electronics in the blast, but if the EMP is deployed away from their own bases/forces it could be followed with an effective strike with whatever technology you need (such as flamethrowers or chemical weapons).
[Answer]
Assuming these ants are susceptible in the same way Earth ants are, the answer is **chemical warfare.**
The fact that ants are [highly susceptible to thiol oxidation](http://www.jbc.org/content/280/46/38720.full) is widely established. By breaking the relatively weak bond with [some oxidizer](https://en.wikipedia.org/wiki/Thiol#Reactions) such as iodine, sodium hypochloride (bleach), or hydrogen peroxide, the ants are killed VERY quickly.
Thiols are also used in typical current communications. By introducing competing thiols (like skunk scent or coffee), you can create confusing stimulus to the ants. When widespread in an area, adding massive confusing information to a collective conscious will create an overload of information to slow any coordinated reaction to an attack.
As mentioned in other posts, note that ants can only grow to a certain size due to the air exchange methodology. Unless there is a fundamental change in this physiology, each individual ant cannot support much of a brain. There either has to be something central to coordinate (perhaps for it to be collective between these brains?), or the entire mentality will be extremely instinctual. Depending on which it is will determine the strategy of attack. You could even write your story such that one method was tried as an assumption (say, that they assume it is instinctual and work at killing one hill at a time) only to discover that they need to target several at one time with confusing scents in order to be effective.
[Answer]
A collective mind has one great weakness, its individuals.
Imagine a mind filled with millions upon millions of screaming individuals held in total constant agony until the collective mind goes insane and destroys itself.
Don't kill the ants hold them captive and torture them to the brink of death, but keep them alive.
The collective will break apart.
[Answer]
I would suggest a powerful biological weapon. The only way to destroy a collective is kill every single member. You could do this by bombing every one of their anthills, but since humanity is on the run it might be more cost effective to develop a biological weapon. Even if a small percentage manage to survive you can still hunt them down and take them out with conventional weapons.
[Answer]
Ants communicate also by pheromones, leaving them on the ground as a means of showing "this way lies food/an enemy/whatever", in case other ants come this way. Your Ants are more evolved, and should be able to leave more complex on the ground. Information war by creating pheromones containing deceiving information should do the trick.
Also, ants are constantly at war with other ants, even if they are of the same kind, so long as they have a different queen. Fake pheromones implying that one ant-hill is planning a war on the other should divert your enemies.
Be aware that what holds an ant-hill together is the ant-queen. Poison her via a suicide-squad mission to the heart of an ant-hill. So many possibilities!
[Answer]
The answers currently on the board would work, and work fairly well, but I'd ike to look at this from a different angle.
Terraforming is, by definition, changing the conditions of a planet to become as much like Earth as possible. Since this is an alien planet, the ants have evolved to match the local conditions, while the Humans are trying to alter the local conditions to make the planet resemble Earth. If this is successful, then there is a very great possibility that the ants, (and every other plant and animal evolved on that planet) will die because the Human engineers will be changing conditions far faster than the native creatures could evolve to meet the changing conditions and match the new environment.
Some of the things the Planetary engineers could be doing could be altering the insolation of the planet, using orbiting mirrors or sunshades. They certainly will want to adjust the chemical composition of the atmosphere, and bioengineered plants could be injected into the planetary ecosystem to do just that. Since something like 70% of the Earth's atmosphere is created by photosynthesis in the oceans, the injection of genetically engineered plankton is the way to go.
Even greater changes can be made by using the local asteroids to do flybys of the planet to provide [gravitational torque](https://what-if.xkcd.com/146/). Altering the planet's orbit and rotational period will disrupt the local climate and all the rhythms that local life has adapted to over the eons. This might also destabilize the tectonic plates and cause massive earthquakes and volcanic eruptions.
If the technology is sufficiently advanced, then even stranger things can be done. SF author Paul McAuley has used technologies like "entangled gravitons" to increase the gravity on small bodies, and Will McCarthy has postulated artificial atoms and matter hacking (including a novel where the Moon is crushed by degenerate matter into a dense enough sphere to have Earth like gravity). It is a bit doubtful that ants, no matter how advanced, would have a counter to something like that.
Now of course this means that it is not just the ants that will die, but all the life forms on the planet. It isn't clear from the OP's question what advantages the Planetary engineers see from keeping the other life forms (at best you will mostly get massive allergic reactions to the alien proteins, if not being outright poisoned), and a culture capable of interstellar travel might not even be interested in planets per se (asteroid belts and cometary halos provide everything you need with much less effort and expense). So terraforming is really the ultimate form of xenocidal warfare possible, and the engineers never have to place boots on the ground until they are done.
[Answer]
Ant behavior is completely controlled by chemical triggers, left by other ants in the colony. The humans might engineer ersatz pheromones that would cause mass disruption of an ant hill. Perhaps they all follow a trail into lake, or the mouth of a predator. The Queen would be abandoned and die.
[Answer]
The most viable alternative seem to be some sort of chemical or biological warfare. While intelligent, these ants aren't technological, so they can't filter the atmosphere in their anthills.
Another possibility is to try and rob them of their one great advantage, that of group consciousness. Since this is an evolved trait, it's probably based on either sound waves (low cost, reasonable bandwidth), or pheromones (high cost, low bandwidth), or electromagnetic waves (high cost, low efficiency). All three can be disrupted from above with the appropriate equipment; the ants can't fly, so you can hover over an anthill, bombard it with e.g. ultrasound and make the collective mind fragment, then open up with flamethrowers.
John Ringo in *Black Tide Rising* introduces the *Subedei bot*, a machine designed to entice mindless enemy individuals and terminate them in a sturdy, foolproof package. It is very likely that once their overmind gets disrupted, the individual ants revert to some earlier evolutionary reflex such as mindlessly swarming an enemy by the shortest possible route. So a combination hypersonic emitter plus ant grinder would be a comparatively cheap way to destroy the ants: any group entering the sonic field reverts to aggressive fireant swarm, the swarm "attacks" the grinder and gets mashed.
[Answer]
How about an electrical based assault?
Assuming these ants have similar nervous-systems to Earth-like lifeforms, a big enough electrical surge might just do the trick in exterminating them.
There are a few ways of going about this:
The first involves **large Tesla-Coils**; they are pretty cost effective (compared to terraforming anyway) and can be readily deployed from the air/activated remotely. Powered by industrial motors and heavy-duty friction bands, it is not uncommon for modern units to arc out over a million volts at a time.
Thanks to the ants needing to be in contact with one another for their system to work, the current will be passed through many thousands of the critters on it's path to the ground, destroying their vital physical connections hence rendering the overall organism severely weakened if not disabled entirely.
By enclosing each electrical unit within a ductile metal cage (which can easily electrified) any rogue ants tasked with destroying the devices will be fried on contact. A large enough water moat might work just as well, provided the ants clusters are separate from the main group, but even if they are not, by installing a dispersion field, such as poking many thin conductive rods out of the water, will help in breaking up their formation.
**Note**: Tesla coils throw arcs out in any direction grounded (earthed) objects are present, meaning they could also damage terraforming equipment if not placed correctly. Wetting the ant targets in someway will help in establishing the desired electrical-arc direction.
The second idea is an extension of the last: use an **electrified body of water** to disable the ants.
From what you've said, these ants have evolved to live atop flood waters in a way - I guess - that is similar to ants on earth. This makes them easily able to pass any water barrier placed in their way. Providing then that the ants are in contact with the waters surface during such an event, by electrifying the water through hight output AC generators, an electrical current can be passed through the water and into the ant structure. Such would mean that the longer the ants remain in contact with the water medium they more ants will be electrocuted and with less ants the structure will eventually fail and break apart.
By using moats or other such means of water catchments to surround the generators and your terraforming equipment, the ants will have a much harder time getting through. Powerful electrified water jets (like a mega-firehose sort of thing) can then also be used in conjunction to hit/disperse targets close to the moats edge or nearer to the generators, breaking them apart quicker.
In both scenarios it is important to note that providing a strong and steady electrical current will be imperative to the systems overall success. Ants are also very "robust" creatures in the sense that they are strong and have a natural resistance to small electrical currents, so the bigger charge the better!
[Answer]
So from what I see from the links TrEs-2b has given us. It seems that the ants are really really really tiny and linked together to form a bigger organism.
**Get a real big heavy duty Taser**
Its made of ants, its connected. Which means that if we started electrifying them, ants would start getting fried left and right. If they don't die for whatever reason, they should at least be stunned. If this works, those pesky ant hills will be shocked and immobilized or better dead. Just keep the batteries running. Which leads to...
**Anti-Corrosion Shock Cage/Box**
With all that advanced technology, I'm sure someone can come up with a metal cage or box with electric fences inside that would prevent the creatures from escaping or something. Now just a few million more to go and you have a hopeful alien-ant free planet.
**Get their natural predators to help you**
This only works if the ants are not apex predators, in this case the humans have to breed an army of starving anteaters. They shall hopefully devour the enemy while their human masters distract the ant hills with their highly ineffective bullets and missiles. This will not wipe out the ant hills but could give the humans space to terraform the planet. Humans have done this before where they parachuted cats into (borneo)? So that the local rat population would decrease. Now just parachute a few million anteaters across the planet and hopefully the anthills shall suffer.
**Luring them out of the important areas like forests and then burning with napalm**
I don't see why luring those ant hills out to won't work. They supposedly hate humans, which would compel them to chase after the occasional human bait. Now just lure them to an area where killing them won't do too much damage and start the barbeque with [Napalm](https://en.wikipedia.org/wiki/Napalm), even if the ants split and turn tail, as long as they have been hit by napalm, they should die due to the 'sticky' effect of napalm(provided they burn). Now hopefully their brethren have been informed by pheromones that they have been attacked and will hopefully be enraged and start charging at the human forces. As long as the humans stay safe, out of range and have plenty of napalm to go around, I don't see how the humans would lose. Even if a few ants got away, I highly doubt they alone can create a new ant hill and would most likely join an existing ant hill. This operation could take years with plenty of potential for mistakes but on paper should allow the humans to push back the ant hill horde.
[Answer]
How do we get rid of ants today - chemicals. We spray them, bait them, fool them into taking poison back to the colony.
Combating something this large and organized would just mean more chemical and a smarter way of administering it. Terraforming stations should be equipped with spray foamers and moats containing poison.
Traps should be laid all over a region slated for terraforming, well in advance of a human party. Traps would be food laced with poison that is slow acting and capable of decimating an entire colony, including the queen.
Every thing a human wears, while in country, should be coated in the poison. Every human should be wearing a "fog-suit", with a bio monitor. When the heart stops the suit fogs.
In short, poison them into submission. They'll either go away or die.
[Answer]
You asked for answers other than chemical, and I assume that you mean pheremones.
The only answer I see here is fire then, attack the hordes with leagues of fire.
The ant cells, fire
The ant-hills fire
You get the point, if you want to defeat this type of species **without** destroying the planet (nukes) then fire is the best solution.
[Answer]
(This is based on a collective consciousness that wishes to **protect the majority of the ants of the colony.**)
Since Ants have a tendency to release pheromones to signal that something is happening to them, it might be best to build up a distress signal for ants made up of ants being continually tortured a la Rick and Morty. They will send out a massive stream of "Oh God It Hurts Please Help Me Bro." pheromones. From there the area where the captive ants are being held will continually become stronger and larger leading up to a point wherein if the captive ants reach a point of numbers reaching higher than 50% there will likely be an impossibly large rescue mission, so there must always be less than 50% of the ants pheromones released at any time, so the pheromones released would have a set cutoff, the delivery of these pheromones would be through an aerial delivery, a line of these, "OGIHPHMB" pheromones which would lure more ants into these pheromone producers, via a rescue mission. Now, the "OGIHPHMB" pheromone wouldn't be the only one being produced, technically with some dissection and study, one could learn to produce whatever pheromone required for the ants to have some miscommunication travel through.
[Answer]
The ants are small? no problem; out-small them. Crop-dust them with nanotech bots that rewires their brains so they take orders from humans. Then send the controlled ants out to either nanotech infect 'wild' ants or just fight them. The controlled ants are now the perfect slave race for human protection and terraforming.
[Answer]
When dealing with a collective consciousness of any type the best weapon is logic.
Think of those ancient Star Trek episodes where Spock presents a paradoxical conundrum to a computer about its behavior and it bricks (after a lot of rattling and smoking).
You could do the same to the ants, we're assuming they can communicate and that they're either following the edicts of their queen or some sort of ruling council or quorum. So what argument can you present to the collective consciousness that would show that it needs to stop attacking the terraformers because they are providing something that would help the ant-hill thrive - even while they have some sort of imperative to attack the terraformers.
"Must attack humans, but humans give us "x" with the terraforming, must have "X", but must attack humans...."
Eventually the ant-hills break down and become just a bunch of regular ants which are good for the terraforming process.
] |
[Question]
[
So, the idea in a story is that in far far future there’s a trend that rich people, they are able to buy themselves planets. Tiny little planets with sizes 4-6 km (3-4 miles) in diameter. The company that makes them, seeks for an asteroid which is as round as possible, and then drills and makes a hole in it. In that hole, they put the white dwarf star matter in it. As far as I know, that’s the densest matter after the one inside a black hole and neutron star which are number 1 and number 2 when it comes to matter density.
That small object, which would not have any gravity detectable by a human being, would then have Earth-like gravity, and by installing few artificial magnets, they would create the magnetic field that would stop atmosphere being blown away by solar winds and radiation. The planet would also need to have a really thick atmosphere so that the pressure on the surface is like on Earth as well, but I am wondering what are your thoughts on that. Being that the planet is 5-6km in diameter and 16-20km all around the equator, it would look silly with an atmosphere that goes on 30-40km away from it :)
So, if you think there’a scientific solution for the atmospheric pressure to be the same without the cover having to be as thick as on real Earth, let me know.
My main question is, would the white dwarf matter be stable inside an asteroid with 5km diameter or would it blow it away? Maybe it needs the gravity of said star to be stable :) I mean it is logical.
The rich guys in the story have their own planets with its own little lakes, beaches, rivers, houses, little mountain, etc. They put it artificially in orbit around the Sun in habitable zones, and of course, the gravity of it influences life on regular Earth and people on regular Earth and all sort of weird stuff starts to unfold as more people start getting their own planets.
[Answer]
Sorry in advance. You won't like this answer.
The "stuff" in white dwarf matter is more specifically known as [degenerate matter](https://en.wikipedia.org/wiki/Degenerate_matter#Degenerate_gases). Basically, the more tightly you crush this matter, the more the valid quantum mechanical states for the electrons "fill up." For normal matter, there are so many more valid states than there are electrons, that we don't have this issue. For degenerate matter, you start to run out of states, and that means the matter cannot collapse any closer together. This creates a pressure that holds the white dwarf out against gravity.
This matter behaves funny. It turns out that this pressure does not depend on temperature, but rather depends on mass. The more mass you have, the *smaller* a white dwarf gets, rather than bigger. This strange process continues until you get to around 1.4 solar masses, at which point the hydrostatic pressures from this degenerate electron soup can't compete with gravity, and it collapses into a neutron star (which is held up by neutron degenerative pressure rather than electron degenerative pressure).
You happen to want a white dwarf with a small mass. Paradoxically, this means it is a very big white dwarf. If you took this matter from a heavy (small) white dwarf, it would probably have to expand as you brought it out to maintain that hydrostatic equilibrium (handwaving whatever magic you used to pull it out of the dwarf in the first place).
How big? Well, fortunately, because you are looking for a low-mass dwarf, you are also looking for one where the electrons are not approaching relativistic speeds. That means we can use the easier relationship $R\propto M^{-\frac{1}{3}}$. Using [non-relativistic equations](https://en.wikipedia.org/wiki/White_dwarf), a white dwarf with the mass of the sun would be approximately 0.014 solar radii in diameter, or 9737km. The mass of the earth is about 0.000003 solar masses. $0.000003^{-\frac{1}{3}}=69$, so the radius of your 1-earth-mass white dwarf would actually be 69 times bigger than the 1-solar-mass white dwarf, or about 670,000km. This is actually substantially larger than that of the Earth itself, indicating that at some point, the hydrostatic equations governing white dwarfs stopped being the dominant factor.
In other words, take 1 Earth mass of white dwarf out of the white dwarf, and the pressure will expand it outwards until it ceases to operate like a white dwarf, and starts operating like plain normal matter. You are going to need some handwavium to keep it compact.
You will also need some handwavium to keep the atmosphere. Science does not say the atmosphere will stick around. In fact, it says the atmosphere will flee your asteroid even more than it does on Earth. The acceleration of gravity decreases by the radius, squared. On Earth, the difference of gravity between sea level and 100km (the Karman line, the edge of space) is minimal. It's only about 3%. This is because the radius from your object to the center of the earth only changes from 6,371 km to 6,471 km. It's a pretty modest change. However, if your asteroid is only 5km, 5km+100km is a *big* difference. Gravity is going to be roughly 0.23% as strong at 100km as it is at 5km. If the gravity at the surface of your planet is 9.8m/s2, like it is on Earth, gravity at 100km is a mere 0.022m/s2! That won't hold much atmosphere at all!
[Answer]
# A first approximation
Let's calculate [surface gravity](https://en.wikipedia.org/wiki/Surface_gravity). Assuming an object of density $\rho$ and radius $R$, the surface gravity is
$$g=\frac{4\pi}{3}G\rho R\tag{1}$$
For a white dwarf, $\rho\sim10^9$ kg/m$^3$. If we want $g=9.8$ m/s$^2$, we find an $R$ of 35 meters. If you scale that up to a radius of even 2 km (a 4 km diameter), we find a surface gravity of 559 m/s$^2$. In other words, only a very small amount of your asteroid can be filled with white dwarf matter.
Let's go back to a different way of writing $g$:
$$g(r)=\frac{GM}{r^2}=\frac{G}{r^2}\frac{4\pi}{3}R^3\rho\tag{2}$$
where I've substituted in $M=\frac{4\pi}{3}R^3\rho$. Here, $R$ is the radius of the blob of white dwarf matter. If we want $g=9.8$ m/s$^2$ and $r=2$ km, we find we need a blob radius of $R=520$ meters - roughly one fourth of the body's radius. I've assumed that the mass between the blob and the surface doesn't contribute much to $g$.
The big issue? There's a kilometer and a half of material between the blob and the surface, and the gravitational force at $r=R$ is going to be a lot. $g(R)$ will be about 145 m/s$^2$. Therefore, you need the material inside the asteroid to be able to withstand such forces. That's not easy. The pressure will be pretty large. Think carefully about this before constructing it.
# A true white dwarf
Go read [Cort Ammon's answer](https://worldbuilding.stackexchange.com/a/117208/627) (and upvote it!). They talk about how, thanks to electron degeneracy pressure, white dwarfs obey [a curious mass-radius relation](http://burro.case.edu/Academics/Astr221/LifeCycle/WDmassrad.html):
$$R\propto M^{-1/3}$$
In other words, the more massive a white dwarf, the smaller it is. Now, let's rewrite this as a scaling law, using Sirius B as an example. It has a mass of half a solar mass, and a radius of 0.003 solar radii. We can then write
$$\frac{R}{0.003R\_{\odot}}=\left(\frac{M}{0.5M\_{\odot}}\right)^{-1/3}\tag{3}$$
Now, let's rewrite density. The mean density of Sirius B is roughly $3\times10^{10}$ kg/m$^3$. We then have
$$\frac{\rho}{3\times10^{10}\text{ kg/m}^3}=\frac{M}{0.5M\_{\odot}}\left(\frac{R}{0.003R\_{\odot}}\right)^{-3}=\left(\frac{R}{0.003R\_{\odot}}\right)^{-6}$$
using our mass-radius relation. Plugging *this* into $(2)$ gives us
$$
\begin{align}
g(r) & =\frac{G}{r^2}\frac{4\pi}{3}R^3\left[3\times10^{10}\left(\frac{R}{0.003R\_{\odot}}\right)^{-6}\text{ kg/m}^3\right]\\
& =\frac{G}{r^2}\frac{4\pi}{3}R^{-3}(3\times10^{10}\text{ kg/m}^3)(0.003R\_{\odot})^6
\end{align}
$$
This then gives us $R=37.4R\_{\odot}$. Cort Ammon got something within about a factor of 2, because they chose to not use general relativity (which didn't matter, honestly, for our purposes).
# Degeneracy pressure
This mass-radius relation arises because a white dwarf is supported by [electron degeneracy pressure](https://en.wikipedia.org/wiki/Electron_degeneracy_pressure), arising from the Pauli exclusion principle. Essentially, no two alike fermions (matter particles like electrons, quarks, etc.) can exist in the same quantum state simultaneously. Thus, when you compress a whole bunch of fermions, there's a pressure that resists the compression. In a white dwarf, this comes from electrons; in a neutron star, this comes from neutrons.
The mass-radius relation problem occurs in certain other bodies of degenerate matter, including neutron stars. For neutron stars, [the mass-radius relation is not well-known](https://physics.stackexchange.com/a/187281/56299) because the [equation of state](https://en.wikipedia.org/wiki/Equation_of_state) (EOS), the equation relating pressure and density, is not known exactly. It's a very active area of research, both observationally and theoretically. Nonetheless, if you were to substitute in a neutron star or a quark star or some other body, you'd still have a problem.
Out of curiosity, let's try to calculate the minimum radius of a white dwarf. The maximum mass is given by the [Chandrasekhar limit](https://en.wikipedia.org/wiki/Chandrasekhar_limit) of about $1.44M\_{\odot}$. Substituting this into $(3)$ gives $R\_{\text{min}}\approx0.0021R\_{\odot}$, or about 1467 km. That's not helpful. What it we push things even further, and try to find the smallest a neutron star can be? Well, the [Tolman-Oppenheimer-Volkoff limit](https://en.wikipedia.org/wiki/Tolman%E2%80%93Oppenheimer%E2%80%93Volkoff_limit) is essentially the analogue of the Chandrasekhar limit; it's about $2.25M\_{\odot}$. Optimistic equation of state models give us a radius of about 9-10 km. Again, that's too high.
What about [quark stars](https://en.wikipedia.org/wiki/Quark_star)? These are hypothetical objects made primarily of a quark-gluon plasma, [lying in about the same mass range as neutron stars](https://physics.stackexchange.com/a/127317/56299). They're thought to be denser than neutron stars, and smaller, and, more importantly, from the little we know about their equation of state, the smallest ones should also be less massive. The problem, of course, is that they still aren't small enough. 6-8 km is reasonable for a somewhat small quark star. Additionally, we don't know very well how they behave; our constraints on the EOS are poor.
[](https://i.stack.imgur.com/7On30.png)
Figure 4, [Rodrigues et al. (2011)](http://adsabs.harvard.edu/abs/2011ApJ...730...31R). Mass-radius relations for quark stars.
From the little I know about quark stars, the mass-radius relation depends on the ratio $\bar{\Lambda}/\mu$, where $\bar{\Lambda}$ is something called the *renormalization subtraction point* and $\mu$ is the much more familiar chemical potential. Setting $\bar{\Lambda}/\mu=2$ and $\bar{\Lambda}/\mu=3$ yield *very* different results, possibly differing by a factor of 2 (see [Fraga et al. (2001)](https://arxiv.org/abs/hep-ph/0101143)). *If* $\bar{\Lambda}/\mu=2$, we could see smaller quark stars.
That said, if we use some of the smallest radii fit by this optimistic value by Fraga et al., we find that, for $R=4$ km, $M=0.2M\_{\odot}$, and so $g=1.66\times10^{12}$ m/s$^2$.
That's too high.
# A black hole
We do have one more option. The more massive a black hole, the larger it is, and the less massive a black hole, the smaller it is. Say we instead put a black hole at the center of the asteroid, which has $r=2$ km. For our desired surface gravity, we need $M=5.87\times10^{17}\text{ kg}$. Calculating the [Schwarzschild radius](https://en.wikipedia.org/wiki/Schwarzschild_radius) gives us $R\_s=8.72\times10^{-10}$ m, which fits more than comfortably inside the asteroid.
Now, the black hole might evaporate via [Hawking radiation](https://en.wikipedia.org/wiki/Hawking_radiation#Black_hole_evaporation), but it will take a long time - roughly $5\times10^{29}$ years, or 500 billion billion billion years. So it's going to stick around for a while. *However*, the gravity is still enormously strong, and it's going to accrete the rest of the planet pretty quickly.
[Answer]
The other answers have pointed out why you cannot convert a 5 km planet (asteroid) into a space habitat in the way you have described.
What you *can* do, however, is to construct an [O'Neill cylinder](https://en.wikipedia.org/wiki/O%27Neill_cylinder). Hollow out a cylindrical asteroid, make it rotate, and live on the inside. This concept has been popularised in science-fiction novels such as *Rendezvous with Rama* (Arthur C. Clarke) or *2312* (Kim Stanley Robinson), featured (briefly) in films such as *Interstellar*, and has been the topic of questions on this site such as [here](https://worldbuilding.stackexchange.com/q/14110/2044), [here](https://worldbuilding.stackexchange.com/q/93289/2044), or [here](https://worldbuilding.stackexchange.com/q/93272/2044).
*Source: NASA, [via Wikimedia Commons](https://commons.wikimedia.org/wiki/File:Spacecolony3edit.jpeg)*
[Answer]
I already think that the [@HDE 226868 answer](https://worldbuilding.stackexchange.com/a/117200/35041) should be the accepter due to its always high-quality information. But there is a little thing that I do not agree with and changes the answer dramatically: heat.
A [White Dwarf](https://en.wikipedia.org/wiki/White_dwarf#Radiation_and_cooling) has a surface heat of around **6.000 to 30.000 K**, that is a bit warm!. Your asteroid would smelt due to the high temperature...
That is why I suggest the use of a [Black Dwarf](https://en.wikipedia.org/wiki/Black_dwarf), which is literally a cooled down White Dwarf. Obviously, due to its heat, you will need some of the highly advanced technology in order to cool down one, because its takes **A LOT** (gigayears) of time to cold down naturally. I won't tell you how to cold down one white dwarf, but due to this answer [@HDE 226868 has made a question](https://worldbuilding.stackexchange.com/q/117297/35041) about it!
I am not sure if the change from a white to black dwarf would bring some other changes in its strange physics like the "curious mass relation" talked in his post.
[Answer]
Cort and HDE have already told you why this is not feasible regarding the planet from its core to its surface, and Cort elaborated on atmospheric escape as well.
If you handwave those away, you still got a lot of problems not related to the amount of gravity, but to the size of the asteroid.
On Earth, we have a lot of atmosphere. Your asteroid? Not so much. To keep the same pressure as here, you'd have an atmosphere volume to planetary surface ratio of $\frac{1}{1,000}$ that of the Earth. That's because volume scales down faster than surface area (Square-Cube law strikes again). The asteroid will have much less thermal insulation than here. The temperature difference between day side and night side will be incompatible with life as we know it. That difference will also cause hurricane-strong winds to be not events, but the natural state of the planet's atmosphere.
Also notice that the Sun has a considerable tidal influence on Earth. [The Sun's tidal effect is 44% that of the Moon's own](http://hyperphysics.phy-astr.gsu.edu/hbase/tide.html). On your planet, that influence will cause tsunamis even on lakes.
Geography and meteorology are to to your planet what biology is to Australia: quite the natural hazards.
[Answer]
Other answers show that according to what we know of physics, this can't really be done. Thus, you need some physics we don't know about yet (if your story can stand such a thing).
Assuming you don't want to make a super-dense material that transcends known physics, could you 'import' some gravity from somewhere else? Perhaps instead of putting any matter inside the asteroid, the builders put in a wormhole which is connected to (say) a black hole, or some other high-mass phenomenon. They could vary the amount of imported gravity by altering the size of the hole.
I realise this is a bit of a departure from good, solid, based in fact physics, so maybe too much of a reach to accept. Otherwise, sign up my great, great grandchildren for a personal planet - it sounds pretty cool.
[Answer]
Other than using exotic states of matter, having true gravity the same as Earth is impossible. However, rotational gravity is very possible. Using the equation for rotational gravity, period in seconds equals 2pi multiplied by the square root of radius in meters divided by the meters per second squared, or this [1](https://www.artificial-gravity.com/sw/SpinCalc/), for an asteroid 6 km in diameter you would need it to rotate once every 110 seconds. For an asteroid 4 km in diameter, you would need it to rotate once every 127 seconds.
] |
[Question]
[
In the past, we had black and white photos only, then we got color films to take photos. Stepping into the 21st century, digital photos were becoming popular, and the number of pixels alone are increasing rapidly.
30 years from now, what will a typical photo look like? Does it have much more pixels than contemporary digital photos? Or would it have other improvements over current photography technology?
[Answer]
30 years is not much to drastically change photography, it is basically the same since its inception. Color is a simple step, digital is because now everything is digital. Holograms are out there but not practical, not just because we lack in technology, but it is not very convenient.
Only improvement I could see in 30 years is that stereography would be more common, that trend has already started. I would say, more cameras will be equipped with multiple lenses to construct stereo images. Probably 3D screens without glasses would become commonly available. This may allow almost 100 year old technology to finally soar.
[Answer]
# novel breakthroughs
If you're looking for another advance to use in your story, consider [light-field cameras](https://en.wikipedia.org/wiki/Light-field_camera), single-lens 3D images, or [sensors based on solid diffraction gratings](https://en.wikipedia.org/wiki/Angle%E2%80%93sensitive_pixel) or holograms that don’t require lenses at all, but are flat like bug’s eyes.
# improvements to conventional cameras
Sensors are getting close to the quantum limit in terms of sensitivity. High-end sensors add very little noise on top of that. I see the great expensive side of things moving into cheaper devices.
However, a conventional lens needs to be large, scaling with the sensor size. So very compact or flat devices will start using “breakthrough” lenses on somewhat larger sensors, as sensor size is the ultimate quality limiter.
# display and presentation
We’ve already seen the concept of a few seconds of animation take up a niche of its own. It may become the style for a portrait to use this idea to give an active act of smiling at the viewer, or whatever.
How are pictures presented? An animated picture requires a screen rather than dumb paper. But how many pictures do we print and hang up? The few perminant wall frames might very well be full screens! But even today, most pictures are shared on devices and not made into prints.
Perhaps, when I buy a large framed picture of the Golden Gate Bridge to hang up on a wall, it will not be a static image, but will change with the time of day, the weather, and the seasons.
Perhaps the dedicated frame that shows “Hello, Grandma!” will automatically update every few days when the kid is reminded/prompted to “say hello to Grandma” before dinner.
So, besides improved technology in capturing images, I forsee a maturation of the technology and products for managing and displaying this huge quantity of data being generated.
[Answer]
# Video
While there are going to be more pixels, better focusing and whatnot, I think that the big change is going to be the end of the still photograph.
"Why aren't they moving?", youngsters will ask when watching old photos.
[Answer]
# Light-field/plenoptic photography
[](https://i.stack.imgur.com/tI2D6.gif)
>
> Light-field photography captures information about the light field emanating from a scene; that is, the intensity of light in a scene, and also the direction that the light rays are traveling in space.
>
>
> —[Light field camera at Wikipedia](https://www.wikiwand.com/en/Light-field_camera)
>
>
>
Light-field photography allows you, depending on the specifics of the device that captured the image, to display images with a variable depth of field, as well as holograms. This technology is also the basis ([according to nVidia 1](https://vrworld.com/2016/01/27/nvidia-light-field-stereoscopy-vr-tech-unveiled/), [2](https://www.youtube.com/watch?v=deI1IzbveEQ)) for next gen virtual reality displays, as it would allow you to focus on the details that you want to focus on, getting a more realistic experience.
The technology has a very limited implementation right now because it is very expensive both in terms of money and information storage. A single still picture can weight well over 50 Gb.
If things go right, expect this technology to be commonplace in 30 years.
[Answer]
I expect to see more color depth. Currently we have to do HDR post-processing in order to get a decent result from a scene with great contrast (sky/ground, indoor/outdoor etc.) More bits of intensity data will allow such processing from a single picture.
[Answer]
Ubiquitous sensors. When a photo is snapped it's a collection of all the environmental data and sensor feeds in frame. The photo data itself will likely just be a definition of what's 'in frame'.
The data could be as simple as when, where, and viewport descriptions.
[Answer]
## Holography
Maybe in 30 years from now we'll be able to record not only from one perspective, but record everything in a given radius.
Later we might be able to play that recording back in such a way that it would be possible to watch it from any angle.
A portrait could become fully 3D, allowing the observer to move around the subject and watch it interactively, even from behind.
After all photography just means "painting with light", holography is just the next step.
[Answer]
Regular consumer-grade cameras will be able to capture and store a much wider range of colours than just the visible spectrum, and software will be available to easily redshift or blueshift your pictures, going from a picture of the local wifi at the red end, through a heat map, through visible light, on up through ultraviolet, to an x-ray picture at the blue end.
Obviously the upper ranges would be much dimmer, due to higher wavelengths being absorbed by the atmosphere, and the lower ranges would have lower resolution, but software interpolation will be able to provide a reasonably clear view at all wavelengths.
There will also be much more use of software image processing. Simple picture manipulations like removing background people or creating action shots will be simple and automated.
[Answer]
A 3D animated tactile scented sound "GIF" would be the Holy Grail of photografy.
Though I doubt it could still be called simply "photography".
[Answer]
Embedded micro QR codes (or other data printing tech) on a scale / spectrum invisible to the naked eye. Those photos from Harry Potter are now real.
So still photos would have a wide range of data printed on top of the visible pigments, that would allow smart tech to read it and render additional features on the photograph. The photo can also have its own IP V.xx address, and its own cloud storage online.
So smart glasses would animate the photograph, or add special features, like comments downloaded from the web, stickers, or other stuff. A photo of your children at the festival fireworks show could animate the fireworks at the back.
Smart photos are now like collaborative scrapbooks or social media posts. A visitor can post data to the cloud storage linked to the photo, and it could be visible to selected visitors. So the photos over the fireplace now have their own like counter.
Voice and video data could be added at the time of the shoot or later. Portable laser printers (almost all devices have them now) could burn invisible codes on sensitive areas of the photo, or upload the data to the associated cloud storage to that photo.
[Answer]
Since there already are attempts to make blind people see via sending signals to the brain, I find it quite possible that in 30 years there will be no photos anymore; there will be **visions**. Viewing a photo will mean seeing the captured scene exactly in a way the person who captured it saw it. It will require "just" recording signals from the optical nerve and then playing them in the brain of another person.
[Answer]
More and more mega pixel, maybe even giga pixel cameras.
3d for sure, and models of individual objects.
The spectrum will advance way beyond HDR to possible cover all forms of light.
The cameras will have many improvements like facial recognition,super low light without the need for a shutter speed of 5 minutes. All the features we have today will be perfected.
Tons of new data will be embedded into EXIF,XMP, or whatever the new thing will be called. Think of all the sensors in our cellphones, even more will be built-in to our cameras.
Obviously battery life, and storage capacities will limit the rate of growth.
[Answer]
You'll likely have a AR screen or projected extrapolated 3D image. Granted the original will likely be something close to what it is today. A flat 2D image, maybe with more resolution, but after that we'll be able to take all associated pictures and known environmental informations and extrapolate High poly model with high rez textures projected into AR space. And that's not all, you'll likely be able to move the subject around, walk around them, etc. because the image you'll be seeing is being extrapolated from all known images of the subject, their relatives, the environment, that you have access to as well as their behaviors and all the physics engines involved in 3D art... And here's the thing, this also applies to all past images that you have access to too. Extrapolation and Interpolation will all you to take a drawn image of George Washington, mix it with the images of his descandants and all known facts about his clothing and such and produce a pretty faithful "picture" of him in AR space.
[Answer]
Echographs of Baby.
Although the technology doesn't involve light, per se, but instead sonography, the popular occasion of having "photographs" taken of the en utero child will no longer require a visit to the sonographer.
<https://en.m.wikipedia.org/wiki/File:3dultrasound_20_weeks.jpg>
Sonographs will be available on demand via handy echo-tech and the flavor-of-the-day app built right into your smartphones.
As is often the norm with emerging tech, the first attempts will be low "resolution" versions of the pictures you get at the doctor visits, but once popularity and high demand become evident, this tech gets quickly advanced and echophotos will far outpace any current sonogram photographs.
[Answer]
Combining traditional photographic techniques and utilizing new concepts and the results from recent medical research will develop ways for images to be "seen" in enhanced and useful ways - for example, by applying three dimensional techniques such as Lithothane work, with recent discoveries of thermal and mechanical transducers ( <https://www.nobelprize.org/prizes/medicine/2021/advanced-information/> ) - and possibly by printing with an anamorphic projection - a blind or partially sighted person could "read" and "see" and image by touch.
[Answer]
Aside from the jump from black and white to colour, photos haven't changed all that much since they were created, just the technology used to take them and the medium on which they are viewed.
I wouldn't expect too much of a difference into the future to the actual photos themselves.
* The phasing out of displaying them on paper - screens will become more ubiquitous and you'll probably end up with all your photos in the "cloud" and be able to view them anywhere there's a screen. (which there'll be plenty of) - not just your phone.
This will result in:
**A.I. possibilities**
* an extension of Stig Hemmer's answer - a way of "looping" a short video so it appears seamless or natural. This way you can take a photo which is actually a short video which will appear to give your photo some life.
* "Beautification" - all those people who hate photos of themselves - A.I. will be able to 'clean up' their faces to make them look nicer, or adjust lighting to get rid of the 'camera adds 10 lb' effect.
* Photo editing - i.e. can be done automatically and appear natural. e.g. if you want to take yourself out of a photo, the A.I. can tidy up the lighting, fill in what was behind you and make it look realistic.
* Zoom and Enhance - The oft-pilloried movie cliché! May exist in some form. Yes I know you can't "add information". But the A.I. can either make a decent guess of the missing details or use composites of the millions of other photos (e.g. taken of the same area or person) to estimate what should be there to a reasonably realistic degree.
[Answer]
I think the use of AI to make images more flexible will become commonplace. We already have AI which can take a few images, and extrapolate a complete 3D environment from them. We have AI which can take an image and "enhance" the resolution to see more detail.
Therefore, images taken 30 years from now can be turned into 3D worlds, or zoomed further, and all that on top of the improved sensors, such as light fields or higher resolutions. AI might be used to fuse the data from multiple sensors, such as a wide angle and a zoom lens, or it might integrate data over time while moving the camera around a scene. AI will probably make it easier to select the perfect moments, so the photo you publish will have the exact moment everybody was smiling and not blinking, (or even combine multiple moments for each person in the group,) or automatically give you the perfect shot of an athlete catching the ball. Or the AI could remove the tourists to just show the tourist attraction itself.
You might get some inspiration from <https://www.youtube.com/c/K%C3%A1rolyZsolnai> - he covers many of these types of AI as they are first published, so maybe pick something from there and extrapolate it into the future.
] |
[Question]
[
According to [an answer to a previous question](https://worldbuilding.stackexchange.com/a/88499/41373), it would be comparatively impractical to conduct mining on a rocky planet when there are moons, asteroids, comets, etc. that have smaller mass, so much less fuel would be required to reach their respective escape velocities. Thus, mining would be less cost efficient and generally avoided on rocky planets, *if possible*.
Let's suppose that these spacefaring mining operations were launched to obtain one particularly valued mineral as opposed to general resource exploitation. Because the setting is intended to be a single rocky planet, why might this mineral be found exclusively on said planet (or at least, it has not been discovered elsewhere after reasonably thorough prospecting) and no other bodies in the solar system?
[Answer]
**Organic**
Your mineral could have been deposited millions of years ago by a specific type of organism, class of organisms, or type of biome. For instance, you might have a forest that produces lots of some interesting organic compound, which when put under intense pressure and heat, forms some mineral with useful properties. Because the relative scarcity of "live" planets, you might only have access to one such planet, or another with the same phenomena might be too far for mining to be economical. Furthermore, there is no reason why the same biological phenomina must occur on more than one planet in a finite range (that range being the reach of your civilization). Planets with life are just so much more fun, so much more interesting, but they aren't the only option.
**Inorganic**
Your planet could have been formed from a unique mix of stardust. Maybe it has a lot of superheavy stable atoms in its crust. Perhaps it has interesting temperature or magnetic conditions that caused unique geological formations. I can't really tell you what exactly you ought to choose as your reason, but the possibilities are endless. Ask your friendly neighborhood planetary geologist.
Edit:
**Access and Sensing**
Unless your civilization has found a way to travel, for free, instantaneously from one point to another, anywhere, then there is a cost to travel. The range of planets you can harvest from is first limited by the planets you can find, then by the planets you can reach, then by the planets you can scan, then by the availability of the resource on the planet. A perfect planet might exist, but be too far away. This resource could be on your planet, but it could be too difficult to collect. You can change the parameters of this equation in whatever way you like, but it will still affect the collection of resources in any system to a certain degree. Hell, if you are a sensitive bunch, then you could even honor the claims of existing beings to resources (hello blue people with tails!), the claim of future beings to resources, or even the sanctity of planetary integrity. There are so many barriers to access that we can think of now, but what we can think of now is probably much, much easier than it would be in real life.
[Answer]
[Heavy Metals.](https://en.wikipedia.org/wiki/Heavy_metals#List_of_heavy_metals_based_on_density)
The heavy and rare elements can be produced in Supernova; things like Gold, Platinum, etc. There are other ways, but precisely how isn't important.
But, they can produce them in massive quantities; then heat, explosive forces and gravity can "refine" them to some extent, sorting them by molecular weight. So you can have something like asteroids made entirely of these heavy metals; or even primarily one, like Gold. The Gold on the surface of earth most likely arrived by such asteroids; because any that was present during the planets early molten formation likely sank toward the core.
One planet in the solar system, or even in a large region of solar systems, might be the lucky recipient of such a treasure (gold, platinum, uranium, osmium, etc, see the link above).
Probes might be able to sense the presence of such heavy metals, and as a result the miners are stuck with wherever it might have landed, whether that is Earth-sized or Jupiter-sized, as hot as Mercury or cold as Pluto.
---
*Added to address comment:* [Here is a Harvard study](http://articles.adsabs.harvard.edu//full/1956PASP...68..185G/0000194.000.html) (from 1956, but still relevant) discussing the predominance of elements in Stars, in Terrestrial abundance, and in meteorites (see pages 187, 192, 194). It is simply untrue that it would be better (more cost effective or easier) to mine common asteroids than it would be to mine a large planetary deposit of some rare metal. Gold in asteroids has a concentration of about 1 part per 20 million; while the top gold mines earth are rated in the 25 to 44 g/t (grams per metric ton [which is 1 million grams]), so 25 to 44 parts per million: That is 500 to 900 times greater concentration than one might find in asteroids.
This is one contributing factor supporting the hypothesis of a gold-heavy asteroid; plus the concentration of high yield gold mines is primarily in Africa: suggesting a rather localized event (or events, if the asteroid broke up) deposited the gold in spots after the formation of the planet; it is not a uniformly distributed element.
For the purposes of a story, there is no reason this could not be amplified; that the miners are specifically seeking ***extremely*** high concentrations of precious heavy metals that have some commercial utility. It would be plausible for them to look at rocky planets and moons that might have captured such asteroids in the last few billion years; and somewhat preserved the deposits where they landed. It would be easier than testing billions of asteroids that are probably worthless, and easier than processing 1000 or 2000 times the mass in asteroids looking for some atoms of gold or uranium or osmium or whatever they are seeking. They might not even have the technology to extract a milligram or microgram of an element from a one tonne rock; they may *require* a higher concentration to make it worth their time and effort (just like our modern day gold miners do).
Finally, they may have far more efficient and cheap means of getting on and off planet; like fusion engines that cost effectively zero. Energy is generally not a problem in space, stars generate plenty of it. They could have huge solar generators in space that beam all the energy they need down to the surface in the form of gamma ray lasers or something. And once they finish mining, they only need to get the product out of the gravity well, not the million tonnes of rock they crushed. The robots they are using to do the mining may weigh far more than the final product they extracted, particularly for very rare elements. And again, the energy needed could be ***absolutely free*** to them; captured from the star (even we humans know how to do that IRL).
[Answer]
Access.
Even if a particular resource is found in other places, that doesn't mean that it is accessible and practical to acquire. So only single site may be reachable, hospitable to miners/robotics, have nearby resources also required for mining/fuel/energy, be in an area secure from competition, and reachable in a useful amount of time. There may be only be one known place where the resource is in a high enough concentration to make mining/gathering it financially worthwhile.
The *Avatar* movie had this premise. I'm sure the unobtanium macguffin element was present in other places, but the Pandora moon was reachable, allowed miners to survive there, and was reasonably close to Earth so it was worth the investment to gather.
[Answer]
As @Dent7777 stated, materials like oil are organic based so it's almost impossible to find in other celestial bodies.
If you're talking about an inorganic material then I feel like the 'planetoid from an unknown solar system composed of X material crashed with the planet in its early years' like the Theia hypothesis would work.
[](https://i.stack.imgur.com/YIgJB.jpg)
[Answer]
An obvious answer is that the mineral is artificial, made by an unknown ancient civilization in great quantity for reasons unclear, or as an unintentional byproduct of some other process.
It is possible that the process of manufacture was an automatic one which ran out of control and brought about the end of the civilization before it could be stopped.
[Answer]
Read the novel *Mirkheim* by Poul Anderson. It concerns a planet that was just far enough away from a supernova explosion to survive, but acquired a significant amount of super-heavy elements in the (hypothetical to modern-day science) island of stability, that were created in the explosion. You need FTL interstellar travel for that, of course; a planet in our solar system won't fit the bill.
[Answer]
One fairly obvious reason is concentration. Many useful minerals can be extracted only because they've been concentrated in veins/ore bodies through billions of years of gelogical processes. Many of these processes are geothermal: they require the planet to have both a hot interior and plenty of liquid water.
So your useful material - say gold, for a common instance - might exist on moons & asteroid, but like gold in sea water, in parts per trillion amounts. On an earthlike planet, that gets concentrated into gold-bearing veins by geological processes, then erosion further concentrates it into placer deposits,
and then a guy building a mill can pick up nuggets and start a gold rush :-)
[Answer]
Lots of good answers, but nobody's mentioned metamorphic minerals. There are lots of mineral substances that are formed via the intense heat and pressure under the surface of a planet. Asteroids and small moons do not generate nearly as much heat and pressure. You're much less likely, therefore, to find significant deposits of marble or diamond in an asteroid field unless the field was originally a planet large enough, that existed long enough for such substances to form prior to it disintegrating.
[Answer]
In Earth, there are some elements that are rare on the surface because they're heavy, and sunk to the center of the planet when it was still a molten ball of magma. The best example I can think is iridium, which isn't that rare on our planet, but most of it is deep down in the mantle. Only a very small fraction of it is distributed on the lithosphere.
The planet in question could have formed in a very peculiar and rare circumstance, in a fashion that allows the formation and easy mining of hard-to-form minerals. It could be, for example, a small rocky planet around a metal-rich red dwarf star, which coallesced, cooled and solidified very slowly, so the chemical elements distribution is fairly even all around. Or, the opposite, a planet that cooled and solidified so fast that heavy minerals hadn't time to sink to the core.
In both cases the presence of rare elements near the surface would allow the growth of crystals or ores that we simply don't get here, like samarium crystals for example.
Yet another idea can be a Roche world, a double planet where the planets orbit so close to one another that they've exchanged material between them when they were balls of magma, essentially creating a peanut-shaped double planet with a rocky bridge between them. It couldn't be hard to mine this bridge section for rare minerals.
[Answer]
Similar to @LeeLeon's answer...
What if an ancient space faring civilization has already mined the material from every available source within your civilization's reach; concentrating all that they collected on their home planet where it was valued and revered.
If that civilization then collapsed and the ravages of time slowly erased all signs of their existence, you might find a apparently undeveloped planet loaded with the material to the exclusion of all other planets in the area.
[Answer]
This might stretch the definition of "mining", but if we allow aliens, you could be scavenging alien trash or building materials.
Imagine for a moment if an ancient human civilization were to find one of our abandoned cities. Even our simple building materials (steel, aluminum, plastic, and glass) would be valuable. It could be that when our scouts get to Pluto, they find a large alien outpost that was abandoned, made of a amazing material, that we don't have the tech to reproduce, but we can shape.
If you want to make it more like mining, and restrict access to the original tech, you could have the aliens drop an asteroid on the base before they leave, only leaving pulverized materials that can be "mined" but aren't much use otherwise.
[Answer]
The [Oxygen Catastrophe/Great Oxygenation Event](https://en.wikipedia.org/wiki/Great_Oxygenation_Event) was responsible for one of the most significant extinction events in Earth's history. It is also estimated that the Great Oxygenation Event alone was directly responsible for more than 2,500 new minerals of the total of about 4,500 minerals found on Earth.
There are a number of articles, such as [this one](http://www.abc.net.au/news/2017-03-02/human-activity-helps-create-hundreds-of-new-minerals/8319026), that state that human activity is producing new types of minerals.
All you need is some plausible, unique, large/long lived event to potentially be the trigger for exotic minerals in sufficient quantities to make mining reasonable.
[Answer]
## The previous civilization's nuclear program
There was once a civilization on that craggy rock, and they had a rather robust nuclear program, in which they synthesized a lot of different atoms. A lot.
Many of them decayed into the rare element you want, and are stacked up in their former nuclear waste dumps (which are now largely inert due to countless millennia of decay). Or, they may be scattered all over the planet from a little... thing they did.
[Answer]
The way I see it you have two real options.
**A super rare organic material**
Coal for example. Not rare on Earth, but rare in the solar system. Maybe even rare in the galaxy. You need carbon based life and a long time to make coal so it's not going to be abundant.
**A common but you need a lot of it material**
Heavy metals are a good example. There common because they can be found many places, but you need tons of the stuff.
**Things to avoid**
* Don't choose a material that is only on one planet. That always seems off. If one planet has it then others do.
* Don't base off rarity on earth, Coal is a good example. It's really common here, but no where else in the solar system.
* Don't worry about "carry weight" or launch weight. If you need the material then even if you have to spend huge amounts of energy to get just a tiny bit of it, we do that on Earth. Using what you mined is ok too. Even if you use 90% of what you mined just to get 10% in to orbit, that's ok if there is no other way to get the fuel.
* Stay well away from things like gold, silver, etc. The material you choose needs to have a real use. Mining gold for wires for example could be a by product of the coal mining process. But it's the coal your after.
* Don't rely on gimmicks like "odd solar radiation" to create your material. Unless that part of your story. Stick with "other places have some but this place has more."
[Answer]
There are so called rogue stars, or intergalactic stars. This is a star that has escaped the gravitational pull of its home galaxy and is moving independently in or towards the intergalactic void. I could imagine a rogue star scraping a planet boiling off the outer layer of the planet and blasting said layer away, leaving a planet made mostly of metal.
This would make it very productive to mine, and the planet might have some interesting properties. I imaging it cooling a lot quicker because of the high heat conductivity. You might be able to traverse the planet with maglev vehicles.
The interaction with the rogue star would likely launch the planet itself away from its host star. If it's on a path that's eventually passing one of your planets you could start to mine it, and when both planet are nearest to each-other move all the metals to your home planet.
[Answer]
The mineral is produced by an organism in some way, either as a byproduct (such as from its remains/excrement etc) or for some purpose to the organism (nest building, to feed to its young etc).
The chances of the exact same organism evolving on another planet are so remote that for all intents and purposes it can only be found on your planet.
[Answer]
Maybe an ancient civilization produced/mined/extracted/(or even fetched this mineral from a distant planet), and some apocalyptic event has wiped out that civilization.
[Answer]
Why might a precious mineral only be found on one planet? It isn't. The universe is too big for that.
In reality it's only found on one planet that you know of because of rng. Alternatively, if you don't like rng, it's only accessible and cost effective on one planet. Tectonic activity could easily explain this.
] |
[Question]
[
I'd like to implement a currency that is "alive".
Picture a small, rat-sized animal that is:
* only found in a small geographic region, making it reasonably scarce.
* lethargic, or in hibernation most of the time, unless to fly/burrow away from predators.
* derives energy automagically through exposure to the sun or other celestial body.
* has surface composition such that it is prohibitive, but not impossible, to counterfeit.
* is scratch- and heat-resistant.
* reproduces asexually at a slow, constant rate.
My initial references were something like [Crystal Lizards](http://darksouls.wikia.com/wiki/Crystal_Lizard_(Dark_Souls_II)) from Dark Souls.
Knowing that
>
> "Anything can serve as a currency and ultimately the winners will possess the characteristics that people demand: portable, fungible, easily divisible, and reasonably scarce" - [John Matonis](https://www.theatlantic.com/business/archive/2011/04/how-to-start-your-own-private-currency/73327/)
>
>
>
Assuming a technology level no later than 19th century, does the fact that it is not easily divisible and not necessarily fungible preclude it from being used as a currency?
[Answer]
Could it be used as a currency? Possibly. It is reasonably valuable and durable. There are some issues:
## Inflation
Depending on how slow they reproduce, and how long they live, you could just get a bunch of "money" and leave it alone in the back closet for a while and it would breed new money. You don't even have to feed it. This means, concentrated efforts over time will eventually make the currency worthless, as every available dollar rat would be bred as often as possible (and I'm sure plenty of research will go into making them breed more often). This, naturally, leads to inflation.
## Portability
This ties in with Inflation and Value. Basically, you need to be able to easily transport enough money to buy what you need. A small, rat-sized object might be fine if that can buy something of value, but since you can't "break" a rat into change, that's a problem. Now one small rat is the base unit of currency. Imagine a world where 100 dollars was the smallest unit of currency. If you had to spend 100 dollars every time you bought anything, it'd be a nightmare (one eventually solved by the other side of the problem: low value).
If rats were worth next to nothing, say $1 each, now you need to bring a lot of rats to pay for anything. This is the exact opposite of the too valuable rat problem.
## Value
I touched this in the portability issue, because they are related. Basically a rat, as the base unit of currency, needs to be able to represent the smallest transaction. Since it cannot be divided, you have to spend "whole rats" to buy anything. A rat being too pricey relative the costs of goods makes buying things hard. A rat being too cheap relative the cost of goods makes buying things annoying.
## Conclusion
Rats could conceivably be used in trade, but I doubt they'd be a unit of currency. There are so many other things that could be used that are better stores of value, are more divisible, and easier to manage.
[Answer]
I think the problematic word is "currency". If that word were changed to "**investment**" then you could easily have a situation like the **Dutch** [**Tulip Mania**](https://en.wikipedia.org/wiki/Tulip_mania) that occurred in the 1600s. An investor class awash in money and looking for unexploited niches to return fast cash could create a bubble out of almost anything (for a while), even living things like flower bulbs.
But **currency alone doesn't actually have value**. It's just paper that we agree has a value. We use it for convenience, but it evolved as a receipt for a commodity. In ancient times that was grain in storage, but later it was a banknote serving as a receipt for a bank account. Currency isn't the thing of value, it's the convenient token you carry that represents the value.
**Your "bitcoin rat" would have actual value.** Its scarcity and steady reproduction would guarantee inflation. It's durability and un-counterfietability would make them very reliable longterm investments. The very wealthy might have rats to spend, but the average middle class shopkeeper would still use paper and coin currency.
[Answer]
>
> Assuming a technology level no later than 19th century, does the fact that it is not easily divisible and not necessarily fungible preclude it from being used as a currency?
>
>
>
No, it does not prohibit it, but it makes it extremely unlikely. For one, it is easily divisible; the same way gold was: A "bank" that has many rats can issue a promissory note in rat fractions that becomes money. They can also have something difficult to reproduce or fake on their promissory notes; much like our own money: Special paper, ink, and an extremely intricate design hard to reproduce *particularly with late 19th century technology*. Remember, our own early money IRL **was** a promissory note redeemable in silver or gold. Your is just redeemable in Rat! But it takes (for example) 100 single notes to actually get a Rat. For lesser denominations, they are still good for trade: The baker knows that he needs to sell 100 loaves to get a hundred singles, but at the Bank he really could trade those 100 singles for an actual Rat. If he wants. But he might prefer to let the Bank take any risk of accidental Rat death, and just keep the stack of promissory notes that are just as exchangeable. It is safer.
This is the flaw in your system, I think. It will be replaced by promissory notes almost immediately.
It is a misconception to think **Scarcity** is important for a currency. It is not exactly so. Money must be difficult to forge, and difficult to just find lying around in nature.
The scarcity of gold and silver just meant it was hard to fake, and hard to just go on a hike and get some. In real life, our currencies are hard to fake, but are not themselves made of anything scarce. And they don't just occur in nature, so it is hard to just hike in the woods and find some growing on a tree.
But that said, not everything scarce and hard to find makes a suitable currency: Consider Truffles. They can be extremely expensive, they can't be faked, they are hard to find, but they are an unlikely currency.
The defining characteristic of currency is widespread **trust** that it can be exchanged for equal value of goods, labor or services. Now "equal value" is nebulously defined, a fuzzy definition. Still we know what it means; that if a guy gets paid 100 singles for a day of labor, he knows what else he can buy for that 100 singles, in food, in entertainment, in tools or travel or transportation. He trusts that the five Twenties he was given are going to be accepted in trade for almost anything he wants to buy. The money does not have to be backed by **anything** as long as effectively everybody believes it will be accepted in trade; that is why vendors take it, and workers accept it as pay.
So the biggest concern about money is forgery and theft. If your Rats are very difficult to forge and not easy to find ; and no easier to steal than modern currency, then they can be a basis. But like Gold and Silver, IRL, they would likely be replaced by promissory notes, and then just replaced by hard-to-counterfeit paper products.
**Added:** This occurred to me later: You provide the perfect reason that Banks for rats would arise, how it is in their self-interest and why people would use them (in their self-interest): The rats sometimes reproduce. So the bank, in return for ensuring the life of your Rat (the promissory notes they give you, upon deposit, are redeemable for any Rat, not just your own), also keep any new Rats your rat may produce. Instead of our massive vaults for holding Gold and money, they have massive guarded rat gardens; with the rats in trays, perfectly sunned, watered, cooled or shaded, provided medical care as needed to optimize reproduction: That is their profit; it minimizes rat death and rewards them for being custodians of the rats. Like our own first banks, they can "loan" rats, by producing promissory notes collateralized by real property; e.g. a mortgage on your farmland so you can purchase animals, equipment and seed to farm it. Interest bearing loans, of course. People use the banks because they provide free (or low cost) life insurance on their rats, in return for the rights to offspring. Like life insurance, it is better to give up the rare lucky chance of offspring, to be protected against the unlucky chance of losing a rat in an accident, fire or assault.
[Answer]
**Shells.**
[](https://i.stack.imgur.com/MrDsh.jpg)
from <https://en.wikipedia.org/wiki/Shell_money>
>
> In China, cowries were so important that many characters relating to
> money or trade contain the character for cowry: 貝. Starting over three
> thousand years ago, cowry shells, or copies of the shells, were used
> as Chinese currency.[2] The Classical Chinese character for
> "money/currency", 貝, originated as a pictograph of a cowrie shell.[3]
>
>
>
Your lethargic, unusually-surfaced, scratch resistant creatures are like shell money in all respects except for the energetic automagic. It is not immediately obvious how a creature like the cowrie does get its nutrition; exposure to the water instead of exposure to the sun.
I am not sure if you meant for the creatures to stay alive while they were used as money - probably you did. Live cowries were not used because the organism would die, then stink. But suppose cowries were more robust and durable. Would cowries be less suitable as money if they could survive alive in your drawer / purse / treasure chest? Sure - why not?
That said I would hesitate to use my front pocket to keep something that can burrow.
[Answer]
I don't see why not. We have historical records of cows and horses being used as the basis for a barter economy.
It also has some amusing possibilities for a get rich scheme where someone discovers growth hormones.......
[Answer]
**Hibernating Beetles**
Your currency is not a rat, but a species of incredibly rare beetle. So rare that there is only one queen beetle left, which is firmly under control of the Department of Treasury. These beetles are roughly the size of a coin, and when taken far enough away from the hive mind of the queen and colony, enter a state of hibernation wherein they are not dead, but are simply dormant, and can remain that way more or less indefinitely if kept away from the hive mind. In addition, these beetles have several different morphs in the style of snakes, with each morph having unique coloration and being relatively consistent in the percentage of each generation which will have that coloration, providing you with different denominations for your currency. Obviously the queen beetle is kept in an underground bunker, thoroughly guarded and buried so deeply that even someone walking directly above does not have their beetle purse come alive and trying to burrow through their pants.
[Answer]
**I dont think any living creature could realistically be used as currency.**
Any living thing needs to reproduce, so reproduction alone would cause runaway inflation. Death is always uncontrollable, you wouldnt want to be paid in creatures that suddenly die the next day. You wouldnt want to have to pay to feed your money to keep it alive. Its simply unrealistic any society would adopt such a high maintenance currency.
This being said living organisms have been used as trade goods throughout human history. **Slaves as one example**. As long as the organism fulfills a role people will pay for it, or be willing to trade it for something else.
[Answer]
**Cattle** has been used as currency, means of exchange and wealth store.
Horses in Mongolia, camels in deserts, cows in America, goats, sheep, etc.
The upside is portability (they can be driven en masse), inherent value (can be butchered / milked / shorn / worked), and protection from inflation (they reproduce, but slowly, require a lot of food to grow; reproduction is offset by disease).
However, when you get to 19th century society, your currency is likely to change to account for amount of money available (i.e. trust). A natural transition is to skins or pelts (middle ages to 16th century), and from then on to something more... malleable, like promissory notes.
In summary, **rats are fine** early on, but **not in 19th century**.
[Answer]
A couple points: First to answer your question, I believe your "currency" is fungible. I further believe divisibility is a problem and **I don't think it is a viable currency**. But you have bigger problems.
Your currency does not hold value. Your beings will lose their value by dying or by flying off or burrowing. I would see it as a great risk to have to place my money in the sun to prevent it from dying. Besides, no creature on earth is free from predators.
Further, I would contend that I would prefer not to carry more than 5 rat sized things at a time for any distance to pay a person for a loaf of bread. There is also the chance of dropping one and waking it up and it escaping. You also cannot hide that you are or how much money you are carrying making you especially vulnerable to robbers.
And finally, if anyone finds out the geographic location this scarce (endangered) animal can be collected, its habitat will be devastated is a short time and there will be no more.
BTW, I giggled a little because I imagined this asexual reproduction would not be spontaneous and at some point, when one was about to become two, the value would double. Unless there were complications at birth and you lose both... such risk. Lets go back to trading shiny rocks.
[Answer]
Yes, but:
While Living Beings have been used as trade-able currency, They also produce goods or are goods in their own right, milk, wool, meat, transport.
Currency that does nothing, other than be currency, are so because they have perceived wealth. But originally, they also had an ability: Gold/Silver could be made into jewelry, so large wealth could carried on your person.
So for your rat-coin to be worthy of the title currency in the pre-promissory note world, it would need this 'value' too.
You say it derives energy without physical need, can that energy be transferred partly to the owner? If I carry 5 of them, can I skip lunch? 15 of them, no food required? Or can mages tap into that energy for spells?
If you added worth to the rat (why would I ever want a rat in my pocket - eww) then yes, it could become a 'tradable' currency.
[Answer]
**Inherent vs Backed Value**
Most currencies either have inherent value (gold, livestock) or value backed by a government agency. In both cases it's a matter of perception that grants the currency its purchasing power.
Currencies that rely on their **inherent** value, provide a direct benefit or utility to an individual. Take the example of livestock, which can provide food, labor in the fields, or a means of transportation. Gold or other precious metals are sought out for their chemical, physical or aesthetic properties. In Frank Herbert's [Dune](https://en.wikipedia.org/wiki/Dune_(novel)) a special spice is considered a currency for granting its users psychic powers required for space travel. When a substance, object, or phenomenon grants utility that is fundamental for the vast majority of individuals of a society, then it can easily be integrated as a form of currency.
Luxury goods that are only desired by a small fraction of a society will struggle to be accepted as a currency, unless the target group provides some other function that supports the whole of the society. Example: Mages that provide nation wide transportation and who seek out special crystals that others find useless. Such crystals might become currency for the entire society.
In contrast, **backed** currencies rely on an agency with government-like authority within a society to stabilize and standardize its use. Often such currencies are linked to other goods or limited resources that do have inherent value (e.g. originally USD and gold), which helps build trust in the currency in its earlier stages. Currencies work because members of the society perceive them as having value and are willing to exchange their present goods and services for the reassurance that said currency will allow them to acquire future goods and service when needed.
When a currency functions appropriately each individual will agree for the most part with the value attributed to such a currency (give or take). However, if enough people lose faith in a backed currency or disagree on the inherent value of a currency, then trade is burdened and devaluation or hyper-inflation of the currency may occur.
**Creating a fictional currency**
For your rat-based currency to be believable, you must find either a way for them to have inherent value (e.g. medicinal properties or production of some byproduct) or find adequate reason why society would have decided to use the rats as a backed value. What properties must they have that makes them functionally better than alternatives to be a backed value. Scarcity of paper and metals to mint and print other currency and the lack of digital technology, might be one way to approach the problem.
Issues with divisibility, transportation, and functionality of a currency are moot as long as the perceived value within the currency is apparent. Past societies have managed to get around clunkier means of trading using cumbersome currencies to haggle with.
Forging or in the rat's case breeding *more* currency could easily be avoided by adding some biological caveat. Some ways to address this would either be having the ruling faction or government be the sole owner of the female rat(s) and only male offspring being spread across the society. Another way is to limit the procreation means of said rats making it difficult to breed them.
[Answer]
Genetic-algorithm infused cryptocurrencies.
I would mark it as Sci-Fi, but it's actually happening today, so maybe you're looking for a more fictional and less realistic answer.
* only found in in virtual space, making it relatively inaccessible to those without necessary infrastructure
* lethargic, or in hibernation most of the time, mutations occur at a slow rate so as to allow AB testing via a test user base, imagine Alpha, Beta versions tested and implemented on mainstream after confirmed benefits
* derives energy from miners aka people devoting their processing power to the betterment of the self-improving alhorithm
* has hashed cryptography, making it incredibly difficult, but not impossible, to counterfeit / hack
* is resistant to anything barring a fallout of electrical technology. reproduces asexually at a slow, constant, predetermined rate, impossible to change. bonus: this rate can be self-adjusting to maintain optimal availability and inflation. alternative: can be capped at a fixed rate (like bitcoin), making it a deflationary currency, making it thus an investment asset as well as a currency.
It's a bit difficult to get in the technical aspects of how the genetic algorithm works, but i'll give it a quick shot via [this link](https://uk.mathworks.com/help/gads/how-the-genetic-algorithm-works.html?requestedDomain=www.mathworks.com):
>
> 1. The algorithm begins by creating a random initial population.
> 2. The algorithm then creates a sequence of new populations. At each step, the algorithm uses the individuals in the current generation to create the next population. To create the new population, the algorithm performs the following steps:
> * Scores each member of the current population by computing its fitness value.
> * Scales the raw fitness scores to convert them into a more usable range of values.
> * Selects members, called parents, based on their fitness.
> * Some of the individuals in the current population that have lower fitness are chosen as elite. These elite individuals are passed to the next population.
> Produces children from the parents.
> * Children are produced either by making random changes to a single parent—mutation—or by combining the vector entries of a pair of parents—crossover.
> 3. Replaces the current population with the children to form the next generation.
> The algorithm stops when one of the stopping criteria is met
>
>
>
Basically a currency which self-evolves by assessing the needs of the economy.
For example it could discover bugs and exploits faster than humans could, and fix them before giving anyone a chance to take advantage of it.
In addition to it being a [blockchain](https://en.wikipedia.org/wiki/Blockchain), which would essentially make it a public (but hashed, i.e. encrypted) distributed ledger wherein every single transaction (bonus: and mutation) is recorded in the metadata of the currency itself.
Imagine having a dollar note which has its entire history attached to it, along with key metrics e.g. Money Supply, Inflation, Velocity, etc. printed on it.
Pretty neat.
**EDIT:**
>
> "Assuming a technology level no later than 19th century, does the fact that it is not easily divisible and not necessarily fungible preclude it from being used as a currency?"
>
>
>
Admittedly, I skipped over this part, because there are already great answers pertaining to that specific criterion. However, I'm using a definition of "alive" meant to challenge typical assumptions. The OP takes it extremely literally (an actual living rat), but a self-acting agent such as the one described above is by *most* means alive. Only it was discovered 1 century later than specified.
[Answer]
**Not as currency**
The real problem is size, you can't carry enough rats for workable transactions.
Imagine if every bill in your wallet was the dimensions of a can of soda, now imagine trying to carry decent amount of currency, 20-30 bills of various value. You will need a backpack for a wallet. It's just too cumbersome people will switch to something else very quickly. If you can't fit half a dozen of them in your hand they will not make for good currency.
your rats may be valuable trade goods, they may even be the base value your currency is based on, but as physical currency they are useless.
[Answer]
>
> Picture a small, rat-sized animal
>
>
>
That's not small enough. Think size and weight of coin. A rat is like a large bag of coins.
Which makes them either very valuable (too heavy/bulky to carry many), and so not suitable for normal transactions, or requires them to be of low value and forces everyone to carry a lot of them. This is pointless for a currency.
>
> only found in a small geographic region, making it reasonably scarce.
>
>
>
So in effect the entire world's ability to produce money can be either wiped out by a culling or a bad winter or a virus, or the region can be taken over by force.
That's not a currency, it's a war zone waiting to happen.
>
> lethargic, or in hibernation most of the time, unless to fly/burrow away from predators.
>
>
>
A solar powered creature that burrows ? No.
And a hibernating solar powered creature is even worse.
>
> derives energy automagically through exposure to the sun or other celestial body.
>
>
>
This isn't possible in my view as even if they could somehow generate enough energy to live doing this, they could not grow as growth requires food for raw materials and a digestive system to deal with it. No growth means no way to develop from infant to adult.
And of course if you need to feed your creature, because you can't have a solar powered one, then just having money will cost you money.
>
> has surface composition such that it is prohibitive, but not impossible, to counterfeit.
>
>
>
I don't see how you could counterfeit a living currency. We can't counterfeit a rat in a laboratory now.
>
> is scratch- and heat-resistant.
>
>
>
Everything has some level of scratch and heat resistance. But compared to a simple metal coin, these things won't be durable.
If they have a scratch resistant shell or skin, you'd discard the body and use the skin as a currency. Why would you carry around the live creature at all, when the skin is what's useful ?
>
> reproduces asexually at a slow, constant rate.
>
>
>
Which makes spending them a very poor way to use your money ! These would inevitably be hoarded.
This is not possible anyway with a solar powered rat as it's is prevented by the same issue as my "growth" argument above.
The fact that just leaving them in a heap will produce more of them means that, in effect, the money has a built-in devaluation effect. This is just disastrous for an economy. More of them being "born" is equivalent to printing more paper money - you haven't really made more assets to back the currency, so the currency's value must decrease.
>
> does the fact that it is not easily divisible and not necessarily fungible preclude it from being used as a currency?
>
>
>
As I've explained, that's the least of the problems.
] |
[Question]
[
The traditional Amazon tribe in mythology is a society of only women that reproduces by capturing outside men. Suppose that the Amazons were an actual sub-population/subspecies of humans that, as the mythology goes, was all female and could only reproduce by capturing outside ("normal" human) males. What sort of genetics could produce such a phenomenon?
My naive approach would be to suppose that Amazons have a modified X chromosome: X! that causes their offspring to only be female.
So an Amazon mother (X!X!) and a human father (XY) would produce:
* X!X "mixed" Amazon
* X!Y non-viable
But then the problem is that a "mixed" Amazon would then go on to produce normal human daughters and sons since if you pair X!X with XY you get:
* X!X "mixed" Amazon
* X!Y non-viable
* XX normal female human
* XY normal male human
So this approach doesn't seem to work unless there's some way for the X! chromosome to overwrite the X chromosome from the father (turning X!X into X!X!) during conception. But is that possible?
[Answer]
**Driver chromosome.**
Your Amazons carry a [driver chromosome](https://en.wikipedia.org/wiki/Selfish_genetic_element#Segregation_distorters). Driver chromosomes are examples of "selfish" genetic elements which suppress their competition during meiosis.
[X chromosome drive in a widespread Palearctic woodland fly, Drosophila testacea](https://onlinelibrary.wiley.com/doi/full/10.1111/jeb.13089)
>
> X chromosome drive (X drive) provides a clear example of selfish
> genetic behaviour. This phenomenon was first described in Drosophila
> (where it is called the sex ratio trait) (Gershenson, 1928), but has
> since been found in a wide range of taxa, including rodents, plants
> and numerous flies (Diptera) (Jaenike, 2001). Broadly, X drive is
> characterized by the unequal transmission of the X chromosome, which
> can be achieved in a number of ways. In Diptera, X drive is achieved
> through the action of an X‐linked gene product that destroys or
> incapacitates nearly all of an individual's Y‐bearing sperm during
> gametogenesis. As a result, males carrying a driving X chromosome
> (XSR) produce predominantly X‐bearing gametes and therefore sire
> almost exclusively daughters (Jaenike, 2001).
>
>
>
Your X! chromosome is a driver. In fly males, the competition for the driver X during meiosis is the Y. The driver X in flies ensures all sperm are X. In your human females, competition for the driver X! is the normal X. The driver X! in humans ensures that all eggs are X!.
---
**Androgen insensitivity.**
And here is the mechanism by which there are no males. Male pregnancies do not miscarry.
They just are phenotypically female. The X! carries the gene for androgen insensitivity syndrome.
[Androgen insensitivity syndrome](https://www.ncbi.nlm.nih.gov/books/NBK1429/)
Persons with this X linked syndrome have an XY genotype but an XX phenotype. At its extreme, these persons physically are normal females but they do not have a uterus or ovaries, do not menstruate and of course do not get pregnant.
[Answer]
**Gynogenesis**
[There's a thing in fishes where all-female parthenogenetic species of mollies cannot produce offspring on their own](https://en.wikipedia.org/wiki/Gynogenesis), but can only reproduce after being inseminated by a male. The sperm does not actually penetrate the egg, merely activate it so it can begin development and perform parthenogenesis on its own. The male does not benefit from this act, does not pass on its genes, and overall it's a waste of time and effort for the male. Studies have demonstrated that male mollies prefer to mate with females of their own species and avoid the parthenogenetic ones, so the parthenogenetic mollies have to trick the males into mating with them.
There are some variants of this phenomenon that do take in genetic input from the male, but end up "spitting out" the male sex chromosome, such that the offspring are always female. I don't know as much about these, though.
There is some similar behavior among other parthenogenetic species. Some parthenogenetic species like whiptails still require sexual stimulation in order to ovulate, so females end up mounting females to produce eggs. The mounting female still provides no genetic input into the future offspring, however.
[Answer]
Normal women and Amazon women are essentially the same, since they can both reproduce with human males.
The solution is therefore cultural.
Whenever a boy is born, because one of his ancestors was a normal woman, that boy will be abandoned into a bordering tribe, and he will be accepted as compensation for the males taken by the Amazons.
Don't forget that in China the single kid policy together with the preference for a male son has skewed the balance between the sexes toward the male, so it is totally plausible that a cultural approach controls the reproduction outcome.
[Answer]
## It's Mitochondria, not Genetics
[Mitochondrial DNA](https://en.wikipedia.org/wiki/Mitochondrial_DNA) is inherited from the mother, so handed down from the Amazon mother to her children. Happily, mitochondria are also the energy source for cells in human biology, so some mutation that allows for super-powered mitochondria would then inherit from mother to child.
It's up to you what to do when the boys that are born. You could easily make some genetic reason for them to be non-viable, it just doesn't work with the Y-chromosome. That would also mean either a lower conception rate (50% less viable implantantions), or a much higher miscarriage rate. That may or may not be relevant in your text.
[Answer]
***Trigger-happy genetic repair mechanisms.***
[Somewhat fantasy-based answer ahead, but with a dash of realism](https://en.wikipedia.org/wiki/Gene_drive)
The body has several mechanisms in which it can repair DNA. Your amazons have an exclusive, specially trigger-happy one, that sees most of the non-amazon DNA as "borked" and fixes it by making it more similar to the amazonian DNA - a type of [Homing endonucleases](https://en.wikipedia.org/wiki/Selfish_genetic_element#Homing_endonucleases)
This mechanism enables amazons to be healthier and less vulnerable to diseases that come from genetic damage. It would reduce the chance of them getting cancer, reduce their rate of aging, and enable them to survive in ambients with higher radiation.
However, the same mechanism also ends up "correcting" the Y chromosome from their male partner, effectively rebuilding it into a X chromosome, and thus creating an all-female population.
[Answer]
If you are more willing to make your race more genetically distinct, I have another answer. Your human (sub-)species developed parthenogenesis. Parthenogenesis is:
>
> Parthenogenesis is a natural form of asexual reproduction in which growth and development of embryos occur without fertilization by sperm. In animals, parthenogenesis means development of an embryo from an unfertilized egg cell. In plants parthenogenesis is a component process of apomixis.
>
>
>
If parthenogenesis happened in human, the resulting gender has to be female since female doesn't have Y-chromosome to make a male baby.
This answer works well with L.Dutch's answer. Because you can't have a male baby from parthenogenesis, if someone bears a male baby, it will be a clear sign that the female has been raped or otherwise have sex with the outsider, so the baby is cast outside as not a part of the tribe. (Especially effective if the surrounding tribe is patriarchal)
As for how humans might acquire parthenogenesis, it might originally a random chance. But then since female parthenogenetic gets outcast (as they are unfamiliar with parthenogenesis), the outcasts formed their own tribe.
[Answer]
**If what you want is an actual separate species or subspecies you have to have reproductive isolation which you will never get if they are kidnapping men to breed with, simple as that.**
There's only one way to achieve an actual subspecies (something beginning on the path to actual speciation but not quite there yet) that's all female, [**parthenogenesis**](https://en.wikipedia.org/wiki/Parthenogenesis).
Anything where they breed with normal humans to get pregnant but only birth females (the effect of some form of dominant gene resulting in only female conceptions or early miscarriage or still birth of any males) isn't technically speaking a subspecies, it's the same species, same goes for if they simply get rid of male births by infanticide which would be cultural not genetics anyway.
The constant influx of DNA from other human populations in your example would ensure any form of speciation would never happen, simple as that.
So you're probably looking at some sort of random mutation as in [**whiptail lizards**](https://en.wikipedia.org/wiki/Cnemidophorus) to start off with followed by cultural isolation ('men bad, we don't want men') to allow speciation (or sub speciation if you prefer) to begin to develop.
*If you still really want them to kidnap men then try this on for size, Whiptail lizards often go through the motions of mating with each other even though no genetic material is exchanged (both being female), it's just an instinctive pantomime that helps get the hormones that trigger pregnancy going for them (those that do this tend to be more fertile), so perhaps have your Amazons fully speciated such that they can no longer breed with other humans, the sperm won't penetrate the egg, but the act of sex triggers hormonal changes making their parthenogenic pregnancy more likely & sex with men works better than doing it for yourself or with other women, they may not even realise the men are making zero contribution to the offspring, they could be fully speciated in this way & still look identical to normal humans.*
So the question is do you really want a subspecies or just a cultural thing with a bit of a twist, which has already been done to death in fiction anyway.
Alternatively just have them lie about being a subspecies & not having any male births & toss any boy babies off the cliff out back of the house when no one's looking, much simpler.
] |
[Question]
[
The Enlightenment brought both technological and scientific advancement (starting a period of discovery and achievement that hasn't yet ended) and social/political advancement. We generally think of the revolutionizing of science (towards more fact-oriented, provable science instead of sentimental, unprovable theories) as being linked to the revolutionizing of politics (moving from monarchies and tight connections between the church and state to democracies and republics founded on human rights and freedom), because they happened so close together.
But could a society be as technologically and scientifically developed as our society (or maybe slightly more advanced) exist as a monarchy, or a country using the feudal system? Or is there something in scientific discoveries and research that would lead to a political/social revolution and eventually the replacement of the feudal system and monarchies with a democracy?
Essentially, could a society exist with the technological advancement we have today, but not the social or political advancement?
[Answer]
I've read a book series before which had a technologically advanced feudal society in a very believable way.
While the reasons for feudalism's developement were complicated, one very large reason was **the difficulty of direct control.** After the breakdown of the Roman Empire, and with it both its military might and its intricate postal system, it became highly diffcult for rulers of large kingdoms to maintain control over the vast territories they began accumulating. They didn't have enough military power to enforce their control, and they didn't have effective ways of communication This led to local rulers becoming much more autonomous and gaining more independence, while remaining technically subservient to the king. This developed into feudalism as time passed.
So, if you have a technologically advanced authoritarian society where these two reasons apply, feudalism is quite likely to develop.
And there's a very common Sci-Fi setting where this can easily work - **outer space.**
See, if you have a vast interstellar empire, these two apply. It's very difficult to subdue entire planets militarily without causing immense damage to said planet, and without very effective FTL travel, communication would be even worse then medieval times; with limited FTL travel, it would be around the same.
So take an authoritarian government, give it limited FTL travel, wait a few thousand years for planets to become populated, and with a few other ingredients, you can create a technologically advanced feudal society.
[Answer]
The main feature of a feudal monarchy is the "vassalic contract".
It means that one vassal serves it's liege while the liege provide protection. It can be on a small scale : organizing a local police force to protect from day to day violence, or it can be on a huge scale... organizing intergalactic diplomacy to prevent war between the carebear monarchy and the villain republic of evil.
In this system you can have free men, you can have serfs, slaves and any kind of social class (or even caste) that you want, as long as you have a top down authority with (somewhat) personal link between each strata of your population.
As long as everyone keep to their roles, the structure can keep on working, it can even work along with a capitalistic economy. The higher ups have to keep to their oaths and contracts, still ensuring the working of society.
A good example in literature would be Barrayar from Lois McMaster Bujold. You get an intergalactic feudal empire that works quite well in... a composition of everything you might envision.
So, if
- the lords, through time, kept on their appointed roles (protection of the vassals and self-checking).
- Most traditional limitation on trade and industry for nobles should be lifted.
- Joe Average could get more power with sufficient works without needing a revolution (classical example includes rewards and mariage).
- You can even add vassality transference where someone either go up in the hierarchy or goes to a new liege, ensuring mobility.
- The king/emperor were, globally, capable enough to deal with the most aggressive competition. At least capable at the right time. (meaning no heavy loss of authority)
You can have enough social stability for your feudal intergalactic empire to work, with any kind of economy and in addition to some other ideology to mix up with the basis.
[Answer]
*"Could a society exist with the technological advancement we have today, but not the social or political advancement":* a few examples of modern(-ish) societies which cannot be called democracies, and most certainly are not similar to "western" polities:
* National-Socialist Germany, also known as the Third Realm, 1933-1945.
* The Empire of Japan, 1868-1945.
* The Union of Soviet Socialist Republics, 1922-1991, followed by the Russian Federation, 1991-present.
* The People's Republic of China, 1949-present, and still going strong.
* The Kingdom of Saudi Arabia, 1936-present.
* The Islamic Republic of Iran, 1979-present.
* The Democratic People's Republic of Korea, 1948-present.
So, quite obviously, it is perfectly possible to have a modern(-ish) society in terms of technology without necessarily having the kind of representative democracy which people in the global west take for granted.
The style of political organization prevalent in Europe and the so-called western civilization in general is but *one* possible path of development. We like to think that it is somehow "better" than other types of political organizations, and sometime we even believe that it is *inherently* better. But, as practice shows, it is not really the only possible one.
Now, to the question asked in the title, whether a technologically advanced society exist as a feudal monarchy, the answer is, unsurprisingly, that it depends on what is meant by "feudal monarchy".
* First of all, the type of feudal society specific to the western European Middle Ages and (partially) Early Modern period was *very highly specific* to the the western Europe in the Middle Ages and Early Modern period. Even parts of Eastern Europe, clearly within of the same cultural environment, were profoundly different. (For example, in South-Eastern Europe we never had the kind of inheritable hierarchical titles of nobility specific to the west; basically, one was either a noble person or they weren't; there was no such thing as a hierarchy of inheritable titles. Moreover, the meaning of nobility was markedly different.)
* The basic characteristic of a feudal society is, well, [feudalism](https://en.wikipedia.org/wiki/Feudalism), that is, a system of hierarchical inter-personal relationships of which the most important feature is the holding of lands (= [fiefs](https://en.wikipedia.org/wiki/Fief)) or [appanages](https://en.wikipedia.org/wiki/Appanage) in exchange for fealty, services and labor. *You cannot really have that in a modern(-ish) society.*
First of all, in a modern(-ish) society you cannot have people be loyal to persons, you must have them be loyal to *institutions*. That is not feudalism in any way, shape of form.
Second, land holding is not nearly important enough in a modern society. What killed the feudal society dead was the rise of industry and finance, which made the landed nobility become unimportant at first and eventually irrelevant.
Third, in a modern(-ish) society you need to have a degree of social mobility which is incompatible to the rigidly hierarchical nature of a feudal society.
On the other hand, while you cannot have an actual for-real feudal society with a modern(-ish) economy, you can most certainly have a type of organization which deviates markedly from western-style democracies. *Some* attributes of a feudal society can be present, so that while the society cannot be called "feudal", it may show some aspects superficially resembling feudal structures. For example, in the United Kingdom they still have titles of nobility, which don't really mean much but are useful as marks of social distinctions. In the same United Kingdom, they have a non-elected upper house of Parliament, membership in the House of Lords being awarded for exceptional achievements. In the Kingdom of Saudi Arabia they have a for-real hereditary dynasty. In the People's Republic of China they maintain a neat separation between political power and economic activity.
[Answer]
# Who controls the money controls the power
The rise of the middle class broke the aristocracy, the problem being that the aristocracy were obsessed with land because that's where all the money had been up until the industrial revolution. In practice it mostly remained in the land for a considerable transition period as well.
However if you get an aristocracy who embrace industrialisation and make sure they own the factories as well as the land, then you could potentially maintain feudalism. In that scenario you have to maintain the universities as independent organisations sponsored by either the church or the crown. Engineers become your new "free" masons, able to travel freely to ply their trade.
It wouldn't be an economy as you now think of it. A modern industrial economy is based on the average person's disposable income. To maintain feudalism you're largely maintaining an underclass with minimal disposable income that makes up the majority of the population. You'd have to work out a new model to base it on.
[Answer]
I would say "no", but for economic reasons. The apparent surface link between technology and politics is underneath mediated by economics. In Western history, the three have always been intertwined. And it's difficult to imagine an alternative history where the ruling class in a feudal society have the incentive or even the notion to innovate technologically, since -- absent other influences -- the status quo serves them quite well.
I recommend reading *Talking to My Daughter about the Economy*, by Yanis Varoufakis, for a cogent (if breezy) description of how feudalism gave way more or less inevitably to a market economy with the specific technological advancements in shipbuilding, the compass, and navigation.
(Yes, these three things existed long before European feudalism dissipated, but advanced ocean-going shipping -- the kind that supported robust, reliable, and routine global trade -- is relatively recent. Measuring longitude [3], for example, is a real challenge which we today take too much for granted. And, e.g., "there are no reports of the use of a nautical chart on an English vessel until 1489" [1].)
In short, the landed gentry who had for literally centuries held all the economic and therefore political power just by dint of being land owners, and specifically in societies where if you weren't born a land owner you would never become a land owner, began losing out to the new merchant class who, by dint of robust global trade, could amass the same kind of economic power, which therefore of course threatened a loss of political power.
For the landed class to enter into this global trade, the most efficient thing to do was to change their tenant/commons-based land holdings into means of producing commodities for trade. c.f., the history of British "enclosure" [2].
From that point forward, the surest way to gain an upper hand in the growing global competitive marketplace was innovation. This spurred technological advancement, at the same time as creating a "labor market" -- a concept completely foreign to feudal arrangements of labor and production.
The rest, as they say, is history.
[1] <https://en.wikipedia.org/wiki/History_of_navigation#Medieval_age_of_navigation>
[2] <https://en.wikipedia.org/wiki/Enclosure>
[3] <https://en.wikipedia.org/wiki/History_of_longitude>
[Answer]
One of the key aspects of feudal systems is that all is property of the king, and the underlings are "animated property". What the farmer produces belongs to the king, none of the eventual surplus in production will remain with him.
Based on the current theories on capitalism, the lack of incentive given by the lack of profit for the individual leads to lack of development (see the late czarist Russia or the Tokugawa Japan, where the feudal system was still in use, and how they were lagging behind in development with respect to the contemporary rest of Europe).
However, once you look at the exchanges between nations, nothing prevent a feudal system from importing goods and knowledge from more advanced countries. As long as the country is also able to retain its independence, of course.
[Answer]
Yes.
Techonological advancement is a function of specialization and specialization is a function of the energy sources your society has access. It has nothing to do with political liberalism. If you have more energy you have the greater the farming output and with it more people that can become specialized knowledge workers.
What you need is that your society, somehow, learned how to tap the power of the fossil fuels. It isn't far fetched - the greeks had early steam engines and the chinese and arabs were aware that natural crude oil can be used as fuel. So, that's cover the issue of energy.
About the political system: a feudal monarchy is based on oaths of fealty between the hierarchy of vassals. In our timeline these oaths weakened as the kings started to rely on the merchants to provide taxes to fund more professional armies and the wars of religion broke down the lord-vassal relationship. To deal with these two problems your nobility must have an open path to become merchants, something the european nobility had trouble with, and the reformation must not happen. If you have the Americas in your world, it can serve as a dumping ground for nobles that won't inherit. They will be sent to the Americas, build their castles there, vassalize the natives/bring in indentured serfs, build churches, and sell sugar cane and tobacco. Their children without inheritance (like youngest sons) will go deeper into the continent and do the same.
[Answer]
We've actually had one of those: The [Zaibatsu](https://en.wikipedia.org/wiki/Zaibatsu) era of Imperial Japan. These were large conglomerates (and quasi-dependent smaller companies) that controlled so much of the country's economy that everyone and everything in the country was essentially subservient to their interests.
This is essentially a pseudo-feudal system where loyalties to large companies and the families that run them take the place of loyalties to your local liege lord. The country was nominally Democratic as well, but it was a Democracy where political parties (and even military services) were often tied to specific companies, and failing to be sufficiently politically supportive of their expansionist interests abroad or their domestic political interests at home [regularly got the miscreant assassinated](http://countrystudies.us/japan/32.htm).
[Answer]
Steam engine is one of the most important technological advancements.
Let's compare how [James Watt](https://en.wikipedia.org/wiki/James_Watt) created his steam engine in Britain and at the same time [Ivan Polzunov](https://en.wikipedia.org/wiki/Ivan_Polzunov) created one in Russian Empire.
Watt was a free person - he went to different cities, partnered with the best iron-makers, metalworkers, factory owners. He not only developed his machine, started a prosperous industry, but also propelled forward many related technologies, drove industrial revolution.
Being a serviceman of the state, Polzunov, like most Russians at the time, was not allowed to leave the factory, where he was assigned. He was only allowed to send petitions to the administration. He was lucky - Russian empress was very supportive of his project, but that was not enough. Polzunov asked for copper, iron, led, bricks, wood, etc, but received only a fraction. He asked for skilled blacksmiths, metalworkers, carpenters, but got only few apprentices (all of them were bonded workers since there was no free labor in Russia). Eventually, he successfully built the machine, but died at the same time. The machine was abandoned soon after - human labor was very cheap in Russia. Much later Russia started importing western machines.
Of course, Russia was not an true feudal state. Still, I cannot imagine how a society, which lacks freedom, where people need permission from lords to do anything, can achieve much progress. At best they can import technology from the neighbors.
[Answer]
In addition to the answers already posted, one significant factor to consider is how your hypothetical society musters and applies military force.
Although geography and communications played a role in creating societies with feudal systems, military technology appears to have also played a highly significant role. Western European feudalism, Japanese feudalism, and the quasi-feudalism of Persian society in late antiquity all arose in conjunction with systems where the dominant military forces were made up of highly trained and expensively equipped aristocratic elites. European and Japanese feudalism were both destroyed when changing weapons technologies downgraded the importance of aristocratic elites in favor of mass citizen armies.
So a near-future feudalism might become possible if a revolution in military technology once again favored small, elite forces over mass citizen armies. The use of AIs and robotic or drone forces may end up being such a revolution. If a near future society has military forces that no longer require citizen volunteers or conscripts because they are made up of small numbers of technicians directing mass robotic forces, that has to have a political impact.
[Answer]
I think what you ask for is quite feasible.
You assume that enlightenment sparked the desire for freedom, resulting in democracies. But in my opinion, that is not correct.
Let's take a look at two of the first democracies, namely France and the united states.
The driving factors that mobilized the masses were literacy, i.e. the ability to spread information fast and wide, and, most of all, a feeling of injustice. We may say these were not just feelings, but for my point it's irrelevant.
People only rise up if the expected gain is greater than the risk. And the risk is death or imprisonment, either for oneself or for beloved ones, so the gain must be quite large. Arguably, it's sufficient if the leaders of the revolt convince those people who actually put their lives at risk, but that's a slightly different story.
So, to prevent a revolt, and thus the end of the feudal system, you could either increase the risk, or decrease the reward. The latter has the advantage of being a lot more sustainable.
What i am talking about: Don't let your underlings go hungry, and make sure they feel reasonably safe, respected and prosperous.
It is said that the greatest enemy of liberty is a happy slave. And i am convinced that this is true.
If you put away the idea of slaves as being chained and beaten to death on a whim, but instead think of anybody who is not free to make their own decisions, you will find that for example everybody who has to work as an employee, who has debts or rent to pay, etc, is not a free person.
Yet hardly any one of these people thinks about revolts, let alone takes any action in this direction. One of the reasons is that most people think that they are either fairly well off, or hope to be so soon, in the current system (one could argue if that is reasonable, but again, i digress), so they don't feel an urge t change the system.
So, if you think for example about a post-scarcity society, it is quite easy to think of a feudalistic one. As long as the people are reasonably happy, as long as they are convinced that at least most of their dreams are theoretically fulfillable, they won't endeavour to change society. All you need to do is to fulfill the basic needs of your unterlings, and give them some chance to play a part in your government, for those that desire to, and you stand a really good chance to continue with your feudal system indefinitely.
[Answer]
you are asking about the relationship between political systems and the velocity of technological development.
there is middleman, a link between these two worlds, and that is the economic system.
from that perspective technological development´s main dependance is the extent/magnitude of -> accumulation of capital present in the current economy.
whether this accumulation of capital happens in a stock company or is controlled by public government doesnt really matter. in other words: quick advancement of technology is theoretically compatible with both, "liberal" or "socialist" influenced political systems.
in socialism, the speed of development can be influenced by decisions. yet it is not limitless, because workforce is.
a communist government can tax people and put 50% into space flight, but it can not order to colonize mars within 3 weeks, simply because there is not so much workforce avaliable, under no circumstances.
in capitalism, the demand to make profit does on one hand create advancement automatically, but at the same time in capitalism it has to happen always within the parameters of capitalism.
if you dont make your cars better but somebody makes his cars better, you will be kicked out of the market. so you make your cars better to make profit. == capitalism \_forces technological development.
but if you make your cars a huge step better at once while the concurrent company does not, they will be able to pay a dividend to their shareholders and you are not. some shareholders might leave you and invest in the comapny with the more oldfashioned product instead.
== capitalism \_limits the speed of technological progress because it also requires that the owners make profit. (or at least dont loose money)
now to feudalism: i dont think the level of accumuluation 1000 years would even begin to be comparable to today. however, the velocity of technological improvement is of course always relative to the day before day X.
i have left other possible factors, such as education and culture, aside. 1000 years ago their influence mighht have been greater than today, because huge accumulation of capital was nearly impossible.
but it might still be correct to ignore those other factors (including the "enlightment age") because they also have a strong dependency on economics, i.e. on accumulation. (you can only teach reading to the masses if there was enough disponible working hours available somewhen before to invent the bookprint.)
[Answer]
Arguably they already do: anything with a strong Mafia presence has feaudal-ish feel to it, one swears loyalty a lord, who then allows one to work the land (or run a store, within said land). That lord also offers protection against other lords.
And, of course, plenty of technologically advanced countries are not democratic.
Really the main difference in this alternate reality is that society openly embraces their feudal monarchy instead of trying to hide it, but there could be lots of reasons for that, tradition, religion, other countries trying more liberal ideologies with disastrous results, or what have you
[Answer]
Short Answer:
Yes it is possible for an advanced country to have a monarchy.
Yes it is possible for an advanced country to have a federal political system that is partially feudalistic, with hereditary lords and vassals.
No, it is not possible for an advanced country to have serfdom, so if you are thinking about serfdom as a vital feature of feudal society you are out of luck.
Long Answer:
Today there are about 180 to 200 countries on planet Earth, depending on which polities count as countries in one's definition.
And some of them are more advanced than others, but in every one of them at least a proportion of the population has a degree of access to the most advanced products developed in the more advanced countries. Almost every country in the world is part of the world wide technological civilization.
So advanced countries in the world today have various forms of government.
Most countries have republican forms of government.
There are parliamentary republics where the prime minister is head of government and the president is a ceremonial head of state.
There are presidential republics where the president is both head of state and head of government.
There are semi presidential republics where the president is head of state and the executive powers are shared by the prime minister and the president, making them both partial heads of government.
And today most republics claim to be democratic. Republics generally have positions on the democratic scale between very democratic, mostly democratic, largely democratic, slightly democratic, and not democratic at all, since many republics have authoritarian, dictatorial, or totalitarian governments.
A number of states in the world today are monarchies. Monarchies generally share the same sort of distinctions as republics.
Some monarchies are like parliamentary republics, having a prime minister as head of government and a monarch as ceremonial head of state.
Some monarchies are like presidential republics, having a monarch as both head of state and head of government.
Some monarchies are like semi presidential republics, having a monarch as head of state, and with both the prime minister and the monarch having some of the powers of head of government. In most monarchies today the monarch has at least a tiny little bit of executive power, while the prime minister usually has much more executive power than the monarch.
And today most monarchies claim to be democratic. Monarchies generally have positions on the democratic scale between very democratic, mostly democratic, largely democratic, slightly democratic, and not democratic at all, since many monarchies have authoritarian, dictatorial, or totalitarian governments.
Every Country in the world today, except for tiny little Vatican City, has administrative subdivisions, whose governments are either elected by their residents or appointed by higher authorities.
Some countries, like Azerbaijan, The Bahamas, & Bahrain, for example, have only 1 level of subdivision. The United States of America, has three main levels: states, counties, and municipalities. The People's Republic of China, France, Myanmar, and Pakistan have five levels of administrative subdivisions.
<https://en.wikipedia.org/wiki/List_of_administrative_divisions_by_country>[1](https://en.wikipedia.org/wiki/List_of_administrative_divisions_by_country)
And of course those levels of subdivisions are interesting because in various countries the relations between the levels resembles a feudal monarchy more or less - usually less.
>
> Federalism is the mixed or compound mode of government, combining a general government (the central or "federal" government) with regional governments (provincial, state, cantonal, territorial or other sub-unit governments) in a single political system. Its distinctive feature, exemplified in the founding example of modern federalism by the United States under the Constitution of 1787, is a relationship of parity between the two levels of government established.[1](https://en.wikipedia.org/wiki/List_of_administrative_divisions_by_country) Federalism can thus be defined as a form of government in which there is a division of powers between two levels of government of equal status.[2](https://en.wikipedia.org/wiki/Federalism)
>
>
> Federalism differs from confederalism, in which the general level of government is subordinate to the regional level, and from devolution within a unitary state, in which the regional level of government is subordinate to the general level.[3] It represents the central form in the pathway of regional integration or separation,[4] bounded on the less integrated side by confederalism and on the more integrated side by devolution within a unitary state.[5]
>
>
> Leading examples of the federation or federal state include the United States, India, Brazil, Mexico, Russia, Germany, Canada, Switzerland, Argentina, and Australia. Some also today characterize the European Union as the pioneering example of federalism in a multi-state setting, in a concept termed the federal union of states.[6]
>
>
>
<https://en.wikipedia.org/wiki/Federalism>[2](https://en.wikipedia.org/wiki/Federalism)
In a typical medieval country there would be both feudalism and the manorial system. The holder of a manor would be the lord of that manor.
Counts were originally appointed officials but made their positions hereditary. In the Feudal system a count would be the overlord of most of the lords in his county.
Dukes were originally appointed officials but made their positions hereditary. In the feudal system a duke would be the overlord of most of the counts in his country.
And of course a king would be the immediate or ultimate overlord of all the lords, counts, and dukes in his kingdom.
So in this greatly simplified model of the feudal system there would be four levels of feudal rulers: lords, counts, dukes, and kings. And each feudal ruler would be the vassal of some superior ruler or rulers for his fief or fiefs. And vassals and overlords had mutual obligations and rights.
So there are some similarities and differences between Federalism and Feudalism.
It may be noted that one federal state, the German Reich from 1871-1918, had most of the member states ruled by hereditary monarchs (with more or less democratic governments) with feudal titles, thus having considerable overlap between federalism and feudalism.
At the present time the United Arab Emirates is a federation of seven emirates ruled by hereditary sheikhs, with the president and prime minister elected by the sheikhs. Thus the president is both a sheikh and a president, sort of like the president of France is a co prince of Andorra.
Malaysia is a federation of 13 states, nine of which are hereditary monarchies. The nine monarchs elect one of their number to be the head of state, the Yang di-Pertum Agong, every five years.
So the answer is yes.
Yes it is possible for a country at early 21st century levels of development to have a monarchy, since some of them do.
Yes, it is possible for an advanced country to have a more or less feudalistic type of government, like a form of federalism with hereditary rulers.
But no, it should not be possible for an advanced country to have serfdom. All forms of serfdom or slavery tend to slow down progress and development. So in an advanced country slavery and serfdom would be illegal, and the less widespread any similar and possibly illegal status is, the move advanced the society will be.
[Answer]
There isn't much intrinsically connecting scientific advancement with the absence of autocratic government.
I'd say that, with our worlds history as a model, what you need for innovation is a consistently effective government, where effective here means "keeps (most of) the people (in power) from suffering (or talking to each other about it)", an effective educational / academic system with a focus on observable phenomena, an environment where any external government that wants to impose their way of life on you doesn't have the agency to do so with their guns or wallets, and an abundance of natural resources or the ability to exploit someone else for theirs.
Generally if you don't have an effective government, people get really concerned with survival or killing whoever's in charge so that their kids can go about surviving without putting so much effort into it. In these scenarios, people generally don't have a ton of time to 'innovate' because social instability makes that really hard - mostly because if you have time and energy to tackle scientific questions you're almost by definition not an oppressed individual who is struggling to survive, and if social stability starts collapsing all the people who were struggling tend to be rather cross with all the people who weren't. Of course, democracy does quite a bit to keep social stability high - Making everyone feel like the power to change their fate for the better is in their hands makes a government super resilient to the suffering of the populace. But, you don't NEED democracy for that social stability, you can just keep the suffering under control or under wraps.
If you don't have an effective educational / academic system, people don't learn more than the folks who came before them before they die, and innovation doesn't happen. If you don't focus on observable phenomena, people tend to invent answers instead of discovering them, which is a much slower way to advance. Also important is having enough people participating in this system - Greater numbers help solve problems more quickly, as long as they all talk to each other. Large numbers of people talking to each other freely is not dangerous to an autocracy so long as the topic of their conversation isn't "how do I kill the autocrats," which, historically, can be avoided by not giving the people talking reasons to kill the autocrats, or making sure people who are talking about killing autocrats are quickly removed from the conversation.
It might go without saying, but if some other country/government conquers you or eliminates your government, either you stop existing and can't advance, or someone else ends up carrying the torch forward and taking credit for all the stuff you did to advance. History has shown a general trend of non-autocrats having a great deal of animosity towards autocrats, but whether or not that animosity was effective at eliminating them seems largely a matter of circumstance.
And, of course, all the knowledge in the world won't help you if you can't do something with it - So, you need resources. Once you get into the realm of high energy interactions chemistry gets really hard to advance in after a point because you start needing things like steel and/or rubber in order to keep pushing the envelope, because a bunch of phenomena can't be observed in controlled circumstances unless you can control high energy matter, which requires strong (or non-reactive) stuff.
Also, access to a wide -variety- of resources is very important, because you can't learn about stuff you don't have access to. It is no coincidence that advancement started accelerating exponentially after global trade became a thing.
Having resources or not having resources doesn't seem connected to being autocratic or non autocratic, so, again, I have to conclude that this is independent of being an autocracy.
On all points, I can see no direct connection between autocracy and the necessary ingredients for scientific advancement, but I do see several factors that would make it (and have made it, in the past) more difficult under autocratic leadership - Particularly, ineffective autocratic leadership.
If you allow your people to prosper, allow them to believe they are prospering, or ensure that anyone who complains about not prospering disappears quickly and quietly, and you ensure that scientific endeavours stay well funded and well supplied, I see no reason there should be a limit to what they can accomplish.
[Answer]
No.
As long as people are not free to innovate (with their own means/discretion), in general you will not have innovation.
Henry Ford said "A business absolutely devoted to service will have only one worry about profits. They will be embarrassingly large." The symbiosis and brotherhood brought to life by private property rights, and the failure of every counterinvention proves that private property rights and capitalism are crucial to the existence and success of advanced society. They are essential to civilization.
Ford's observation of the growth and benefit only works in a system where people are entitled both to own the means of production and the fruits of their own labor. Under no other system can such tremendous progress as we have seen be attained.
The idea that one can mix and match sociopolitical and economic ideologies with impunity is bunk. All freedoms are ultimately economic, and all wars are ultimately economic. You cannot break the commandment "thou shalt not steal" and expect to prosper indefinitely in other areas, nor can you slight human relations and expect to prosper materially in the long run.
If I say you don't have a right to what you produce, is that not an economic (albeit dead) theory? Is it not also a social and a political theory? There is no such thing as an ideology devoid of taint--that is, all ideologies influence all things that they touch. We live in one world, not two or more.
For a complete bibliography, see history.
[Answer]
Yes. But only if it reached it's advanced technologies in more democratic state and transformed into autocracy. Or that it has more democratic neighbors from which it can import advances in technology.
Monarchies are autocracies. That means that small group(s) of hereditary rulers rule over huge swaths of peasants. To keep the regime stable, people need to be indoctorinated and fed lies about the ruling caste deserving their positions due to whatever reason. Those reasons are usually religious. Once people stop believe that, they will find it unfair that some people got power just because they were born in the right family, rebellions happen.
To stop that, the ruling cast must make sure that people are not taught critical thinking, world history, or any real science. Intellectuals get killed or dragged into work camps and access to information is heavily limited. This wasn't problem in the past, because education and access to information cost lots of money, so keeping peasants fed lies was easy. In modern age of printing press, radio, television or internet, that becomes difficult, but not impossible.
But limiting intellectual's education and free through and limiting access of people to information will stifle any technological advancement. Any any small hole in the indoctorination or the "great firewall" will lead people to demand more rights and access to more freedoms and autocracy quickly topples as politicians who can give those freedoms quickly gain popularity.
] |
[Question]
[
With the increase in living standards, the number of children by women is decreasing in highly developed countries.
**Question:** Is it conceivable (with the aggravating factors proposed below) to see this tendency become global in the future, and the population ending up decreasing up to extinction level?
Aggravating factors:
- Humans go live on a range of planets around close stars, thus the population becomes more scattered.
- There is little to no awareness of the matter, nor any propaganda about making more children.
Note: This question can be considered the opposite of:
[What should three men and three women do if everyone else is dead?](https://worldbuilding.stackexchange.com/questions/3188/what-should-three-men-and-three-women-do-if-everyone-else-is-dead/3212#3212)
(but its answers contain interesting information like the minimal number of individuals in order for a population to survive. (e.g. 4169))
[Answer]
Short answer: **No, it's not plausible for humans as we know them.**
You cannot look at the population as a while when determining the long-term growth curve. Ideally, you would look at individual fertility, but that's neither practical (at the present) or possible (for the future). Instead, you need to look at factors that influence individual fertility, and (on average) the strongest of these is the local cultural expectations. So, you project fertility on a culture-by-culture basis, along with factors (such as wealth) that change cultural expectations, to get the future population curve.
For example, consider a population that, as a whole, has a fertility rate of 1 (half the replacement rate), while a small subculture has a fertility rate of 4 (twice the replacement rate). Fast-forward a few centuries, and the "small subculture" is now the dominant culture, and the population fertility rate is approaching 4.
There are a number of cultures on Earth with high fertility rates. Probably the most prominent are the Mormons, with a strong religious imperative towards large families, and thus a strong resistance to the normal influences towards smaller family size.
In your future scenario, if you go away for a thousand years or so, you probably won't come back to a dying humanity. More likely, you'll come back to a rapidly expanding one, driven by the need for new homes for its ever-growing population.
[Answer]
**Yes.** At least in a science-fiction setting, you can construct a plausible scenario where this might happen.
If there is one child per couple on average, the population will halve with every generation. This would result in a long, slow decline. For example, after 14 generations (say, about 420 years), the Earth's current population of 7 billion would have fallen by a factor of 2^14 = 16384, to less than 500,000. If the birth rate is closer to replacement level, the decline will be even slower.
It is possible that no individual generation would see the fall in population as an urgent problem, especially if robot servants were able to make up for shortages in labour.
This scenario forms the background to the novel [Saturn's Children](http://en.wikipedia.org/wiki/Saturn%27s_Children_%28novel%29), by Charles Stross, in which humanity is (possibly) extinct and a robot civilization occupies the solar system. Some of Asimov's robot novels explore similar ideas, notably [The Naked Sun](http://en.wikipedia.org/wiki/The_Naked_Sun) and [The Robots of Dawn](http://en.wikipedia.org/wiki/The_Robots_of_Dawn).
The animated series Futurama has humorously [observed](http://en.wikipedia.org/wiki/I_Dated_a_Robot) that if you want human beings to have children and perpetuate the species, an important rule is: Don't Date Robots. A clip illustrating the dangers is here: <http://vimeo.com/12915013>
[Answer]
>
> There is little to no awareness of the matter, nor any propaganda
> about making more children.
>
>
>
I don't think that part is plausible unless demographers and economists are not doing their job properly. Most developed countries today are under the replacement rate of 2,1 children per women and they are aware of this. The increase of life expectancy or what we can also call the aging of the population contributes in maintaining and even increasing the population on the short term. But the median age is increasing. It's probably over 40 years old in most developed countries.
**Measures to counter the problem:**
* Some countries, if not all will try to attract immigrants to lessen
the demographic problem. In some case, it's not enough or it's just a
temporary measure. In Germany, on the long run, the immigration rate
will have to increase in order to keep the same population level. But
then the local population will be flooded with strangers and it's not
going to work well.
* Countries can also adopt birth policies to increase the natural
number of birth. Most already have but it's not always enough. China
decided to abandon the one child policy but the birth rate remained
stagnant in the urban areas. It's because people do not feel
comfortable enough financially to have a second child. I have to say
that the inflation rate is fairly high in China and predicting the
economic future is no easy task. And China doesn't have a lot of
measure to help young families like family leave or daycare centres.
>
> Is it conceivable (with the aggravating factors proposed below) to see
> this tendency become global in the future, and the population ending
> up decreasing up to extinction level?
>
>
>
It's already becoming global. In almost all the countries, the birth rate is decreasing. Most countries in Latin America are close to the replacement rate and so does other counties like Thailand or South Korea. Other countries are already facing a decline in population. Most are located in Eastern Europe. We know that this is coming and yet, it's is something that is very difficult to stop. Just like the climate changes.
**Does it mean it will lead to the end of mankind?**
That is very hard to tell. We would need to predict the future. Some said that reducing the population could be a good thing. On the long term, the living conditions could improve even in industrial countries. More resources per capita, more space, less pollution... Good standard of living could increase birth rate enough to keep the population stable but at a lower level.
On the other hand, a society affected by a problem like the aging of it's population is under a huge economic strain. For example, if the number of children per women is only 1, it mean that each new generation will be half as numerous that the older one. The gap might be hard to fill and the young will have to take care of the old. This is likely to become impossible if things get really bad and will lower the life expectancy. Eventually, it will reach something close the the age of retirement, around 50 or 60, like it was before WW2. Before 1945, people worked almost all their live and many did not have the luxury of retirement. If this happens, we could get rid of the economic problem.
But would people want to have more children, I'm not sure. They do not think at the survival of the species when they consider having or not having a child, only at their own survival.
[Answer]
## It's All About Fertility!
The possibility of humanity's population reaching near extinction levels from economic pressures *alone* seems infeasible. As economic pressures reduce birthing rates, our population will stabilize and then begin to reduce. As it reduces the economic pressures will subside and birthing rates will rise and the population will increase. This cycle should oscillate and an equilibrium population would be reached, according to basic economic principles.
There are several scenarios in which reduced fertility could cause humanity's population could decline to extinction levels and be masked by economic explanations. The economic explanations for humanity's declining populations might just be an [Occam's razor](http://en.wikipedia.org/wiki/Occam%27s_razor) rationalization of an unrecognized, systemic and growing fertility problem. I will lay out a few plausible examples in order of descending probability:
**The Natural Selection by Economic Pressures:**
Perhaps the economic pressures of raising a child of high [reproductive value](http://en.wikipedia.org/wiki/Reproductive_value_%28population_genetics%29) create a [fitness criterion](http://en.wikipedia.org/wiki/Fitness_%28biology%29#Measures_of_fitness) for lowered fertility or libido. If such a fitness criterion were persistent though several generations, humanity may [evolve a biologically lower fertility rate](http://homepage.psy.utexas.edu/HomePage/Group/BussLAB/pdffiles/SnowballMS.pdf). Once the economic pressures which induced the fitness criterion of lowered fertility have subsided, it may be difficult for humanity to revert back to a higher fertility rate. One such reason is that with a lowered fertility rate, evolution occurs at a slower pace because fewer births mean that there is less chance for variation in each generation. It may be conceivable that if not reverted quickly enough, humanity passes an evolutionary tipping point, past which we cannot evolve a higher fertility rate before reaching extinction levels.
**The Folly of Man:**
What if mankind, by accident or malice of forethought, introduced a fertility reducing agent to our species. There are many possibilities such as weaponized bacteria or viruses, [synthetic chemicals inducing an auto-immune response](http://humrep.oxfordjournals.org/content/18/5/915.full.pdf), [genetic modification of our food supply](http://www.responsibletechnology.org/article-gmo-soy-linked-to-sterility) all causing reduced fertility.
It may go unnoticed for a few decades before economists & actuaries denote that the population is declining greater then expected. Identifying the agent, eliminating it's exposure to our species, and remedying the damaged caused may be millennia long, Herculean task that brings humanity's population to near extinction levels.
**The Extraterrestrial Soft Kill:**
Suppose an extraterrestrial species desires earth for reasons unknown. They could fling some asteroids from our kaper belt at earth, decimating human life at the expense of the rest of the biosphere. That's easy for an interstellar species, but what if they don't want to destroy other life on earth? They could attack in a more conventional warfare to selectively target humanity and preserve the biosphere, but they would likely suffer some casualties and humanity may adapt to the foreign threat.
A better way for an extraterrestrial species to kill humanity would be to introduce a fertility reducing agent to our species. Then they need to only wait a few centuries as our population declines. They could attack us via conventionally warfare when our species is militarily weak from generations declining population or just wait for us to die out naturally.
[Answer]
No. Not under any conditions I can imagine occurring at random. *(Excluding the case where a lack of resources, or competition for them, renders children unaffordable.)*
This follows from basic evolution: if there exists any trait that randomly occurs, increases the tendency to have children, and can be passed to children via genes or cultural memes, it will expand exponentially.
It is highly unlikely that no such trait would exist.
---
**Plausible explanations** for the outcome described in the question are extremely hard to find, because all evolutionary mechanisms will work against you. If there is the tiniest loop-hole to the conditions -- anything culture or genes, amplified by the use of intelligence, can exploit -- it will be increasingly be used against the conditions, with disrespect of the things we normally value in life. *Remember, everyone who goes with the flow dies; after every generation, only the children of the previous generation will be left, the others are gone from the gene pool. This is a very very strong force to drive evolution.*
Finding conditions for this to work in a large, heterogeneous population is probably too hard. The most plausible way to get there I can think of is a highly intelligent entity that is systematically detecting and removing groups of people that go against the desired outcome. Otherwise, there would have to be a reason that only few people are alive at the onset of this, and that they are fairly homogeneous, so that they all fall into the same trap.
[Answer]
No. The current trend of having less children (than our grandparents did) is tending to less, but not tending to zero. People like having children - well, most of them do. People are fine having as many children as they can care for and still survive. Our grandparents had no reliable form of contraception and children could be an asset as unpaid labourers.
In (what I shall lazily define as) modern Western culture, people want children, but they also want everything else. This results in the 1 - 3 child household so common these days. In countries moving up from 3rd world status the number of children per family declines but is not zero.
Anecdotally I would say, if there were more programmes supporting young parents, people like me and my neighbours would have had one more, maybe, but not 6.
[Answer]
The biggest problem might actually come from humans extending their life expectancy to hundreds of years. If we lived for a very long time, we would generally reduce the number of children we had (or at least try to spread them out over a long period). Otherwise we could have 30 generations living at the same time.
What might happen as people postpone having children until later, they might die before procreating. Another problem, might show up in the human reproductive system might not survive hundreds of years, so too much postponing and you might have a near immortal group of humans who can't procreate.
[Answer]
I think a remote colony could die out because of lack of kids, even though they don't have issues with resources or dangers.
For example, a colony on Mars or the outer system if that's not remote enough misses out on prime child-bearing years because they are pressured to work on building and maintaining the habitat, doing science, and whatever-they are persuing careers not having families. Meanwhile, economic decline leaves them more isolated than intended, with no fresh colonists.
Very few youngsters eventually have fewer kids: why, if they are doing OK? Maybe they are still waiting too long, not worried or in denial about a problem, as mail-order brides will be coming Next Year For Sure.
Or, they do try and breed and increase the number in the next generation, but the gene pool is too shalow. How would that show? As disease that affects everyone, or genetic flaw that becomes prevelent. But then the primary cause of dying out would be blamed on the disease, only secondly explained as being possible due to lack of diversity.
[Answer]
>
> **Question: Is it conceivable (with the aggravating factors proposed
> below) to see this tendency become global in the future, and the
> population ending up decreasing up to extinction level?**
>
>
>
**No. Not because of the factors you mention, anyway**, specifically:
>
> * Humans go live on a range of planet around close stars, thus the population becomes more scattered.
>
>
>
I don't see how this would have any meaningful effect at all on human population on Earth, except for the reduction on Earth of people who leave. So unless Earth becomes a horrible place to live, so that most people want to leave Earth, I don't see this being able to endanger the survival of Earth's human population. That's quite possible, but that would be a factor you did not mention. The populations on other colonies might be in trouble from conditions there, but that too would be a problem you did not mention.
>
> * There is little to no awareness of the matter, nor any propaganda about making more children.
>
>
>
This isn't plausible because already humans have awareness and propaganda about the lower birth rate for more highly educated women, generally for economic/workforce/healthcare worries, but not for extinction worries.
>
> With the increase in living standards, the number of children by woman is decreasing in highly developed countries.
>
>
>
I tend to think this has less to do with "living standards" and more to do with higher levels of education, and more choices for women in terms of professions, ability to support themselves, access to reproductive rights and services (birth control, abortion, marriage rights).
So, the issue you mention, which is that women tend to have fewer children when they have more education and choices, is something humans have been studying, but is in no danger of resulting in human population evaporating simply do to that trend, and certainly not without humans noticing it.
Most of the many actual threats to human survival have to do with the opposite problem, of increasing human population, leading to disasters from us destroying our planet's ability to support life through non-human habitat loss, non-human extinctions, climate change, pollution, WMD proliferation, pollution, clean water use, GMO pollution, nanotechnology, overfishing, ocean acidification, etc. We'd be better off with a declining population, and would have a much easier time surviving as a species and a planet if we lowered our population even to 1% of what it now is.
Industrial food consumption and other modern life conditions may lower fertility, and some future accident might make that situation far worse. But again, that's also not what you were asking about.
However, I suppose if we consider a future where humans overcome our current problems and survive long, long into the future and become very civilized in some form that has a situation where the fertile women are choosing not to have children very often, and perhaps that far-future civilization has become disinterested in maintaining its population levels, I could see it being a kind of issue, but I think attitudes towards reproduction and extinction would need to change, and/or some other factor such as greatly reduced fertility, before this cause would threaten humans with extinction.
[Answer]
Many thanks to all of you! I think you all have good points, and the real answer to my question would be a combination of these.
**No: Economic or climatic (lack of ressources) pressures couldn't do the trick**
As @WorldSpinner and @Vandroiy point out above, these types of pressure can only force a population drop for a limited amount of time. Indeed when the humans are less numerous, then the pressure fades and restrained fertility rise again.
As the population is spread on a lot of planets, the risk for a great catastrophe to kill enough humans at once to get passed the minimal amount for specie perpetuation is also really unlikely.
**No: It's all about culture!**
As @Mark remarks in his answer, even if the mainstream culture discourages having lots of children, in time it would be replaced by the subcultures with higher fertility rates.
Even if global human fertility is decreasing, (for w/e reason) the individuals from the fertile subcultures willing to have children will try everything in order to do so, and probably succeed thanks to advanced science. (in vitro fecondation and so on) As @Vincent points out, individuals mostly do see their interest before such things as their specie's destiny.
**Yes: It would require intervention of a greater institution or entity**
As @WorldSpinner and @Vandroiy emphasise, the only way to go past these barriers is to postulate that an extremely well informed and patient institution or entity works in the shadows to lower the overall fertility (using viruses or chemicals) and break the most fertile subcultures. (using manipulation)
I think we proved here that this is necessary as else evolution or fertile subcultures (that we can see as a social mutation towards specie surviving) would always take over.
**Alternative possibility: coincidences**
The only other way is if an extremely unlucky chain of coincidences happens. For example first the economic pressure makes couples less eager to procreate, then a few catastrophic events dynamite the most fertile subcultures, while a very hardcore sect takes over...
With the dramatic combination of all these economic, climatic and cultural factors, humanity could end up being a very infertile and fanatic small group of individuals.
[Answer]
Its interesting that you as that because it is already happening on earth as far as the Western world is concerned.
It turns out that you need a birth rate of about 2.1 to break even - you have to account for sterility, accidents, homosexuality etc. The West and those other groups close to the west such as Singapore Japan and Korea are running between 1.5 and 1.8 depending on the cycle as a consequence of feminism, contraception and abortion.
To make the math easy consider it is 1.5. That would be 8 grandparents, 6 Children and 4.5 grandchildren. So in the time between grandparents and grandchildren - lets say 50 years you have a halving.
Now I am lowballing the figures here but certainly you would see a halving in less than a century.
In the west at the moment we are about to see all the baby boomers die - born around 1947 they are about 65 years old now. These guys will drop off the twig fast once they hit seventy. I saw it happen with the WW1 guys and WW2 guys. One minute they were there then poof! gone.
When that happens the demographics of the whole western world will shift dramatically.
So yes a population could certainly become extinct - but would also be displaced by more fertile groups just as we are seeing at the moment.
It puts a whole different spin on classical "Moral" arguments - contraception, abortion, homosexuality etc - but that would be begging to go off topic....
[Answer]
Not in real life - @Mark has right answer. All sci-fi around this concept are just that: a sci-fi novel to get some interesting setting, not to investigate a probable outcome.
That said: **Yes, in a sci-fi, because but it would involve some extraordinary intervention.** Like virus making women sterile, targeting only women, or making the birth fatal. And in this situation, focus of all humanity, all resources, would be focused on solving the problem: curing the virus, or developing artificial womb.
Virus able to kill women selectively is the fastest solution - you need to find a cure withing a single generation, or the game is over. I recall such sci-fi novel (with world wars to protect enclaves with uninfected women).
Making the birth fatal is the most interesting sci-fi setting, assuming you need say 100 years to develop solution. Any aspiring sci-fi writers: this one is for you! And please let me know! :-)
[Answer]
A sufficiently scattered human population could make this more plausible. Having millions of humans alive isn't helpful if they are scattered around in groups of a few hundred each and are unable to intermingle. So if something were to happen that would prevent humanity from traveling freely between many small settlements (which is no small feat if the settlements are on different planets around different stars), that could have disastrous effects.
And shrinking populations could have issues beyond genetic diversity. As the population ages, the ratio of working people vs retirees (assuming they retire much like we do of course) will fall, so a smaller group of youngsters suddenly have to support a relatively large elderly population. This would suck many resources out of many more luxury pursuits, potentially including maintaining the infrastructure necessary for interstellar travel.
[Answer]
As a matter of fact, **yes**.
A recent study published in *The Lancet*, and [reported upon by the BBC](https://www.bbc.co.uk/news/health-53409521), projects that the global birth rate will soon drop below 2.1 - the "replacement rate" at which births outnumber deaths - and fall to 1.7 by 2100. The result is that global population will peak at just under 10 billion and then begin to decline, with 23 countries projected to lose at least half their current population by 2100.
Professor Christopher Murray, the director of the institute behind the research, was quoted as stating:
>
> I find people laugh it off; they can't imagine it could be true, they think women will just decide to have more kids.
>
>
> If you can't [find a solution] then **eventually the species disappears**, but that's a few centuries away.
>
>
>
It's worth noting that in reality, most of those countries projected to be worst-affected are not only aware of the issue but [actively fighting to reverse it](https://www.bbc.co.uk/news/world-53424726), including with propaganda (Japan's efforts [have actually become a meme](https://knowyourmeme.com/memes/people/shinzo-abe)). The first BBC article notes a recent upswing in Sweden's birth rate, for example.
However, you've stated that in your world, this isn't the case, and humanity remains blissfully unaware of the declining birth rate. If they remain that way until it's too late, then yes: **humanity could genuinely die out**. It'll just take a while.
[Answer]
**With current technology, no.** I have nothing to add to [Mark's answer](https://worldbuilding.stackexchange.com/a/4790/581) regarding why.
Here go two possible technology change scenarios that could bring that about.
1. **Our robot overlords won't let it.**
Machines have taken over. Either as a compromise or as plain mercy, they'll allow humans to live - possibly with a lot of luxury and a lot of freedom - but no reproductive freedom. The "problem" will take care of itself in due time, even if lifespan was greatly increased.
2. **Entertainment got way better, child care is still very hard**
Advances in technology made video games, food, travel, TV, social networks, and Stack Exchange much more appealing than today. Not to mention the new entertainment options that came about later.
Child care is still basically the same. No robot will change a diaper.
Humans nature has limits to the super-stimuli it can resist, and, referring to Mark's answer again, the Mormons could go the way of many Catholics and just succumb to their own preferences, failing to follow their religion in that particular aspect. If the change is strong enough, no human subculture will remain with a fertility rate beyond replacement. I don't think a lack of propaganda would be plausible, but individual preferences can still overcome it.
[Answer]
Genetic engineering would be one cause. We aren't too far for being in control of our evolution and while the obvious removal of genetic diseases from our gene pool would probably be the first thing we did, it's not the only way we could make our lives easier. And if genetically engineered offspring became the norm, we might eventually just choose to become biologically, but not medically, infertile. Especially since the menstrual cycle is not a biological feature you would want to have if you could live without it.
Now how would this lead into extinction? We would have to lose the technology somehow or access to it would have to be limited. Wars or natural disasters would work as possible limiting factors.
Now the beauty in this idea is that infertile humans wouldn't only knock themselves out of the reproductive cycle, they would also limit their partners. That's if monogamous relationships were still a thing.
] |
[Question]
[
I have seen a similar-ish question on here, but it doesn't quite match my inquiry.
Suppose you have an interstellar civilization (the means of travel between stars being stable two-way wormholes on the outer edges of each system), which has somehow also circumvented the light speed problem for communications. In other words, there is an interstellar internet equivalent present, so anyone anywhere can indeed communicate instantaneously with anyone else, digitally.
Also assume that this civilization descended from our world, albeit several millennia ago. Obviously, economies that far in the future aren't guaranteed to resemble anything we recognize, but let's assume the presence of fiat currency does exist.
What would be a justifiable reason for there to be at least small-scale, limited usage of physical currency in the form of coinage or minted bills, when for the most part, digital currency is honestly more convenient (even in our comparatively primitive world)? Assume that this digital currency is pretty much tamper-proof, protected by honest-to-god quantum encryption and other means that make it risk-free.
Excuse the verbosity, I felt things needed clarified for a comprehensive answer!
[Answer]
**Let's start with a bit of a [Frame Challenge](https://worldbuilding.meta.stackexchange.com/questions/7097): you really don't want perfect digital currency**
It's important for you to understand that you can always ascribe more magic to digital currency. You can declare it to be secure, less costly to use/process, better synchronized, etc., etc., etc. If you're going to do that, then why ask the question?
Hard currency Will always permit particular forms of fraud, not the least of which is [tax evasion](https://www.youtube.com/watch?v=zTV2zaEGPPA), which no government wants. It is, indeed, *unreasonable* to assume that governments *want* hard currency. All that instantaneous communication means equally instantaneous control and accounting because governments can more easily mandate the operations of a business than an individual (this becomes *really important* in a moment).
So if your story needs hard currency you want to avoid perfecting digital currency like you would the proverbial plague. In fact, it might be more efficient for you to ask a second question: what weaknesses in digital currency are justifiable in an interstellar civilization.
**And if you think about it, there's no such thing as a completely cashless society anyway**
Unless you only think of "currency" in terms of pieces of paper and bits of metal. *Value* is assigned to everything from real estate (the land my house sits on) to cows (which I intend to BBQ sometime this week) and my time (which I do *not* have enough of). The direct exchange of these valuable items is usually called "barter," but that's just a word that separates that particular kind of exchange-of-value system from another.
To make matters worse, there will always be *concepts* having intrinsic value that I would find a challenge to believe would ever become 100% digital (and this coming from a dyed-in-the-wool EE): contracts, stocks, bonds, etc. These are convenient outside-of-government-control *representations of value* that people stick in fireproof safes and safety deposit boxes because the potential loss of value due to the EMP of a nuclear strike (or government or Google snooping) is... well, it's devastating.
So, from a very real and practical perspective, there has always been and always will be "hard currency." It only depends on whether the two or more people involved in the transaction agree that the "hard currency" is appropriate for their business transaction.
Having demonstrated that physical currency in some form or another will always exist, it's trivial to jump to fiat currency (pieces of paper and bits of metal). Why? Because actually getting rid of the physical aspect of value transfer requires *monstrously egregious use of Clarkean magic!* Yes, you think it's digital... but you're using plastic cards, your phone or tablet, something completely *physical* to process that digital information. It's not like you can telepathically verify a financial exchange. Digital information will always require a physical manifestation.1
Which is just another kind of "fiat money," it just has a variable value and the physical manifestation, which must exist, doesn't change hands.
**But why is this important? Wouldn't the proverbial debit card be more convenient?**
Not always.
*One of the funniest moments of my life was when I had set up a new retail store for my employer and a teenager with a debit card tried to buy 89￠ worth of product. The chain had a \$3 dollar limit for using cards. He grew angry and tried to explain that we'd lose all kinds of money for not allowing transactions of the type he wanted. He was too inexperienced to realize that the cost to us to process that card for such a small amount meant we were guaranteed to lose money on the transaction.*
**Processing fees** will always impose a practical minimum for digital currency exchange. Oh, stores (etc.) may suck it up and take the plastic (or bitcoin, or anything else) at some loss of profit, *but they'll never be happy with it.* And there will always be processing fees.2 People don't realize that the exorbitant cost of manufacture of a humble penny compared to its intrinsic value is *irrelevant!* The transactional value3 over the lifetime of the penny is thousands of times greater than its cost of manufacture. And once that penny has been released into the wild — it remains a penny so long as it exists. *There is no additional cost to personally hold onto it or to use it in any transaction.* Yes, a bank may charge you to hold those pennies for you ... but that's the point: once you convert to digital money, there will always be fees somewhere. Said another way, computers always have maintenance and operational costs, whereas a penny in your pocket doesn't. Therefore...
*Physical currency maximizes profit and will always be preferable, even if government would sell its soul to get rid of it to maximize its tax revenues.*
**Security is relative**, meaning that digital may be convenient, but it's anything but secure. Digital currencies like Bitcoin are (theoretically) impossible to track, but they also represent a total amount of GDP value so small it's frankly zero. As soon as cryptocurrencies begin to make a substantial dent, government will once again step in and force tracking. And the moment you do that, security goes out the window.4
Worse is the fact that digital currencies always rely (and will always rely) on some form of pass-coded system. A card+PIN, a phone+password, a cryptocurrency wallet+key. In short, while they're a bit more difficult to steal5 than the dollars in your wallet, when they do get stolen, *you lose much more than a few dollars.* Remember, we're not looking for Clarkean magic to justify digital solutions, we're looking for practical weaknesses that rationalize continued use of hard currency.
**What you're using the money for matters.** If you're stashing it away, digital is a horrible solution (physical financial instruments can't be erased with magnets6). If you're just going out for dinner and a movie, it's simply unkind to the business to use a card. On the other hand, large rapid transfers have been "digitized" (from the perspective of a *wire transfer*) from a time long before "digital" even existed.
Like valence electrons, there are bands of "value" that are simply easier to use via one method than the other. A \$5 burger honestly makes little sense using digital (processing costs!). A \$25,000 car makes even less sense *using* hard currency. I want my \$250,000 bearer bond neatly typed on a piece of paper in my safety deposit box where nobody can get at it easily! But a billion-dollar business buy-out simply requires the facility of a digital escrow.
Valence electrons... yeah...
But in the end, **your population may simply demand it.** There's something emotionally grounding about holding "real money" in your hand — and no matter how large the percentage of the population that is completely comfortable with never seeing printed money again (like printed books and vinyl records), there will always be a chunk of the population that simply wants the security blanket of that crisp *Benjamin!* (Or book, or vinyl record....)
And the government may actually permit it (with careful and prudent regulation, of course), because by that time 99% of all transactions may be digital, and so it's willing to take the "loss" of tax evasion because the comfortable happiness of the interstellar population may actually be a bargain at twice the price.
*I'm going to add one more, which I didn't think about before. **Anonymity.** If you can't figure out reasons why this might be valuable, I'm not going to help you.*
---
1 *And only humanity at its best could claim that society is free from the physical hassle of printed/minted money when they still need to pull their phone from their pocket (or at least have it with them... bluetooth...) to buy a Big Mac. What a coup! The government no longer need shoulder the cost of printing the money! The idiot population will buy their phones themselves!*
2 *The cryptocurrency purist will point out that cryptocurrency operates on donated CPU power. Right you are! Financial institutions around the world will be thrilled that the population is willing to relieve them of the burden of expensive server farms. It's not a processing fee anymore, it's a mandatory minimum CPU/Bandwidth requirement for individual households to ensure that everyone has the equal benefit of a secure digital currency. If you think this has the look-and-feel of a certain national health care policy, you're paying excellent attention!*
3 *I've met people who don't get this, so let me explain. Yes, it costs far more than a penny to manufacture a penny. But if you add up all the times in a penny's life that it's used to represent one cent (the transactional value), that penny was used to represent thousands of dollars — which is much more than the cost of the penny. If you consider the same issue from the perspective of electrons, the same number of electrons must be pushed around each and every time a "penny" of digital currency is used, substantially lowering the transactional-value/cost-of-use-or-manufacture ratio. Somebody's paying for all those electrons... and it's not the power company.*
4 *To all the promoters of cryptocurrency: when it comes to software, where there's a will, there's always a way — and few entities on Earth have a bigger will than a government. If you seriously think Bitcoin and its ilk can avoid government oversight, you just hold that happy thought as long as you can. Or hope it never actually becomes popular.*
5 *Biometrics obviously ups the game, but I saw this wonderful episode of* The Blacklist *where James Spader invaded an airplane to pull some dude from cryogenic freeze just to cut off his thumbs to get at his safety deposit box, which was biometrically secured. Oh, yeah... it can be done! Hollywood has proved it and Hollywood is always right!*
6 *There's probably a statistic that claims that fiat money stuffed in a mattress is less safe than numbers stored on a proverbial index card at your local bank. Which is why we don't actually need the [FDIC](https://www.fdic.gov/) in the U.S. anymore, right?*
[Answer]
Reasons hard currency might still have a place in an interstellar society
* Diverse levels of technology between different star systems or planets or groups of that trade with each other. If the technology is ubiquitous and homogenous then cryptocurrencies would be sufficient. But on a frontier world or a mineral prospecting or animal hunting environment where the low-tech people need goods (fuel, heat, light, food, weapons, medicine, etc) and the high-tech people want what is mined, skinned, grown, or harvested then they could resort to barter or use hard currency
* Criminal activity. Since cryptocurrencies maintain a blockchain record of transactions, they could be used to convict someone of a crime. So to conduct illegal business some parties might demand payment in fungible resources. Just because the coinage is minted and accepted doesn't mean that a government had to issue it. A crime syndicate could mint coins that criminals could use to pay for services and items in a clandestine manner. Either the coins could be intrinsically valuable like gold or diamond or thorium or the crime syndicate could redeem them for cryptocurrency
* For commerce between civilizations, both might be high tech and have their own cryptocurrencies but there may not be an agreed upon measure of exchange or a way to spend the other civilizations currency in their own borders. Again, barter would work, but coinage is more convenient.
In general, both the Star Wars and Star Trek universes illustrate where cryptocurrencies would work and where the equivalent of cold hard coinage is required.
[Answer]
In the modern world, we all still use physical currency in certain situations and places because it can serve as a useful failsafe for small transactions in remote areas.
The problem with your digital currency is connectivity. That is going to be the case no matter how 'secure' and ubiquitous you make your communications. There are going to be disruptions. Your work experience quantum tunneler accidentally puts his axe through your wormhole, the comms system is disrupted in certain sectors by that pesky super nova that just HAD to happen while you're buying that moon you always wanted...
There simply is no such thing as uninterruptible communications.
So you're in some backwater out past Betelgeuse, trying to buy a coffee, and all of a sudden the cafe's transactional comms go down - what do you do? you pull out a couple of notes or coins.
It's true that physical currency is on the wane around the world now because digital currency is much more convenient, and arguably even safer (or at least requires a higher level of technical expertise to steal) but neither solution is perfect. Ideally, to get by you need a mix of both, especially in remote areas that can struggle staying connected.
Having some 'hard' currency on you for those little purchases for which a record of the transaction isn't so important may well be the order of the day in many places, especially if the cost of maintaining stable communications turns out to be prohibitive. I can't imagine *any* government (for example) investing in a wormhole to a given planet if the number of transactions being processed falls well below the break even point. While it is still incumbent on the state to provide the critical infrastructure of business, regardless of whether or not it will make a profit to do so, governments tend to get pragmatic about these matters and find workarounds that save them money.
Just ask those people in outback Australia about their promised NBN internet connections...
[Answer]
One thing you may have overlooked, is your digital currency won't be instant. Depending on where the gates are exactly, if they're at the edge of the solar system it's still probably 4-6 hours for a signal to get from earth to the gate (assuming approximately Neptune's orbit as edge of solar system). You'd also end up with a similar delay on the other end of the wormhole, so if you want to transfer funds to your friend on Betelguese IV it could easily take 12 hours.
With these kind of potential delays there's all sorts of situations where you could have a temporary hold on some of your digital funds. OTOH physical currency is right there and can be spent.
[Answer]
### Electronic interference
The area in which you live has electronic interference. So vending machines and stores need physical currency that can be verified immediately and mechanically rather than something accessed by a credit card that can't be checked half the time.
Note that black holes create this kind of interference, so it may be that your wormholes do as well. So someone who mostly travels through wormholes might normally be in a situation that required physical currency. And of course physical currency would be used near spaceports, as spacers both need and have physical currency for use on their ships.
[Answer]
Digital currency and encryption in general is about the ratio between the work required to crack something and the work required to verify something.
A physical digital currency token is a token that can be *verified* to contain some digital currency cheaply and reliably *without* having to actually transfer the digital currency.
Moving digital currency around requires the permission/effort of the network, be it some centralized store or a distributed ledger like the blockchain. That permission both costs privacy, bandwidth and computational effort.
So instead of going back to the centralized store all of the time, you simply embed a signed guarantee that the digital currency inside this coin is unique and unshared, backed by a major bank, state or other "trusted" organization.
You can verify this *locally* by communicating with the digital currency and checking the signature. No record of this verification is made.
The physical token will have an expiration date, at which point it needs to be "refreshed" by transferring it (either by refreshing it, or by transferring it to a digital account, or transferring it to a new physical token).
Part of the security of these physical tokens is that they have unique internal secure hardware. Transferring the currency data from one physical token to another is a security hole.
So, we have physical tokens which carry money. They have their value displayed on them. They can be remotely powered to light up and say if they have money, and they can be negotiated with to digitally prove they have value in them, without communicating with the central system.
Minting such a coin and converting it back to digital currency costs something like 10% of its value, but they are intended to pass from hand to hand to hand at least 100 times before they are liquidated.
Pure digital exchange, due to the risks of hacking, costs 50 cents plus 2% of the value exchanged for a high-security link, or 10% for a low-security link (including insurance from losses), or 100$ and 0.5% of its value for a Bank-level transfer. All 3 of these involve mathematically distinct operations that move different *kinds* of digital value around, and the costs are almost entirely in the form of computation to ensure that nobody can be faking the transfer.
This makes using pure digital currency for many purchases impractical or inefficient compared to physical tokens. Physical tokens, with their hardware encryption and security, are simply cheaper to pass around than doing it digitally.
---
As mentioned by @TiStrga, another possibility is a one-time pad.
You could imagine computation reaching the point that there is no longer a secure means of cryptography other than the one-time pad.
Then high quality random noise stored securely in a physical object, with a serial number, in pairs, could have value.
Communicating OTP over any communication link makes your communication no more secure than that original link. If physical tokens can be made *more secure* than the internet, then cash with said tokens becomes valuable.
And given that digital currency relies on cryptography, quite possibly the only safe way to exchange your digital money requires you to have OTP at both end of the communication link; a coin at both ends, which loses a certain number of bits.
Note that the failure of all cryptography would have other interesting effects on the universe's information economy and science in general.
You could suppose P=NP in your universe with an efficient algorithm, which means that everything efficiently provable is efficiently *solvable*, a radical and huge change in how we think about information.
Or you could go more hand-wavey, and make the coins contain entangled quantum systems which can be correlated using classical information in order to exchange a quantum OTP to secure the communication channel somehow. Now both parties in an exchange have to have coins from the "same mint". For interstellar trade, possibly the delicate quantum state of the coins doesn't permit FTL travel; STL shipment of quantum coins is required to permit secure trade between systems.
Now you'll have various currencies, one per system, with high barriers to trade of currency or other secure information between systems.
A step further and said coin technology might even be required to send *any* information FTL, including safely doing a jump of physical matter from system to system. But that probably makes travel too expensive.
[Answer]
# Energy as a physical currency
In a high-tech civilization, it would be possible to calculate how much energy it takes to produce something. For example, that 1000-Calorie burger you want to eat might cost something like 15,000 Calories of energy (or something like 2,000 Calories if you have replicators that can produce it on the spot). If the production of many items is automated, then the cost could represent how much energy the automation consumes in order to get an item to you.
If you have a ubiquitous, easily transferable energy source, it would make sense to use it as a physical currency. One option would be a battery or super-capacitor that you could carry around with you. Another option would be what your spaceship uses as fuel. Your spaceship would have its own reactor or energy store, and you could use it to refill your portable energy store. Then as you go to the market, you would use that portable energy store to either give energy directly to a machine producing a good, or transfer it to a merchant in the desired amount.
One nice benefit that this shares with digital currency is how you don't need to worry about small change - it would be easy enough to transfer exactly the amount of energy you agree upon.
It also has the advantage of not being based on something arbitrary. Money in our civilization basically only has value because people have agreed that it does. Energy, on the other hand, can easily be translated into work.
[Answer]
**Dystopian government**
Everyone except the very elite depends on the black market for non-essential goods. If you're not well-connected enough, you often depend on it for essential goods too.
The government controls the official currency (numbers in a database), and will crack down on sufficiently large cryptocurrency networks.
A few small, local cryptocurrency networks thrive, but the bigger they get, the bigger the odds that the government will notice them. The tamper-proofness assumption doesn't hold for physically invading the datacenter of the biggest miners and traders with overwhelming force, does it? The government holds all territory, there's no other jurisdictions to go to.
Meanwhile, gold has made a comeback. Cheap, portable and ubiquitous mass spectrometry had been long a reality, so convincing fakes are rare and elaborate.
Soviet-style totalitarian centrally planned socialism on steriods is the dystopia that first comes to my mind, but I suppose this could be made to work with other style dystopias.
[Answer]
Biggest factor is trust.
In an evolving digital age, more transactions are becoming digitalized. Much of those digital exchanges are indeed backed by some hard currency somewhere. There is the cryptocurrencies out there that are not backed by anything, but the trust come from the fact that the currency will always be there and will always be exchangeable. Now if a server storing the currency data gets destroyed or the one person holding all the encryption codes dies (this did happen) then the whole currency becomes worthless over night.
To ensure security, a massive level of encryption is required. This would be troublesome for small, quick transactions at remote location. having local decryption machines may not be feasible. This would erode trust in the system when you cannot use your money when and where you want.
[Answer]
# No reasons
I'll take opposite view. Our all physical currency exchange places operates effectively because country at hand has plenty of metal and wood resources or can import them easily from other countries for manufacturing physical currency units.
Now consider such scenarios:
1. Zerg from **Albinos** planet wants to buy 1 billion gold coins which they operate in it's home planet - where gold is an abundant resource - from our earth currency exchange. Where do we get such enormous amount of gold ? Should we build millions of different warehouses for being able to suit each alien civilization's needs in currency exchange ?
2. Merchant ship of **Ktulahu** civilization crashes and it's pilot comes to us with 200 000 coins made from [Uranium-235](https://en.wikipedia.org/wiki/Uranium-235) radioactive material which they operate normaly in their home planet. Pilot asks to exchange his money into our dollars, because he likes our earth so much that he don't plans to return back to home and wants to live with us. How we will store such huge amount of radioactive material ? Should we accept the risk of chain-reaction of coins ? Maybe Ktulahu member itself is radioactive and sees no problem in this, however it is an issue in earth.
3. In a distant planet, named **Trodontax**, a dinosaur species [Troodon](https://en.wikipedia.org/wiki/Dinosaur_intelligence) had evolved into very intelligent creatures which brain is of same capacity of human, because Trodontax never had a cataclysmic event which have made dinosaurs extinct as in earth. Their coin has a mass around `1 kg`, and in recent times they had an economic recession which invoked inflation. So if Troodon would like to buy an ice-cream in an earth - we would need *a truck* to carry that exact amount of Trodontax money to a currency exchange.
4. Local currency value problem. It will be a lot harder to establish an institution which would set-up a fair rates of native currency exchange rates for all alien civilizations.
Given this and many many more issues with native's local currency, the only reasonable way is to use a virtual-digital currency everywhere globally.
[Answer]
# Physical security
Digital currency can be hard to properly secure. A society that's a couple millenia ahead of us is so hard to imagine computer security for that it's nearly impossible to make predictions about digital security, but one thing is for sure: there will always be people who are interested in getting money through theft. And there might be A LOT of people that want to steal money. And if you got a nice juicy digital money steak in the form of poorly secured cryptocurrency wallets, or a small backwater planet bank with outdated security protocols, or some other form of digital money, that's going to attract a lot of people. Security needs to win all the time. the attacker needs to win only once. At some point, the attacker is going to win. And all those people can attack at the same time through automation and remote attacks.
Meanwhile, physical currency needs physical presence to steal. It's in one location, and you can defend that location with whatever measures you deem necessary. An attacker will need to bring whatever tools he needs with him for the heist. So you can put that currency in a close orbit around a neutron star, protected by a dense network of automated mines that only listen to the combined signals of the kill switches you and the 14 other members of the board carry, and make it so you need to find 3 separate wormholes in various star systems across the galaxy to get to it, and one of those wormholes is close to a military academy, and whatever other measures you can think of. And in case someone does manage to get to the vault and is robbing you, you can trigger the emergency fail safe and propel the entire station into the neutron star. Sure, you may have lost the money, but no one else will have it too. You can do the fail safe thing on a smaller scale too: thieves are robbing your bank? Set off a ink bomb and noone can use that currency anymore.
[Answer]
Non-artificial scarcity is how actual hard currencies evolved and any society which has centralized power must have centralized access to some form of non-artificial scarcity.
You say the travel is accomplished with wormholes connecting remote worlds. Well, can anyone, from any world, go to any other world for lunch, go to another one for dinner and come back "home" to sleep? Probably not.
There is some restriction on resources needed for travel. Some form of ownership of such resources requires either individuals who can own and transfer these resources by themselves or some form of fractional contractually-guaranteed ownership of whatever powers the travel. This makes either the containers carrying the resource a form of currency or fractional-ownership contracts a form of currency.
[Answer]
### Global Usability
However advanced your *average* tech level, you probably still have a few people that can't afford — or for whatever reason, don't use — the necessary equipment to deal in digital currency.
### Privacy
Cryptocurrencies are complicated and their value isn't entirely stable. (It's also not inconceivable that your technology has advanced to a point that makes cryptocurrency impractical for whatever reason.) Cold hard cash has always been the ultimate "untraceable" currency. As long as there is crime, or just people that want their spending habits to remain "discreet", there will be a demand for cash. (Take a look at how David Weber's Honorverse deals with this for a good example. The "cash" there is in the form of credit chits, which are something of a hybrid between physical cash and cryptocurrency.)
---
Given that tech advances create an arms race between currency issuers and forgers, your "cash" is likely to be either a) something similar to "credit chits", or b) something that has a very high value-per-mass that is both easy to authenticate and cost-prohibitive to reproduce. The latter category has included salt and gold at various times in history. Note that this *can* be something that anyone can make, as long as the production cost is on par with its trade value, especially if its something that your civilization consumes.
Ultimately, keep in mind that the only purpose of currency is to simplify a barter economy. Even if there isn't a *standard* form of "cash", you can still have commerce that doesn't involve exchange of digital currency. "Money" is just a convenient way to assign value to stuff so that a) there is less dickering over prices/values, and b) it is easier for me to trade your money for what I actually need than to re-trade whatever alternate form of compensation you can offer.
[Answer]
How exactly do you get a "tamper-proof" digital currency? I'm not sure, but that sounds complicated, and by complicated, I mean expensive. If you were running a store, you would spend the $2000 needed to purchase the currency trader, plus the monthly fees needed to rent the remote quantum link. But let's say you're not running a store. Instead you rent locker space at the spaceport, or operate a bunch of vending machines, or run a food cart or something. You're certainly not going to add a currency trader to every locker bank or vending machine, I mean, most of them don't even have access to power, not to mention the effect it would have on installation cost. Instead you just add a slot for space quarters and call it good.
In general, this leaves you with an environment where banks and chain stores work with the tamper-proof digital currency, but still leaves plenty of room for physical currency to still have a presence.
[Answer]
Simple. Unless you have FTL (or faster) communications that can't be sliced, spoofed, jammed, or hacked, nobody can check if your Pan-Galactic VIP Diamond Encrusted Platinum Nova account backed by the Royal Bank of Alderaan is currently good or not.
(Hint: it's not good anymore, because the bank, and everything and everyone that was on the planet is so much space dust and asteroids now.)
Thus cold hard cash or other similar valuables will remain and be used in most corners of any and every galaxy, even one long ago and far far away.
[Answer]
Because the vast majority of digital currency isn’t actually “real” money: it’s just a number in a bank’s balance sheets that says that they owe you some amount of actual money: it’s not money, it’s credit, which is why bank runs are a thing that can happen.
There’s only two types of real money, both of which are issued by the national central bank (or, in America, the Federal Reserve): physical currency that they’ve minted, and a special sort of electronic currency that is only used by the banks, and is stored on special servers that the banks have access to. This special electronic currency is used to facilitate the transfer of funds between banks - and since the banks have agreements to total up the net value of the transactions between them (almost all of which cancel out) each day, and only transfer the net value, they don’t need anywhere near as much of this special currency as they would if they needed to actually hold any reasonable fraction of the “fake” digital currency on their accounts.
[Answer]
**It's useful when you want to put hard limit on a stock exchange.**
Intergalactic traders could find digital currency, and the ease of transferring it too tempting to not try to game the system with faster and faster communications. This has [already happened IRL](https://en.wikipedia.org/wiki/High-frequency_trading#cite_ref-47).
Imposing an artificial limit on all communications is much easier to do if you use physical currency. Artificial limits on stock exchange trading speed [already exist IRL](https://en.wikipedia.org/wiki/IEX)
] |
[Question]
[
After asking my question about seeing [black holes](https://worldbuilding.stackexchange.com/q/5262/19) in your path between the stars, I also wondered abut other more mundane objects. Black holes affect large areas of space so even if you didn't get 'close' it could still affect your trajectory. The answers there are good for black holes.
Now, say we get to traveling at very fast speeds. How do we keep from going splat? Running into almost anything at say .75 light speed I think would be catastrophic. Even something the size of a marble would have devastating consequences. (someone want to do the math?)
I know space is huge and it's actually fairly unlikely that you'd ever hit anything between planets much less between stars, but...
So I'm guessing we'd have to have some kind of deflector shields for small object, maybe even a way to turn the impacts into energy for the ship. But at some point the objects will be dangerously too big and avoidance would be the better idea. How do we detect and avoid object the size of a pickup (or larger maybe a small mountain) when traveling at these speeds? Or does our reaction time (light bouncing off object and returning to be observed + the time it takes for the ship to adjust course) dictate how fast it is safe to travel?
I'm assuming the ship would be doing the monitoring and course adjustments. This question is for conventional linear travel, I want to ask a question about 'Alcubierre drives' later.
[Answer]
In real life, the issue would not be rocks or even dust particles, but single atoms. The presence of a small but not insignificant number of atoms/ions/molecules in any volume of space would create enormous amounts of both friction and radiation for any vessel traveling at that speed.
The best solution I've seen that is physically realistic is a large (1000's of km in extent) magnetic field and a laser/EM beam sufficiently strong to ionize any matter in front of the vessel. Once ionized, the gas/dust will be affected by the magnetic field and can be funneled either A) into the ship's engines for fuel, as in the [Bussard ramjet](http://en.wikipedia.org/wiki/Bussard_ramjet) or B) around the vessel.
Larger objects are *extremely* sparse in the universe and if you happen to come across one, realistically speaking, you're dead. It's unlikely that you will, but not impossible. Very large objects could be seen using a telescope and navigated around.
[Answer]
Just to answer how catastrophic the marble would be:
$$\text{marble size} = 1 \text{ cm}$$
$$\text{glass density} = 2.65 \text{ g/cm}^3$$
$$\text{marble volume} = 4/3 \times \pi \times 1 \text{ cm}^3 \approx 4.2 \text{ cm}^3$$
$$\text{marble mass} = 11.13 \text{ g} = 0.01 \text{ kg}$$
$$\beta = 0.75$$
$$\text{lorentz factor} = \frac{1}{\sqrt{1- \beta ^2}}$$
$$\text{lorentz factor} \approx 1.5$$
$$\text{traditional energy} = 0.01 \text{ kg}\times (224844343 \frac{m}{s})^2 \approx 5.05549788 \text{ PJ}$$
$$\text{actual energy} = 0.01 \text{ kg}\times 1.5 \times (224844343 \frac{m}{s})^2 \approx 7.58324682 \text{ PJ}$$
$$\text{hiroshima bomb} = 67 \text{ TJ}$$
$$\text{marble energy} ~ 7583 \text{ TJ}$$
$$\text{ratio} \approx 113$$
or alternatively, for $0.2c$:
$$\beta=0.2$$
$$\text{lorentz factor} = \frac{1}{\sqrt{1-\beta ^2}}$$
$$\text{lorentz factor} = 1.0206$$
$$\text{trad. energy} = 0.01 \text{ kg}\times (59958491\frac{m}{s})^2 = 35.950206429 \text{ TJ}$$
$$\text{actual energy} = \text{trad. energy} \times 1.0206 = 36.690780682 \text{ TJ}$$
$$\text{ratio} = \text{just about a half} :($$
That means that marble hitting your spaceship/whatever at 75% the speed of light would deliver the equivalent energy of 113 time the Hiroshima bomb, but at 20% the speed of light, it is reduced significantly, to just over a half of the Hiroshima bomb. It may be a little less or more, as these are quite rough, and it doesn't answer your actual question, but there you go. I was just wondering.
[Answer]
## In true Sci-Fi fashion, someone has thought of that!
In Star Trek, the [Navigational Deflector](http://en.memory-alpha.org/wiki/Navigational_deflector) is used for everything imaginable as a shield for just this purpose, deflecting small debris that could otherwise damage the vessel. It works alongside the [Deflector Shield](http://en.memory-alpha.org/wiki/Deflector_shield).
It's operation is like this:
[](https://i.stack.imgur.com/aJHxe.gif)
In order to prevent crashing into debris, I can imagine something like this would be highly desirable. Any sort of shield should do, however.
# What about bigger stuff?
Star Wars uses the [Navicomputer](http://starwars.wikia.com/wiki/Navigation_computer) and [Astromech droids](http://starwars.wikia.com/wiki/Astromech_droid) to perform the large calculations required for plotting a complex series of jumps through space. Initial plotting would have been done with meticulously short jumps to slowly plot out the rough locations of large stellar bodies. To help with large bodies that may move (or be moved by pirates!) into common hyperspace lanes, the [Hyperdrive](http://starwars.wikia.com/wiki/Hyperdrive) has built-in fail-safes to cut power if a gravity well is detected. This isn't just about collision avoidance, of course, but that's out of scope here I feel.
Star Wars also has its own [Deflector Shield](http://starwars.wikia.com/wiki/Deflector_shield), which is designed to prevent collisions or damage of any kind, it seems. There are a few references to meteor protection being a benefit, specifically the [Particle Shield](http://starwars.wikia.com/wiki/Particle_shield) variety.
[Answer]
I think this might be one of those times where 'shipping lanes in space' actually makes sense as we'd be able to clear a line of space and ensure there aren't large objects in the way. Best theory I can come up with is the deflector beam theory...detect the object infront of you and use a beam of sorts to push it out of the way.
going to assume:
* nothing can go faster than the speed of light for this answer as it's the best we know right now.
* We can deflect. If an object was moving directly at the ship, could we really deflect it, or would we just push back on it with a deflector beam?
Lets say an object is 1 'light minute' in front of us. That would mean we could hit it with a detection beam in 1 minute. At 75% the speed of light, we would be 45 seconds of the way there with 15 seconds remaining by the time the detection beam strikes the object. When the detection beam turns around and bounces back, we are approximately 51.5 seconds towards it (8.5 seconds away). If a beam travelling light speed could be instantaneously generated (assume zero cal time), we then have 2.125 seconds for the force of this to deflect it...which I'm going to assume is improbable to impossible. Of course we can extend this so we are detecting further than 'one light minute' infront of us, and I'd have to go down the path how long it would take such a body to deflect out of our path to get an idea of how many 'light minutes' we'd need to detect these in advance.
Should also note that generating this beam and projecting it forward will slow down the ship generating it, requiring more propulsion to keep the craft at 75% the speed of light.
I would think this ultimately comes to the conclusion that there would be two very separate travel styles...one that goes into the unknown at a significantly slower speed, and one that travels known routes that are intentionally kept clear (space highways?) where speed could be significantly faster (then you get into the issue of a slower space craft getting in your way)
As an expansion, I'd be curious what type of force would be needed to change direction as some objects would need to be avoided entirely (say it's a comet that is coming into the pathway).
[Answer]
Much safer and faster is to make hyperspace jumps, where you skip (move discontinuously) over all the areas with debris. Of course to calculate hyperspace jumps you need to see into the future (because you arrive there sooner than light can), so you need spice from Dune :-)
[Answer]
How to detect things coming at you at 75% lightspeed? Radar.
**REALLY POWERFUL RADAR**
One scifi series I read had ships with radar, lidar and other sensors that were so powerful they would actually act as weapons at closer ranges. This is necessary, because you need a really long range to detect objects so you can dodge. And this was only at 20% lightspeed.
The math is bad. You need to spray a cone ahead of your ship with enough RF to guarantee a return signal from anything big enough to hurt you and far enough out to react. Things big enough to hurt you are quite small and you're approaching them very quickly.
I'm not going to do that math now but I suspect the ship won't need any additional laser weapons. Anyone foolish enough to approach it can have their individual atoms blown into plasma just by being scanned.
[Answer]
Just because no one else has offered it…
How about using Larry Niven's Slaver Stasis Field. He describes it as a bubble of space/time in which time is effectively stopped. Objects enclosed in the bubble cannot be affected in any way by objects outside.
So, for a long space journey, you just get up to your desired cruising speed and then turn on the field. Your now invulnerable ship barrels forward, along your desired course, crashing through the small stuff and boring through or bouncing off of the bigger stuff. Then, at a pre-designated time (controlled by a glorified egg timer and an accelerometer, both stored outside of the stasis field, in a heavily shielded box), the field turns off, allowing you to "wake up" and see if you are anywhere near where you wanted to go. If not, turn the ship, ramp up the speed and do it all over again.
So my answer to your question, with all credit going to Mr. Niven, is that you don't navigate around the stuff that is in your way. You just plow on through it.
[Answer]
**It is a non-problem.**
If we want to stay within limits of science: **edit: and engineering**
* It will be extremely hard to accelerate to 0.75SL and then decelerate to 0. Fuel would need to be like 99.999% of the weight of the rocket, even with stages. So expect to travel at 5-10% of SL.
* It will be extremely hard to shoot any bullets forward, to destroy any objects, again because of relativistic physics, because they would be moving extremely fast relative to our ship.
* And of course shooting anything forward to destroy obstacles slows you down. Newton's laws apply for relativistic travel too.
The only way to travel within the limits of physics as we know it now is to travel slowly, in multi-generation ship, of some hibernation. At such speed, detecting obstacles is simpler, and you have more time to eliminate them by laser (which has less impact on your forward momentum than shooting a bullet to destroy such object).
Of course it is less fun to travel that slowly.
Another option is to discover new physical approach. Like discontinuous jumps in hyperspace, but those are not within limits of laws of physics.
If you want to stick within laws of physics to solve this - you will not be able to get to such speed, and if you ignore physics, you can hyperjump or tractor-beam obstacles or whatever your imagination wants.
Edit: [numbers provided by relativistic rocket](http://math.ucr.edu/home/baez/physics/Relativity/SR/rocket.html)
* to get to Vega (27 ly) and stop there, we need 57kg of fuel for every kg of payload, using 100% effective engine.
See also <http://en.wikipedia.org/wiki/Space_travel_using_constant_acceleration>
* Soda can is 94% fuel, 6% of construction. Build structures capable to withstand such forces and cary huge amounts of fual is very hard - read [The Tyranny of the Rocket Equation](http://www.nasa.gov/mission_pages/station/expeditions/expedition30/tryanny.html)
That's why I argue **it is not feasible to travel at such speeds** (within limits of physics **and engineering** as we know it today) so you don't need protection for such speeds. And I agree that it is less fun than zoom around like in Hollywood movies. Tough beans.
In other words: **when we will have (now unknown) technology and engineering capable of building such ships, protecting them would be relatively simple task.** That's why I say it is a non-problem.
Edit2:
* if rocket will not carry fuel/reaction mass with it, where it will come from? From empty space? Or it will be powered by magic? Wishful thinking cannot power a space ship.
* Of course shooting at rest and at 0.7c follow the same laws - that what EXACTLY theory of relativity says. Problem is the lead time. At 0.7c, universe looks "[length contracted](http://science.howstuffworks.com/science-vs-myth/everyday-myths/relativity8.htm)" so distant object are closer. And they are coming at you at 0.7c speed, so even if you hit target, you have good chance to get hit by debris, because it is not much time to disperse.
* rifle recoil does not "seems" to slow locomotive because of difference between mass (and inertia) of rifle and train. But Newton's laws still apply, action = reaction force. Anyone who believes that there is no effect on train by shooting rifle from train, cannot expect his opinion about physics be taken seriously.
Physics continues to work, even if some people prefer downvote my answer when I remind them inconvenient facts.
Edit: length contraction - that's cool part about relativity:
* in spaceship: ship length remains same, universe contracts.
* for external observer: distances in universe remain same, ship contracts.
[Answer]
Neither fictional example is "hard SF" which I assume is what the question means by *science based*.
A realistic answer is that objects need to be detected far enough away to do something about it. A real-life magnetic shield works for gas and space dust when facing forward; when decelerating the exhaust will clear your way. Larger items, found by lidar, can be blasted apart or hit by an advance countermeasure bullet. I suppose those should be hit as to throw the debis out of your path. Finally, a static shield will take impacts. This can be your reaction mass store in the form of ice, or a tower of plates with gaps between them to isolate events from the body of the ship.
In short, you have three options: get out of the way, get it out of your way, or take the hit.
[Answer]
Alastair Reynolds had a pretty nice way of dealing with it in his books. If I remember correctly, the ships in his books solved the problem by wrapping the hull in a very thick (I think it was something like hundreds of meters) layer of ice. All small particles would impact the ice without causing any direct damage to the ship itself. It seemed plausible when I read it, but can't really recall all the details.
[Answer]
This very issue has been adressed in Orson Scott Card's series called Ender's Game.
More precisely, we travel into the book called Ender in Exile.
Just to throw a little bit of background: Earth was attacked by an alien race, called the Formics. They had much better technology, etc.
**Warning: some might consider it as a spoiler.**
>
> "All those old vids showing spaceships dodging through asteroid
> clusters — they weren't actually far off. Because when you hit a
> molecule of hydrogen when you're near lightspeed, it releases a huge
> amount of energy. Like hitting a huge rock at a much slower speed.
> Tears you up. Any shielding scheme our ancestors came up with involved
> so much additional mass, or cost so much energy and therefore fuel,
> that it simply wasn't practical. You had so much mass that you
> couldn't carry enough fuel to get anywhere."
>
>
> [...]
>
>
> "So how did we finally solve it?" asked Ender.
>
>
> "Well of course we didn't," said the captain.
>
>
> "The formics did it for us," said the captain with delight. "When they got here, yes, they devastated parts of China and damn near whupped us in the first two wars. But they also taught us. The very fact that they got here told us that it could be done. And then they thoughtfully left behind dozens of working starships for us to study."
>
>
> [...]
>
>
> "Please don't tell me it's an egg," said Ender.
>
>
> The captain chuckled. "Don't tell anybody, but the engines of this
> ship, and all that fuel — they're just for maneuvering near planets
> and moons and such. And getting the ship going. Once we get up to one
> percent of lightspeed, we switch on this baby, and from then on, it's
> just a matter of controlling the intensity and direction."
>
>
> "Of what?"
>
>
> "Of the drive field," said the captain. "It was such an elegant
> solution, but we hadn't even discovered the area of science that would
> have gotten us to this."
>
>
> "And what area is that?"
>
>
> **"Strong force field dynamics," said the captain. "When people speak of
> it, they almost always say that the strong force field breaks apart
> molecules, but that's not the real story. What it really does is
> change the direction of the strong force. Molecules simply can't hold
> together when the nuclei of all the constituent atoms start to prefer
> a particular direction of movement at lightspeed."**
>
>
> Ender knew he was pouring on technical terms, but he was tired of the
> game. "What you're saying is that **the field generated by this device
> takes all the molecules and objects it runs into in the direction of
> movement and uses the nuclear strong force to make them move in a
> uniform direction at lightspeed.**"
>
>
>
[Answer]
I just had a novel idea.
Consider an "erasure channel" in broadcasting data. If you are sending some resource to another star system, break it up into small loads (say, n loads) and add redundancy, launching (n+k) loads.
If this is a seed infrastructure to set up a self-reproducing manufacturing capability, then the parent can continue sending "packets" as it manufactures them.
Some loss in transit is expected. Only n (any n of the set) need arrive safely.
Obvious approach if framed this way. What about people? Well, why aren't we sending information by laser (or whatever) and reconstructing on the other side? Or living as pure software all along.
If it's easier to "sneakernet" than beam a powerful laser, then the information making up the passenger would be treated in the same way, and included in the shipments.
[Answer]
Just make an ice shield in front of the spaceship, in order to absorb impacts.
] |
[Question]
[
This is a rewrite of [this](https://worldbuilding.stackexchange.com/questions/92525/if-an-inventor-discovered-how-to-build-a-teleportation-device-and-used-it-what) question in an attempt to bring it back in topic and avoid the story based objections.
---
Imagine a world like ours but where a temporary portal could be constructed between two different locations allowing people to simply walk between these two places with a single step. The places to be linked could be anywhere on earth. The portal could be switched off and on from either side of the port by its owner. It doesn’t matter how this happens, it is simply something beyond current science that one person has invented or discovered.
If the inventor of such a device was careful that no one saw him use it, but broke laws when he did so, such as failing to get a visa or worse, would it be possible for the police to successfully prosecute him if the device could not be found and he claimed the case against him was preposterous nonsense as he physically could not have been at that location and he had police witnesses who would testify that he was thousands of miles away just a few minutes before the crime (with expert evidence from professional scientists if required who would explain that traveling through a portal to another location was not possible and would break the laws of physics).
This is a legal issue about prosecuting illegal activity when the methods used to commit crimes are way beyond our current scientific understanding.
Arguments about physical aspects of the device or its workings are off topic.
Arguments about Governments acting illegally are off topic.
No doubt this device will be considered to be “magic” but if so it is the only magical element allowed. Answers may be from the perspective of any western jurisdiction.
[Answer]
Imagine the trial in something roughly like a Western legal system:
* Most jurisdictions require proof "beyond reasonable doubt" for a criminal conviction or words to a similar effect (it comes down to the old Roman [in dubio pro reo](https://en.wikipedia.org/wiki/In_dubio_pro_reo)). It is the duty of the prosecution to **prove** what happened. So if the claims of the prosecution require technology beyond what is currently known, it should be *relatively* easy for the defense to knock holes into the theory and to raise reasonable doubts in the mind of the judge and/or jury.
* That being said, the prosecution does not have to demonstrate *every little* step of what happened. There have been murder convictions without the [body of the victim](https://en.wikipedia.org/wiki/Murder_conviction_without_a_body). So there might be convictions e.g. of theft if the inventor left DNA traces in a locked vault where he should not have been, ever.
* Of course an alibi would be a powerful defense, but not foolproof. The prosecution would not have to prove when the inventor broke into the bank vault.
*"Ladies and gentlemen of the jury, we have shown that somebody who looks like the defendant was in the vault in LA. The DNA traces match. We have no idea how the defendant traveled to Paris afterwards, but we are not charging him with any traffic offenses, speeding, or immigration violations. We are charging him with theft, and you must convict him on that count."*
*"Ladies and gentlemen of the jury, the prosecution suggests that the defendant was in LA sometime during the night from Thursday to Friday. We have shown that has been in Paris on Friday morning. There is no plane in passenger service today to make that possible, and the prosecution has proposed no other explanation how he traveled that fast. Surely you don't think he has a Concorde stashed away on some private airfield."*
If the jury and judge are reasonable, the prosecution would have a hard time to overcome the alibi. But it might have equally strong evidence the other way.
[Answer]
If there's enough evidence of wrongdoing, of course it would be possible to prosecute, it would just be a long process - but also, I assume this teleporting person isn't just shoplifting, but is in fact breaking major laws. I say this because a years long investigation into a rash of shoplifting incidents doesn't seem realistic. Even with major crimes, this person would have to be committing them over and over in places extremely far apart (which seems like a massive lack of awareness on the part of this criminal)
First, we'd have to know the suspect is committing crimes. We'd have to have some kind of evidence that it was this portal user. Eyewitness accounts, video footage, you name it. Unless this portal system is invisible to camera and to the naked eye, both of these would probably result in the witness or viewer of the camera footage saying that this person's method of travel was some kind of portal, or some form of teleportation. Whether that gets believed immediately, especially from an eyewitness, is a different story.
With the suspect identified, it's up to investigators to find and present evidence of the fact that the teleporting suspect committed the crime and has the means to teleport. Police would also have to find a way to bring the suspect into custody in a way that mitigates their teleporting, since it goes without saying that they are nearly impossible to contain while still able to use the technology.
With all of that in place, a court case only needs evidence compelling enough to convince a jury.
**Alternatively**
Let's assume the teleporting criminal is smart and doesn't have the cliché character flaw of being oblivious to the implication of being over 200 miles apart on camera within a matter of 15 minutes. They travel disguised, make sure to come and go in places where there are as few witnesses as possible, commit their crime cleanly and efficiently, and in general leave as little proof as possible...
At that point, I think the odds of successful prosecution are slim to none. Various areas in the world would have different accounts, eyewitnesses would be describing a different perpetrator (as would video footage), and if the teleportation was done away from as many people and cameras as possible, the act itself would never be seen. After long enough, if enough eyewitnesses in enough places say they're seeing the perpetrator literally disappear, it *might* be a detail of interest to police. This person would probably remain an uncaught criminal for the duration of their life thanks to this technology, and until it becomes publicly available (or at least more widely known), no one would know to suspect it.
Think about missing persons like D.B. Cooper or unsolved cases like the Zodiac Killer - even without crazy teleporting technology, they got away. All it takes is covering your tracks.
[Answer]
This trial is not too different from real trials. It ultimately will become a battle of evidence. Prosecution has evidence suggesting that the perpetrator committed the crime, the defense has evidence suggesting that he couldn't, because he could not physically be present. The strategy at trial from each side will be about convincing the jury that the evidence and story presented by the other side does not represent what actually happened. This is what actually happens in trials in real life. Each side may have what it considers to be definitive proof, but in reality, it comes down to how much weight the jury members attach to each testimony, witness, and exhibit.
There was wisdom in the construction of our judicial system that required the convincing of a jury of peers. Outside of the mathematical realm, there exists no objective standard of proof. As such, our system challenges the prosecutor of proving, beyond a reasonable doubt for criminal cases, to the jury the details of his case. Each person of the jury has their own internal standards of proof, and it is the goal of the prosecutor to select a favorable jury and then convince them of his case. Alternatively, it is the goal of the defense to also select a favorable jury, and then to obfuscate or disprove the case. I would challenge you to find a type of evidence that is above reproach. Pictures and videos can be faked, witnesses are unreliable and can fall apart under cross examination, and physical evidence can be contaminated, the chain of custody called into question, or the conclusions of the experts challenged.
The fact that the potential defendant can manufacture, at the time of the crime, seemingly exonerating evidence gives him a tremendous advantage, but it makes him nowhere near invincible. Jurors can choose to ignore evidence, there may be enough evidence on the prosecutors side that they are convinced "beyond a reasonable doubt" to ignore the exculpatory evidence. Additionally, the jurors may not make decisions that are entirely cerebral. They make make decisions based upon emotions and intuition.
It is my estimation that this guy will ultimately get caught. He may be able to buy a few passes with his exculpatory evidence, but if he continues in his life of crime, he will ultimately get stuck. That type of life changes a persons psyche, and most other humans will pick up on those danger queues and intuit the correct decision in opposition to what may be exonerating evidence.
[Answer]
If he is that careful, how does the government know who committed the crimes or (in the case of visa violation, that a crime was committed)?
There would be no prosecution because they wouldn't even be looking at him as a suspect.
Now, if the bank had whole stacks of serialized currency and he started spending that currency. It could be traced back to him and he could be charged with a number of offenses from receiving stolen goods (good luck explaining how you got the money) to money laundering.
If he starts selling a bunch of gold bars or other artifacts in a big way, people will wonder where he got them. If he doesn't have a good answer, he may be treated as if he was selling stolen goods.
If some of the people he takes on trips start talking about it, there is witness evidence. The government may then try to infiltrate one of the trips with tracking and recording equipment. All of that is legal to do. All they have to do is record a crime that he or one of his other passengers commit to get him with aiding and abetting.
[Answer]
I think the answer to this might be relatively simple. Even though they might not completely or at all understand how he managed to leap from one place to another with a portal, the most important thing is prove beyond reasonable doubt that he's capable of doing so and that he actually did it to facilitate his crimes. Then there is the fact other physical evidence might be left behind like shoe prints or even the purp's DNA. If someone manages to teleport, it can be forensically proven without too much of an issue except of course the question how he did it, but they can determine he did even though unaware of the method through circumstantial evidence.
This becomes stronger the more cases are stacked against the purp with the same M.O. If a lot of evidence is stacked up that the purp indeed is able to travel huge distances in unreasonably short times, it changes from unreasonable to plausible.
If for example, the purp lives in LA, is spotted on a traffic cam, goes to new york to kill someone and gets spotted there on a traffic cam and then an hour later gets spotted in LA again, if it's a single incident people will be baffled. If it happens consistently people will investigate and draw the conclusion of teleportation. This is a somewhat simplified concept but it works in a general sense.
[Answer]
In all honesty, this case is likely to not even reach the level of prosecution. If there is evidence to suggest he was no where near the scene of the crime during the time of the crime, then it's likely the prosecutor will call the evidence placing the man at the scene of the crime into question. No good prosecutor moves on evidence they feel is not enough to merit "Beyond a reasonable doubt" needed for conviction. The fact that all evidence collected from the crime scene suggests this man is our guy is still called into doubt by the fact that the man was no where near the scene when it happened is a huge doubt, especially if there is evidence to suggest that he was out of the area at the time.
Assuming the government is not corrupt (the prosecutor recognizes the doubt) and assuming the only person aware of this ability is the accused, then the explanation of "teleportation" is an unreasonable doubt. The prosecution cannot make the assertion that the man did it by teleportation in a jury system without one of 12 people saying "Really... you want me to believe /that/." Proprietorial discretion demands that until evidence of teleportation becomes a demonstrable scientific reality, that can be explained by someone other than the accused (who cannot be compelled to testify on his work) the reasonable Prosecutor will likely never charge the man with a crime in the first place.
[Answer]
If the inventor steals something in the US and returns to say Paris and then makes sure they get a valid alibi with lots of witnesses they would be excluded very early on in any investigation.
It would have to be a very skeptical/determined detective looking over a long history of repeated cases that would ever get this to court.
So the assumption that this would be even be in court means that the inventor has made some big mistake.
Here's a couple ways they could get caught:
1. (as others have said) If they are caught with whatever is stolen - but they would only be charged with handling stolen property, not doing the stealing
2. If they got caught before transporting back
3. Video evidence of the transport, you see the inventor disappear from one camera **and** appear in another camera at the same time (but this wouldn't happen if as in the question the police could never find the transport)
But none of those is due to the transportation itself, just to the inventor making a separate mistake.
There's reasonable precautions that the inventor can take:
1. Only teleport to countries where they've never travelled to through regular means - so it's easy to show you've never been there
2. Be careful with DNA evidence. I guess this means having some clean room to transport from.
3. Any other precautions that people take who regularly steal things do - so steal in very separate locations so that they don't get linked together
4. Don't do this too often
So having the teleporter makes crime much easier, but criminals get caught in many other ways - Al Capone for example.
[Answer]
1. **He is going to get caught, and likely sooner rather than later.**
If he's invented a personal teleportation device and the best use he can come up with is petty larceny for self-enrichment, I'm not going to credit him with a surfeit of imagination, restraint *or* common sense.
Taking that into account, he's going to make mistakes and get blatant -- and the thing is, when you rob a bank the bank's owners will *very badly* want to know how precisely you pulled it off, because that will make it much easier to promise their clients and shareholders that it won't happen again. And so will the security company that serviced that bank. And the insurance agency that insured that bank against disasters like that. And so on...
*All* of the above will be looking very hard because if they answer "I have no idea" then they'll be the ones on the block when someone calls for heads to roll after a disaster like this. Between each other they will eliminate pretty much every alternative -- no one was bribed, none of the physical security measures were disabled, the vault's seals were not breached -- until the only possible remaining answer is that, regardless of how crazy it sounds, "Someone teleported into the vault, stuffed his pockets, and teleported out".
So when, later on, someone on another continent who happens to match the security footage of the robber but has never been out of the country, is found spending money matching the number sequences of the stolen bills, Occam's razor applies, especially if he decided to pull this stunt more than once. Clearly it's possible as it has been *done*. All the evidence points to him. The prosecution rests.
2. **Professional scientists as expert witnesses will not help his case.**
Because every testimony they give about how it's impossible will include the phrase "as far as we currently know". Science is a moving target. Good scientists *always* grok that there's more to learn. If they see the impossible happen, then clearly it wasn't as impossible as they thought and the proper thing to do is start figuring out what they've overlooked so far.
(This is also why I politely called him an idiot in the prior point: Whichever scientist first figures out how he's doing it and reproduces the process will likely go on to win the Nobel Prize and go down in history as the person who revolutionized particle physics and opened up an entirely new field or two, while your hero gets to serve multiple consecutive prison sentences for everything from grand theft to tresspassing to crossing international borders without a visa.)
3. **Stealing stuff is only the start of his problems.**
What did he steal? If it was just money, see the above problem with known bill sequences. If it was other objects of value, he's going to have to fence them somehow. When did this genius scientist first learn the identity of someone willing to fence, say, the Hope Diamond? More importantly, criminals tend not to be terribly trustworthy and even *more* inclined to act illegally given sufficient inducements than governments. He's not known as a master thief before this, and heists like the ones he's pulling will get a lot of media attention. Someone is going to decide they want to know how he does it (and maybe extend a job offer he won't be allowed to refuse) and they'll have a word with every fence in the area...
[Answer]
The question seems to be: can the trial proceed? Answer: sure! People get tried for actions "beyond current understanding" every day.
Any patent law case, computer fraud, securities fraud, industrial liability, really any highly-technical crime is going to consist of actions that the average cop, the average time-constrained judge, and the average high-school-diploma juror, just will not even attempt to understand.
They'll muddle through. I make no claim about whether they get the right answer, but the resulting decision will have the same legal authority as the ones for the simple cases.
[Answer]
## It would not be possible to prove he teleported.
Provided that 1) no one caught him doing it, 2) no one found his device, and 3) no one else has ever done it or thinks it's remotely possible.
Given our current understanding of physics, the odds of creating a teleportation device are so small as to be essentially zero. When the odds of an explanation are that small, *any* other explanation is more likely, no matter how strained. Modified footage. Contaminated DNA samples. Bribed or brainwashed witnesses. Secret identical twin. Doesn't matter--any of those is more plausible than teleportation. You may find some jurors who would be willing to speculate about it, but once a competent defense attorney gets through with them, I doubt you could get all twelve of them to accept it as fact.
## But it *might* be possible to convict him of the crime.
The problem is that seemingly contradictory evidence goes both ways. The same guy was seen in New York and Los Angeles? One of them must have been someone else. But which one? If our suspect's fingerprints and DNA are found in the bank vault, *and* he's suddenly flush with cash and spending bills with serial numbers matching the stolen ones, then it sure looks like he did the crime and his alibi was a setup. At the very least, he and his secret twin plotted the crime together.
On the other hand, there might be scenarios where you couldn't prove that he committed the crime. For instance, suppose our suspect was already in prison on an unrelated charge. The guards are positive that he's never escaped, and that it's been the same guy the whole time. They saw him in his cell at 10:00 and again at 10:30. The crime in a distant city was committed at 10:15. In this case, the jury has to weigh which of these is more likely:
1. The suspect was in prison the whole time and is not guilty of this crime. Someone else committed it and either looks like him (down to similar fingerprints and DNA if necessary) or was trying to frame him for the crime.
2. The suspect switched places with his secret identical twin, without the prison staff realizing it, committed the crime, and switched back.
3. The suspect used a secret teleportation device.
I know which one I would pick.
[Answer]
## Contradictory evidence is nothing new
It does happen all the time. For one thing, defense tries really hard to introduce evidence which contradicts prosecution, to muddy the wayer. Also Rashomon effect, or carefully fabricated evidence, or honest misunderstanding. Juries take the pile and try to sort it out.
## If they gotcha, they gotcha
That's what physical custody and all those biometrics are all about. They don't want you slipping off with a claim if "mistaken identity" at trial. You'd have to show you have different height, face, eye color, fingerprints, retina, or DNA than the guy they collared and booked.
So you have evidence that a guy who looks like you was in L.A. an hour before. It wouldn't matter if a guy with your fingerprints and DNA was sampled in L.A. an hour before. They got you.
## Nobody cares what the method is.
People get convicted of murder all the time without a body. Nobody cares whether they burned the body, buried at sea, dissolved in acid Heisenberg style, or they teleported to the Tunisian desert, Asgard, Earth-43717, forward or back in time, or something weirder.
All that matters is that person is GONE, which for a child or person with community ties means "murdered" in almost every case. If a search for reasons revealed that you had means, motive and opportunity... you're going down.
## Method isn't a defense, either
They will go with evidence in front of their eyes over evidence that is more foreign or less certain.
So your "can't be me, I was in L.A. an hour before" falls apart if they have evidence that you were also here. They will never rely on LAPD's evidence over their own.
[Answer]
## Would it be possible to prosecute him?
Depends.
If he gets caught redhanded or with evidence or simply testifies, a contemporary legal system should be able to prosecute him (unless he gets sent to a psychiatry in case of testimony), nothing simpler than that.
However, depending on the nature of his "legal adventures", it might even be possible to prosecute him in certain cases even without direct evidence. All it needs is a single failure (slip of tongue, lost personal artifact, an introduction too much) or a very convincing correlation of data points (granted, this would require a very thorough amount of research on at least a large subset of cases).
Some crimes, like having no valid visa, would require special circumstances to be revealed. It basically means he has to get into a situation where he is unable to procure a valid visa, like getting caught in a traffic accident and being questioned by the police. Or he could have a (public or recorded) personal meeting after which the government could research that he has no visa and there are no recorded border crossings of him (ouch!).
Other crimes, like robbing a bank, especially if done repeatedly, might be possible in case there is any indication of his involvement. A single DNA trace or fingerprint would not be enough, but both of that and his figure being similar to the one on camera might get him at least an interview. If done multiple times, even if he has some alibi for each occurrence and he doesn't get caught with other evidence, there might still be a correlation between his crimes and him (like: he has been at the banks 2 weeks in advance to scout them, or the only banks to get robbed are the ones he has no account, or ...). If the correlation is strong enough, it might be enough to prosecute him even despite his alibis.
What can make his prosecution easier is if he somehow reveals his ability to teleport (e.g. appearing inside a bank lobby without any trace of how he got there or left afterwards). If the investigators somehow become aware of that tidbit, they will scrutinize their findings much harder for indirect evidence (like pollen in the air from where he teleported), and any possible alibi will loose credibility if he can't validate he's there in person.
Of course, there's always a chance his alibi might disproved anyways (e.g. "I went shopping at XY at 21:10 and after that I was walking to Z where I arrived at 21:40, where the distance between those to locations would take 30 mins of walking" could fail if he managed to miss an event on that route, like getting recorded on a camera).
However, ideally he would want to avoid any action that would even cause the prosecutors to even look after him. If he only robs banks half a globe away while never being even in the same or neighboring countries, always with explanations for how he got in and out, it would be hard to even fall under the radar of the responsible detectives. After all, international crime investigation would require a high degree of cooperation between the countries involved...
TLDR: If he is smart about his crime(s) and target selection and doesn't slip up during the execution, it would be very difficult to prosecute him. However, tiny slip ups during execution or "dumb" crime(s)/targets can lead to a prosecution.
[Answer]
I would think they have every chance of being found not guilty provided they could establish a strong 'practical' alibi -
1. They were having lunch with a notable figure in front of witnesses
(the more the better);
2. They went to the lavatory for 5 minutes. During this time they established the portal, carried out the crime a substantial distance away, and by substantial I mean a distance that could not be covered by any 'known' transportation method in that time and returned;
3. They gave no indication of having carried out the crime when they return to the previous engagement.
Evidence for the prosecution is likely to be in the form of witnesses, DNA or fingerprints all of which have a probability of error that can be argued to apply in this case.
Where they could be found guilty is if they have evidence on them that can only have come from the crime scene.
[Answer]
I will try to draw together the best answers as I see it from the posts made to date.
The main barriers facing the authorities would be detection, capture and conviction. The fact that teleportation is so unlikely would at least seriously hamper each of these.
Two very important aspects that need to be clarified are the ability of the Teleporter and the seriousness / regularity of the crimes.
**Petty crimes**
Assuming the crimes are petty such as avoiding immigration controls or small scale theft, there is little or no chance that the Teleporter would ever be caught out side of the most serious blunders on his part (see below).
**Major crimes**
Assuming his crimes are major like rape, murder and grand larceny and are carried out on a regular basis, then the situation might be different. Given the enormity of the discovery of teleportation and the imbecilic use that he is making of it, it is reasonable to suppose that although he might be a genius, he also has serious mental deficiencies and might be expected to lack common sense, restraint and be generally careless. In this case there is a chance that he would eventually be detected and caught. Serious blunders might include:
**Indirect prosecution**
Stealing traceable property such as paintings, new bank notes, high value gem stones or similar. In these cases the teleportation would be immaterial as he would eventually stand trial for handling stolen goods rather than stealing the goods and would have difficulty in explaining how the goods had come into his possession.
**Capture and prosecution by reason of teleportation failure**
He might foolishly visit the same location repeatedly and be caught red handed before he could teleport. Or he might carelessly wander too far from the device only to find that it had been stolen or damaged while he was away or he might be unable to reach it if he was injured in car accident (for instance). In these cases he would also likely be prosecuted as the teleportation device is again irrelevant.
**Capture and prosecution by aided by notoriety**
He might simply be so careless that even if he can’t be caught he accidentally gives away his secret. After enough people and news teams have captured footage of his teleportation “trick” there would be a media sensation and his notoriety would be such that he would eventually be identified.
Having been identified he will either have to go on the run or stand trial. This is perhaps the hardest case and the most interesting one. If he stands trial then it is likely there would be conflicting evidence, however because of his notoriety (as the vanishing man or whatever) he might find it hard to get people to vouch for his being at a locality and any jury might be more willing to reject any claims based on sightings given the strength of the other evidence.
**Going on the run**
If he went on the run he would have access to anywhere on earth in seconds so might escape capture for some time, but would eventually fall foul of the teleportation failure case as described above and would be convicted.
**Government involvement**
Initially any Government would be dismissive, but at some point the level of his notoriety would reach a level sufficient to trigger alarm bells and National Security fears. At such a point the Government would be forced to take action. They might just assassinate him (out of scope) or try to capture him to learn his secrets which would happen faster with coordinated Government action and faster again if he had a criminal record already. When he was caught the Government would have serious issues to consider in terms of how to proceed. They would want to obtain the device and understand how it worked. But they might also be concerned that he was working for a foreign Government or had an accomplice. Such a situation would complicate matters further as it might prover impossible to hold him in any prison if a third party could open a portal into his prison cell and release him.
**The evil genius with restraint and common sense**
Assuming he did have common sense, restraint and was very careful, but still insisted on committing serious crimes (highly unlikely as described above), it would be very difficult or impossible to stop him, catch him or successfully convict him. He would always avoid repeat visits, would always take precautions concerning an alibi, would go in different disguises, would avoid leaving finger prints or DNA and would teleport to selected locations that minimised the risk of capture by reason of teleportation failure.
There are many other potential situations involving various combinations and degrees of motivation and evidence. The outcomes would be even harder to distinguish and even more open to opinion based answers.
] |
[Question]
[
A mutant who sees multiple futures has predicted that the world will be invaded by aliens. Every future ends disastrously for the human race with us being wiped out. The only one in which we survive is one in which the American mob retains its power into the modern age and plays a vital role in our survival, and determines that the criminal organization is somehow the only hope of our species.
Unfortunately, the mob is on the decline. The useless degenerate John Gotti, along with the RICO statutes and other missteps, have led to the loss of much of its power. The time traveler decides to send a criminal known as Sylar back to the early 1960's where the mob in NYC was in its heyday, and gives him one single mission:
>
> Save the mafia, save the world
>
>
>
Sylar arrives back in time, but is unable to divulge what he knows about the future. He ruthlessly rises to the top of the Gambino crime family and becomes the most powerful mob boss in America. He then eliminates all the people who would be instrumental in the organization's downfall (John Gotti, Rudy Guiliani, Donnie Brasco, etc). However, he realizes that killing people would be curing the symptoms of a disease rather than getting at the root of the problems. These people can simply be replaced by others in history, leading to the same situation the mob faces in the future. What can he do to ensure the secret society that the mafia has built and prepare them for the future to ensure survival?
[Answer]
**Hard Drugs Never Hit the Streets**
The beginning of the end for the mafia was when drugs came involved in mafia business. The mafia made a pretty tidy racket doing some rather laughably mundane things prior to the hard drug trade. One such racket was stealing tanker trucks full of gas and using them to refill mafia owned gas stations. The gas stations would sell the gasoline without having to pay the taxes or purchase the gasoline. Rackets like this would bring in anywhere from \$15,000-\$20,000 a month. That's good money, but it's not "beat somebody to death with a baseball bat and ditch their corpse in the harbor" levels of income. People usually don't start committing heinous impossible to ignore crimes like torture followed by murder and mutilation over numbers like that.
Once drugs became the mainstay of mafia income you're talking about street level goons suddenly running drug rings that are cranking out a million and a half a month. The mafia wasn't ever really comprised of sophisticated people, they were largely uneducated and their scope of reach wasn't really all that great. They tended to for the most part be dumb thugs who might rough you up but rarely killed and usually had to watch their backs because johnny law would get interested in too many corpses started turning up. Once the mafia really became too successful due to drugs is when you saw massive infighting and a lot higher level of violence on the streets. This ties in with something else as well.
**The War on Drugs Never Happened**
Today we simply take it for-granted that entire swathes of the city are junkie riddled virtual no-go zones. It really wasn't always the case. When honest to god hard drugs like crack and heroin started hitting the streets it hit the lowest common denominator of every city like a figurative nuke. Massive crime waves, massive social decay, it terrified people. Street level meat heads could suddenly make enough to switch out their crappy .32 autos and .38 special revolvers for Uzis and street sweeper shotguns. Guys with switch blades who would have been content to just stick you up for your wallet were suddenly hooked on crack and shooting up the corner store with 1911's and Berettas to get their money for their fix. Lawlessness had always existed on some level, but hard core drugs hitting the streets changed things pretty radically. The war on drugs was a knee jerk reaction to this wave of violence and crime that was threatening to overtake our cities.
One of the biggest death knells to the Mafia rose out of the War on Drugs. Mandatory Minimum Sentencing. Believe it or not there was a time in our history not too long ago when getting caught committing various felonies only netted you 3 to 4 years in the clink. You could get caught with a bunch of stolen goods, or illegal weapons, or hard drugs, or even murder and not actually get all that much time in prison for it. The new much harsher sentences created by Mandatory Minimum Sentencing meant that once a made man was nabbed by the cops he might be taken off the streets for decades. This really harmed to mafia's ability to maintain and pass on power. Previously getting arrested was just an inconvenience, albeit a major one. Now it was a career ending event.
What's more, when the big Dons started getting locked up by these new harsher sentences the guys who replaced them were not very smart. The real dons were replaced by street thugs in fancy suits. When you give a guy whose job qualifications are "breaks kneecaps real good" and "scares store owners into paying their protection payment without a fight" several million dollars and the reins to a few hundred guys just like him things get... messy. Once the officers and bosses got locked up and the soldiers started running things is when the crazy over the top violence and endless cycle of back stabbings happened. You can't run an organized criminal enterprise that violently and get away with it for long. Thanks to mandatory sentencing decapitating their actually qualified leadership they started killing each other over the drug money they were making like feral dogs fighting over a steak, or got arrested for multi decade long sentences.
**This Means That The Police Never Militarized**
Again, up until very recently in police history the cops weren't really very well armed. They didn't need to be. A .38 special K-frame revolver is more than enough to handle some punk with a switchblade or a .25 auto pocket pistol. Today, modern police are basically a military organization complete with huge budgets, machine guns, hard core organization, and nation wide data (intelligence) sharing and collecting. This largely happened in response to the crime waves sparked by hard drugs hitting our streets, which largely happened because the mafia realized they could really make a ton of money selling the hard stuff and started the first major drug smuggling operations on our shores.
More devastating to the Mafia than cops with bigger guns, was the addition of military level surveillance tools to the police's arsenal. The various espionage gadgets that police got a hold of really were nothing the mafia had ever seen before. They knew about wiretapping, but had no idea about remote surveillance like hidden cameras, bugs, worn wires etc etc. They really had no idea how to deal with it. Quite a few mafia higher ups got blindsided by the police using tools that had formerly been only available to the CIA. In addition to this, departments began connecting more and more. Moving around wasn't protection anymore since with the click of a mouse every last detail down to your fingerprints could be available to every cop in the USA. These tools introduced to the police alongside the rest of the revamp the police got as part of the war on drugs really tore through the mafia something fierce.
**Summary**
I think that if somehow the hard drug pandemic that swept our cities never happened and the mafia never got in on it they would till be stealing gasoline tankers and shaking down business owners for protection money. The drugs made the mafia too much money, which made them too aggressive and too high visibility, which made them rather deserving scapegoats for the pandemic levels of street violence and crime that resulted from their drug trade. No hard drugs hitting the streets, no massive crime wave, and no draconian new sentencing laws and militant police to deal with. In addition to this, the 4 decade long morality crusade of "tough on crime!!!" wouldn't have placed the mafia directly in the cross-hairs as the (mostly rightful) scapegoats for the chaos overtaking the cities. The mafia see the hard drugs coming into their neighborhoods, but in this alternate timeline they resist the urges of greed and decide that crack and heroin cause too much damage to their community. Obviously if this stuff gets out of hand the police are going to go ballistic and become VERY bad for business. The mafia begin very strongly opposing the influx of hard drugs and a quiet and unofficial alliance develops between them and the cops. They keep selling TV's and VCR's that "fell off the back of the truck" and the cops don't notice as long as they keep putting the cops onto incoming drug shipments. The massive crime waves of the 80's never develop as hard dope remains a rather fringe thing that is hard to get a hold of (and VERY bad for your health to be caught selling.)
[Answer]
He knows the future. He knows that real money/power comes from technology. He needs technology for the future invasion.
So... he educates the mob's children. Send them to college/university. Have them study in economics, chemistry, physics, law. Have them become doctors and engineers. After graduation, establish companies, research centers, law firms, shipping companies etc
Buyout all, to create the first mega-corporation, a multi-billion international one.
Invest in researching new drugs, new weapons, whatever you will need to fight the aliens.
The old Mafia will continue its traditional methods, until the fathers die.
The new Mafia (their children) will become "modernized" - electronic espionage, hackers, R&D of high tech, drug testing, ... whatever you want/need.
[Answer]
**Short answer: Bring the mafia into the political / governmental sphere**
The destruction of the Mafia was due to a variety of factors including:
* New laws that dismantled corrupt organizations (RICO)
* Edgar Hoover's FBI focused more on mafia crime as it was exposed
* Italian immigrants began to have more job opportunity outside of direct crime
* Culture began to change among young men, especially in terms of independence from parental roles.
Luckily there's still hope for the mob!
This movement really only started after an exposed mafia operation in 1957, which gives the mafia plenty of time to snake their way up into political spheres. The mob could adopt a role similar to Pablo Escobar and weave their way into government itself.
This circumvents issues that could arise from incorruptible members of government (as you are the government), pressure from the FBI, and easily results in quicker and more efficient cover ups to large scale exposure.
Eventually, those politicians could have children, who, similar to today's politicians, follow the family up the chain of command (imagine George Bush Sr. and George W Bush).
As long as the FBI stays either unaware of the mafia's ever-encroaching control or stays pocketed in the control of a mafia member themselves few laws would pass, there would be less investigation, and the culture would become far more sustainable.
[Answer]
**Just to make a point...**
Who says the mafia isn't alive and well in NY?
* The politicians? Getting elected means showing results, but it's also expensive.
* The attorneys? They've been on the take forever.
* The cops? Some die-hard "we gotta clean everything up" types might exist, but most would be happy just dealing with gas station burglaries.
So, who says the mob didn't go underground (like the Illuminati...) decades ago? Which leads to the only actual viable solution: they go underground.
**I'm not purporting an actual conspiracy (maybe...)**
But until someone can show me that racketeering, drugs, prostitution, corruption, greed, unions, etc. are gone in NYC, there isn't any actual proof that the Mafia is gone. They're just no longer *visible.* They offered up some sacrifices to calm the population (you know... John Gotti, Rudy Guiliani, Donnie Brasco... you know their estates are really *wealthy,* right? Ever wonder why that still is?) but in the end, they're secretly still very much relevant and very much in power.
Frankly, retaining power is easy. Make sure the concrete is good quality... Make sure the right palms are well greased... Stop whacking people in public (better still, clean up after yourself)... And you have all the power you want.
*Who knew that the Mafia would someday become truly organized?*
**TL;DR**
Organized crime exists all over the world. Some of it is overt. Some of it is covert. Some of it is the clowns in Congress. My point is, the Mafia need only go underground, removing itself from the public's eye, and they'd quickly be forgotten while retaining their power base.
[Answer]
Go watch *Wise Guys*. The real reasons the Mob collapsed were illegal drugs and the declining power of the unions.
1. The old timers knew that drug dealing was a bad idea, but there was/is soooo much money to be made that there's no way you can stop aggressive young members from getting into that line of business, since if the Mafia doesn't, other gangs will.
2. Unions became arrogant, and ovegrabbed for power and wages and stifling work rules, which collapsed when -- along with the two oil crises and environmental legislation -- the Far East finally recovered after WW2 and became the go-to place low-cost, good quality manufacturing.
## So...
1. Prevent illegal drugs like marijuana, heroin and LSD from becoming popular in the 1960s. (Demand reduction is the only feasible method, but *how*?)
2. Convince unions and employers to move to the [German Model](https://en.wikipedia.org/wiki/German_model) of industrial relations.
3. Point out to the relevant parties of the threat from Japan and the [Four Asian Tigers](https://en.wikipedia.org/wiki/Four_Asian_Tigers) as the need to keep wages moderate and quality up, while not killing those economies, since you don't want their economies collapsing, either and them becoming Communist.
4. Solve the Palestinian Problem before the 1973 Yom Kippur War and the resulting OPEC oil shock. (My personal favorite is to have let the Six Day War play to the end and one side actually *beat* the other. It would have necessitate convincing the Russians to not directly intervene.)
Good luck changing the country in such deep and radical ways!
] |
[Question]
[
As stated in the topic: I would like to have [Project Olympus](https://www.wired.com/2013/09/project-olympus-1962/)-style space stations served by Apollo-like spacecraft in a world where neither nuclear power (and weapons) nor transistors were developed into actually workable devices.
My problem is: where to set the Point Of Divergence for alternate history of physics in order to achieve this?
Unfortunately, [taking out Einstein does not seem to make a trick](https://gizmodo.com/if-einstein-had-never-been-born-would-we-still-have-nu-1597200914). My bet for now is to stuck physics in [ultraviolet catastrophe](https://en.wikipedia.org/wiki/Ultraviolet_catastrophe) with nobody coming up with the idea of energy packets known as "quanta". Is it sufficient? How the science would develop in such alternate timeline?
[Answer]
**Move the space race earlier. 1931.**
There are not transistors or nuclear power because neither has been developed. But space is in reach.
[](https://i.stack.imgur.com/liLVq.jpg)
from <http://www.computerhistory.org/revolution/calculators/1/44/157>
1925: The Treaty of Versailles is enforced, and German re-armament does not happen. The Germans are, however, recognized to be masters of technology and innovation and their European adversaries allow this aspect of the German economy to flourish. Seeking an outlet for feelings of nationalist competition but with military competition out of reach the Germans turn to space, just as similar factors would produce the space race in our timeline - except thirty years and a devastating war later.
Without the prospect of war, the efforts of rocketry pioneer Hermann Oberth are undistracted and backed by the full power of a resurgent German state with something to prove.
<https://en.wikipedia.org/wiki/Hermann_Oberth>
>
> In the autumn of 1929, Oberth conducted a static firing of his first
> liquid-fueled rocket motor, which he named the Kegeldüse. The engine
> was built by Klaus Riedel in a workshop space provided by the Reich
> Institution of Chemical Technology, and although it lacked a cooling
> system, it did run briefly.[13] He was helped in this experiment by an
> 18-year-old student Wernher von Braun.
>
>
>
Two years later in 1931 and 10 years ahead of schedule, what in our timeline was called the [V2 rocket](https://en.wikipedia.org/wiki/V-2_rocket) reached the edge of space, and later than same year a rocket based on these principles put the first artificial satellite in orbit.
<http://www.bbc.com/future/story/20140905-the-nazis-space-age-rocket>
[](https://i.stack.imgur.com/I31dQ.jpg)
Western Europe (with the belated assistance of the US) rushes to keep up with the Germans while at the same time keeping a thumb on the scale in the form of monitoring for "treaty violations". The Soviets foray into this competition in their own fashion. Both of these parties are uncrushed by war and so resource and energy rich although neither has the benefit of the captured German rocket scientists who would lead the space race in our timeline.
None of this requires nuclear power or transistors. If the space race is the war that happens instead of WW2 - a war of technological prowess and bragging rights - there is not a need for weapons of tremendous destructive power.
But this space race is not just for bragging rights: it is actually a race to Mars. In this timeline observations around the turn of the century showed that although no atmosphere of significance is now present, there was very likely intelligent life on Mars at some point in the past. The first colonists on Mars can claim the planet for their side, and alien technology, if present, could be a game changer as regards the world balance of power.
[Answer]
In our history, the idea of spaceflight was pretty well established as far back as Voltaire ([*Micromégas*, 1752](https://infogalactic.com/info/Microm%C3%A9gas)) and Jules Verne did many of the numerical calculations to get a good ballpark as to what was expected in his 1865 novel [*From the Earth to the Moon*](https://infogalactic.com/info/From_the_Earth_to_the_Moon). Edwin Everett Hale published another science fiction story [*The Brick Moon*](https://infogalactic.com/info/The_Brick_Moon) in 1869, concerning the launching of an artificial satellite.
So in a real sense, people were already primed to go into space long before the discovery of nuclear energy or electronic computers. (Sadly for your scenario, [Charles Babbage](https://infogalactic.com/info/Charles_Babbage) published a paper proposing a mechanical calculator on 14 June 1822, which led to the [Difference Engine](https://infogalactic.com/info/Difference_engine) and eventually the conceptual [Analytical Engine](https://infogalactic.com/info/Analytical_Engine), which is considered the precursor to all programmable computers).
The only thing lacking was technology to actually do the deed (the Difference Engine was actually doable with the technology of the day, but Babbage was a horrible project manager, the method of getting into space was the issue), but even here, help is on the way in the form of [Konstantin Tsiolkovsky](https://infogalactic.com/info/Konstantin_Tsiolkovsky), the visionary Russian schoolteacher who laid down the theoretical foundations of rocketry in 1896. He also did a great deal of theoretical work on the practical issues of spaceflight, such as this sketch of a rocket powered spaceship:
[](https://i.stack.imgur.com/gDzaY.jpg)
*Tsiolkovsky anticipated things like reaction wheels, and clearly understood the concept of free-fall*
So now the contrafactual:
Konstantin Tsiolkovsky had been in contact with various authorities in Russia with various proposals like metal airships and monoplane aircraft, but unlike OTL, his proposals were received with enthusiasm. Russia was in a difficult situation, having a very anemic economy, outdated industry and a very outmoded aristocratic form of government. The aristocracy could see that there was great danger both within (internal rebellions) and without (European Empires ready and willing to pounce on any perceived weaknesses). Having advanced aircraft and now rockets would allow the Russian Empire to leapfrog past the British, French, Germans, Austro-Hungarians and even those upstart Americans, and avoid the fate of the Chinese, whose empire was being divided among the various Imperial Great Powers of the age.
[](https://i.stack.imgur.com/gu89E.jpg)
*Model of Tsiolkovsky's spaceship*
While the Russian Empire can throw massive resources and fine engineers into the problem, they will essentially be hand building everything. At this point, word could leak out and the other Empires become interested in the problem(s), either out of self interest or out of fear of Russian intentions. The Russians have plans for space greenhouses and long term occupation of space, after all.....
[](https://i.stack.imgur.com/miqNs.jpg)
*Tsiolkovsky's space greenhouse. Sunlight enters from the rounded end towards the pointed end....*
So in this contrafactual, the Space Race is actually triggered by the Russians, but in the early part of the 20th century, rather than 1957....
[Answer]
Having a whole space program without Atomic Energy is not a problem as the two things are largely unrelated.
Managing a whole set of space flights without numerical computers is much harder to imagine.
In order to do so you would need to have some kind of mechanical computers much better than what available (partly due to obsolescence of what available (e.g.: [Olivetti Dvisumma 24](https://www.youtube.com/watch?v=ELoObUPFdP0)) due to rise of electronic calculators).
The real problem, though, would be how to prevent quanta discovery. It would not be enough to have Max Plank to have an accident before his discoveries. History of Science have multiple examples that discoveries are almost never really linked to a physical person, but at a general "ripeness" of cultural society of the time.
There are several examples of multiple, independent, discoveries of essentially the same thing at almost the same time. Everybody knows what Lobacewsky did to Geometry, but almost none remembers [Bolyai](https://en.wikipedia.org/wiki/J%C3%A1nos_Bolyai).
OTOH if someone was really "ahead of the times" often died without honor, possibly to be remembered many years (sometimes centuries) later; this is what happened to [Evariste Galois](https://en.wikipedia.org/wiki/%C3%89variste_Galois) and [Gregor Mendel](https://en.wikipedia.org/wiki/Gregor_Mendel), among many others.
In order to steer our history away of transistors "killing Plank" won't suffice; you need to come up with a complete steering of the whole technology (toward mechanical devices, for example), but it's difficult to imagine a Space Race without a corresponding race to miniaturization... which will inevitably lead to the "infinitely small" and its quantization.
[Answer]
Just make life developing on the planet take a few billion years longer then it did, the U235 will be largely gone, and without that bootstrapping a fission reactor is kind of tough.
Nuclear science is there, people have built accelerators and colliders, but a reactor is (while understood in theory) impractical because producing sufficient fissile material is seriously problematic (read orders of magnitude too expensive for even nation states), you cannot breed meaningful amounts of fissiles if you don't have a decent source of neutrons to start with.
make the atmosphere contain more argon, and the star somewhat more active, then the prevalence of Si32 from cosmic ray bombardment will be greater in the silicon, and that is a beta emitter, so all of a sudden your transistors are a lot noisier and things like flash memory are a non starter due to SEUs generated by the decay of the chip itself, this forced development first of miniaturised field emission valves then of machines using non linear opticsal effects for computation...
QM is well understood, but if you cannot get reasonably pure Si28, then integrated circuits are not happening any time soon and you force the technology down another path. Don't diddle with the science, diddle with the materials availability.
[Answer]
**Realistic requirements**
It would probably be extremely difficult to launch and operate a low-Earth-orbit space station, moon landing, or mars exploration without any numerical computers at all -- but the computers do not need to be anywhere near as powerful as a modern smartphone. A 128KB PDP-8 per spaceship would do it.
See, space is big. Really, really big. So even though rockets go kinda fast, it takes them a long long time to get anywhere interesting. Three days just to the moon, with maybe one mid-course correction. A few months to Mars. Maybe two years to Titan or Io.
This means that the on-board computer has plenty of time to carry out any navigation calculations. With lots of time available, the computer can be small and slow. I'm picturing a machine with few registers, no pipeline, and magnetic core memory, like a 1959 minicomputer but with valves instead of the discrete transistors. An astronaut would awaken, load the next task into the machine, press [Enter], and go about other business. Some time after lunch the computer would go ding ding and display the remaining distance to Jupiter or whatever.
Space travel would also be supported by several large valve-tech computers on the ground. These would, inter alia, precompute large ephemeris tables which would be preloaded into the onboard computers' ROMs. During missions the ground computers would also communicate by digital radio telemetry with the onboard machines via what we would think of as an infuriatingly slow LAN.
**Alternate technologies**
At the time that transistors became available, vacuum-tube technology was still quite immature. Although a valve needs to be an inch or so long if it has to switch significant power, it can be much smaller if it only needs to switch another tiny valve. In 1959, RCA and Sansui manufactured pentodes about the size of a pencil eraser. Some further miniaturization might have been possible.
Some other technologies were discovered but never developed because integrated circuit chips dominated the solution space. For example, the Hall effect can be exploited as part of a solid-state switch.
Of course, exactly which other devices and methods would have expanded to fill the gap depends on exactly why transistors were never developed into usable devices, and exactly what you insist on calling a transistor. Are Josephson junctions still possible? Superconductors? Liquid-crystal displays?
Ah, well, never mind. Vacuum plasmonic valves, magnetic cores, and wire-wound ROM ("rope" memory) are quite sufficient for the modest computing requirements of space travel.
[Answer]
Mechanical calculators have been mentioned already, but imagine a strong focus on them with a strong drive to miniaturization. It's thinkable they work out intricate compact designs with small precise gears to make advanced calculations. A mechanical pocket calculator that is able to do all basic operations seems not impossible, and as such space ships that do automated calculations using nothing but such gear-driven devices. But you will need electricity nonetheless for space flight, unless you want your astronauts to work in the light of petroleum lamps.
To prevent transistors you'd have to prevent your society to discover the use of semiconductors, something which doesn't seem easy to prevent, see <https://en.wikipedia.org/wiki/Semiconductor#Early_history_of_semiconductors>
EDIT: Make is so that no world wars happen so that there is no strong need to develop certain technologies with important militaristic uses.
[Answer]
In our history, spaceflight was a spin off of the nuclear arms race that, when transistorised telecommunications became prevalent enough that extra bandwidth was required, was also used for telecommunications purposes. So without either of the two main reasons for funding development of space-faring rocketry, we would need to be looking at some other reason for going into space. Some ultimate disaster, such as crop disease in "Interstellar", might force us off the planet and into a space station. Mining rare elements from asteroids wouldn't make sense, since without post-transistor technology there's little need for them.
[Answer]
There was a lot of early science fiction that imagined space travel without the information revolution. Any story that visualizes space travel without advanced computers represents an alternative future that meets the requirements.
For example, Arthur C. Clarke's "The Sands of Mars" was first published in 1952. The space ship has an atomic drive, but that does not affect the story - it could equally well have been chemical.
The viewpoint character, a science fiction writer, takes photos with a camera that does not let him view the results immediately. He uses a typewriter and carbon paper to produce two copies of his writing. Although much of the operation of the ship is described as being automatic, some automatic monitoring gear is described as making noises.
The point of departure is simply things that do not happen.
[Answer]
One possibility to even avoid vacuum tubes (and discovery of their physics which could indeed lead to inventing a solid state equivalent) would be to use magnetic amplifiers - they were invented IRL in the early 1900s but work on sufficiently different principles to not steer you right into the wrong direction.
[Answer]
if your world isen't meant to be 100% realistic you can alwais go for analogue style devices that look more like clocks than computers and some steam punk-esk inventions...
the spacecraft flight is the easy part because it's mostly chemical reaction ... the only problem is to know where you are going ...
Edit: The divergence point should be somewere during the WW2 or after it , ofuscating the way the war is actualy won would resolve the nuclear weapons problem , say somthing like the last remnants of the axis were forced to surender after a few years of alied siege. As for einstein and the nuclear fision dilema just go the rout of political partys demed it to dangerous and didnt' give the funds.
[Answer]
To avoid nuclear weapons, you have to remove radioactivity research: Have the Curie kicked out of college, before they could prove that grinding a metric ton of pitchblende ore to extract 0,1 g of radium was worth it.
[Answer]
Impossible, unless you change the physics of your alternate world so transistors or nuclear power don't work. In a world with millions of scientists, *everything* gets discovered when the time is ripe.
And without transistors, spaceflight is so terribly expensive that nobody would start a large-scale operation such as Project Olympus.
] |
[Question]
[
I see this in so many maps. Normally, the water flows downhill because of gravity but here it is the opposite, rivers will go above the hills. When you mention this incoherence, the authors refuse to change it because that's how they want it. Apparently, the laws of physic does not need to apply with rivers.
Is there any phenomenon that could explain this even if it's only on a short distance?
[Answer]
Since the question specifically refers to maps, I should mention that it is quite normal for it to appear that rivers run towards higher ground, such as hills or mountains, on a map showing only the large scale details. This happens because you can't see the actual terrain the river flows through, which can be much lower than the large scale features that you can see on the map. The river can erode itself quite a deep and narrow canyon given time.
Two possibilities are obvious:
1. Water level used to be much higher due to an ice dam or similar and this forced water to flow through the high ground and erode itself a canyon.
2. The terrain used to be lower and has risen slower than the river can erode its channel. This can be due to plate tectonics or past glaciation.
While this does not quite answer the question as asked, I think there is some value in directly addressing the stated motivation for the question.
[Answer]
Water can flow uphill in a formation known as a [hydraulic jump](http://en.wikipedia.org/wiki/Hydraulic_jump). These phenomena are most visible in two types of locations:
1. In some rapids, the speed of a river drastically decreases when fast-moving water discharges into a slow region of the river. If the speed of the water is greater than a certain threshold (see the linked article above for calculation of this speed), the force that the fast water exerts as it slows down can force the following water to rise slightly.
2. Some dam spillways use an engineered hydraulic jump to slow the speed of the water coming off the spillway. These represent a best-case scenario: the spillway is a smooth, low-friction surface, and it usually is a long, steep fall with the jump directly at the bottom (no horizontal distance for energy to be lost). However, even under ideal conditions the jump will be tiny compared to the initial fall. Even a "ski jump" type spillway, where the water is launched into the air, achieves very little height.
Finally, as Serban alluded to in a (now deleted) comment, if the speed of the water is high enough to force it uphill over any significant distance, it will tend to erode the obstacle over time, or push out of the riverbed and flow around the obstacle. (See the answers to [this question](https://worldbuilding.stackexchange.com/q/1144/3407) for some of the problems associated with trying to naturally constrain high-pressure water.)
[Answer]
Here's one river attempting to flow vertically downhill, and failing.
All you need is a good stiff breeze (in Skye terms) or perhaps a full gale in normal language, and you can induce water to flow uphill, at least on a local scale.
You will note that the shape of the beach is fairly close to the curve of a turbine blade, to accelerate onshore winds into an upwards direction. Not so apparent is the way the curve of the bay helps concentrate the wind onto that spot.
(Location: Talisker Bay, Isle of Skye. Windspeed : moderate, probably 40mph or less)
[Answer]
With the science covered, I thought I'd mention two examples on Earth of this occurring for relatively longer times and distances.
The first is the [Tonle Sap](http://en.wikipedia.org/wiki/Tonl%C3%A9_Sap) in Cambodia, which is a tributary of the Mekong. It reverses directions twice a year in response to seasonal rainfall changes. In the wet season, the larger Mekong river starts flooding. These flood waters then push *up* the Tonle Sap. Essentially, the regular downhill flow is overcome by uphill flow caused by the large increase in the volume of water.
A second example, which is cheating a little, are the sub-glacial rivers of Antarctica. Here gravity is less dominant in determining direction of flow, as the pressure of the ice takes over. I have not yet been able to find a reference for the distances that may be involved here, and it appears to be an active area of research.
[Answer]
As user3453518 says, this could happen for a short distance by inertia. I advise you to read his answer; there are some very good points made well in it. I'll add some science to it.
The formula for gravitational potential energy is
$$ \large E\_\text{GP} = mgh $$
where $m$ is the mass of the object in question, $g$ is the gravitational constant, and $h$ is its height above the turning point. On Earth, $g = 9.81\text{ Nkg}^{-1}$.
So let's say we have 1 cubic metre of pure water, weighing in at 1000kg. It's starting down a hill of 50m vertical height (we'll assume this hill is somehow made of super-hydrophobic material so as to easily discount friction). It has:
$$ E\_\text{GP} = 1000 \times 9.81 \times 50 $$
$$ E\_\text{GP} = 490.5\text{ kJ} $$
At the bottom of this slope, since energy is conserved and we're discounting friction, it will also have 490.5 kJ. It'll be travelling at a velocity we can determine using the formula for kinetic energy:
$$ E\_\text{K} = \frac{1}{2} mv^2 $$
$$ v = \sqrt{\frac{2E\_\text{K}}{m}} $$
$$ v = 31.32\text{ ms}^{-1} $$ or about 70 mph.
Using this, we can show how high it could go if projected straight up with no loss of kinetic energy:
$$ v\_f^2 - v\_i^2 = 2as $$
We're looking for $s$, the displacement from the original position. $a$ is deceleration due to gravity, so just −9.81, $v\_f$ is the final velocity (0) and $v\_i$ the initial velocity which we just found.
$$ s = \frac{v\_f^2 - v\_i^2}{2a} $$
$$ s = \frac{0 - 980.9424}{2\times -9.81} $$
$$ s = 49.9971\text{m} $$
---
That's close to the original height of 50m (it's not exact because of my rounding)—but here's the crucial part: **it's not over it**. Unless you can manipulate gravity specifically for water without affecting anything else on the planet, it's physically and scientifically impossible to go over the value of the original height. Moreover, in these calculations I have excluded several important considerations such as friction and air resistance. In reality, you'll never get anywhere near this value.
[Answer]
For a very short span, this can be explained by inertia. But, this means that the river might climb a slope no bigger than what it came down.
IE.: The river came down a 10m steep descent, followed by a very short plain (to avoid losing speed to friction) followed by, say, a 3m climb.
But, if you measure the place where water started versus where the water ends, the start level MUST be higher than the ending level, because all of the water's kinetic energy comes from gravitational potential energy. Anything else would defy the laws of physics. Gravity is a fundamental law of the universe and one where this does not hold true would make for a totally different universe. If gravity could be defied in such way, you could very well have a river that does not follow a riverbed. Water might take off right from the sea, climb to stratosphere and flee the planet, etc. To remove gravity as a limitation means to remove it as a limitation everywhere.
[Answer]
To add to the other answers, there's also the possibility of the water *appearing* to run uphill due to a an optical illusion.
I'm not aware of any river where this is the case, but since it happens [with roads](https://en.wikipedia.org/wiki/Gravity_hill) I see no reason why it couldn't also happen with rivers.
[Answer]
For particularly extreme topology, a possible explanation could be [vertical deflection](http://en.wikipedia.org/wiki/Vertical_deflection) due to gravitational anomalies. Basically, the local gravity at a point on the surface of a planet may not point directly towards the planet's center of mass, in a similar way to how a moon does. The water is still flowing downward - the difference is that that might not be the same as decreasing elevation.
However, this effect is very small - the largest vertical deflection found on Earth (in some parts of the Himalayas) is a measly 100 arc seconds, or about 5 inches per thousand feet (or 48 cm per km). So, assuming that you have a super-massive mountain next to a super-flat plain, you might have a river that flows in a direction of increasing elevation continuously in a small area, for a few decades until it eroded the land enough to change the direction again.
[Answer]
I just skimmed over the other answers but I think they all miss the point of water actually flowing uphil over an extended distance. Actually this is possible! There's a road (IIRC) "devil's road" in North Africa. This road runs up a lonely hill in otherwise flat terrain. If you put a ball on this road, it will start rolling uphill slowly. People thought devils would be doing that, hence the name.
In fact the hill is just the peak of a massive stone formation, which due to its increased density "bends" the gravitational field of earth a little. The effect is just enough to overcompensate the slope of the hill making balls and potentially also water run uphill. A pendulum would point slightly sideways compared to the flat terrain. So it's more a visual thing: If you define "down" perpendicular to the majority of ground you can see, this is what you're searching for. However if "down" is defined by a pendulum, the water is still flowing downhill up that hill.
Extending on that a shallow river might **seem** to run uphill, if some extremely big and dense mass is under the hill, which in turn is surrounded by flat and less dense terrain, e.g. barren soil. It's important to define where the river runs to. I'd imagine a small lake from, which the water evaporates quickly enough to make space for more water to run uphill.
The above makes for a shallow and slow stream under extreme conditions. You can go a little bigger, if you add the wind idea: Constant wind from one direction will make trees grow into that direction, instead of growing straight up. This will add to the visual effect of the landscape and add more push to the water running uphill. The hillside can be or at least look steeper. However if more water ends up in the hill's lake, where does it go? I'd recommend a small siphon draining the lake through an underground river. The pressure of the lake regulates the speed of the underground river so that the lake won't overflow easily. You could have stories about people vanishing when bathing in the hill's lake, because they could be sucked into the underground river.
Actually I just noticed there's already an answer by celtschk mentioning the exact same effect. Strange that my two paragraphs were too few but his two lines are good. Maybe someone can merge them up into one answer and then delete mine, because celtschk came up with it first.
[Answer]
So, working off of @NoAnswer's answer, you could have a bit of ultra-dense (say some neutron star material) formations hidden in the top of hill, which has such extreme gravity that everything flows upward toward it. Not enough to cause a black hole, but enough to overcome the gravity of the entire rest of the planet. And this stuff would have to be sitting on some very strong foundation so as to resist sinking to the core of the planet.
ALTERNATELY
You could have some algae or fish spawning goo that is seasonally secreted into the river that turns that section of the river into something like polyethelene oxide ("the liquid that pours itself").
It would work like this: river runs parallel to raised area with sharp drop off, then down hill. Fish spawn temporarily changes the viscosity of river, which then tends to pool up in places in the raised area. Eventually a pool reaches the edge of raised area and spills over, which pulls the down-river part of the river back uphill.
I don't know.
[Answer]
Glacial compression can cause water to flow uphill as the pressure from the ice forces the water to travel upwards - this can be seen in areas of the Pennines and can travel a few hundred metres with ease.
] |
[Question]
[
So, suppose a medieval society knows how to create vulcanized rubber. (As long as they have rubber sap, sulphur, and the recipe, it shouldn't be outside of their capabilities. The process is super simple, and Charles Goodyear stumbled onto the process by accident.)
It just occurred to me that these people would probably use rubber tires for horse-carts rather than the iron tires used in the real world.
Would these rubber tires make horse carts better able to traverse rough terrain, and thus increase the effectiveness of horse cart travel?
Note: just because they have rubber tires doesn’t necessarily mean they have pneumatic tires. Rubber tires could, in this context, mean a solid rubber tire. For the context of this discussion, I would like an answer regarding both possibilities. That is, I am interested in knowing whether pneumatic rubber tires or solid rubber tires would significantly improve performance on a dirt road.
[Answer]
## Wooden Leaf Suspension Made Flexible Carriage Wheels Obsolete
The Ancient Egyptians beat modern man to the idea of flexible wheel materials... by a LOT. From around 3500-2000 years ago, wheels were normally made from flexible wood or wicker to conform to the ground and absorb the shock of rough terrain... basically acting very much like the rubber wheels on a modern wheel.
Around 1000BCE, you start to see the first iron-tire wheels. They reduced drag and were more durable making them useful in certain contexts like chariot racing on a properly prepared field or for transporting heavy loads, over short distances, but they lacked any shock protection; so, they were not popular in any general since.
However, some time between about 500BCE and 55BCE, the British Celts invented the first true suspension system. This suspension system was very similar to a modern leaf suspension system used by many trucks, just made out of wood instead of spring steel.
When the Romans adopted this suspension system and paired it with hot shrunk iron tires, this combination spread very quickly throughout Europe and became the standard for wagon construction up until the invention of the automobile.
The reason automobiles went back to the flexible tire design was because a car has to produce its own propulsion. This means it needs friction with the ground in order to move at all. However, carriage wheels only need to be pulled so reducing friction with smooth hardwood or metal tired wheels improves their performance over flexible materials. So if you were to introduce rubber to a wheel-wright any time between about 55BCE and the late 1800s, they would intrinsically understand that it is a bad material to make wagon tires out of.
The only performance advantage of rubber tires over steel for a carriage has more to do with the road than the carriage. Modern roads are paved with concreate or asphalt. Softer tires are easier on a hard road; so, if your medieval community also has significant networks of paved roads, a local lord may require that you use wood or rubber wheels so he does not have to repave so often.
[Answer]
The process is vulcanized, not galvanized. (That's coating metal with another metal to reduce corrosion, e.g. zinc-coated steel.) But in general rubber tires would be a bit less efficient, due to sidewall flex. That's why railroads have steel wheels running on steel rails.
On the other hand, rubber tires would be more comfortable, and quieter. Solid rubber tires were used from at least the mid-1800s. The pneumatic tire was invented in 1845, but didn't catch on: <https://www.wired.com/2007/12/dayintech-1210/>
If you're interested, you can buy both solid and pneumatic tires for your horse-drawn carriage, so you could easily do some testing.
[Answer]
No, I don't think that rubber tires (pneumatic or not) increases efficiency high enough to produce a "revolution in horse powered carting".
Using rubber tires on carriages has some value on efficiency, but is the value is limited to distributing the weight of the carriage on a larger surface on *soft soils* - thus preventing the sinking of the carriage. On paved roads, the use of rubber has to do mostly with the comfort of the ride - less high frequency vibrations and noise.
The most efficiency gains for a carriage comes from:
* using larger wheels - less prone to follow the small irregularities of the road - important at low speed, where the inertia in the "forward" direction is low. Also important, for larger wheels, the momentum of the friction between the wheel hub and the axle (at the bearing level) is smaller when compared with the momentum of the (external) traction force. Speaking of axle/hub - larger wheels means less revolutions, less revolutions means less energy transformed into heat in the wheel bearing.
* spring suspension - counts mainly in high speed situation - a *sudden/momentary* "climb" over a rock means displacing only the weight of the wheel and deforming the spring rather than a moving the weight entire carriage over the rock (the more efficiency is to be gained by the closer to the ideal [critical damping](http://hyperphysics.phy-astr.gsu.edu/hbase/oscda2.html) of the suspension). High speed also puts a pressure on the size of the wheel, larger wheels are less maneuverable, so there's a need of some other solution to compensate.
The things started to change with the increased popularity of the car and trucks, where:
1. the surface of the tire is used to transmit the traction on the ground
2. higher speeds and vehicle control make skidding a problem that didn't exist on... vehicles with external propulsion
3. the weight of the "carriage" itself is quite high so that the pressure on the road is a contributing factor to the cost of road maintenance (experimentally determined as [going with the 4th power of the weight/axle](https://www.insidescience.org/news/how-much-damage-do-heavy-trucks-do-our-road) in the 1950s). When rolling space is not an issue, one can dispense oneself of the tires in the [favor of larger steel wheels](https://www.youtube.com/watch?v=xU_fshxE3Gk).
[Answer]
I live in a place where one can occasionally see a horse-powered cart used for daily commute and work instead of a show.
They generally use rubber wheels (scrapped from cars or other wheeled machines).
Why do they use them?
Because scrap cars are much, much easier to source. The alternative is a crafty wheel-making that requires both carpentry and blacksmithing skills - and the payload becomes limited.
On the other hand, rubber wheels have more rolling resistance (reducing the horse speed and endurance) and perform worse in mud. They both adhere to the mud and tend to slip sideways.
[Answer]
The big win for pneumatic rubber tyres wasn't with cars, it was with bicycles.
Penny-farthing bicycles needed those huge wheels because the spokes were the suspension which enabled the bicycle to travel smoothly over rough ground (and all roads at the time were basically rough ground, of course). The so-called "safety bicycles" with a more modern shape of frame were commonly known as "boneshakers" because they lacked anything to deal with bumps. Pneumatic tyres gave safety bicycles the suspension they lacked. With the reduced size of frame and with compliant tyres, safety bicycles were instantly faster than penny-farthings and the older design died almost immediately.
Bicycles don't need to take very much weight though. Uprating pneumatic tyres to the point where they could handle the weight of a carriage was *hard*. Carriages and early cars all used wheels with spokes to give the necessary compliance in the wheel to let the vehicle roll over small bumps, until well into the start of the 20th century.
[Answer]
A big advantage of rubber over iron-shod tyres is *grip*. Grip matters when braking as well as when accelerating, and carriages had brakes. So if you're descending steep hills, rubber will have an advantage on pretty much any surface. Grip is also important when cornering at all but the slowest speeds.
Mediaeval dirt roads would be mud roads at some times of year, and wider tyres would help here to reduce sinking. Although width doesn't necessarily require rubber, iron would add weight, and this is weight below any suspension.
Solid rubber provides next to no suspension value, unlike pneumatic tyres, and the construction of inner tubes is much harder than a solid rubber tyre (especially the valves). Pneumatic tyres would be nice but would need a much higher technology level.
Whether this adds up to a game-changing benefit is another matter - a slightly reduced risk of accidents descending probably isn't worth the extra cost/difficulty of repair, but being able to transport over a longer season than rivals could be very benefificial
[Answer]
The inefficiency comes from lifting and dropping the whole carriage. Mechanical engineers talk about sprung weight. If a single wheel can lift over the cobble, it takes less energy than lifting the whole corner of the cart.
A modern car has two sources of suspension: The springs, and the pneumatic tire. The tire absorbes the small things, the springs the large things.
While a solid rubber tire on a cart won't make a lot of difference in energy efficiency, it will make the ride a LOT quieter when in the city on cobble streets.
---
Look at harness racing rigs. They use what amount to two bicycle wheels. A metal spoke wheel is lighter (less unsprung weight)
] |
[Question]
[
I am developing a (magical) first-millenium CE alternate history based on an extension of historically matriarchal societies, and am trying to decide how this would affect the stereotypical male personality. To obtain the desired cultural shift, I have applied a few magic-based tech changes, specifically:
* The drug of forgetfulness, nepenthe, is available in the wild, and it disproportionately affects the male brain. A brain lacking information will grab onto whatever it is given, so a person influenced by nepenthe will likely believe whatever he is told. This is a short-term effect.
* Use of nepenthe for personal gain is culturally discouraged (and illegal in most places), but it still happens on occasion -- much as date-rape drugs are still used in our society today.
* Culturally, this led over time to men begin perceived as "fragile", "easily manipulated" and "not to be trusted with important decisions". Education may be limited to women as a result (Compare: US attitudes towards women before the 19th Amendment and in higher education before Title IX).
* Nepenthe has been weaponized, for defense against brigands or enemy armies.
This changes the way the military is structured. It also provides opportunity for unscrupulous people to manipulate or even kidnap young men. Native nepenthe must be eaten to have its effect; weaponized nepenthe is a gas.
* In response to this risk, golems were developed to handle some tasks for rich women who don't want to put their sons at risk. Among the poor, however, manpower is still measured in man-power (e.g., no significant biological differences in musculature for people).
* A man grows up in his mother's house and is expected to help raise his sisters' sons. As occurred in certain matriarchal cultures of our past, a woman may invite a man she likes to share her bed, but marriage per se is not a thing -- his sister expects him to return to her house afterwards. Since women control the property and wealth, a man is essentially "orphaned" if he has no female relatives.
* The upper-class philosophy of "protect your sons" has grown into a broader idea that women are responsible to protect men from harm -- effectively, a reverse-chivalry attitude. This idea is particularly strong within families, but some women may hold it more broadly.
* There is some other magic present in the world, primarily related to augury, agriculture, and medicine. It is expensive and may require blood or other complex chemistry to accomplish. As a result, while famine, war, plague, and pestilence may still be as common as they were in our history, it is the matriarchy (government) that is expected to keep those things at bay.
In this context, I am trying to understand how this inverted power structure would affect human behavior. Specifically:
1. In our world, women are often perceived as talking more than men -- both in a positive (social) manner and in a negative (gossipy) one. In this revised world, would men in this culture be increasingly quiet compared to women ("your voice is unnecessary"), or would they become more social and talkative as their ability to influence society in other ways decreased?
2. In this alternate society, women hold both the financial and sexual controls. Put in that position, what (apart from words) would a man do to attract a woman's care and attention? Would the stereotypical "male ego" be completely destroyed by this level of financial dependency?
---
Notes:
* In this world, magic is intended as technology. It has been around long enough to affect culture, but not evolution. You can safely assume that biological sex differences are still present, though they may have a differing impact on society for the reasons described above.
* Magic is not cheap in this world, and is therefore limited to government or the wealthy. At the same time, culture is often established by the rich, so opinions would not necessarily match reality.
* I've done a lot of reading about real-world matriarchal societies, but this is not intended to be a direct analogue to any of them. For this question, I'm trying to understand the psychology of power -- how much is nature, and how much is nurture.
* As with the prior item, the magic/chemistry that leads to the manipulation of men is not intended to say anything about the real world. It *is* intended create a situation where a son or brother left alone might be drugged and kidnapped by unscrupulous persons. This would understandably make the women who care about them want to protect them (think: maternal instinct). It would also lead to unfortunate consequences when people decided their sons couldn't take care of themselves.
[Answer]
If males still tend to be *stronger* than women, you won't quite the a mirror of the historical patriarchy. Women are merchants, men are porters and caravan guards. Women are architects, men are masons and bricklayers. Women are weavers, men are herdsmen.
If males "make themselves useful" by using their muscle, that will influence their social status and the appearance of desirable males. A "good" male trusts his wife and butts heads [whenever she says so](http://tvtropes.org/pmwiki/pmwiki.php/Main/BrainsAndBrawn). That means standing up to other men and other women, it wouldn't do if they were easily cowed. Of course bringing the trash out or hauling crates into the attic are much more common than confrontations, but also less memorable.
---
*Follow-Up:* Yes, I ignored the golems. I had subconsciously assumed that magic would be scarce enough that there won't be a golem in every house. If a bunch of men go *look at my biceps and obey*, a golem constable will show them the error of their way. If you need somebody to chop wood at a farm, a man would be more cost-effective.
[Answer]
This is a case where the problem is still insufficiently bounded. Social structures are incredibly complex and varied. Consider the role of women in American society vs the role of women under theocracies that give them no rights at all. Men in your world would likely see a similarly large gamut of possibilities.
In fact, they might even see things we don't see in human culture. What you describe is not all that far from how beehives operate. You may find that your males turn into drones! This extreme points out one major challenge with your questions: if you're going to the point of inventing entire new brain chemistries and adding magic, concepts like "male ego" turn into really whatever you want them to be. You've made so many changes that something small like that is easily adjusted to fit your story.
The one thing you can rely on is waste-not-want-not. Evolutionary processes hate to see resources go to waste. If there's no particularly strong value to a male at all, then they will likely find themselves given extremely small resources to work with. All males may be put on starvation rations simply because there's no reason not to. Or perhaps they will be killed at birth. Waste not want not. On the other hand, if males do actually get a chance, that means they have some value to the society. It's your job as an worldbuilder to try to figure out what that value would be *in your specific society*.
Pay attention to your magic system. "Due to the availability of female-controlled magics (e.g golems), the benefits of male physical strength are less useful..." suggests your magic is *very* powerful in how it will shape society. If your female magic is too strong, it will simply be a waste of time to raise a male. I suggest exploring the weaknesses in your magic system, whatever they might be, and seeing whether a male might be able to scratch out a living operating inside those weak regions.
In all, societal structures are very complicated systems with few right or wrong answers. However, one tool you can always rely on is efficiency -- there will always be a sense of efficiency built into the deepest traits of society (such as gender relations). Each culture's sense is different. We may not appreciate the efficiency of that of another culture, but it's there. If you build up that sense of efficiency to meld correctly with the rest of your world, you'll have a reasonable society to share with your readers.
[Answer]
## These real world [examples](http://mentalfloss.com/article/31274/6-modern-societies-where-women-literally-rule) should give you some considerations
1. MOSUO
The Mosuo live with extended family in large households; at the head of each is a matriarch. Lineage is traced through the female side of the family, and **property is passed down along the same matriline. Mosuo women typically handle business decisions and men handle politics. Children are raised in the mother's households and take her name.**
The Mosuo have what's called “walking marriages." There is no institution of marriage; rather, **women choose their partners by literally walking to the man’s home and the couples never live together. Since children always remains in the mother’s care, sometimes the father plays little role in the upbringing.** In some cases, the father's identity is not even known. Instead, the male’s childrearing responsibilities remain in his own matrilineal household.
2. MINANGKABAU
At four million people, the Minangkabau of West Sumatra, Indonesia, (pictured above, during a harvest season celebratino) are the largest known matrilineal society today. In addition to **tribal law requiring all clan property to be held and bequeathed from mother to daughter, the Minangkabau firmly believe the mother to be the most important person in society**.
In Minangkabau society, women usually rule the domestic realm while the men take the political and spiritual leadership roles. However, both genders feel the separation of powers keeps them on an equal footing. **Upon marriage, every woman acquires her own sleeping quarters. The husband may sleep with her, but must leave early in the morning to have breakfast at his mother’s home.** At age 10, boys leave their mother’s home to stay in men's quarters and learn practical skills and religious teachings. While the clan chief is always male, women select the chief and can remove him from office should they feel he failed to fulfill his duties.
3. AKAN
The Akan people are a majority in Ghana, where they predominantly reside. The Akan social organization is fundamentally built around the matriclan, wherein one's identity, inheritance, wealth, and politics are all determined. All matriclan founders are female, but men traditionally hold leadership positions within the society. These **inherited roles, however, are passed down matrilineally—meaning through a man's mothers and sisters (and their children). Often, the man is expected to not only support his own family, but those of his female relatives**.
4. BRIBRI
The Bribri are a small indigenous group of just over 13,000 people living on a reserve in the Talamanca canton in the Limón province of Costa Rica. Like many other matrilineal societies, the Bribri are organized into clans. Each clan is made up of extended family, and the clan is determined through the mother/females. **Women are the only ones who traditionally can inherit land. Women are also endowed with the right to prep the cacao used in sacred Bribri rituals.**
5. GARO
Much like their Khasi neighbors in the North-East Indian state of Meghalaya, the **Tibeto-Burman-speaking Garos pass property and political succession from mother to daughter—typically, he youngest daughter inherits her mother's property.** Much like the Akan, however, the societiy is matrilineal but not matriarchal: the men govern the society and manage property.
Oftentimes, the youngest daughter's marriage is arranged for her. But for non-inheriting daughters, the process can be much more complex. **In Garo tradition, the groom-to-be is expected to run away from a proposal of marriage, requiring the bride-to-be's family to "capture" him and return him to his potential bride's villiage.** This back-and-forth is repeated until the bride either gives up, or the groom accepts her proposal (often after she has made many promises to serve and obey him). Once married, the husband lives in his wife’s house. Should it not work out, the union is dissolved without social stigma, as marriage is not a binding contract.
6. NAGOVISI
The Nagovisi live in South Bougainville, an island west of New Guinea. Anthropologist Jill Nash reported Nagovisi society was divided into two matrilineal moieties, which are then divided into matriclans. Nagovisi women are involved in leadership and ceremonies, but take the most pride in working the land entitled to them. Nash observed that **when it comes to marriage, the Nagovisi woman held gardening and shared sexuality at equal importance. Marriage is not institutionalized. If a couple is seen together, sleeps together, and the man assists the woman in her garden, for all intents and purposes they are considered married.**
## Considerations
* Men would likely become trophy objects based on appearance
* Some limit upon male aggression and testosterone would need introduced
* Sexual subjugation would be a staple of life (see: Tease&Denial or Femdom)
* I agree with others above; feral men would exist, become antagonists
* Male involvement in child-rearing would be reduced
* Male necessity for pregnancy would be drastically reduced and possibly automated through the use of sperm collection and delivery, sale
* Child-bearing men of superior genes would be highly valued and possibly traded, sold
* Male without valid child bearing sperm would be outcast from society
* A male who is unable to find a wife would likely suffer lower economic status and less influence (like females in Victorian England)
* War would be reduced as matriarchal societies seek consensus and community across larger groups
* Female attitudes to sexuality would be drastically different (See the work of Nancy Friday)
## Amazonian Women
You might also be interested in this [article](http://www.smithsonianmag.com/history/amazon-women-there-any-truth-behind-myth-180950188/).
>
> Starting with Friedrich Engels, Bachofen inspired generations of
> Marxist and feminist theorists to write wistfully of a pre-patriarchal
> age when the evils of class, property and war were unknown. As Engels
> memorably put it: “The overthrow of mother-right was the world
> historical defeat of the female sex. The man took command in the home
> also; the woman was degraded and reduced to servitude; she became the
> slave of his lust and a mere instrument for the production of
> children.”
>
>
> **There was, however, one major problem with the Bachofen-inspired theory of matriarchy: There was not a shred of physical evidence to
> support it.**
>
>
>
and...
>
> The trail of the Amazons nearly went cold after Herodotus. Until, that
> is, the early 1990s when a joint U.S.-Russian team of archaeologists
> made an extraordinary discovery while excavating 2,000-year-old burial
> mounds—known as kurgans—outside Pokrovka, a remote Russian outpost in
> the southern Ural Steppes near the Kazakhstan border. There, they
> found over 150 graves belonging to the Sauromatians and their
> descendants, the Sarmatians. Among the burials of “ordinary women,”
> the researchers uncovered evidence of women who were anything but
> ordinary. There were graves of warrior women who had been buried with
> their weapons. One young female, bowlegged from constant riding, lay
> with an iron dagger on her left side and a quiver containing 40
> bronze-tipped arrows on her right. The skeleton of another female
> still had a bent arrowhead embedded in the cavity. Nor was it merely
> the presence of wounds and daggers that amazed the archaeologists. On
> average, the weapon-bearing females measured 5 feet 6 inches, making
> them preternaturally tall for their time.
>
>
>
[Answer]
In question number one you would end up with two groups of males:
* The first would be "family" males who would like you say be quiet. Seen not heard would be a good term here but waiting to do anything they could to be perceived as beneficial. The women would exert an extreme amount of control by either recommending or not recommending their brothers to their women friends as mates to produce children. Men who had too many male children or disappointed their sisters in other ways might even be shunned — which brings up the other group of men.
* Feral or maybe wild men: If they have no family they are not going to remain with civilized society and they are going to gang together. They will be violent, cruel to both civilized men and women. Not only that but you might want to consider the saying only the strong survive. In this case though only the smartest survive so these groups of me will end up being somewhat smarter than the average civilized male. Capture a few females and it could cause all sorts of havoc in your nicely planned society (he, he, he). Don't know what your projected audience is but for the younger ones you might not want to even consider going there though.
As for the second question, men would be very careful about unwarranted attention just as women are in male dominated society. Without protection it could cause some very difficult situations so men would be dependent on female relatives for protection. Ego is something we all have, damaged or not. Since female power is dangerous you would have males picking on lesser males and something else interesting.
A lot of males would secretly harbor resentment, and while occasionally lessor males would be targetted, the primary targets would be golems because they are a symbol of female power. Sabotaging and destroying those golems would be something the pissed–off males could occasionally not be able to resist.
[Answer]
Another answer after OP's clarification.
*I still can't bring myself to believe that without biology change you would achieve your cultural shift.* But let's hand-wave this and assume that a society like that exists and think how it would have came to be like that and see where it leads us (because it is fun). In meantime I hope it will provide the answer to OP's questions or at least some useful thoughts or ideas.
So I assume next things:
1. nepenthe - is a relatively easy-obtainable plant, which is not normally edible so the biological evolution of humans took place the same way as in our world, then relatively recently it was discovered that it has OP's effect on human males.
2. nepenthe's effect lasts for no longer than a couple of weeks until it dissolves from body, then the victim can remember everything or almost everything that has happened to him.
3. you can relatively easy make a liquid extract of nepenthe plant in order to add to victim's food (so you don't have to add the raw plant itself) but it requires significant knowledge and equipment to make gas (so you still can make a weaponized form in military facility but not in your garage equivalent)
4. magic can be used by both genders, but doesn't allow to be immune to nepenthe's effects. Also men can control golems and be a magic user in general (but may not have access to magic items, knowledge etc)
So a country Kramain was founded in year 300 CE which is the same as a country in year 300 CE would have been in our world. In year 367 CE a relatively common plant was discovered to have an interesting effect on males only. It was called nepenthe. Since then the cultural shift has started to form in Kramain. Men who controlled everything has started doing strange things like giving away cattle for free, doing work for free, killing their entire families and doing strange things in general.
It has quickly become apparent that men can no longer do business and make any serious decisions, at first women in their households have been given the obligation to be present at all important decision making times to verify sanity of men. Soon it happened so that all of the business had to be conducted between women to exclude fraud and other issues related to the drugged men. After some time it led to a situation that women has become household masters and got the real economic power. Which in turn let to cultural shift to matriarchy (in whatever meaning you put in it). Along this shift some other things has become more apparent - more women were needed as only women could have been trusted with dealing with mistress' children, especially females. So the cast/order of guardians was born, these women had to be childless and serve to the mistress, protect her from manipulated household males and other enemies. On the other side man started to avoid accepting food from outsiders and especially share meals with women. It has become customary to carry a box with a lock when traveling to keep the food which was prepared by household members or by the man himself. This box had to be locked at all times and key had to be kept very securely. A lot of outside household interactions of men had to be made with a presence of women to protect from drugging effects. After some time cultural norms were adopted which would discourage or prohibit usage of nepenthe.
Men still were used for manual labor and for military service. All under supervision of women. They started to feel oppressed but that was a natural order of things. Marriage in the form we know it dissolved from top of the society to bottom. While richest women would pick their lovers to stay with them for some time either to be a toy or to produce offspring they didn't posses any material rights in household. For poor people it was a bit different and was more resembling marriage but women had the right to 'let' the man go as they seen necessary. This made men even more dependent on women. Wealthier men were educated in craft and basic sciences and women were also getting business, political and military education. Men were taught to obey women.
On the outside men has become more silent and obedient, they didn't talk back to women, they were told to not speak on important matters. In order to get a good place for their sons (basically to let them stay by marriage women for longer, where they were financial responsibility of those marriage women), rich women started to train them in music, dances, poetry, painting etc. On the inside evolutionary aggressiveness and male traits were still present, although somewhat suppressed it had still to get a way to let the steam out which was usually done by bullying weaker men.
At some point a way to create magic golems was discovered and rich women has started to keep these along with female guards from guardian cast to protect themselves from dangers. In year 534 when everything was already under control of women in a local war which was fought under command of female general Luise and has consisted of 500 untrained man foot soldiers and 100 women cavalry, the enemy has used nepenthe in gas form. While the cavalry was away from foot soldiers, foot soldiers were brainwashed to attack their allies after being gassed and told the 'truth' about the sides of this war. General Luise was herself tortured and killed by foot soldiers which then went into slavery with smiles on their faces, and only a handful of cavalry survived and fled to tell the story. After major defeat the way the war was fought changed. To each squad of 10 men there was a woman political attendant attached to quickly refresh men's memory in case of gas attack. In order to keep those women safe to each 5 attendant there was a female golem user attached. It was done to make sure that in harsh conditions of war men would not attack their attendants.
The increased usage and demand for golems put more stain on the economy. Lower classes have been pressed into more poverty and more work. Men started being treated as commodity, more men were sold into other household because of inability to feed them. They became more aggressive because of bad treatment but this was easily suppressed by militia with golems.
In year 943 new threat to Kramain has arised, as men became more and more discriminated but still being quite good in crafts and physical power some of them started to run away from Kramain and form man bandit groups. At first these groups were easy to deal with, but after some time they have started to join forces around a man named Dilak who founded a new religious cult. In this cult women were proclaimed tools of evil, which should be slaves and used only for making more soldiers in order to liberate all the other men. Eating unchecked food was a sin, drugging fellow man was a sin punishable by death, even possessing of nepenthe was a deadly sin. The Dilak cult has started to raid remote villages sacking them and taking or killing men and taking all women into slavery. Them being very agile and small it was hard to fight them off and using gas was expensive and relatively ineffective. Whenever zealots of the cult were seeing or smelling nepenthe gas they would kill themselves, they would never attack in large numbers or directly. They would try to destroy all facilities to produce nepenthe gas and what was more worrisome, the Dilak cult has started to silently spread inside city walls. Followers of the cult started to sabotage work of the cities making them easier to attack.
It was rumored that Dilak is a third son of Dilla, aristocrat in the second largest city of Kramain. As he was the youngest among his siblings, he was raised spoiled by his mother who even gave him a military education which was unheard of at that time. After he started to express some strange thoughts and spoke up at his mothers party, he lost his prospects of getting an invitation to any major house in the country. Eventually even his mother lost interest in him and he was downgraded to do manual labor at his mothers household, he fled. There is no historical record of any of this since records for men were usually not kept as they couldn't inherit.
In year 996 a large scale application of nepenthe was used on men in Kram, the capital of Kramain, to get information on Dilak cult followers withing the city. While it was a great success and more than two thousand believers were uncovered (~1.5% of male population), this has caused a great uproar in masses. It was estimated that in 1015 there was already around twenty thousand believers in Kram, which was around 20% of male population of the city. As number of believers grew, the magic items flow to Dilak cult increased dramatically. Economy started to suffer because of sabotages. The number of female by male victims of assaults has increased dramatically. The cult had invented masks which would delay and decrease the nepenthe gas effect. The Dilak cult has become a major military force and it was estimated that more than 200 thousand women were enslaved by them across the country.
In year 1137 a successful assassination attempt on the queen Lanua, by Dilak cult zealots, marked the end of Kramain as a country.
---
Well, to be honest, after typing this, I realized that it is not really a direct answer to the OP's question but it was quite fun to write.
I would say, that in my version of OP's universe men would psychologically behave almost as in our world. The main reason for this is that I really doubt that because of nepenthe drug they would be perceived as `fragile`. Not trustworthy - yes, fragile - no. So I don't think they would feel physically defenseless.
Since men would be used in manual labor and I think they would retain craft/intellectual/hunt jobs also, so they would still have their ego. I don't think that even in our world in older times women didn't have ego because of financial dependency on men. It was just focused on other things like being pretty (which is of course an effect of dependency). Probably men would have ego in terms of who is the best craftsman or hunter.
Another thing I remembered is, that AFAIK in our world in year ~1000 CE there was not that many marriages for love. In most cases parents would pick up pair for their children, so mothers would pickup marriage(or mating) partners for their daughters, and they would probably look on health, family tree and benefits for household from man, basically the same stuff which was done for son's in terms of wives in our world.
[Answer]
The best answer is to look at current societies which are female led and extrapolate from there.
So, if you know anything about your sex/gender models, then currently, you'll be aware that, for reasons that aren't scientifically clear yet, what we think of as sex tends to be divided into two different parts in our brains.
On one hand, there is the social gender component, which seems to create individuals which are *gender-variant*. These are individuals that show many of the characteristics of acting out the opposite gender, but are unquestionably of their sex.
The other component is the sex part, and this is what creates trans people (people who want to change their physical sex to match their internal sex).
Both of these are independent of each other (and also of sexual orientation), so you do get trans people who change sex yet will act out the opposite gender role, while gender-variant people may be trans (but won't necessarily be). Likewise, social gender expression is what gives us butch dykes and camp gay males, but the general impression that you *have* to be gay if you're gender-variant is wrong.
With that in mind, the question you're really asking is "what happens to men in the gender-variant community?" because all cultures and societies have small numbers of gender-variant people (and with the awesomeness of the internet, they can seek each other out and build their own spaces on the net). However, you would have to correct for the fact that such cultures are basically subcultures of the main non gender-variant norm.
As a summary, broadly, male people still remain interested in physical things while female people go with emotional and social things (this seems to be a sex-based characteristic). However, competitiveness vs cooperation seems to be a more social gender-based one, so politics would be done by women, who would handle things by inclusion and exclusion of social networks (in other words, you get excluded from things that matter and if you really mess up, you get completely excluded, which can kill you). Women would also do trade, as they'd be more temperamentally suited to it than men (again, ties in with social gender rather than sex, I think). Men tend to be kinder and more decent people, though possessing a bit of naivety too, so would probably do more of the family stuff and later-stage child-raising, as well as more empathetic careers (though, in the modern world, lots do IT, because it's a support thing involving physical stuff).
Rather than the traditional physical violence in non gender-variant communities, you'd get women being emotionally abusive to their menfolk (and each other), so the usual rules of dating apply, just men would be looking for someone who isn't a completely horrible person to date while men are looking to get powerful leaders in their communities.
[Answer]
>
> Would men in this culture be increasingly quiet ("your voice is
> unnecessary"), or would they become more social and talkative as their
> ability to influence society in other ways decreases, while women
> become less talkative in their authoritative role?
>
>
>
Neither; their personalities would be the same. Men are neither talkative nor silent due to patriarchy/matriarchy/egalitarian societies - it's a personality thing. Some people are introverts, some people are extroverts, and some people are ambiverts. All genders included.
>
> Since women hold both the financial and sexual controls in this
> society, what would a man do to attract a woman's care and attention?
> Would the stereotypical "male ego" be completely destroyed by this
> level of financial dependency?
>
>
>
Look at very successful women today with many resources and ask, how do men try to attract these women - and is there anything special about how they do so? I am a boy and I am friends with a lot of boys and none of us do. If we're attracted to a girl, we'll ask her out.
Sexual control? Unless masturbation doesn't exist in your fantasy, I'm not sure how women or men can ever have sexual control (and societies that always try always fail). If women can use their magic to stop it, that's one thing, but even that seems absurd because if women have super powers, why would they even care if men masturbate? Unless you're aiming for a comedy, it becomes hard to imagine this.
**If You're Aiming For Closer To Reality**
Since women have magical powers in your fantasy, I don't see why they would want or need men. They could reproduce with their magic powers; so .... If I was reading your book, this would be a question that would stop me from probably reading further - nothing in your description answers this elephant in the book.
[Answer]
>
> 1. Would men in this culture be increasingly quiet ("your voice is unnecessary"), or would they become more social and talkative as their ability to influence society in other ways decreases, while women become less talkative in their authoritative role?
>
>
>
Not sure how much male psychology is influenced by the proposed pharmaceuticals... Currently, males establish a form of hierarchy among themselves. Would this change? The lower types are more likely to become passive-aggressive, exhibit their frustration in petty ways. Men would not be quiet, so much as the "poor decision making" would mean they would be emotionally less contained in a male way. Look up the effects of Fetal Alcohol Spectrum on poor behavior as an example, or consider what happens in a rowdy bar full of drunk men. I assume what you are suggesting is some form of the reversal of the Victorian attitude, that "women were too emotional to be trusted to lead"? I suspect your society will have males who are more like rowdy children, leave too many of them unsupervised and all hell will break loose.
How about female psychology? The trope is that men are more cooperative, hunter-gatherers evolved to cooperate in the big hunt, while women are more individualistic, vicious and competitive among themselves (mean girls? The female is the deadliest of the species?)
As for LGBT - that all depends on attitudes. Is someone "different" persecuted, mildly tolerated with amusement, or allowed to act their self-perceived role? Where would lesbians fit in this? One presumes the "Bull Dykes" would come to rule, exhibiting the added aggressiveness/assertiveness associated with men to end up dominating leadership roles, while avoiding the deleterious effects of whatever drug is messing up male psychology. Oh, and they would also not be burdened with children to look after.
>
> 2. Since women hold both the financial and sexual controls in this society, what would a man do to attract a woman's care and attention? Would the stereotypical "male ego" be completely destroyed by this level of financial dependency?
>
>
>
Are we suggesting a significant change in sexual behavior? Both sexes preen to look attractive for the other. In many typical societies, men ask/chase and women try to look pretty and wait to be asked. If the roles at reversed, men will be the ones parading themselves in social settings trying to look attractive.
But what about the "ladder theory" that men are attracted to good breeding stock, women are attracted to social status? So men go for young and healthy (hence trophy wives). Women go for large wallet and big pe.. pe... pectorals, ie. the Alpha male. OTOH, as Helen Gurley Brown remarked, "men will schtupp mud", ie. are a lot less picky in who they mate with.
All this is evolutionary - A man who spread his seed around will likely have more offspring; a woman wants a mate who will provide and protect for her and their children. If you're bored one day, find a copy of Jared Diamond's *The Third Chimpanzee* for more of this topic. How does your proposed society handle this?
Remember, too, the female as housewife role evolution-wise is due to the need to breast-feed and tend to children for a year or so. Only women can work as wet-nurses. (What did people do to bottle feed before rubber nipples?) This could be a major distraction to women doing other work. Would they mainly be desk jobs? You can't be the sailors on the trading ship and be hauling around 2 or 3 kids at the same time. Also, the birth rate was much higher due to high childhood mortality from disease - maybe half the children died before the age of 5; so women might have a baby to care for every other year from their late teens to early 30's. Think about your demographics and how that is handled.
How well do golems work? They can do grunt work, but are they stymied by complex tasks? Could you run a sailing ship using golems as the physical labour? How about a caravan? Could they defend the caravan against an attack by feral men, or would smarts allow the men to beat the golem every time in 1st-century combat, by applying a little brainpower?
[Answer]
Perhaps a better way to consider the dating/hookup dynamic- how did lower class men connect with upper class women in The Good Old Days? Answer - unless thrown together by circumstance or initiated by the woman, they didn't. People knew their place, and the overall consequences of a peasant pestering an upper class woman were all too clear - up to and including arrest, whippings, and physical attacks by her "protectors". No reason to think men would act outside their social roles in your world.
[Answer]
papidave (OP) has to really provide more details on how exactly men can be drugged/magically manipulated. In my opinion this would greatly influence the society.
*Further is based on the premise that biology, except from manipulation is the same as ours.*
**If easily magically manipulated (even only by the rich, because magic is expensive)**
Then I assume that it can be done by women only. Which in turn means that any woman can to some extent control male (ranging from full mind control to ability to immobilise). *This can have interesting societal impact, like female status in society to be decided by means of who can win control of a man/larger number men by their magic.*
If that is the case then I have to agree with others who can't see the reason why men would be needed as free human beings. The only reason to have them is for reproduction.
Which in turn would probably boil down to the situation as we have with cattle. Men of the 'best' (whatever it means in your world, but usually physical beauty and health) qualities would be kept in semi-animal state and used for reproduction only.
The other side of the spectrum of possible scenarios: is that they are still fully human but are slaves, those women who are wealthier would train their slaves to be smart and to know how to keep an interesting educated conversation, but still being a slave or circus animal.
The quantity of men then would greatly depend on environmental situation as you only need one man to impregnate multiple women:
* enough food in all times - lots of male slaves (keep all male babies)
* not enough or other problems - only small amount is kept for stable reproduction (dispose of weak, sick, disabled and so on)
DIRECT ANSWERS:
1. Influence on women: wouldn't matter, no influence
2. Attract care and attention:
* be healthy and pretty, produce a lot of healthy offsprings
* be somehow fun to keep around (ranging from be smart and obedient to be a circus freak)
---
**If magically manipulated but magic is prohibitively expensive to enable full scale control**
you would get 'civilised' countries with semi-enslaved man and societies of 'barbaric' man who would capture/breed magically weak women and keep them locked/separated for reproduction. These societies/clans would have their own culture built on 'religious' prohibition of man-manipulation (unfortunately don't have more time to fantasise into this direction).
DIRECT ANSWERS:
1. Influence on women:
* know women psychology etc
* be a strong barbarian, overpower weak women, take them as your slaves
2. Attract care and attention:
* be healthy, pretty
* be smart, strong and obedient, know some craft
* be a strong barbarian, overpower weak women, take them as your slaves
---
**If easily controlled by some drug (let's use wine for the sake of example) and magic expensive**
You would probably get something close to our world now. Assuming that average female in our world is weaker than average male, she can be relatively easy kidnapped/drugged so in some cases she needs protection by male but not in all. For your world it would be reversed - there would be places and times when men should be accompanied by woman/en. The men would be forbidden to drink wine or be in places where they can be easily tricked to drink it. But in general I would say you can pick any specific time in our history and reverse women and men roles.
It would probably gravitate with passing of time to more rights given to men (basically as it happened with women in ours)
DIRECT ANSWERS:
1. Influence on women: be a smooth talker, know women psychology etc
2. Attract care and attention:
* be pretty
* be smart
* strong
* know some craft
So yeah, I would love to give it more thought if OP can give us more details on how precisely men are controlled/manipulated.
[Answer]
1. I think they would become even more quiet, because it's in their nature, but because they would not have the chance or the privilege to always speak their mind, the aggression that they now express in words would manifest in other ways. Maybe they would rebel very often, or pick fights with each other, because men are more aggressive naturally. And some of them would just practice a skill to gain the favor of women and thus gain some power.
2. I think apart from words, they would just work really hard at whatever job they have and that would be the measure of their value, in their eyes and the eyes of society. Also, you need to determine what the women would reward as desirable behavior, and what they would punish, that is also going to be a determining factor.
Like in our past, the women were rewarded for being good housewives, raising children, being gentle and sweet and prudes when it comes to sex, and punished for being too interested in sex, having too many partners or wanting to be independent. It's not OK, of course, but it kind of corresponds with the fact that naturally women have a lower libido then men. In your world, if women will punish the men for something that is in their nature to do, the society is going to become tyrannical and oppressive, if it's just encouraging their natural tendencies, it's not going to be that bad.
Depends what you need for the story.
] |
[Question]
[
On Earth, all plants are green because they contain the pigment chlorophyll, which photosynthesizes by absorbing all light except green light.
However, it is quite possible - if not likely - that alien planets would have plant life (As in, organisms functionally similar to Earth's plants) containing different pigments, especially since green is an non-optimal colour.
There are several common pigments which could be used as plant colours, but their shade differs depending on the spectral type of the star. The cooler the star, the darker the hue, meaning that F-, G- and some K-type stars have the potential support the widest variety of colours (The coolest stars make all the pigments black or near-black, and the hottest ones make them whiteish).
The star which my planet orbits is a G-type star, so it's got a good selection of possible colours.
These are the plant colours, with their pigments, which I have considered having (Definitely green):
* Green - Chlorophyll (Confirmed)
* Purple - Bacteriorhospin
* Yellow/Orange - Carotenes
* Pink - Phycoethryn
* Blue - Phycocyanin
So, my question is: **Can a planet support flora of different pigments, living alongside eachother, without one pigment outcompeting the others?**
I don't see how pigments could "occupy different ecological niches", because their job is just to absorb light. And since some colours absorb more light than others, I'm not sure if green, orange, pink and blue plants could live in the same ecosystem.
[Answer]
I would say yes, if one of the pigments was not the result of the need to attract light. Suppose the planet had a secondary source of nutrients ( possibly older, e.g. geothermic vents) that was much more prevalent than on Earth. That source could influence the pigmentation of the plants that feed on it.
In order not to be relegated into niches like pools of sulfuric water or deep waters, the plants that feed on that secondary source would have to survive in the oxygen-rich environment generated by the other plants (something that the Earth anaerobic organisms can't do well, by definition).
We could imagine that some genetic family could have made the breakthrough of, e.g., turning some part of their reproductive system into a "respiratory" organ: it would fuel a chemical reaction to recreate the chemical formula that was originally best for their metabolism.
That would make them functionally closer to animals, but they would still be plants. In fact, they could to some degree take the place of animals, by consuming the oxygen of the other plants, and reconverting it into CO2. There would be a "balance of power" between the two sorts of plants, and each feeding the other in the ecosystem.
Such plants getting nutrients from the soil and breathing oxygen would be highly "irregular", but the Cambrian explosion showed that many solutions could exist and in nature anything that works can buy survival... at least for a while. I am sure any biologist or a specialist of organical chemistry might find a number of serious objections with such a scenario, but at least it would sound plausible to a layman.
[Answer]
Green is the most common color for plants, but they are not exclusively green already on our planet.
Cyanobacteria, for example, uses other pigments together with chlorophyll, and same do red algae (from which the obvious name).
Chlorophyll is just the most widespread, but there are examples of other colors, like the *[Cordyline australis](https://en.wikipedia.org/wiki/Cordyline_australis)*
Coming to your question
>
> Can a planet support flora of different pigments, living alongside each other, without one pigment out-competing the others?
>
>
>
The answer is definitely yes.
[](https://i.stack.imgur.com/DqFI5m.jpg)
[Answer]
**Lifetime/Growth rate trade-off**
The reason plants do not absorb in the green is to avoid damage.
As a PhD student working on organic solar cells, I can tell you that finding organic materials that can sustain light exposure over extended periods of time is very challenging.
Perhaps on your planet different lifetime/harvest strategies could co-exist: some plants would be long-lived, with sub-optimal absorption (pretty much like ours). Other would harvest at higher wavelengths, grow very rapidly, reproduce quickly and die. Depending on their predators, either of these two strategies might be optimal.
[Answer]
There are two situations I can foresee in which two or more pigments might co-exist:
1. niche lighting; if one pigment takes up red light preferentially while the rest of the spectrum passes through then other photosynthesisers, lower in the biosphere, may use pigments with high efficiencies on other wavelengths to get all they can out of the light that makes it through the red-hungry canopy layer.
2. matching efficiency; if there are two or more photosynthetic pigments with the same performance efficiency at a given light intensity then it's possible that both/all of them would compete on an even footing with each other until something finds a better pigment.
[Answer]
As noted in other answers, multiple colors will be equally viable and thus exist side-by-side if there are multiple ways to achieve equivalent energy. One way that might occur is a planet in a binary star system. The two stars could have each a different spectrum. As the planet turns, the planet would see different suns at different hours. Some plants may efficiently harvest light from A while others harvest B.
For example:
At one sunrise you might see the green plants unfurl, and then at the other sun's rise, the other color plants unfurl. Then when the first sun sets those plants furl up for their "night", while the other plants have the second sun all to themselves. Some plants might have both types of pigment or may even change color through the solar cycles to optimize for the light at that moment.
[Answer]
To have them all be roughly equally prevalent, you need each to have some specific advantage that doesn't edge out all the others, otherwise random variance will cause one to eventually be the dominant form. Plants on Earth are mostly green because green light accounts for the largest amount of solar energy coming through the Earth's atmosphere (well, the largest amount that hits the surface), and therefore the most likely source of over exposure (and thus degradation) of the pigments.
So, the easiest option here is that *something* causes a variation in the spectrum of light hitting the planet's surface. Possibilities I can think of for this include:
* Something about the atmosphere varies based on the time of day or the season. As a result, certain pigments are better either at different times of day, or during different seasons. Seasonal variance is probably more likely here as it already happens to a slight degree on Earth and allows for a more sensible life cycle for the plants.
* Something about the star itself varies on a periodic basis. Orbiting a binary with two different star types (G and something else) would do this, and I would argue that this is actually the most plausible option. Having either an F type or K type star as the other partner would give the best overall stability of the spectrum reaching the planet while still providing enough variance to periodically favor one variety over the others, although I don't know anything about how astronomically possible a G/K or G/F binary system would be.
* Possibly the most interesting, but least plausible: The planet is on a long elliptical orbit around the star (like a comet). Distance from the star impacts the energy of the various frequencies, and thus you get 'seasonal' differences in what pigments are best. Such a planet would have a very hard time supporting life as we know it however.
Alternatively, make it such that green is still the 'best' color in terms of lifetime, but the others have some other advantage not related to energy conversion. Maybe they make the plant more resistant to some types of disease. Maybe they indirectly encourage certain species to more actively pollinate that plant. Maybe they are toxic to certain herbivores, and therefore give the plant an edge in areas where they are prevalent.
[Answer]
There shouldn't be any issue. However, there are a few paths here based on some unknowns:
**Can differently colored plants interbreed?**
If they can, then it's likely that they will mix genes to a point of turning into an averaged color over millions of years. You'd expect the color to fade towards the predominant color mix.
**Are differently colored plants found in the same region, or are they separated?**
If they're separated, then the color muddying won't happen as fast, but it should eventually still happen (birds carrying seeds, humans traveling, even the wind would carry an errant seed now and then.
**Are there notable survivability differences between the plants?**
If, for example, pink plants need less C02 than green plants, they're capable of living in areas with less C02 prevalence.
In areas where green plants can survive, pink plants would have excess resources that they can dedicate to growing larger in size. This can be a cause for slightly varied plant life: pink trees, green shrubs.
Different survivability factors can be a cause for the separation. Inventing some traits to prove the point:
* Pink plants need less oxygen => High altitude locations are predominantly pink.
* Orange plants dramatically drop in efficiency in the cold => The tropics are predominantly orange.
* Blue plants die in warmer environments => Cold regions are predominantly blue.
And so on. The separation doesn't need to be perfect, i.e. other colors can still exist in the same region, but you'd expect a particular color of plant with a particular genetic "skill" to be more prevalent in the region that matches said skill.
But if they can interbreed, and they're in the same region together, they will over time mix their genes enough to lose their individual distinct qualities (including color).
I notice you mentioned:
>
> I don't see how pigments could "occupy different ecological niches", because their job is just to absorb light.
>
>
>
But that is somewhat contradicted when you said:
>
> **On Earth, all plants are green because** ... containing different pigments, **especially since green is an non-optimal colour**.
>
>
>
If you extend your observation that *green is non-optimal yet **ubiquitous***, you will find that just because a trait is predominant doesn't always mean that it was the **key** to the creature's genes increasing their evolutionary prevalence.
How did green become the predominant plant color, if it's not the most optimal color? Because the ancestor plants that were the best survivors just *happened* to be green. They were optimal species for reasons *other than* their color.
Similarly, the plant color traits I mentioned are not necessarily caused by the color. Maybe the cold-resistant plants just *happen* to be blue. Maybe the low-oxygen plants just *happen* to be pink. **There is no inherent requirement for one trait (e.g. survivability factor) to be caused by the other (e.g. color.** They can be coincidental.
And this is how different colors could occupy different niches:
* Initially, there are several colors of plants occupying the same niche.
* Let's assume these plants do not interbreed.
* Over millions of years, one species of plant has adapted to the niche better than any of its competitors.
* Over another million years, this plant slowly takes over the niche and basically turns into a monopoly. So far, it has maintained that monopoly.
* This plant just *happens* to have a certain color.
In other niches, the same thing has happened, but because one niche has nothing to do with the other, the second niche's monopoly ca be maintained by a plant of a different color.
[Answer]
Answer: Sure, it's perfectly possible.
The key point is that the photosynthetic pigment is merely one part (albeit an important part) of the whole photosynthetic pathway, and it's the whole photosynthetic pathway that is important and which evolves. And right here on Earth in the vascular plants, we have two significantly different photosynthetic systems: C3 and C4.
(See Wikpedia's [C3 article](https://en.wikipedia.org/wiki/C3_carbon_fixation) and [C4 article](https://en.wikipedia.org/wiki/C4_carbon_fixation) for details.)
The point is that C3 and C4 plants have co-existed on Earth for millions of years. (Most plant species are C3; the biggest group of C4 plants is the grasses. C3 species tend to do better with moderate temperatures, high CO2 and abundant water. C4 species tend to do better in hot dry environments with less CO2.)
So while it may be difficult for a new pigment to evolve, assuming that the both pigments are roughly comparably efficient, them coexisting over a long period would be nothing special. Been there, done that.
(Of course, we're "only" talking millions of years here. Even a relatively small absolute advantage might push one or the other to complete dominance over a hundred million of half-billion years. But each pigment having advantages over the other in some environments (like in the case of C3 and C4) might prove stable over a much longer time.)
[Answer]
## Different minerals, different colours.
Although many pigments have more to do with chemical structure, some pigments do derive their colour from elements within them like iron or copper. In any case, different regions might be rich in different minerals and plants might be adapted to whatever is present, whether it gives them their colour directly, or by changing their approach to photosynthesis.
[Answer]
Not ALL plants on earth are green, although these are the most widespread. A long, long time ago, we did learn in school about algae, there are of four colors: green, red, brown and blue. The blue ones seem related to cyanobacteria, one of the oldest lifeforms on Earth!
So, it is a fact that here on our own planet, besides the most well-known chlorophyll a and chlorophyll b, there are also other colours of pigment that effectively photosynthesize.
[Answer]
Yes, a planet can harbor plants of different colors. We know because the Earth does.
The color of light changes underwater. Therefore at certain depths red pigments are more efficient than green ones at gathering light, and red algae take profit from that. In any other planet different circumstances may make change the color of light in different places leading to different pigments of photosynthetic organism.
[Answer]
**Your plants have more than one pigment in the same plant.**
There is one easy (relatively) way to do this, plants on your planet don't have one pigment they have two or more in the same plant, if they each catch about half of different but roughly equal parts of the spectrum this should work. For example one blue and one orange, or cyan and orange so the default color is not black. It would be unlikely to evolve in the first place but not impossible and once it did occur having more coverage and controllable variability in absorption will have benefits. This will also allow trace pigments to affect the color more easily since there is less of each pigment.this pigment plant will be relatively stable allowing for a lot of color diversity.
keep in mind plants likely won the "pigment competition" for reasons having nothing to do with color, our best guess is salinity tolerance or by forming a symbiotic relationship with early eukaryotic cells first, so your bi-color plants would be the a similar case it just happened to have a bi-color system just like early plants just happen to be green when other factors made them win.
[Answer]
Remember that colors are not an absolute but a subjective interpretation of electromagnetic waves.
The human eyes and the parts of the human brain which interpret their signals are the result of millions of years of evolution. Our color perception is the way it is because being able to separately filter frequencies of 440 THz (red), 560 THz (green) and 640 THz (blue) has proven to be useful for surviving in our environment.
That means other planets will generally seem less colorful for the human eye, because we did not evolve to perceive and differentiate the color nuances of that planet.
This is, by the way, also the reason why many telescopes operate in ultra-violet or infra-red. Just because these are colors of light our eyes can not see at all does not mean there is nothing interesting in space which shines in those colors.
] |
[Question]
[
Requirements:
1. There is a solid surface.
2. Somewhere on the surface, the temperature exceeds 2,230 C, such that pure silica vaporizes.
3. Elsewhere on the surface, the temperature is at most 25 C, such that humans can be comfortable.
Nice-to-haves:
4. In the human-comfortable temperature region, the surface gravity does not exceed 2g.
5. The surface atmospheric pressure is at least 0.25 bar.
Life does not need to have arisen naturally.
I think I have figured out a way to achieve this, but some peer review would be appreciated! What I have in mind is a sort of hot mini-Mesklin--a super-Earth that rotates extremely quickly, such that it has extreme obliquity, and is also sufficiently close to a hot star. (This may need to be a close system of multiple stars for the planet to get enough light while also being far enough away to not end up tidally braked, and keep its high rotation.)
With little or no axial tilt, such a planet would present a small region near the equator straight-on to its sun, receiving the maximum concentration of light. Over the majority of the surface, the ground would be at a very low angle to the sun, thus being heated considerably less. Extremely fast rotation would also produce a large number of atmospheric circulation cells, impeding the transfer of heat from the equator towards to poles. Thus, with just the right parameters, we should be able to get a planet on which silicate rocks vaporize on the equator, then condense and rain out as glass in the low latitudes where the surface begins to curve away from the sun, and temperatures drop to survivable levels near the poles.
So, what have I got wrong? Am I overly optimistic? If this can't be made to work, is there any alternative approach that can get me glass rain on a planet that humans could land on?
[Answer]
**Meteoric ablation spherules.**
Stony materials entering the atmosphere can vaporize - these are shooting stars. Meteorites reach the melting point of silica and also metallic components which is why they disappear on the way in. Then the vaporized stuff can recondense. This forms meteorite ablation spherules. Those rain down.
[Very high-temperature impact melt products
as evidence for cosmic airbursts and
impacts 12,900 years ago](https://www.pnas.org/content/pnas/109/28/E1903.full.pdf)
[](https://i.stack.imgur.com/MgFuc.png)
>
> Three sites contained conspicuous assemblages of both spherules and
> SLOs that are composed of shock-fused vesicular siliceous glass,
> texturally similar to volcanic scoria
>
>
>
If your planet was traversing an area that was full of siliceous stuff (perhaps kicked up from a big impact on a neighbor planet) that stuff would come in as meteorites. The meteorites melt as they do and then condense into your glass rain.
You can have the weather be whatever you like. But if you are going to sit outside at night and watch the light show, maybe bring a fortified umbrella.
[Answer]
## The parameters are: Glass rain as a weather phenomenon
Specifically, evaporation of silica at the equator, atmospheric currents carry it away to condense and rain. Mechanisms to make glass fall from the sky may exist, but I will try my best to reality-check the OP within the constraints provided:
Silica quartz vaporizes at over 2230C which is a temperature that won’t co-exist on a planet with balmy 65° evenings. I’m sorry, the reality-check answer will be, no glass rain at the beach. But even I wouldn't beleive me on say-so. So let's just check the barometer on this question then.
**Fast Rotation?**
Doesn’t matter. Slower rotation would make a longer day and allow the planet to be further away actually. But that matters like a black head on the nose of our damsel tied to the railroad tracks.
**Wind?** If any planet could have this temperature gradient, the air won’t be happily staying in its zone. You did point this out. But how bad would the currents be? Would circulation cells hold back the storm? No. Storm [winds worse than Saturn](https://www.weather.gov/fsd/saturn#:%7E:text=Saturn%20is%20considerably%20colder%20than,mph%2C%20considerably%20higher%20than%20Jupiter.) will be carrying horizontal rain (shards of glass??) at speeds well over 1,000mph, ripping flesh from your settlers’ bones. Look at the temperature gradient discussed below, and the speed of rotation, and we don't need any math to conclude this point.
**Close to a hot star?** Well then, that *is* the way we go about it. Let's consider how close to a star you need to be to vaporize silica sand (quartz). Remember that before it vaporizes, it becomes liquid. Liquid quartz is, as the question states, glass. Glass is transparent, and this is a problem when you want to absorb radiation to vaporize it. So to be clear, we are using the radiation of the sun to melt quartz (silica) into glass, and then boil that glass into silica vapor. The temperature we need to reach to boil the liquid glass is the important number. It will be T$\_2$ below. The starting temperature, T$\_1$ is how hot the sand is without the sun. That would basically be the night time temperature on the planet. For mercury, that is -180°C. But let's say some atmosphere exists and it's normal. Give it a warm 20°C night time temperature. OK, that starts us off.
We can call the sun a blackbody radiator but glass definitely doesn't absorb everything. The radiation heat transfer between graybody surfaces is more complicated than between blackbodies, because graybodies cannot completely absorb radiant energy projected onto them—instead some of the energy is reflected off the glass, generating multiple reflection and absorption values between the surfaces. But in the end, glass absorbs some energy. The problem is, it absorbs each wavelength differently, so some colors are heating it up, and others are passing right through. Bottom line, a rough approximation of the absorption coefficient of silica glass is $\alpha = 0.2$
The heat transfer from a black body (the sun) to a gray body (our transparent liquid quartz glass) has the following formula:
$$ q=\frac{A\_1(T\_1^4-T\_2^4)}{\alpha}$$
Well, OK. We at least know the two temperatures. These have to be turned into Kelvins to work here. So at your picnic table in Santa's Workshop, it is currently a comfortable $T\_1=293°K$. Down in the tropics, the beautiful, glowing molten beaches at Rio are boiling into the sky at a somewhat less comfortable $T\_2=2503°K $. Oh, look! That cloud looks like a giant glass bunny :)
Sorry, where were we? Oh yeah. Math. Now, these temperatures need to be raised to the 4th power and find the difference:
$$ (T\_1^4-T\_2^4) \\= 2503^4-293^4 \\= 39250337770081 - 7370050801 \\= 3.924e-10^{13} $$
And we know the $\alpha$ is 0.2, so divide our temperature difference by that to get a total power needed to vaporize the glass as $\frac{3.924e-10^{13}}{0.2}=1.9621484e-10^{14}$ times the area of the glass. Well, the area doesn't matter, we're exposing each square meter of it to a square meter of the sun. We just need this planet to be close enough to push $1.9621484e-10^{14}$ Watts into every square meter of glass, and the glass will boil into vapor.
So how close do we need to be to get that kind of energy density? Well, luckily, the power density falls off very predictably with the square of distance. The solar radiation intensity, H$\_0$ in (W/m$^2$), incident on an object is found by:
$$ H\_0=\frac{r\_{sun}^2}{D^2}H\_{sun} $$
Well this is cool, because the radiation intensity we want for H$\_0$, happens to be the radiation intensity that will vaporize our glass, which was our $q$ from the last calculation. H$\_0=q$, radius $r\_{sun}$ we can look up, just like $H\_{sun}$, and $D$ is the thing we're trying to find! So, do the algebra here, get $D$ on the right:
$$ D=\sqrt{\frac{r\_{sun}^2 H\_{sun}}{H\_0}}\\
D=\sqrt{\frac{(6.95e-10^8 \text{km})^2 H\_{sun}}{q}} \\
D=\sqrt{\frac{4.83025e-10^{17}
H\_{sun}}{1.9621484e-10^{14}}} \\
D=\sqrt{\frac{4.83025e-10^{17}
\times6.4e-10^7}{1.9621484e-10^{14}}} \\
D=396,925 \text{km}$$
As you can see, when your planet is almost inside the sun, then glass will boil nicely away into the sky. I do hope you brought your tent stakes, because the Ez-up may have trouble staying put. And the reason that would be bad is because even before you spread the mustard on your ham and rye sandwich, a rain of glass shards at 1,000mph will make for a Bad Day at the picnic grounds, and you will have nothing at all to keep the rain out of the biscuits.
I truly think your planet will be torn to shreds by the tidal forces inside it's Roche radius before any glass rain condenses, and I really don't think there is any place to have a picnic on this planet. The [reality-check](/questions/tagged/reality-check "show questions tagged 'reality-check'") tag has to be answered with a "no."
[Answer]
If you're not insistent on getting reasonably pure silica glass (fused quartz, borosilicate, soda-lime, or optical formulae equivalent), you can find it raining glass *on Earth* several times a year -- more or less continuously for months at a time, some years.
I mean, of course, volcanic ash. These particles are mostly volcanic glass, which while not silica of any purity, is mineral glass formed by rapid cooling of magma at the time it's erupted and sprayed into the air. This is often ejected many kilometers high, and in my own lifetime has drifted all the way around the world (though the fall isn't usually noticeable unless you're within a couple hundred kilometers of the eruption site).
I was under the plume from the Mount St. Helens eruption on May 18, 1980; where I was, we got a fall of a bit more than a centimeter, and areas nearer the mountain (but outside the immediate destruction zone) got up to twenty times that depth. The ash made a pretty unique pottery glaze, but did nothing good for the engines of cars that were driven within the first couple weeks after the eruption.
[Answer]
## Possible, but Highly Unlikely
It's possible via volcano, but it requires a few additional steps. Lava can get pretty hot, but it peaks at around 1100C. Pretty good, but not enough. So instead of using a volcano for lava, we'll use it for something else - aluminum deposits. Aluminum is quite rare, but it [does occur naturally](http://webmineral.com/data/Aluminum.shtml) - only in low oxygen environments like volcanos.
Now let's say you were to mix that aluminum with, say, iron oxide. Iron oxide does occur naturally in large quantities. Mixing them poses a challenge, given that there's a volcano in this area, but it's not *impossible*. Just highly unlikely. (Also, ideally, both objects should be powdered beforehand.) However, there's an interesting scenario which should take care of that - a tornado.
Picture the scene - a tornado whips through a quarry and takes up aluminum stones alongside iron oxide deposits and then bashes them against each other to form a sandstorm-esque debris field. Now, this is important because mixing aluminum and iron oxide is a crude recipe for **thermite**, which burns at a crisp 2,200 C. A bolt of lightning (or honestly just the friction from the tornado) will light it on fire, and given that thermite is self oxidizing, the fire will not go out.
If this thermite-tornado hits a silicon deposit (like a beach, for instance), it may be capable of generating these shard of glass you desire. I would also like to point out that I would never want to live on a planet where 'thermite-tornado' is a weather condition.
[Answer]
Why didn't anyone mention the [eyeball planet](https://en.wikipedia.org/wiki/Eyeball_planet)?
This is the only way that allows not being inside the sun, not being ripped apart by tidal forces, not relying on rare events like meteorites or volcanoes.
With this config you can have high temp on the side that is directed towards the sun, and people living at the dark side of the planet, with constant wind with sand that originated as boiling glass. As planet is tidally locked, people are always in the dark. Even the [twilight zone](https://en.wikipedia.org/wiki/Terminator_(solar)) is too hot for the people, so people can't even collect the sunlight. Surviving there will be hard.
And sandy air doesn't really feel like a rain of lava, but that is as close as you can get to what you want.
For keeping 0.25 atm and temp diff at the same time you will likely need very large planet. Small planet will easily equalize the temp with 0.25 atm. As gravity is limited to 2 g, planet will need to have very low density in order to maintain the size as large as possible.
So it will have to be a tidally locked planet, people in permanent darkness, a low density planet with a large size.
Also this planet makes interesting point of not being able to use rockets due to scorching sun, part of orbit going across the molten lava eye of the planet that will even make heat shield an impossible task, large gravity well. As planet grows in size even with the same g on the surface, leaving it with a rocket becomes harder and harder. This planet is probably even worse than a [Kessler syndrome](https://en.wikipedia.org/wiki/Kessler_syndrome) planet in terms of 'nope' for space travel. Leaving Kessler syndrome planet is risky but possible and gets better over time. This hell will never get better, never improve, no option to gradually solve the issue. Just an eternal hell with no way out.
P.S. Your idea won't work because such a large temp diff requires people being away even from a twilight zone. Your people are placed in a twilight zone.
[Answer]
**A Self-Answer**
For additional background, this is a question I have been thinking about off-and-on for many, many years, originally inspired by exoplanet [HD 189733 b](https://en.wikipedia.org/wiki/HD_189733_b), which may very well actually have [silicate clouds and glass rain](https://www.nasa.gov/image-feature/rains-of-terror-on-exoplanet-hd-189733b). (And which has a *very weird* atmosphere, quite far out of chemical equilibrium!) Combine that with Larry Niven's worldbuilding idea of finding planets with a habitable *point*, and you get this question--is there a possible world which has glass rain like HD 189733 b, but also has a habitable point?
The radiative temperature of [HD 189733 b] is only about 700C, which is not hot enough to produce a significant vapor pressure of silica; it's silicate clouds are almost certainly a result of higher temperatures in the lower levels of a very thick atmosphere. To have any hope of finding a habitable point, we will need a much thinner atmosphere to minimize heat transfer, which means a much higher stellar power input.
With particular thanks to [Vogon Poet](https://worldbuilding.stackexchange.com/a/224689/2800), I think it's quite clear that a mini-Mesklin isn't going to work out after all--there's just no realistic way to get enough power input in an orbit that won't also lead to tidal breaking... unless, perhaps, you are orbiting a supergiant, but then the angular size of the star in the sky becomes seriously non-negligible, and polar cold isn't a thing anymore. (I will point out that natural glasses tend to be brown or black, so the 0.2 absorption coefficient for pure silica is likely extremely pessimistic; but, that doesn't make a big enough difference to save the mini-Mesklin concept.) Avoiding the Roche limit is, fortunately, not too big of a deal--we just need a star that is hotter than our Sun, to provide equal power at a more tidally-favorable distance. (That's less than ideal if we want interesting aliens to evolve here, but note that native life--let alone interesting native life--is *not* a requirement.)
And I had previously dismissed the tidally-locked, eyeball-world possibility, because even relatively thin atmosphere turn out to transfer heat surprisingly well, per [Simulations of the Atmospheres of Synchronously Rotating Terrestrial Planets Orbiting M Dwarfs](https://www.sciencedirect.com/science/article/abs/pii/S0019103597957936), and boiling silica at 2230C (boiling anything, really, if there're planet-forming quantities of it around) will produce a thick atmosphere; literally, 1 bar of atmosphere, based on the definition for how boiling points are measured! (I.e., standard boiling point = the temperature at which the vapor pressure of a substance is 1 atmosphere.)
But then I discovered [this lovely paper](https://arxiv.org/pdf/1312.7592.pdf) on the phase diagram of of high-temperature silica, which has all sorts of useful information--but, most critically, it turns out that the vapor phase boundary curve of pure silica is not particularly steep, and silica actually still has fairly significant vapor pressure at much lower temperatures. E.g., a "mere" 1160C still gets you a vapor pressure of approximately 0.25 bars. Additionally, the vapor phase has *strong* dissociation, with the largest fractions of gaseous components being silicon monoxide and diatomic oxygen--and silicon monoxide has a much lower boiling point than silica (silicon dioxide)--and has much higher optical absorption and emissivity!
So, strictly to meet the requirements of the question, we need one point--the substellar point--on the surface to actually hit 2230C, but things can cool off rapidly moving away from that point and still support a very wide region of silica clouds and glass rain. And really, it doesn't actually *need* to get up 2230C--the boiling point of silica under 1 full Earth atmosphere--at all. And we can also, quite fortuitously, end up with abiotically-generated free oxygen in the atmosphere!
Now, the question remains--can we isolate this high-temperature silicate atmosphere from a lower-temperature region that humans could survive in? Well, by the time the temperature drops to around 500C, vapor pressure drops to the millibar level, so there won't be much further atmospheric heat transport past that point. Thus, I suspect that, yes, we *can* isolate the heat to the dayside of a synchronously-rotating eyeball world. As long as the temperature is not *too* hot across *too much* of the dayside, which would result in producing a globe-spanning high-pressure silicate atmosphere, it should be possible to arrange for relatively low pressures produced by evaporation near the substellar point supporting silicate clouds and glass rain across most of the dayside, with the boiling-induced atmosphere all freezing out not too far past the terminator. This sets up a geologic-recycling system where material is evaporated away from the subsolar point, deposited to form lava oceans across the dayside and eventually to build mountains near the terminator, and returns in the short-term for re-evaporation through surface lava current flows, and in the long-term through mantle circulation and the weight of mountains pushes the mantle downwards and causes upwelling near the substellar point.
(Note that, while some *pure* minerals and metals have melting points above 2230C, such substances are relatively rare in a planet of vaguely Earthlike composition, tend to be heavy and so not concentrate at the surface of a lava ocean, and will dissolve into each other, such that pretty much *everything* is liquid by the time you hit 1200C. So, we don't need to worry about continents of refractory materials forming and halting the liquid/vapor silicate cycle.)
This would leave the dark side Extremely Cold, just as it is on Mercury, because rock is not a great conductor of heat through the bulk of the planet. However, that's easy to fix if we just add a second star to the system which will provide a regular day-night cycle to the dark side.
So, all that remains are some nice-to-haves; we can heat the dark side comfortably by introducing a second star, but can we put a region with .25 bars of atmosphere that's not in thermal contact with the dayside somewhere on that dark hemisphere? For that, I have to give a solid *maybe*, based on the concept behind Larry Niven's world of [Canyon](https://larryniven.fandom.com/wiki/Canyon) and the real-world [Hellas impact basin](https://en.wikipedia.org/wiki/Hellas_Planitia). Put a Sufficiently Deep impact crater or crust-contraction canyon like Mars's Valles Marineris on there, and abiotically-dissociated oxygen can just slowly fill it in....
[Answer]
## Part One: Gravity-Related
First, the last sentence of the question asks for glass rain on a planet that humans can land on. But the rest of the question asks for a planet which would be in parts habitable for humans. There is a big difference between a world haBitable for humans and one which humans can land on and even take off from alive, as any astronaut who has ever been to the Moon can tell you.
Leaving aside the question of the temperatures, would the world as described be habitable for humans?
The nice-to-have section includes:
>
> In the human-comfortable temperature region, the surface gravity does not exceed 2g.
>
>
>
In [*Habitable Planets for Man*](https://www.rand.org/content/dam/rand/pubs/commercial_books/2007/RAND_CB179-1.pdf), 1964, Stephen H. Dole discusses the requirements for a world to be habitable.
Dole discusses the human gravity requirements on pages 11-13. Doles says that there was no evidence of a minimum gravity requirement then - now there is much evidence that extended stays in microgravity have bad effects on human health, and nobody know what the lower gravity limit will be yet.
For the upper gravity limit, Dole discusses experiments with men in centrifuges. Men with suitable support and in the correct postures can endure a few gs for short times. Men can also walk and move and manipulate objects in higher gravity than 1 g.
Tests showed that the time it took to complete various task increased with increased gravity, and that the times became quite excessive over 2 g.
Dole doubted that humans would ever want to colonize a world with a surface gravity over 1.25 or 1.5 g.
There are several ways you can react to this info:
1. Dig up research that indicates that humans would be willing to colonize a 2 g planet because its effects are not as bad as was thought when Dole wrote.
2. Decide that the surface gravity in the human habitable parts of the planet will be no more than 1.25 g or 1.5 g.
I note that will result in the surface gravity at the equator being somewhat less than at the human habitable regions. Which may or may not matter much if nobody ever goes to the equator.
As I just stated, if you go with a disc-shaped planet, a mini-Mesklin, the surface gravity will vary with latitude. And so will the escape velocity, I think. And unfortunately for science fiction writers, surface gravity and escape velocity do not increase or decrease at the same rate but need to be calculated separately. And the escape velocity is important for the planet's ability to retain an atmosphere for long enough for the planet to become habitable for humans.
On pages 34 to 35, Dole discusses the relationship between escape velocity and atmospheric retention.
You may also need to calculate the orbital velocity at the equator of your planet design.
3. You may decide that the human colonists are descended from many generations of humans who colonized planets with higher and higher surface gravities, thus becoming conditioned to survive and be happy in higher gravity than humans from Earth could.
4. Or maybe the colonists on your planet have been genetically modified to have greater tolerance for high gravity than unmodified humans.
5. Maybe the colonists on your planet use anti-gravity to make their buildings and settlements comfortable and healthy, and maybe they use anti-gravity vehicles and wear anti-gravity belts when exploring or working outdoors.
6. Or maybe the humans have colonized another world in the system with a lower gravity, and only come to your high gravity planet to take rich tourists for short visits that don't endanger their health. Maybe the tourists come to the planet to hunt exotic creatures, or to see a great natural wonder, or to experience the glass rain, or for some other reason. And possibly a discovery that the visits to the planet of grass rain actually involve too long exposure to the high gravity and are endangering people's health could be a plot point.
**Part Two: Rapid Rotation**.
The planet Earth has an equatorial radius of 6,378.137 kilometers and an equatorial circumference of 40,075.017 kilometers. Since it rotates once a day, once in 24 hours of 3,600 seconds, or once in 86,400 seconds, mater on the Earth's equatorial surface has a rotational speed of 0.4638312 kilometers per second.
Actually 24 hours is the synodic day of the Earth, the time it takes to rotate 360 degrees with respect to the Sun. That is slighty longer than the sidereal day, the time it takes the Earth to complete one physical rotation with respect ot the stars, and the time period which causes the equator to bulge slightly.
The sidereal rotation period of the Earth is about 23 hours (3,600 seconds each), 56 minutes (60 seconds each), and 4.100 seconds long. So it is 82,800 seconds plus 3,360 seconds plus 4.100 seconds. Or 86,164.1 seconds. So material at the surface of Earth's equator travels at a speed of 0.465101 kilomters per second.
Imagine a planet which has twice the equatorial radius and circumference of Earth, and has the same sidereal rotation period. It will have an equatorial surface rotation period of 0.930202 kilometers per second.
A planet which has three times the equatorial radius with the same rotation period as Earth will have an equatorial surface speed of 1.395306 kilometers per second.
A planet which has four times the equatorial radius with the same rotation period as Earth will have an equatorial surface speed of 1.860404 kilometers per second.
And so on.
So imagine planets which have the same equatorial radius as Earth but rotate faster that Earth's equatorial surface speed of 0.465101 kilomters per second.
A planet rotating twice as fast in half a sidereal rotation period will have an equatorial surface speed of 0.930202 kilometers per second.
A planet rotating three times as fast in 1/3 of a sidereal rotation period will have an equatorial surface speed of 1.395303 kilometers per second.
A planet rotating four times as fast in 1/4 of a sidereal rotation period will have an equatorial surface speed of 1.86040404 kilometers per second.
A planet rotating five times as fast in 1/5 of a sidereal rotation period will have an equatorial surface speed of 2.325505 kilometers per second. It will rotate once in 17,230.82 seconds, 4.78 hours.
A planet rotating ten times as fast in 1/10 a sidereal rotation period will have an equatorial surface speed of 4.65101 kilometers per second. It will rotate once in 8,615.41 seconds, 2.393 hours.
A planet rotating fifteen times as fast in 1/15 of a sidereal rotation period will have an equatorial surface speed of 6.97515 kilometers per second. It will rotate once in 5,744.27 seconds, 1.596 hours.
A planet rotating twenty times as fast in 1/20 of a sidereal rotation period will have an equatorial surface speed of 9.30202 kilometers per second. It will rotate once in 4,308.205 seconds, 4.78 hours.
Of course planets roatating that fast will becomemoreoblate, so Earth mass planets with those rotation rates would have larger equatorial diameters and thus would have faster rotational speeds on their equatorial surfaces.
Dole discusses the oblateness of rotating planets on pages 41 to 46. And from his discussion it would seem that it would probabily be difficult for a planet to stay intact with a high degree of oblateness due to rotation.
Dole, on pages 58 to 61, discussed the effects of rotation rates on planetary habitability. If the planet rotated too slowly, the long days and long nights would get too hot and too cold, and plants might die from lack of sunlight during the long nights. Dole decided that a rotation period of 96 hours (4 Earth days), would be about the maximum length consistent with habitability.
And Dole said that if a planet rotated too rapidly its surface gravity would fall to zero at the equator or it would become unstable.
>
> If rotation rate were increased steadily, a limiting point would be reached when surface gravity at the equator fell to zero and matter was lost from the planet, or when the shape of the surface became unstable and axial symmetry was lost.
>
>
> Just what extremes of rotation rate are compatible with habitability is difficult to say. These extremes, however, might be estimated at, say, 96 hours (4 Earth days) per revolution at the lower end of the scale and 2 to 3 hours per revolution at the upper end, or at angular velocities where the shape becomes unstable due to high rotation rate.
>
>
>
Earth has an equatorial radius of 6,378.137 kilometers. According to this orbital calculator, a satellite of Earth 6,378.14 kilometers from the center, or 0 kilometers above the equator, would have an orbital period of 1 hour 24 minutes and an orbital velocity of 7.9053 kilometers per second (km/s).
<https://keisan.casio.com/exec/system/1224665242>
A satellite at twice that distance, would have an orbital speed of 5.5899 km/s and an orbital period of 3 hours 58 minutes.
A satellite at 3 times that distance would have an orbital speed of 4.5641 km/s and an orbital priod of 7 hours 19 hours minutes.
A satellite at 4 times that distance would have an orbital speed of 3.9526 km/s and an orbital priod of 11 hours 15 minutes.
A satellite at 5 times that distance would have an orbital speed of 35353 km/s and an orbital priod of 15 hours 44 minutes.
A satellite at 10 times that distance would have an orbital speed of 2.4998 km/s and an orbital priod of 44 hours 31 minutes.
A satellite at 15 times that distance would have an orbital speed of 2.411 km/s and an orbital priod of 81 hours 48 minutes.
A satellite at 20 times that distance would have an orbital speed of 1.7676 km/s and an orbital priod of 125 hours 56 minutes.
So if a world with the mass of the Earth has a diameter too many times larger than Earth's and rotates with the same period as Earth, material at the equator surface will have will have a surface velocity greater than orbital velocity and will move to a higher orbit, leaving the surface of the planet.
And if a world with the mass of the Earth has the same diameter as Earth but rotates too many times faster than Earth, material at the equator surface will have will have a surface velocity greater than orbital velocity and will move to a higher orbit, leaving the surface of the planet.
Thus there are limits to how fast a planet with the mass of Earth can rotate,and how oblate it can become, before it starts to break up.
Of course a way around that is to increase the mass of the planet to give it a higher orbital velocity at different distances from the center, thus making the orbital velocity higher than the equatorial surface speed.
But there are limits to how much you can increase the mass of the planet, without increasing the surface gravity and having other bad effects.
For example, plate tectonics, and a magnetosphere generated by an liquid interal region of the world, are considered to be desirable for the habitability of a planet.
This article suggests that the mass of a world determines whether it can have those desirable features.
<https://faculty.washington.edu/rkb9/publications/hb13.pdf>
On page 20:
>
> A minimum mass of an exomoon is required to drive a
> magnetic shield on a billion-year timescale (MsT0.1M4;
> Tachinami et al., 2011); to sustain a substantial, long-lived
> atmosphere (MsT0.12M4; Williams et al., 1997; Kaltenegger,
> 2000); and to drive tectonic activity (MsT0.23M4; Williams
> et al., 1997), which is necessary to maintain plate tectonics
> and to support the carbon-silicate cycle. Weak internal dynamos have been detected in Mercury and Ganymede
> (Gurnett et al., 1996; Kivelson et al., 1996), suggesting that
> satellite masses > 0.25M4 will be adequate for considerations
> of exomoon habitability. This lower limit, however, is not a
> fixed number. Further sources of energy—such as radiogenic
> and tidal heating, and the effect of a moon’s composition and
> structure—can alter the limit in either direction. An upper
> mass limit is given by the fact that increasing mass leads to
> high pressures in the planet’s interior, which will increase the
> mantle viscosity and depress heat transfer throughout the
> mantle as well as in the core. Above a critical mass, the dynamo is strongly suppressed and becomes too weak to
> generate a magnetic field or sustain plate tectonics. This
> maximum mass can be placed around 2M4 (Gaidos et al.,
> 2010; Noack and Breuer, 2011; Stamenkovic´ et al., 2011).
> Summing up these conditions, we expect approximately
> Earth-mass moons to be habitable, and these objects could be
> detectable with the newly started Hunt for Exomoons with
> Kepler (HEK) project (Kipping et al., 2012).
>
>
>
This suggests that the upper mass of a habitable world should be about 2.0 Earth mass.
Their sources are:
Gaidos, E., Conrad, C.P., Manga, M., and Hernlund, J. (2010)
Thermodynamics limits on magnetodynamos in rocky exoplanets. Astrophys J 718:596–609.
Noack, L. and Breuer, D. (2011) Plate tectonics on Earth-like
planets [EPSC-DPS2011-890]. In EPSC-DPS Joint Meeting 2011,
European Planetary Science Congress and Division for Planetary Sciences of the American Astronomical Society. Available
online at <http://meetings.copernicus.org/epsc-dps2011>.
Stamenkovic´, V., Breuer, D., and Spohn, T. (2011) Thermal and
transport properties of mantle rock at high pressure: applications to super-Earths. Icarus 216:572–596.
And a rocky planet with too much mass will have a high enough escape volocity to reain large amounts of helium or even hydrogen,thus becoming a gas giant. The tremendous pressures and temperatures at the cores of gas giants mean that they have no solid surfaces to stand on.
**Part Three: Suggestions**
One) Perhaps your planet has or had several small moons. A collison of moons might have turned them into lava, which is sort of a glass. The molten lave would gradually cool and solidify into amoon of pumice. Then another collison with another moon could have shattered the pumice moon into a ring. Particles of different masses might move to different distances from the planet, and collisons between particles might result either in them clumping together into larger pieces, or shattering into smaller pieces.
And perhaps tidal interactions with the planet, the star, other ring particles, and any surviving moons, might cause ring articles of the correct size to spiril in toward the planet and eventually fall onto the surface in showers.
It is speculated that falling ring material might have created the equatorial ridge on Iapetus, a moon of Saturn.
However, the creation of the ring would proabably have happened early in the history of theplanet, before it was capable of supporting advanced oxygen breathing lifeforms. And the ring system would proably only last for a few tens or hundreds of millions of years, so the planet would probably still not be habitable for advanced lifeforms by the time the ring system was gone.
Maybe the collisons and formation of the ring system happened unusually late in the history of the solar system, when the planet was already habitable. Or maybe it happened when the planet was young, but an advanced civilizaiton terraformed the planet to make it habitable billions of years before it otherwise would have become habitable.
Two) Cryovulcanism.
An example of cyrovulcanism is on Triton, the large moon of Neptune.
>
> The Voyager 2 probe observed in 1989 a handful of geyser-like eruptions of nitrogen gas and entrained dust from beneath the surface of Triton in plumes up to 8 km high.[32][58] Triton is thus, along with Earth, Io, Europa and Enceladus, one of the few bodies in the Solar System on which active eruptions of some sort have been observed.[59] The best-observed examples are named Hili and Mahilani (after a Zulu water sprite and a Tongan sea spirit, respectively).[60]
>
>
> All the geysers observed were located between 50° and 57°S, the part of Triton's surface close to the subsolar point. This indicates that solar heating, although very weak at Triton's great distance from the Sun, plays a crucial role. It is thought that the surface of Triton probably consists of a translucent layer of frozen nitrogen overlying a darker substrate, which creates a kind of "solid greenhouse effect". Solar radiation passes through the thin surface ice sheet, slowly heating and vaporizing subsurface nitrogen until enough gas pressure accumulates for it to erupt through the crust.[7][45] A temperature increase of just 4 K above the ambient surface temperature of 37 K could drive eruptions to the heights observed.[58] Although commonly termed "cryovolcanic", this nitrogen plume activity is distinct from Triton's larger scale cryovolcanic eruptions, as well as volcanic processes on other worlds, which are powered by internal heat. CO2 geysers on Mars are thought to erupt from its south polar cap each spring in the same way as Triton's geysers.[61]
>
>
>
<https://en.wikipedia.org/wiki/Triton_(moon)#Cryovolcanism>
>
> Turbulence at Triton's surface creates a troposphere (a "weather region") rising to an altitude of 8 km. Streaks on Triton's surface left by geyser plumes suggest that the troposphere is driven by seasonal winds capable of moving material of over a micrometre in size.[45]
>
>
>
<https://en.wikipedia.org/wiki/Triton_(moon)#Cryovolcanism>
So the winds in Triton's ultra thin atmosphere are capable of moving tiny particles in the pluse of vapor from the geysers.
Suppose that your planet has a lot of icey materials and lots of mineral glass from volcanic eruptions, asteroid impacts, or whatever, mixed in with the ices. Internal heat and heat from the star may melt a lot of ices into liquids and evaporate them into gases. When gas pressure builds up too high, the gases will burst up through the ices and enter the atmosphere, carrying small particles of glass with them.
The glass dust might later rain down in various locations. if the glass is the same size as the dust that water drops form around, it might be the nucleus of actual rain drops which rain down. I don't know if the rainwater would have to be deglassified before it was safe to drink.
But how can there be cyrovulcanism on a planet that is as warm as Earth?
I personally, have observed patches of ice over liquid water just a few days ago. The dog I was walking sat down in one, cracking the ice so it could wallow in the mud.
There is lots of permanent ice on Earth,an d much more seasonalice. And during glacial periods there was more ice.
Possibly if the planet has long enough days, most of the ice in equatorial regions might sublimate into water vapor during the long days. During the long nights, most of the water vapor becomes liquid water and dew, and then ice forms over the liquid water. In the morning the sun warms up the trapped water mixed with glass dust udner the ice, and water vapor builds up until it erupts in gyesers, carrying much glass dust with it. The rain of water and glass dust might happen soon after sunset.
So those are my suggestions.
[Answer]
## Things will settle down after a certain period of time.
Let us suppose that it is happening as you stated. Then over a period of time, *all the silicate rocks on the equator will vaporize and condense and rain out as glass in the low latitudes*.
After that there will be no more *silicate rocks on the equator* and no danger of glass rain.
[Answer]
A different approach:
**Volcanism.**
We have something like this on Earth. Volcanic ash (depending on the chemistry of the particular volcano) can be raining glass - except that we have quite small particles.
What we need to make the particles bigger:
1. The erupted material needs to fall down slower (less surface gravity)
2. It has to cool down slower (less atmosphere)
3. A small planet with active volcanism means that the planet is quite young and/or contains greater proportion (than Earth) of radioactive elements.
[Answer]
It's been raining glass here on earth since the Jurassic. Just on the ocean floor which is 70% of the planets surface. Diatom plankton build their cell walls out of sillica. If your world has similar critters that store hydrogen inside themselves to float and live high up in the atmosphere after an aquatic phase building their adult shells. It would rain beads of glass often, even having clouds of the skyplankton coloring your sky or even glowing at night.
[Answer]
A world that rain glass would need to have clouds made of silicon and oxygen or other exotic composition. Anyway this planet cannot be habitable because either the lifeforms in such a planet would be severely hurt by the fall of solid glass pieces making the evolution of life pretty hard or life could not evolve at all as solids are made of molecules that have a fixed position and the chemical reactions needed for the creation of biomolecules like RNA and DNA need to take place inside a fluid which in the case of Earth is water.
] |
[Question]
[
Let's assume that we live in a world similar to ours, but with bio and nanotechnology that is 25 years (give or take a few) ahead of what we have today. Few years ago scientists in most advanced country created a programmable nanobots. They were able to withhold this information from public for a time needed to infect around 99,9% of their country population, and currently around 70-95% of the world is infected (most developed countries are at average 95%, while least developed are at 70%). Moreover only government is able to tell with 100% accuracy who was infected and who was not.
Since then single government has assumed total control of people lives: they are picking your partners, job, education, even your lifestyle. Any disobedience is severely punished.
Let's assume that nanobots can do following things:
* Control your basic feelings (fear, joy, rage, ...)
* Check what you are seeing or hearing
* Cause pain on different levels
* Control your hormone levels
* Kill you
* They operate on the same substances your muscles are using
* They can replicate inside your body
* They have capabilities similar to nowadays cell phoenes (GPS, Wi-Fi, GPRS, 'background' offline programs, ...)
* They cannot read your mind.
Of course in such a world it would be expected for people to form some kind of resistance. No matter how much I have thought about it I was unable to find a way for rebels to win against government. Every scenario I have considered was ending in (usually quite swift) government victory. Is there any, even remotely possible, (let's not consider multiple asteroids hitting every possible command center) way for people to restore democracy in such world?
Side note: Please forgive me any possible grammar mistakes. Please suggest corrections, and I will try to include them.
[Answer]
**TL;DR** EMPs probably won't work and simple magnets won't help on silicon machines. But offering honey-pot-counter-bots that attach to the offender and render them useless or use blood transfusion and a cleaning mechanism might work.
---
## Reality Check
[Professor Bradley Nelson of ETH Zürich](http://www.micronano.ethz.ch/people/bnelson) managed to build a nanomachine that could be remote controlled and moved through a (hopefully dead) cows eye in 2004 [Research site of the institute](http://www.micronano.ethz.ch/research/index).
[Raymond Kurzweil](http://en.wikipedia.org/wiki/Ray_Kurzweil), director of engineering at Google, has published the book [*The singularity is near*](http://books.google.at/books?id=9FtnppNpsT4C&pg=PT388&lpg=PT388&dq=Ishiyama+nanobot&source=bl&ots=K24pUD_0Bw&sig=gUWRwBsVOge1vuQgOSxEq1KdAOg&hl=de&sa=X&ei=nOl1VLbeAuOaygP3ioDIBw&ved=0CDUQ6AEwBA#v=onepage&q=Ishiyama%20nanobot&f=false), which is quite some detailed reality check - with some restrictions (taken from one of the reviews)
>
> This starts with the thesis: Technological change is exponential!
> This has been true for many measures such as micro-processor size, cost of mass-produced goods, etc. It is not, however, a general rule of thumb to apply blindly to all things "technological"! This seems to be Kurzweil's big mistake. He extrapolates features of technology to an unrealistic infinity. [...]
>
>
>
By "remote controlled" and "stearing", they actually mean metal coated boxes (namely: "Nano Containers") that move along a persons veins. [Professor Zhang Li from University of Hong Kong](http://www3.mae.cuhk.edu.hk/people/list.php?name=lizhang) claims that he can remote control nanobots in a body. In fact it's nothing more than a magnet moving a box in a tube forwards or backwards. So they are far from real external controls as the electromagnets probably house the person in total.
>
> the nickel-coated microbots are steered wirelessly by electromagnetic fields
>
>
>
Quite interesting are the mentions (incl. footnotes that I can't verify as I don't have the book at hand) of Professor Kensall Wise of the University of Michigan who seems to have built monitoring probes that allow precise monitoring of neural electrical activity and of [Prof. Kazushi Ishiyama](http://www.riec.tohoku.ac.jp/lab/elecbio/index-e.html) head of *Ishiyama Laboratory* of the [Tohoku University](http://www.tohoku.ac.jp/en/) who [acc. to R.Kurzweill] has built micromachines that deliver drugs directly to "precise locations in the brain". I would take this info with a grain of salt, as the university [does not have any research paper](http://db.tohoku.ac.jp/whois/e_detail/979e1832e59b042fd4660ab5170e3203.html) about this.
According to Chris Phoenix, director of Research at the *Center of responsible Nanoresearch*, who has written about Nanofactories in his [paper for the Journal of Evolution & Technology](http://www.jetpress.org/volume13/Nanofactory.htm), the major problem seems to be mass manufactoring. In the paper he reviews the major previous ideas in the [Background chapter](http://www.jetpress.org/volume13/Nanofactory.htm#s2) showing the logic gaps in all the existing sketches and concepts.
**Manufacturing** While an optimistic view, like the one of *Kurzweill* states that if everything goes well, we will have usable nanomachines by 2020, there's no sign of mass production in the near future. *Phoenix* shows exactly how problematic design changes are when operating mass manufacturing at atom level. While building a prototype in a laboratory might already be possible, there's a lot of missing pieces to make this possible in a production chain.
**Communication** It may be possible that there are already prototypes (of which I couldn't find a paper) that could be remote controlled already, it won't be possible in near future to send a constant stream of visual real time data. The human eye is far beyond HD vision and is able to see up to 225 fps [Fighter pilots, no citation found] in a field of view, close to 180 degrees at around 550MP. Now try to transfer that amount of data and imagine how much energy you would need to transport that. So this is the most unrealistic part. Pretty much the same goes for audio data. Another problem will be that even when all the data *can* be read and transported LoFi, there would be constant interruptions through steel-concrete ceilings and walls, subway stations, etc. Also the range of field would be quite small and therefore would need a quite dense network of relays and signal amplifiers and relay stations.
Let's go through the list:
* ✓ Control your basic feelings (fear, joy, rage, ...)
* ✗ Check what you are seeing or hearing
* ✓ Cause pain on different levels
* ✓ Control your hormone levels
* ✓ Kill you
* ✗ They operate on the same substances your muscles are using
* ✓/✗ They can replicate inside your body (depending on the time this scenario is in)
* ✗ They have capabilities similar to nowadays cell phones (GPS, Wi-Fi, GPRS, 'background' offline programs, ...)
* ✓ They cannot read your mind.
## Who is Who?
[IEEE Spectrum](http://spectrum.ieee.org/computing/hardware/whos-who-in-the-singularity) has a nice PDF that shows every (in their view) important actor in this research field, allowing you to weight one opinion to the other more easily. **Stay critical** to everything you read as everything is just an assumption. Remember what we imagined the future to be in 2015? Flying rocket cars, holograms, etc. What have we got? Supercomputers in our pockets that we use to watch and share baby pictures and cat videos with people that we mostly don't meet in the real world. The future might no be what gets predicted by scientific researchers (in a single field).
## Fighting off the Singularity
An interesting thought that goes against the assumptions made by *transhumanists* - who think that we will have better blood cells able to repair wounds quicker, transport more oxygen, fighting bacteria and viruses, etc. - is stated by Richard A.L. Jones in his article *[Rupturing the Nanotech Rapture](http://spectrum.ieee.org/semiconductors/nanotechnology/rupturing-the-nanotech-rapture)*
>
> First, those building blocks--the cogs and gears made famous in countless simulations supporting the case for the singularity--have some questionable chemical properties. They are essentially molecular clusters with odd and special shapes, but it's far from clear that they represent stable arrangements of atoms that won't rearrange themselves spontaneously. These crystal lattices were designed using molecular modeling software, which works on the principle that if valences are satisfied and bonds aren't too distorted from their normal values, then the structures formed will be chemically stable. But this is a problematic assumption.
>
>
>
This means (more detail in the article) that the carefully crafted atomic structure of one molecular machine could be easily damaged if exposed to a substance it wasn't crafted for. So simply making a blood transfusion (as in exchange) with non-infected blood will give you a lot of chances to extract the machinery: Starting with mixing blood with water to destroy them and then using a simple filter mechanism to divide blood and water by its specific weight would be possible. It would as well be possible to craft your own nano machines that mimic target cells to attract an enemy machine and expose an atom on contact that attaches to the offending machine on contact rendering them useless or blocking their movement. Another possibility might be to use silicon magnets, as research by a team of scientists led by Paul Snijders of the *Department of Energy's Oak Ridge National Laboratory* and published in the *New Journal of Physics* in 2012, to extract **nano machines built out of silicone atoms**:
>
> [...] The surprise is that while bulk silicon is non-magnetic, the edges of nano-ribbons of this material are magnetic. [...] the electron spins are ordered anti-ferromagnetically, which means they point up and down alternatingly. Configured this way, the up and down spin-polarized atoms serve as effective substitutes for conventional zeros and ones common to electron, or charge, current. [...] "By exploiting the electron spins arising from intrinsic broken bonds at gold-stabilized silicon surfaces, we were able to replace conventional electronically charged zeros and ones with spins pointing up and down".
>
>
>
[Answer]
Anything that is programmable, is hack-able. The first thing to do would be to hack the nanobots. Also 'tinfoil' hats come in here, block the incoming and outgoing signals and you have some control and privacy.
The most likely scenario would be for the resistance to find a 'kill' switch for the nanobots so they become inert or permanently shut down. That is one problem with this type of technology, someone else could hack the system and make it do things the originators didn't want or intend.
[Answer]
You can also use the great power of physics. A high intensity [electromagnetic pulse (EMP)](http://en.wikipedia.org/wiki/Electromagnetic_pulse) could shutdown every nanite in a given area. This could be used.
An atomic bomb exploding safely away could destroy nanites of a entire city. You could build a EMP generator only for you, with "few" use of electricity, an using accessible material to everyone.
You can build a disguised EMP generator bit by bit patiently, so they will never notice.
[Answer]
Ok, here are my thoughts on this:
First of, I assume that only those who are not infected with nanobots will be part of the revolution. Since the bots can manipulate people to a high degree (even control their emotions), the government could program the bots to keep infected people happy, thus giving them no reason to revolt.
So the minority of the uninfected would have to conduct the revolution. If we assume that fighting the nanobots by weapon power is futile (those little bastards are hard to hit!), the only way to stop them would be to destroy the chain of command. So if there is a central control center, the uninfected could blow it up (remember Star Wars - The Phentom Menace? The space station was destroyed and the robots on Naboo stopped working). Of course that only works when there is one central control units (or several units that are destroyed simultaneously) which the bots depend on to make decision; if the bots keep on working and manipulating the humans after the control facility was destroyed, the only way would be to subsequently destroy the control units, the nanobot factories and then either kill the remaining infected or find a way to get rid of the bots that have taken control over them.
So let's assume there is a central control unit and that destroying this would solve all problems, because this is really the only way the uninfected would stand a chance.
Then there are a couple of problems you will need to adress:
**How to find out if people are infected?**
Assuming the Nanobots leave no visual trace on infected humans, it would be difficult to determine if someone is infected or not. Furthermore, even if it was possible for someone to accurately tell if someone is infected, they would need to recheck everytime they meet after spending some time alone - every one of them could get infected at any time. So the uninfected would need a scanner or something like this to check for nanobots. Even then, they would need to constantly check everyone for Nanobots.
**How to protect against Nanobots?**
If you have established a group of uninfected, how do they protect themselves against Nanobot infection? A full-body armor may sound cool, but this scenario is not really sustainable, so I assume hiding is the only way. Then again, a swarm of Nanobots are very effective at searching large areas. Maybe an underground facility that is somehow protected against all sorts of scanning devices? Even then, the uninfected would eventually have to come out (at least to destroy the control unit), so they definitely need some way of holding off the Nanobots, at least for some time ...
**How to fight an entire people**
We've established that the infected are under full control of the government, so they would certainly fight the uninfected if they were revolting. Because most of the humans are infected, the few uninfected would have to fight the majority of all people on the world. Since the government probably has superior weaponry, again hiding from the infected would be the only way to keep uninfected and alive. The uninfected could e.g. try to blend in and act like the infected, but then again, if the bots give off GPS signals and communicate with each other, as infected person could definitely tell if someone standing next to them is infected or not.
**Moral problems**
As mentioned above, the uninfected would probably have to fight the infected that they are trying to save. Cue moral queries, doubt, some self-hatred and stuff ... you will have to adress that.
All in all, it is possible that the uninfected find a way to destroy this control unit, thus giving people back their free will (again, assuming that there even *is* a central control unit), but it's highly unlikely. I would probably try to make the nanobots not so overpowered (it's anyway unlikely that technology will advance this far in 25 years) to give the uninfected a decent chance. For example remove the GPS capability and communication between Bots so that your uninfected can blend in with infected, pretending to be infected as well.
[Answer]
You have created a frighteningly powerful device, combining the thought police capabilities of 1984, the homicidal capabilities of Saw, and the subtlety of a ninja assassin. There's no surprise that you can't find a way out!
My recommendation would be to treat your ideal nanobot as just that... the ideal. The resistance will **never** overcome the ideal nanobot army because, if they could, the government wouldn't have released it until they perfected the nanobots. If the resistance can take on the ideal nanobots, imagine what they'd do with an implementation!
**The implementation is where the resistance really would take foot. *Something* would give in that perfect storm you wrote to yield breathing room for rebels.** For example, consider one example, "wifi communication." You can't actually do that with nanobots. The best you can do is create the illusion of doing it:
* Transmitting wifi any non-trivial distance requires an actual antenna. If you don't have a full sized antenna (26mm, from one antenna I just looked up), the power costs of sending and receiving skyrocket quickly, and power storage is not easy for nanobots.
* Wifi uses lookup tables to remember the addresses of nodes. That takes memory, which takes space (also not easy for nanobots)
* 802.11b antennas usually push 500mW. For a nanobot to push that kind of power with physically realizable components, it would pop like popcorn.
So what WOULD your "wifi communication" look like? It would take advantage of the ability for a large number of separate nanobots to cohere into a "virtual group" so they could emit signals together. It doesn't have to be physically touching... just all of them agreeing enough on timing to get a common message out, sharing the power and antenna requirements between all of them. It would also involve routing messages through thousands of short hops, rather than our modern "3 hops takes you to the Internet backbone" approach.
**That is now an opening for a weakness for the rebels. Whatever system they use for communication would behave more wavelike, like ocean weaves.** If the rebellion can structure their life to make that wave-like communication harder for the nanobots, then they have more room to operate.
Likewise, human emotions are hard. One nanobot cannot possibly comprehend your emotions. They have to be working in a communal process to read emotions. This means:
* Its going to take a lot of data to relay someone's emotions... so if you can find ways to keep the communications busy long enough, they may forget to relay your information out!
* You may be able to learn new ways of managing emotions which leverages the same
ocean-wave communication weaknesses to let you show emotions that don't register to the nanobots.
**In all, don't try to beat the ideal monster. Try to make him, claws and all, and then find the weaknesses of that realized monster instead.** The entire point of ideals is that they're tough to beat when you analyze them. Beat the implementation instead!
[Answer]
Fight fire with fire.
I think the suggestions already made here of hacking the nanobots or using EMP devices are some of you best options here.
The hacking idea in particular got me thinking (so credit for this really should go to bowlturner), a resistance with sufficient resources could effectively create a set of counter-nanobots.
These nanobots would have the same properties as the ones you describe, except they would also be able to detect the government nanobots and either destroy them or re-purpose them.
The resistance nanobots could transmit false data to the government, letting those in charge believe that they are still in charge.
This way the government in charge would end up with the same problems as the resistance - they wouldn't be able to tell resisters from their own subjects.
This also has the potential for leaders within the government being unwitting pawns in the resistance, perhaps not even aware that the nanobots within them are not under their control.
[Answer]
You say "only government is able to tell with 100% accuracy who was infected and who was not". Sorry this fails the reality check. If the nanobots are transmitting via radio waves quite simple equipment can tell the transmitter's location with a precision of few meters."Sorry dude but you're sending" is quite telling that he's infected (or carrying around a mobile phone). I assume that each individual Nanobot has to send the collected data at regular intervals to free its memory to collect new data. Probably the Nanobots also need to communicate so that they work in a concerted effort. Single or uncoordinated nanobots should be quite ineffective.
Plus, it's easy to tell that someone is not infected. Just open your microwave oven. Bypass its safety, put it on high for a few seconds and direct it at every part of your body. The burning sensation tells that it's working. Afterwards any transmitter is toast thus you can safely tell: "Dude you're not infected, anymore." Of course this is much better than just determining who is not infected, because you can define someone is not infected. Maybe the rebels set up an array of microwaves at the entrance of their hideout and "clean" everyone who enters. I don't think it will be pleasant, but better than having an unintentional spy around. In fact it's probably not the question, if microwaves destroy nanobots but at which power and time. The second question is how much does living tissue suffer from this. Plus it may be very painful, if high settings are required. And the rebels may go with a setting like "better safe than sorry".
You think the easy way out is boring? Well that's reality for you. You can check how long a fine electrical circuit can withstand high energy microwaves using a SD memory card. Maybe you want to wrap it into a steak, which you don't intend to eat. My guess is that the SD card won't last 3 seconds at 700W while the steak won't be recognisable warmer.
[Answer]
It would be hard to maintain/govern that kind of state given the massive apparatus needed to run, maintain, and enforce a regime.
Why would a government of 30,000 people let alone 50 share all that power? Or would there be a different set of nanobots to enforce loyalty by the despot?
Given these questions of power, countermeasures come into play. Perhaps government officials have developed an immunity to these nanobots. They could also have different flavors of nanobots...Chinese, Russian, anonymous...
In this state, humanity would totally join the "internet of things" and the computer virus/worm would be just as deadly as a physical virus.
I think one of the responses addressed throughput of visual cues, but there are several ways around this. Cloud, hive-based decentralized computing where the localized nanobots cluster and also collective lo-fi processing similar to how compound eyes of a fly would operate.
This also brings the question of the power of computing when these nanobots have these molecular "supercomputers" (by today's standards) and could collectively network and share computing bandwidth on demand.
Perhaps it doesn't take 3000 people to run this spying state, but rather one looming Skynet.
Other potential musings aside. If there were a romanticized struggle of hackers who fight each other through their collective bot-net powers (human slaves...aka the 99.9%), one could posit the nanobots could also enhance rather than inhibit.
In exchange for your freedom, privacy, and Facebook photos, you get to live forever, never die of sickness or cancer, and lift 3 times your body weight thanks to your nano-buddies. As with the internet of things, you'd also have the best Audio-Visual center with entertainment streaming through your noggin 24/7.
I know this steak doesn't exist. I know that when I put it in my mouth, the Matrix is telling my brain that it is juicy and delicious. After nine years, you know what I realize?
[Answer]
I think the following approach will always work:
Such a complex network of control, need a lot of supervisors. The bots need to be controlled, updated, distributed. And there is probably a supreme council of politicians, who are not infected, since the danger would be too great, that one of them could seize power and control all of them.
So you will have a bunch of people, who are unaffected and who are sitting at the source, of the controls. All it takes is one of them deciding to start a revolution - be it for personal gain or higher moral reasons. If it is an unaffected politician, he can use his power to undermine some of the efforts. If it is a nano-bot-programmer, he can insert bugs into the software, so that 0,1% of the population will become unhappy and invisible - he could even transmit a message to them in their heads, bevor their nano-bots self-destruct. The Message could also contain vital detail about the government...
In the end any system composed of humans has a social angle making it vulnerable. This could be the stepstone for any of the other proposed scenarios, because with an insider collaborating with the rebels most of them are possible!
[Answer]
since i cant comment - im going to make some assumptions. Citizens know they are monitored. And citizens know all the capabilites of the nanobots that you mentioned
communication is of first concern.
Cant revolt if what you see and hear is being monitored.
Have you considered braille. You can read a message without looking at the page. Maybe even Tactile Sign Language from <http://www.aadb.org/factsheets/db_communications.html>
You can have your rebels go to braille school under the guise of in-house training for teaching assistants.
Additional edit
control basic feelings (fear, joy, rage...)
Alcohol, drugs do the same thing. You should be able to find a counter-agent.
Hypnotism? (I'm on the fence on that, I've never been hypnotized)
About Killing rebels
you did not specify how they identify who to kill or how fast is their response time.
If it is by camera I would disable the camera before any attack
Cut power supply
Hack computer identification systems
if the nanites are in the blood (would a syringe full of blood fool sensors to think you are in two places at the same time)
The more intelligence gathering you have on your enemy the easier it is to find weak points that you can exploit.
[Answer]
Many answers, but I think **nanobots as described are magical, because their capabilities are contradictory.** Required capabilities are feasible separately, but not combined.
(1) There is no feasible way for them to `see what I see` because image what I see is not formed in eye but in brain, by interaction of millions of neurons. So either nanobots would have to sit inside each of photoreceptor cells in the eye, or in neurons. To be that small, they will have to be molecular size. Very many molecules try to sneak inside cell all the time, and cell have very effective protection mechanisms to prevent that.
(2) If they `operate on the same substances your muscles are using` - that would be [ATP](http://en.wikipedia.org/wiki/Adenosine_triphosphate). So such "nanobots" are complex organic molecules, like bacteria.
Surprise surprise! Our body can very effectively deal with bacteria! it is called immune system! So you will need to invent something why our immune system will not kill such nanobots/bacteria.
**Answer to original question is "mu" - it does not make sense,** unless you want to employ magic (and then, anything will work within your magical rules, so tell us the magic rules).
To make question more feasible (answerable), you need to relax most of the requirements, to bare minimum.
I suggest to **make your nanobots a virus** (uses same substance for power as our muscles, and can replicate). On some signal, it can activate and cause pain or death. Making such signal chemical will be much simpler.
Someone with better understanding of high-frequency electronics may say how they can communicate wifi. I believe that **nanobots will \*\*NOT** be able to receive GPS because they are too small to contain antenna.\*\* They are also way too small to have "hive mind" or capability of swarming, sorry to break bad news to you. For that you need some computer, power source (converting ATP to electricity), all would be **hard to make from materials freely available inside the body. Especially metals.**
Hive mind based on chemical signals - possible but take into account that chemical signals are smeared all over body by metabolism, blood etc. Would be hard to focus such swarm.
As a bonus, EMP cannot kill them. Our immune system might.
Then we are back to question about werewolf virus - make virus infection necessary for survival.
For some reason many of my answers don't make people happy, because instead of pretending that magic might work, if only we wish strongly enough, I show why it does not. I bet this one will get plenty of downvotes too. Oh well. I don't mind, just say why.
[Answer]
I agree with the "fight fire with fire" approach. "The Government" is just a group of people and those who misuse technology are usually not technologists.
My thought is that the resistance would be primarily those who created the technology and saw it being used in ways contrary to their benevolent vision. Since they created the technology they would know its weaknesses and be able to construct nanobots to counteract the original ones.
Since you said the nanobots have to be 'instructed' to do things it is logical to conclude that they do not have any 'reasoning' skills and must have their data sent to a computer to analyze and act on that data.
Given that, if researchers were able to 'jam' the incoming AND outgoing signals then the nanobots could 'see' everything and yet nothing would come of it.
[Answer]
Because part of the population is not infected, I would expect them to be the only rebels (at least at first). Then, because their hopes and chances are rather slim, I'd go for terrorism. By that I mean (and I'm shamelessly gonna use some of the tech evoked in other answers):
* explode EMP bombs in as many populated areas as possible. This has 2 benefits: those people get rid of their bots, and because they couldn't see it coming, they can't be killed by their puppeteers before it happens.
* infect food/water sources with other nanobots with just the function "search & destroy" other bots.
* take control of existing bots through the same communication doors that are used by the puppeteers (there's always an open port to exploit).
* techniques that "might work", not related to techonology: kidnap high-profile targets (or their families) until situation has improved. More dangerous, success is improbable but possible. Also kidnap some of the researchers involved in the creation/control of these bots. Force them to help you.
Wether your resistance leader always acts with good moral or not is your choice. But in this case, I don't think moral will help you get your democracy back.
[Answer]
So, how about a 3 way war?
The AI system that controls the nano bots becomes sentient and tries to take over mankind.
Meanwhile, the government realizes the AI is trying to take over, but fights to maintain its own power over both the nanobots and the rebels.
The rebels begin to realize that the AI may be trying to over power the government to gain control of human kind. Meanwhile, they still have to fight the government to remain alive.
I would think there would be a lot of intrigue that could include the covert passing of information on how to destroy/control the nanobots including the methods above. Think secret and double agents working for each of the factions…
[Answer]
What if the "stuff" itself develops intelligence, and either dupes the government controllers (it can make them shape policy, decide who gets appointed) so you have a neat twist about who is the tool and who is the ruler.
Or, it decides to help the people, with its own ideas of controlled libertarianism. After the victory, you still wonder if they *really* live happily ever after, or it just made you want the kind of civilization you know have.
A wilder idea: aliens come and help. Turns out later that they have a hive mind and want humanity to become part of that rather than forming its own, which is what the nano road was rapidly leading towards.
[Answer]
The most 'realistic' protest, in this sort of enviroment, is protest. Imagine people who are infected doing sit-in or even suicide. Everyone refusing to work or do anything to support the government as long as they are utilizing nano-bots. Imagine Ghandi and MLK style protests and fights. Sure the government will know what their doing, but so what that's the point. They could be killed instantly, but the government isn't going to kill everyone under them.
The ability to control emotions would be more complicated, but one must assume there are limits. Presumably a robot can't 'really' control your emotions unless it can fully control you brain. If they can't read your mind they can't control it. Thus any emotion control is limited to messing with hormones and similar effects. They may be able to inspire a general sense of fear or joy, but you would *know* it's fake if they try anything extreme. They can make you feel happy, but they can't make you feel happy about nanobots specifically, just a general sense of happiness. They could try to use fear or pain to discourage protests, but the whole point of protests is to allow people to use those tactics and endure them until the people with power realize how horrible their being.
Similarly a general work slowdown and apathy, massively increased suicide, and general destruction of society will occur. People do NOT work well when they feel forced, no matter what you use to force them. The countries without the non-bots will ultimately do better then those with them because of the internal strive the bots would cause. Eventually the government would need to turn them off because society is crumbling and doin far worse then it was without the bots.
On the more 'action hero fighting dystopia' vibe one can still plan out and commit assassinations pretty well even with the 'bots'. Even if you can record everything one sees and hears you can't PROCESS it. Without *very* advanced AI's that information will be mostly worthless. You can watch people you have reason to already suspect, but someone can get away with "allot" without anyone noticing. A hunter can 'forget' his gun in the car. a week later he may go driving to see the next president speak and stumble upon it etc. He will have some time before anyone registers something wrong, he has to be fast and suicidal, but he can still do
[Answer]
Unless these nanobots are sentient with above human capabilities, they need to report to someone. These reports will need to be interpreted by humans. These humans would need to outnumber the reported on humans by about 3-1, since even at 7 days a week and no vacations they only can work 8 hours a day and the watched person is doing stuff 24-7. So the watchers would need to outnumber the 70-90 percent infected by a factor of 3, which is impossible.
So this system collapses by its own weight. The watchers would only be watching you a vanishingly small amount of the time.
The POW camp at Castle Colditz in WWII had more guards than prisoners. They still had escapes, and even managed to build an **airplane** in the attic without detection.
] |
[Question]
[
Consider such a tidally locked planet:
[](https://i.stack.imgur.com/CdW6x.png)
Many issues with tidally locked worlds have been discussed, but I'm not clear on how the water cycle for an otherwise Earth-like tidally locked world, would be sustainable.
Basic assumptions: Weather would vary very little since there would be no seasons and no day-night cycle. The planet would be scorching hot on one side and freezing cold on the other. A strip straddling the terminator, the midpoint between the dayside and the nightside, would have water within the temperature range for it to be liquid. Atmosphere is dense enough for the necessary heat distribution to have a reasonably broad habitable "ring" around the terminator.
Let's pretend the problems of solar winds slowly stripping the atmosphere and of solar flares are solved.
Instead of warm air rising at the equator and settling at the poles as it does on Earth, it rises on the dayside and settles past the terminator line. It carries with it moisture, from the evaporation of water on the dayside. Some water precipitates past the terminator line and, if topography is kind, runs from one side of the ring of life to the other, to repeat the cycle.
But what happens to the water that rains on the wrong side of a mountain or hill and is forced down, deeper into the nightside? Some water should end up frozen, trapped where sun won't ever come to melt it, removed from the water cycle.
**What keeps my planet's water from irreversibly concentrating over time on the frigid wastes while the rest of the planet dries up?**
[Answer]
There are atmospheric models for tide-locked worlds that show a permanent cyclone on the light side, with constant winds blowing between hot and cold sides. As with Earth, heat makes air lighter and decreases pressure. As such, hot air moves up and cold air falls down. This drives low-altitude wind from cold to hot regions, and high-altitude wind from hot to cold regions. On Earth, things get complicated due to rotation, forming [Hadley cells](https://en.wikipedia.org/wiki/Hadley_cell), and then even more by continents and oceans.
In the case of a tide-locked world, you would have permanent wind blowing from the cold to the hot side on the ground, and in reverse at high altitude. This would help equalise temperature between both sides.
Additionally, you would have the oceans themselves move heat. On Earth, this is visible with [thermohaline circulation](https://en.wikipedia.org/wiki/Thermohaline_circulation), driving the Gulf Stream among other currents. Without it, it is estimated that Europe, for example, would be 10°C colder (something they would probably like at the moment this answer is written, if not anytime). Water can move enormous amounts of heat in as slow cycle.
There are some models that estimate that the cold side could actually still have an ocean under its enormous, possibly km-thick ice sheet, with the ocean extending partially to the hot side.
With both those mechanisms, water would always be partially liquid, enough to have a large band of open oceans.
As an aside, I am curious how you will solve the effects of solar flares, atmosphere stripping and possibly water being cracked when it is high-altitude vapour on the day side.
[Answer]
>
> What keeps my planet's water from irreversibly concentrating over time on the frigid wastes while the rest of the planet dries up?
>
>
>
When ice piles up, it will exercise pressure. The closer to the terminator, the less the ice.
As a consequence, pressure gradient will tend to push the ice sheet toward the terminator, where it will melt, returning water to the cycle.
You can add to this local orogenetic factors, and your water cycle will be present.
[Answer]
[Librations.](https://en.wikipedia.org/wiki/Libration) That is, the tidally locked planet is not in a perfectly circular orbit, and so the portion of the planet that is sun-facing is not constant. This is because the rate of rotation is (extremely nearly) constant, but the rate of revolution around the sun changes due to the non-circular nature. For the Earth's Moon, this is only a few degrees. If the orbit were a little more extreme the wobbling could be more extreme. This would mean that water near one side was melting while the other was freezing, then the other way around the rest of the year. It might well mean that there were some pretty extreme storms due to the temperature differences.
[](https://i.stack.imgur.com/4Hnzn.gif)
Also note that a tidally locked planet is still rotating, just once per year. And so it has an axis of rotation. If the axis of rotation of the planet were not perfectly perpendicular with its orbit, you get a different kind of wobble. This is also happening for the Moon. Just as the Earth has summer in the northern hemisphere when it is tilted toward the sun, you would get an apparent movement of the sun due to the axis tilt. You could arrange to have this be quite large. It would mean you had a severe set of storms that followed the part that was cooling, where water condensed out as rain, then later snow.
Possibly the large volumes of water moving around have important consequences as far as things like earthquakes. If you moved km deep piles of ice back-and-forth each year, it has an effect on the crust of the planet. Parts of the Earth are still [rebounding](https://en.wikipedia.org/wiki/Post-glacial_rebound) from the last ice age.
[Answer]
## "Life will find a way" (to melt the ice)
If there's a flourishing ecosystem of extremophiles living in or under the ice-sheets on the night side, near the border region, the heat produced by their metabolism could create liquid water, which could flow back into the border region.
The obvious difficulty with this solution (besides how the ecosystem got there in the first place) is what this probably-mostly-microbial life is eating to sustain itself, as well as to generate the useful extra heat. Some kind of vent-creatures would be plausible, though sufficient vulcanism would generate a fair amount of heat on its own, leading into wpokdljnlnmn's suggestion.
[Answer]
As I mentioned in the comments above, current models of tidally locked planets *do not* support the conclusion that the antistellar (night) side will be a permanent frozen waste and the substellar (day) side a relentless scorched desert.
I will repost [the relevant part of my answer](https://worldbuilding.stackexchange.com/a/150751/25189) to [this question](https://worldbuilding.stackexchange.com/questions/150612/looking-for-a-review-of-my-tidally-locked-red-dwarf-planet-system-specs/150751#150751):
>
> Given the large amounts of heat-transporting surface water and an atmosphere, your assumption of significant nightside ocean freezing and a permanent hemispheric ice age [may be wrong](https://iopscience.iop.org/article/10.1088/2041-8205/796/2/L22/meta):
>
>
>
> >
> > Surface liquid water is essential for standard planetary habitability. Calculations of atmospheric circulation on tidally locked planets around M stars suggest that this peculiar orbital configuration lends itself to the trapping of large amounts of water in kilometers-thick ice on the night side, potentially removing all liquid water from the day side where photosynthesis is possible. We study this problem using a global climate model including coupled atmosphere, ocean, land, and sea-ice components as well as a continental ice sheet model driven by the climate model output. For a waterworld we find that surface winds transport sea ice toward the day side and the ocean carries heat toward the night side. As a result, night-side sea ice remains O(10 m) thick and night-side water trapping is insignificant. If a planet has large continents on its night side, they can grow ice sheets O(1000 m) thick if the geothermal heat flux is similar to Earth's or smaller. Planets with a water complement similar to Earth's would therefore experience a large decrease in sea level when plate tectonics drives their continents onto the night side, but would not experience complete day-side dessication. Only planets with a geothermal heat flux lower than Earth's, much of their surface covered by continents, and a surface water reservoir O(10 %) of Earth's would be susceptible to complete water trapping.
> >
> >
> >
>
>
>
[Answer]
**A Venus with magnetic field**
Venus is planet that rotates very slowly. It's not tidally locked, but even if it was, the climate would not likely be affected because thick atmosphere distributes the heat evenly to the night side. A problem with Venus is that it lacks water. It likely had water in the past, but lost it all to the space. However, if Venus had substantial magnetic field, like Earth, its atmosphere would be better protected from solar wind, perhaps enough to keep water for billions of years.
Note that this is a "formal solution" - the planet will be wet, but conditions would likely be not what you wanted. It will be hot and humid, maybe not as hot as Venus, but still unlikely to be habitable for humans.
[Answer]
Well, the *real* answers that you are probably looking for have already been posted (glacial flow and libration/nutation), so I'm gonna add a **frame challenge**.
Why does solid or liquid water *need* to get back to the dayside?
Say the world doesn't have *enough* water for nightside glaciers to make it back over to the dayside, so almost all of the world's water is locked up permanently in ice. Even then, it will only be *almost* all--because ice still has a sublimation vapor pressure. That means that there will still be water *vapor* available on the dayside. Now, terrestrial organisms don't actually much care about whether or not there is any liquid water in their external environment--only whether or not they can maintain liquid water in their own cells. And in fact, we have many examples of desert-dwelling terrestrial animals which never drink, and get all of their water from the food they eat, and their own metabolism (note that respiration produces water as a byproduct).
So, you merely need to ensure that plants can acquire their water from the air, and then animals will take care of themselves. (Although animals may find it advantageous to be able to retain water from the air as well.) So, you just need to have some plants evolve to produce and tolerate high concentrations of deliquescent compounds (i.e., materials that are so strongly hygroscopic that they will dissolve themselves by pulling moisture out of the air) in their tissues. Things like calcium chloride and sodium nitrate. Or even hydrogen peroxide.
[Answer]
I think the models for habitable tidally locked worlds have oceans that are liquid around the whole planet. The floating ice insulates it on the dark side, and circulation replenishes it as it evaporates on the daylight side.
You could even imagine continental drift moving a continent to the dark side, locking all the water into a giant icecap, and then having the oceans reform half a billion later as the continent drifts to a warmer region.
[Answer]
I would assume the way that this could work would be to have some sort of volcanic activity on the night side, or assuming you wanted the night side cold, you could have this activity just on the slopes of the termanidor mountains. Alternatively, you could have the water gain a lot of salt on the slopes, which woukld lower its freezing point.
] |
[Question]
[
In an act of magical warfare, a wizard opens a gateway leading to the center of the Sun. Matter can pass through the gate freely in either direction. The gate does not last very long -- the wizard dies immediately and the gate vanishes shortly after that.
The gate is 20ft in diameter and is positioned a few hundred feet off the ground.
How fast does matter and energy pour through the opening? How long does the gate need to remain open in order to kill everything in a 10-mile radius? How long does the gate need to remain open in order to destroy the biosphere?
I am hoping the answer will contain math -- for example, X amount of energy will pour through per second, after Y microseconds this will be the equivalent of a large nuclear weapon which might kill everything in a 10-mile radius, after Z microseconds this will be the equivalent of the dinosaur-killing asteroid.
[Answer]
I'd like to take Lio's numbers and spin them a different way. [His research](https://worldbuilding.stackexchange.com/a/71313/2252) found:
>
> [The sun] has a density of 150 g/cm³ (150 times the density of liquid water) at the center, and a temperature of 15 million degrees Celsius. The core is made of hot, dense gas in the plasmic state (ions and electrons), at a pressure estimated at 265 billion bar (3.84 trillion psi or 26.5 petapascals (PPa)) at the center. Due to fusion, the composition of the solar plasma drops from 68-70% hydrogen by mass at the outer core, to 33% hydrogen at the core/Sun center.
>
>
>
Two things are going to come through this portal:
* EM radiation
* Hot matter
EM radiation is going to consist of photons passing through the portal while it is open, while hot matter is matter which will pass through first and then transfer its heat to the environment once it's on this side.
The key question is going to be how much energy gets to the Earth, so we can focus entirely on that.
One thing which is not explicitly specified in the question is how the expansion of the matter occurs. As the high pressure plasma from the sun spews through the stargate, it is going to pick up velocity and it is going to drop in pressure. The balance of these will affect the flux of matter. If the stargate acts like a giant nozzle, then all of the pressure will be converted to forward velocity, and the exit of the stargate will not result in a sudden decrease in pressure. If this is the case, we will see the entire raw temperature of the sun on both sides of the gate. On the other hand, if it acts more like a hole in a pressure cylinder, there will be less time to accelerate the matter. Less matter will pour through per second, and the matter that does pour through will undergo rapid expansion and cooling. In this case, the temperature differential across the gate will be larger, and infra-red radiation passing through will matter.
Fortunately, there is a reasonable guess as to what will happen: [choked flow](https://en.wikipedia.org/wiki/Choked_flow). Under choked flow conditions, the exit velocity of the material is the speed of sound at the outside pressure. This is a natural limit if you aren't paying attention to what you're doing with a nozzle, so its reasonable to guess that our wizard, failing to specify the conditions of the gate, will run into this limit. This limit is quite slow compared to the speeds that could be achieved with a better nozzle shape, but it does mean that calculating the EM radiation will be difficult because there will be a sudden drop in pressure. I'll ignore EM radiation from here on out (the matter itself is damaging enough).
The speed of sound is roughly 340m/s. Your 20ft diameter gate has an area of about 30m^2. This means we will have a volumetric flow of plasma around 10,200 m^3/s. At the specified density, that's 1530000000kg/s of matter streaming through the gate!
That's a lot of matter. This is going to get hot quite quickly!. The center of the sun is mostly helium. To keep the numbers simple I'll just pretend it's all helium. Helium has a heat capacity of 5.19 kJ/kg-K. Since the sun is roughly 15 million degrees K hotter than the earth, each kilogram of helium will carry 77,400,000 kJ of energy. Multiplying this by our mass flow rate we get a total energy flux coming through the gate of: 118,422,000,000,000,000 kJ/s. That's 118 EJ/s, or 118PJ/ms, if I do some conversions.
I do those conversions to make it easier to reference [Order of Magnitude (Energy)](https://en.wikipedia.org/wiki/Orders_of_magnitude_(energy)), one of the more fun pages on Wikipedia. They list:
* 210PJ - Energy released in the detonation of Tsar Bomba, the largest nuclear weapon ever detonated.
So right off the bat, we can see the thresholds. In the first millisecond or two that the gate is left open, the damage will be as mighty as the strongest nuclear bomb ever tested. Your 10 mile damage marker would have been more in line with what Fat Man did to Nagasaki in WWII. Fat Man was a mere 21kT, cmpared to Tsar Bomba's 50Mt, so your 10 mile line is broken in the first microseconds that the gate is left open!
As for ecosystems, it's not clear how resilient ecosystems are. However, it is worth pointing out that in the first hundred seconds, this gate would pump out more energy than strikes the earth from the sun in a single day. I would not want this gate open for any measurable periods of time!
[Answer]
## Your blast radius encompasses more than the size of earth, plus you evaporate all rock in said planet:
Firstly lets have a look at the centre of the sun - the stuff you want to pour out on your unsuspecting enemies (and quite possibly everyone else). [This link](https://en.wikipedia.org/wiki/Solar_core) (emphasis by me) says:
>
> It has a density of 150 g/cm³ (**150 times the density of liquid water**) at the center, and a temperature of **15 million degrees Celsius**. The core is made of hot, dense gas in the plasmic state (ions and electrons), at a pressure estimated at **265 billion bar** (3.84 trillion psi or 26.5 petapascals (PPa)) at the center. Due to fusion, the composition of the solar plasma drops from 68-70% hydrogen by mass at the outer core, to 33% hydrogen at the core/Sun center.
>
>
>
So lets compare that to your standard day on earth:
* Average air pressure of [1.01325 bars](https://iridl.ldeo.columbia.edu/dochelp/QA/Basic/atmos_press.html).
* Average temperature [$16^{o}C$](http://www.space.com/17816-earth-temperature.html)
* Air density [$0.0012gcm^{-3}$](https://en.wikipedia.org/wiki/Atmosphere_of_Earth#Density_and_mass).
The main driving force here is the difference in pressure being about 265 billion bar higher so the stuff at the center of the sun will flood through and quickly increase the temperature of the surrounding area to $\approx 15 million ^{o}C$ (not quite ideal conditions to support life). After 6 seconds, at this temperature difference we can expect to have boiled off [the ground](http://hyperphysics.phy-astr.gsu.edu/hbase/Geophys/meltrock.html). The rate at which this will happen is given by:
$$ \frac{dT}{dt} = k (T\_{s}-T\_{e}) $$
Where $T\_{s}$ is the temperature of the sun $T\_{e}$ is the temperature of earth and k is some proportionality constant (depending mostly on the make up of gasses). Since this isn't hard science I won't go much further into this than to say that we can assume, at these temperatures and pressures that your particles are travelling around the speed of light so if we look at a basic radius calculation of $r= c t$ where r is the radius, c is the speed of light and t is our 6 seconds, we get a radius of $18\times 10^{8}m$, for a sense of scale [Earth's radius](http://nssdc.gsfc.nasa.gov/planetary/factsheet/earthfact.html) is $6.4\times 10^{6}m$. Now perhaps some argument can be made for the boiled off rock delaying this rate of travel but you have to reduce it by a couple of orders of magnitude just to make it that you're only just about evaporating earth...you would need to have it open for much less than six seconds to even have a chance of keeping your planet in tact let alone anyone left alive.
Edit: Okay, you changed it from 6 seconds, however the whole idea is **still going to wipe out all life unless you put the portal somewhere other than the *center* of the sun** (the surface is around 6000 degrees rather than the ridiculous 15 million). Whatever you do you'll have to deal with the hydrogen gas which will come through hot enough to ignite and, with some tiny margin where you could possibly survive, you will burn off all the oxygen on your planet.
I know you want it to work though, so picking somewhere hot but much less dense (like the surface) is your best chance of keeping a planet intact.
[Answer]
Well. A fun question.
Lets ignore the physics of how the gate was created and just assume that there's a nice little hole in the centre of the sun where matter (and forces) go in on one side and comes out the other on Earth. This is where specifics about the operation of the portal matter.
Firstly: if you're not careful gravity is going to be fun. You've just opened a portal with half the mass of the sun on one side of it. If we say that the portal only lets forces through from the 'open' side (like a Stargate) then that's a whole lotta mass in a not very large area. Depending on the orientation of the portal you could be exposing *the other side of the Earth* to over 33000 g (this is a very naive calculation and assumes the portal just became a 20 foot wide ball with half the mass of the sun, but only if you're on the right side of it). Just for reference: The surface of Jupiter is dealing with 26 g.
If we assume the portal is barely open long enough for any plasma to get pushed through (See Leo Elbammalf's answer for more on that) then you still have issues: Namely that gravity propagates at the speed of light, passes through everything and doesn't discriminate between forms of matter. No matter how briefly the portal is open you just transmitted a shockwave of unimaginable magnitude not only through the crust of the planet (neatly cracking it like an egg hit by a nail) but also through the rest of the solar system, briefly creating a second gravitational body capable of knocking pretty much everything out of orbit including (and this is why we all hate instantaneous portal technology) the sun itself, which eight minutes later would find itself momentarily trying to orbit half of itself.
And that's not even all the fun! You've just blocked gravitational forces acting on half the sun, momentarily throwing the delicate balance of radiation pressure <-> gravity way, waaaay off. It might not seem like much time to you, but the energies involved here are mind boggling and very finely balanced. I don't even want to think what such a shock would do to the sun, but you can bet it wouldn't be pretty in the slightest. While the sun would probably survive there would (at the least) be a huge uptick in solar activity (you might even cause a small nova) scouring the Earth clean of all life.
Of course: If your portal doesn't transmit gravitational effects until you're already in it (a'la Portal) or transmits forces from all sides (a spherical portal of some form) then opening it in the middle of the sun won't have any meaningful gravitational impact. It will oddly be in a place where all the forces cancel out.
So: The specifics of your portal might matter more than you think. On the one hand You kill the Earth with superheated plasma, on the other you kill pretty much the whole solar system...
[Answer]
Due to scale, the vast majority of initial energy released will be "black-body" radiation. This will be released at close to the speed of light in a hemisphere shape. The angle of the gate relative to the surface of the earth is obviously important if enough energy is released.
The effect depends on the amount of energy required to destroy your gate-structure/mage. As soon as that much energy is released "into" the gate-structure/mage itself then the gate will (presumably) be instantly destroyed.
Then you need to know what percentage of the released energy is intercepted and absorbed by the gate-structure/mage. The rest is what effects the surrounding area.
If your gate-structure/mage blocks $1\%$ of the radiation and requires $n$ joules to destroy then the gate will release $n\times 99$ joules before closing.
If the physical gate doesn't have a structure as such and it only shuts down when the Mage is "incapacitated" then just calculate as if the mage was the "structure". How many joules does it take to vaporise your mage?
Note that it may also depend on how close the mage is to the gate. Light travels about $30cm$ in $1 nanosecond$. It may also depend on exactly what part of the mages body needs to be destroyed to close the portal. Hippocampus? The entire brain?
Based on Mrkvička's "Stefan–Boltzmann law" calculation above the joules of energy from black body radiation works out to the equivalent of about $2,002,582,949$ 1 megaton nuclear bombs per second.
Or about 2 every nano second.
Note that it is entirely likely the gate will be destroyed before there is time for any matter to push through, regardless of the pressure. Matter is just too slow compared to electromagnetic radiation.
This [wikipedia page](https://en.wikipedia.org/wiki/Orders_of_magnitude_(energy)) gives lots of examples of orders of magnitude for energy.
[Answer]
Opening such a portal for even a fraction of a second would be like setting off a large hydrogen bomb.
The effect of an atomic bomb's detonation is to release a lot of energy (although not very much compared with the activity within a star's core). The bomb's initial radiation is blocked after the first fraction of a second because the air around the bomb becomes too hot and becomes opaque. After a fraction of a second, the sphere of air itself begins to glow intensely via black body radiation because it is now at several million degrees. This sphere expands rapidly because it's at extremely high pressure because of the heat. This expanding sphere becomes the blast wave. Objects in the path of the blast wave get turned into shrapnel. If the ground gets hit by the blast wave while it's still superhot, you get a lot of radioactive dust as well.
A mass of solar core material suddenly deposited into the air 100ft above the ground would behave very similarly- the main immediate effect on the surroundings would be to ionize and superheat the air around it and create a massive blast wave. Any wizard standing near (ie, within several miles of) such an event would be quickly killed unless they were standing behind cover (ie hiding in a trench or behind a mountain). At an elevation of 100ft, it would probably throw up a lot of radioactive dust since that's a very low altitude for even a kiloton class weapon- essentially you're getting the effects of a high yield groundburst.
And that's only the effect of keeping the portal open for a fraction of a second. Assuming no gravitational effects coming through the portal (as in Stargate SG-1), the jet of solar material would come through very rapidly (like a giant firehose of superheated plasma, producing similar atomic bomb effects down the entire length of the stream) and continue to produce unpleasant effects in an increasingly great radius. Keep in mind that a lot of the effects would actually be dissipated upwards out of the atmosphere, kind of like an enormous solar flare made from burning atmosphere and solar mass. For the most part, I suspect the stream of plasma would have sufficient velocity and mass that it would probably proceed in whatever direction the portal remained pointing, resulting in a stream of burning hydrogen and helium spraying out into space. I think you can mostly ignore the effects of gravity on the stream of solar mass if you chose to leave the portal open.
It would probably constitute an extreme hazard for thousands of miles and would considerably increase the heat of the atmosphere over time, but I suspect most of the energy of the phenomenon would end up dissipated into space around the planet. If the portal was pointed downwards, this analysis would not apply. In this case, my prediction is lava. Lots of lava.
] |
[Question]
[
I found an interesting [Wikipedia article](https://en.wikipedia.org/wiki/Death_Star#White_House_petition), quoted in an [answer](https://worldbuilding.stackexchange.com/a/3378/2072) here.
I'm looking into writing a story where someone has built a [Death Star](https://en.wikipedia.org/wiki/Death_Star). The purpose of this craft is important to the story (and the world) because it's used to keep the populace of the planet in check (it's easy to get world leaders to agree to your "requests" when you can obliterate their country, easily....)
The questions are:
* Given current technology, how many [man-years](https://en.wikipedia.org/wiki/Man-hour) would it take to build? (assume you already have enough steel, see question below)
* How much metal is needed to build this ship?
* Would it really take 833,000 years to get the necessary steel (as quoted in WP article, above)?
* What would it cost? (anywhere near the White House's estimate of $850 quadrillion?)
* Any scientific reason (ignoring the superlaser) why this ship is scientifically impossible?
[Answer]
>
> **Update:** The original version of this answer was based on an arithmetic error which underestimated the required material by factor 1000. It was subsequently rewritten.
>
>
>
How do you define "Death Star"? Depending on what your space station is going to be capable of, there is no upper bound to how complicated the engineering challenges can become. But to establish a lower bound for the project, let's take the most basic implementation: **A hollow sphere, 120km in diameter, constructed from aluminum** (like the hull of the international space station) with an **average thickness of 1mm**.
# Material cost
A 120km diameter sphere has a surface area of (4\*Pi\*60²) 45216 km².
One km² covered with a 1mm layer requires 1000 m³ of material, so we need to launch a total volume of 45 million m³.
Aluminum has a density of 2.7 g/cm³ so a m³ has a mass of 2.7 metric tons.
That means the **total mass** of our aluminum sphere is about **120 million tons**.
[The world production of aluminum is about 5000 tons a month](http://www.world-aluminium.org/statistics/#data), so when the whole worlds aluminum production would be routed towards this project, we would require 2000 years to mine it all.
# Launch cost
[A present-day commercial heavy-lift rocket brings up to 25 tons to low-earth orbit](https://en.wikipedia.org/wiki/Comparison_of_orbital_launch_systems). There are some super-heavy launch vehicles in development like the SLS Block 2 or the Long March 9 which can carry up to 130 tons. These currently only exist on paper, but there is no good reason why they couldn't be built with present day technology. So depending on which rockets you use, you need **about one million rocket launches**.
Launch costs could maybe be reduced by optimizing the rocket construction process or by using something other than rockets. But you said *current day technology* and any [alternative launch systems](https://en.wikipedia.org/wiki/Non-rocket_spacelaunch) are still in the realm of science fiction.
This does not yet include the price for launching any personnel and equipment required for the assembly. Humans working in space suits are neither very productive nor very cheap to accommodate and we are talking about a very repetitive task here, so I believe that having it built completely robotic would likely be more effective. The number of assembly robots you need depends solely on how fast you want to finish, so let's ignore this factor.
# So would it be possible?
Not within our lifetime and not without unreasonable economic sacrifices. Even if we would focus the whole world economy solely on this project it would still take centuries, maybe millenia.
And this just gives us the most basic version - a paper-thin, hollow aluminum sphere which doesn't do anything. Depending on how you want to design the interior, [the cost can only go up by several orders of magnitude](https://worldbuilding.stackexchange.com/a/3468/2072).
[Answer]
If the design goal is to have weapons that can wipe out all life on a planet, and move between planets, then the main problem is just transporting planet-destroying weapons (with existing tech, probably thermonuclear warheads) to other planets, and largely depends on how far away the other planets are, and how much range, desired operating time away from base, and how many planets you want to be able to destroy before returning. And, countermeasures against existing weapons. Every requirement adds weight, which adds to fuel requirements. The most efficient in terms of cost might probably be a stealth vessel that returns to resupply after every attack, depending on the layout of targets, but that would reduce its terror power, since with existing technology, it would take a long time to return to resupply.
The part about building a metallic small moon seems to not help the stated intention much at all. In fact, it makes it infeasible in many many ways, and accomplishes very little against current technology other than making it a great big slow-moving target.
So, missing features of the design listed (compared to Grand Moff Tarkin's Death Star) above include, in ascending order of impracticality:
Omitted features that might be practical and useful in a sci-fi fututre with somewhat higher technology levels and higher-tech-opponents than currently exist:
* No shields.
* No TIE fighter squadrons.
Impractical features that don't materially aid planet-destroying goals, but are quite possible with current technology:
* No pits to knock victims into.
* No trash compactors with monsters living in them.
* No place to land the Millennium Falcon.
* No equatorial trenches.
* No thermal exhaust ports.
Features which are theoretically possible with current technology, but are so impractical that they are almost impossible to do, and are crazy:
* No small-moon-sized massive metal ball.
* No lodging for millions of stormtroopers.
Features which there is no known way to do with current technology:
* No ability to jump the giant metal moon into hyperspace and quickly travel to other star systems.
* No ability to race a giant metal moon around a solar system.
* No conversion of planet into asteroid field.
* No artificial gravity.
* No long-range tractor beams.
* No giant flashy laser effects on planet-destroying weapon.
>
> Given current technology, how many man-years would it take to build? (assume you already have enough steel, see question below)
>
>
>
Practical version: Depends on range specs. To make something to go nuke Mars - ~10 years?
Giant moon version: Insane amounts of man-years - you need to get the workers into space and keep them supplied, etc - use droids - you will still be overthrown (and/or die of old age) first unless you have an actual galactic empire with Star Wars technology.
>
> How much metal is needed to build this ship?
>
>
>
Practical version: Probably not more than for a carrier battle group or two, probably best is light aluminium and other light materials.
Giant moon version: Using heavy metal is probably mostly silly, but if the point is you want a metal moon, then you want crazy amounts of metal. Probably your best bet is to find a way to use an asteroid belt (planet-size quantities, already in space), assuming you have one with high iron content.
>
> Would it really take 833,000 years to get the necessary steel (as quoted in WP article, above)?
>
>
>
Depends on what is working on it in what conditions on what kind of planet etc., but I can imagine trying to model it and getting a result like that, yes. I think you'd be much better starting with an iron-rich asteroid belt or an existing small moon...
>
> What would it cost? (anywhere near the White House's estimate of $850 quadrillion?)
>
>
>
It would cost letting go of the idea that money is meaningful, and imposing dictatorial rule.
>
> Any scientific reason (ignoring the superlaser) why this ship is scientifically impossible?
>
>
>
Practical version - nope.
The big metal moon version:
* It's too heavy to move around.
* No hyperdrive.
* No artificial gravity.
* No long-range tractor beam technology.
* Mad impracticality.
[Answer]
# Customise a moon
Current answers have required that the aluminium be extracted from the planet and launched into space. There is an alternative.
A metallic moon, or a moon with a metallic core could be landed on and hollowed out. Solar powered mass ejectors could remove extraneous rock from the planet surface. Mass ejectors could be constructed in situ, you would only then need to land an automated robot factory in the surface, capable of processing the metal into tunnelling robots, rail guns, ammunition, security droids, and additional factories.
Assuming the moon was once molten, heavy metals such as uranium should be found near the core. There should be plenty of material for bomb making, power generation and propulsion.
A massive iron skin, a mile or more thick should provide effective shielding from any nuclear attack.
Extra material could be processed into an armada of deadly spacecraft.
## Weaponry
Weaponry could be nuclear, or simply impact based. A chunk of uranium the size of a city block hurled at a planet with speed would pierce the crust of that planet like a bullet causing massive devastation, earthquakes, volcanoes, etc. It would be a shock and awe weapon, impossible to counter.
A vacuum arc weapon might also be viable provided sufficient voltage could be generated. Imagine a 5000km electrical spark stretching from one planet to another.
## Potential issues
You will have issues with generating and holding an atmosphere, as you would have an absolutely enormous volume to fill. It would be likely that only certain parts of the station would be pressurised with the rest given over to shipyards, hanger space, power generation, engines and extremely big guns.
You would also have issues with gravity (or lack thereof), perhaps you might have rotating habitation modules within the hollow core.
All docked ships would need to be securely attached. Accelerating the station would cause unattached ships to smash into the walls.
[Answer]
As an alternative answer with a much more pessimistic estimation I would like make a rough estimate for a fully functional station by taking the International Space Station for comparison and scaling it up linearly.
The [international space station](https://en.wikipedia.org/wiki/International_Space_Station) has a pressurized volume of $837\text{ m}^3$. Let's be generous and round this up to $1000\text{ m}^³$ to account for the non-pressurized parts.
A $120\text{ km}$ sphere has a volume of about
$$\left(\frac{3}{4} \times \pi \times 60^3\right) 500 \text{ km}^3$$
or $500 \text{ trillion m}^2$, so we would need 500 billion International Space Stations to fill it up.
The [total lifetime cost of the ISS project is estimated to be about $100 billion](http://www.esa.int/Our_Activities/Human_Spaceflight/International_Space_Station/How_much_does_it_cost) shared between the participating nations.
When you want a death star filled to the brim with expensive equipment just like 500 billion international space stations, you would end up with a cost of US$ 50 Sextillion (50.000.000.000.000.000.000.000). The total economic power of the whole humanity ([gross world product](https://en.wikipedia.org/wiki/Gross_world_product)) is currently estimated at 85 trillion dollar per year, so when the whole world economy would be concentrated solely on this project, it would take 600 million years to complete.
When we only spend one tenth of our economical resources (we still need to survive), we might get finished in 6 billion years. Coincidentally, [this also happens to be the time it will take until our sun burns out, turns into a red giant and destroys Earth](https://en.wikipedia.org/wiki/Future_of_the_Earth), so we better start building now.
[Answer]
The "Death Star" as you describe it has already been built:
>
> The purpose of this craft is important to the story (and the world), because it's used to keep the populace of the planet in check (it's easy to get world leaders to agree to your "requests" when you can obliterate there country, easily....)
>
>
>
**Let me present to you the [LGM 118 Peacekeeper](http://en.wikipedia.org/wiki/LGM-118_Peacekeeper).**
You really do not need to have a spherical launcher in orbit, nor does it have to be an directed-energy based weapon. **Nuclear weapons have been, and currently are being, used exactly for the purpose you describe.** Using nuclear weapons even gives opportunity for some [interesting plot twists](http://en.wikipedia.org/wiki/Mutual_assured_destruction).
[Answer]
How about a smoke and mirrors solution?
Let's say that you own the world's only civilian space tourism business and you decide to take over the planet. Being patient in your quest, and having read the other answers to this question, you decide to fake the whole deathstar thing. After all, do you really need to own a whole deathstar, or is it enough that people just think that you own a deathstar?
Concluding that perception is 9/10ths of reality, you start by investing a billion or so in creating a space station. Competitors are already gearing up to compete with you in the orbital tourism business, so you raise the stakes, adding a "party island" to your tour. Your passengers not only get to orbit the planet a few times before returning home, (which is the current business which your competitors are targeting), now they can also hang out in your gravity free space station for a few hours midway through the flight. Your competitor's don't stand a chance! and as a side-effect, you now have a place to start staging your planetary take over. The best part is that it's all paid for by your wealthy passengers, who are literally paying you to take over the world.
So, now you have a space station and several shuttles visiting it every day. What do you do next? You start ferrying Mylar canvas up in bundles and tethering them to the outside of your station. You will need a lot of it, so keep that up for a few years, while the rest of the plan comes together.
Now all you need is some paid-off astronomers and one nuclear bomb.
On the night of the "deathstar's arrival", you go to the station and wait until both the sun and moon are below the earth's horizon. Then, under cover of earth-shadow, you spread out the Mylar into space around you, forming an enormous flat disk. With thin aluminum tent poles, you hold the fabric flat so that its broad face reflects down towards earth. You and your crew have got to work quickly because there is a lot of Mylar and tent poles to set up, but by morning you own an enormous pizza pan, floating ominously above the planet, visible for all the puny humans, striking anxiety and fear.
Suddenly your paid-off astronomers start screaming to the press, describing how they had watched the enormous artificial moon approach for deep space. Then New York is vaporized as a breathy baritone voice asks for the planet's surrender...
The next day, you're addressing the world court, accepting their surrender and becoming the Earth's first Planetary-Emperor. With total control of the world's economy and its labor force, you begin the 40-year project of building an actual deathstar.
[Answer]
# Asteroid belt extraction, mining and modification
# +
# Kinetic Bombardment
I think a few points are important.
1- How would that be done in secrecy? If other countries get a hold of what you are doing they may try to prevent the construction to ever be finished.
2- The cost for mining here on earth and then moving all the materials to space is outrageous and downright inneficient.
# Solution:
Start a modest asteroid belt mining program, and start to invest on it heavily as the years go by.
Focus on autonomous machines to do the work on site, and start moving a big chunk of rock towards a lagrange point.
You need to build a self sufficient habitat on the inside of the asteroid to prevent retaliation and to have a place to run to when things go to hell on earth.
Try to use an asteroid with tungesten on it. You dont need a death ray, just melt it in big heavy rods and use them as missiles to hit your target. Thats kinetic bombardment.
From wikipedia:
>
> *A kinetic bombardment is the hypothetical act of attacking a planetary surface with an inert projectile, where the destructive
> force comes from the kinetic energy of the projectile impacting at
> very high velocities. The concept is often encountered in science
> fiction and originated during the Cold War. The typical depiction of
> the tactic is of a satellite containing a magazine of tungsten rods
> and a directional thrust system. When a strike is ordered, the
> satellite would brake one of the rods out of its orbit and into a
> geostationary position while directly over the target. The rod would
> then begin to fall towards the earth, picking up immense speed until
> it reached terminal velocity shortly before impact. The rods would
> often be shaped so as to increase the terminal velocity. In science
> fiction, the tactic is often depicted as being launched from a
> spaceship, instead of a satellite. Kinetic bombardment has the
> advantage of being able to deliver the projectiles from a very high
> angle at a very high speed, making them extremely difficult to defend
> against. In addition, projectiles would not require explosive
> warheads, and—in the simplest designs—would consist entirely of solid
> metal rods, giving rise to the common nickname "Rods from God".
> Disadvantages include the technical difficulties of ensuring accuracy
> and the prohibitively high cost of positioning ammunition in orbit.*
>
>
>
# Extra
All the rocks excavated to give room for the habitat and other facilites can be repositioned in front of your asteroid for an extra shield or just stay there untill you decide to hurl them at one target in a shotgun style attack (hits multiple areas, no total obliteration of target, leaves something to conquer).
# Cost? What cost?
If you have the cash or manage to get the money from investors, the project pays itself. Many asteroids have rare minerals and elements in much bigger concentration than here on earth. Aside from the initial cash to get things started (it wouldnt be cheap) the extraction of rare materials could at some point pay for everything, and maybe even spill some profit.
As some minerals/elements start to get scarce on earth (or just too cost prohibitive to find/reach) you could be the only source of some materials in the near future.
Also from wikipedia on asteroid mining:
>
> In 1997 it was speculated that a relatively small metallic asteroid
> with a diameter of 1.6 km (0.99 mi) contains more than $20 trillion
> USD worth of industrial and precious metals.[6][47] A comparatively
> small M-type asteroid with a mean diameter of 1 kilometer (0.62 mi)
> could contain more than two billion metric tons of iron–nickel
> ore,[48] or two to three times the annual production of 2004.[49] The
> asteroid 16 Psyche is believed to contain 1.7×1019 kg of nickel–iron,
> which could supply the world production requirement for several
> million years. A small portion of the extracted material would also be
> precious metals.
>
>
>
[Answer]
I think that limiting yourself to "today's tech" is too limiting. If someone really *needed* to build a Death Star they would have to plan ahead and build the tech to build it.
I would go for self-replicating robots of some kind. I think that with current technology and a lot of research we could build a robot space probe and factory that would go out and find asteroids, set up mining and processing, and build more mining robots and more robot factories.
At some point the robots and factories are directed to start building and assembling Death Star components instead of more robots.
This assumes that all of the necessary minerals can be found in the asteroids which may not be actually true. We haven't really looked very hard yet.
There are too many variables to estimate the time needed, but with an exponential growth curve in robot population, the time is a *LOT* less than 833,000 years. A lot depends on how fast the robots can reproduce and how fast they "die" from hardware failure.
The cost would be the initial development and ongoing monitoring and programming updates. The cost of the actual building would be zero because the robots would be doing it like a giant 3D printer and providing the material too. Unless you start using economics and calculate the opportunity cost of building a Death Star instead of all the really useful things your space industry could be doing.
] |
[Question]
[
As a series of anatomically correct myths, here we have the griffin. Is there a realistic way that [griffins](https://en.wikipedia.org/wiki/Griffin) could evolve? Using Earth or near-Earth biology, how close could I get to the classic griffin? Is there a reason that a griffin couldn't evolve?
A list of all of the Anatomically Correct questions can be found here
[Anatomically Correct Series](http://meta.worldbuilding.stackexchange.com/questions/2797/anatomically-correct-series/2798#2798)
[Answer]
I hate to say it, but I can't really come up with a way to justify gryphons, or at least flying ones. Their body structure is such that flight seems impossible, and if they could fly they would have such hollow bones that they would be little threat on the ground (they lack strength and their bones would snap like twigs), making the idea of sharp claws and a hunter build rather impractical. I don't believe any plausible gryphon would be capable of flying.
Thus to justify them I look at land based animals that still use wings.
...This changed from lots of options to a slow progression to a final gryphon. You can skip to the bottom if you just want to see the end result.
**Ostrich approach**
Look at Ostrich as a land based winged bird for a starting format. They use wings for balance when running, not for flight. A similar approach could be taken for gryphons. They are land based predators (thus the teeth and claws) that evolved from birds but but now use wings entirely for maneuvering while running.
However, justifying four legs is hard here. Four legs provides balance and stability. Four legs and a tail does the same thing for balance as ostrich wings do. Wings on ostrich work by allowing an ostrich to stick to two legs while still having a means to control their balance and adjust their direction better than two legs alone allow; but ultimately they are an adaption needed only because two legs are less balanced then those with four.
I toyed with the idea of saying that they developed four legs but still prefer to run on two for speed, using only four legs when not at full speed, but this doesn't really work either. Two legs are more efficient for walking then four, in fact the efficiency of two legs is thought to be why humans adopted it.
One option is to mix in a little t-rex into your ostrich template. Maybe their front claws are not used for walking at all, but are grabbers used for catching prey. They run on two legs and grab their prey with front claws. You could perhaps have them then evolve to look somewhat similar to gryphons this way, but they would behave different. Ultimately it feels like a creature that is grpyhon in name only, even if at a distance they may pass for one.
**Raptor approach**
lets move from t-rex to raptor! It's theorized that birds evolved from creatures sort of like raptors, and in fact raptors likely had feathers. In this case the raptors were believed to use their feathers and wing-like appendages to help them leap at prey and then cling on, balancing by flapping their proto-wings.
Something similar could be done with gryphons...sort of. Again the four legs become a hindrance to justify here. Four legged creatures would leap in a different way and would control their leap by twisting their body like cats. Wings would allow slightly more control, but not enough to really justify evolving them.
**Tree Cat approach**
One option I can think of is to have leaps not come from the ground, but from above. Imagine a scaled down gryphon that is something like a treecat. It lies in wait above it's prey and uses wings when it leaps down on it's prey to help guide it's fall and help it stay on it's prey while using all four limbs. This would require a very mobile prey that is difficult to stay on. Likely prey that is relatively large compared to the size of the gryphons, such that they can have four claws dug in and be using wings to help hold on to it.
This is a concept that could...somewhat work (honestly, the wings still don't quite seem useful enough to be justified), but explaining it's evolution is hard. If it started out as a bird the wings make more sense, they may be vestigial and while they were adapted to help with hunting they will eventually be adapted away from entirely to be more pure-cat. Their reason for evolving away the ability to fly could be because they tree cover was so extreme that it's hard to hunt land animals through the tree, and the extra mass and stronger bones they gain by giving up on flight allows them to have more lethal poncing power (and more ability to SURVIVE pouncing on something nimble that will try to buck them off and/or kill them) However, justifying the evolution of front paws is quite hard then. It would likely be that front paws started as some way to help them better cling to prey but it feels like a chicken and the egg problem. Once the front claws have reached a certain level of usefulness they're clearly advantageous, but they must be useful through all stages of evolution, not just the final one, and I don't see how the original proto-claws would ever be useful.
If you started with tree-cat format and tried to add wings later you have the problem that wings aren't all that useful compared to a well developed tree-cat. Watch a slow motion video of a cat leaping any large distance, they are really impressive at it without wings helping them. Again this is because the approach used to handle balance and leaping in a four limbed creature is different then the two limbed creature, as described with the ostrich example; rendering the wings less useful when four legs exist and hard to justify evolving towards.
There is also the problem that four limb creatures are larger and thus heavier. The heavier a creature the less wings help because it becomes harder to produce sufficient thrust from the wings to counteract the weight of their body enough to modify their flight/fall pattern.
One option is to try to focus on wings being needed primarily to help them stay on to a creature that they had pounced on, perhaps one that had evolved a thick or scaled coating that is resistant to their claws digging into. Or alternatively if they actually have to crawl along the length of a creature they already pounced on (by slowly moving a limb at a time) the presence of wings would help them stay on while they had fewer than four limbs dug into their prey.
Then we get the problem of how do they kill any prey that is large enough to require clinging on like this; where the cat's body is a small enough weight compared to the prey to be easily carried or bucked off. Maybe it climbs it's way to the neck of the prey and attacks with smaller cuts that are not instantly fatal but will kill the creature eventually. Imagine something only slightly larger than a cat pouncing on a deer, climbing along the deer to reach it's neck, digging in claws and flapping wings to hold on to the deer's frantic attempts to buck the cat off, eventually using it's claws (likely one specially adapted super-claw) to cut a long gash along the neck, or a few, and then clinging on while the prey slowly bleed out and died.
In fact, this could solve another problem, the beak. Beaks don't make much sense on land animals, they need their teeth to help rip meat off of a large prey (where as birds tend to eat their prey whole in one gulp). Perhaps the prey that the gryphon adapted to is hard to kill because of it's size, and a beak is developed to be able to kill the larger prey more effectively. It would be rather different then traditional falcon beaks, but look similar enough. Give it a hard pointy end with serrated edges and it could act like an extra long claw to cut at a throat while your cat holds on with all it's claws and wings. It would then have to be able to cut up the prey into beak-sized bites since it lacks teeth, but surely its claws or serrated beak could be used to cut off pieces.
This in turn leads to two questions, one, why is such a large prey animal in a forest so dense to make flying birds give up on flying (this is the most forgivable, and the prey doesn't have to be quite as big as a deer anyways), and two, why does our gryphon need to kill something so big? It can only eat so much food at once, killing such large prey is overkill, and hunting things larger than you increases the risk of being killed by the thing you're hunting.
One option is that the gryphons are pack hunters, with a large pack attacking the same prey animal, dividing the meat of the large prey across multiple animals so less meat is wasted. However, I'm not sure why they would benefit from being in a pack if they relied on ambush tactics like pouncing from above. There isn't much reason three attacking the same prey are more likely to secure a kill then three attacking their own separate prey. Perhaps if they kill not through an exact cut to the neck but through lots of smaller attacks that slowly weaken the creature there would be an advantage on having three or four all attacking, but frankly this seems unlikely since a cut to random non-vital areas are not likely to lead to quick kills, and because their wings would get in the way of each other if they were all fighting on the same creature.
Maybe their pack hunting consisted of spreading out to spot potential (semi-rare) prey and communicating it's presence over large distances to help set up an ambush by letting the attacking gryphon know where to attack. They benefit from the pack not because it helps take down the chosen prey, but by help finding and setting up the ambush for their prey. This helps a good bit, but it still doesn't seem a sufficient justification for living in a pack.
Perhaps if you also added in predators that prey on the gryphons as well, such that the pack behavior is as much about defending against those that would eat them as it is getting something to eat yourself the pack can be justified. Though the argument about them hunting by spreading out to find prey runs counter to the argument about them being in a pack for mutual protection. Maybe the pack is more about defending young that are particularly vulnerable and need a pack of non-hunters to defend them, while the fully grown hunters are mostly safe when working semi-independently to identify and work to help set up ambush of prey. This could work, packs form up for defense, then the males collaborate to kill larger prey to feed the many hungry beaks of the pack with a single very large kill. Cats are already well adapted to living on small number of successful large kills compared to other hunter species, which works well if much of hunting is about finding hard to find vulnerable prey; leaving one to the whims of chance as to when a kill can be obtained.
There is still the problem of chicken meets egg. Even if you assumed this approach worked once a fully formed gryphon existed (and honestly I would need to do some more work to justify the mini-gryphon final form, I think the basis could work but there are still a lot of holes to patch), you still have to ask how they reached that point. The creature isn't hunting large animals like this from start, it must have originally preyed on smaller species. More importantly, How did proto-wings prove advantages enough to stick around and develop into full wings? In my example above it's the flapping of wings that prove useful, until you develop a certain degree of strength in your wings they aren't too useful for staying on prey, so what good were they as proto-wings that justified their sticking around long enough to develop into full wings? well..maybe I can handle that too.
**Flying Squirrel approach**
Flying squirrel have their own wing-like appendages which they can spread to allow them to glide between trees. If we stuck with mini-gryphons as cats adapted to living within trees then perhaps you could claim that wings were used in much the same way that flying squirrels did, to help with gliding.
In this case imagine cats that not only hunt from trees, but live mostly within them. Presumably there are land predators much larger than them that are dangerous enough that gryphons avoid land whenever possible and travel from tree to tree. They have developed cats tremendous leaping ability and instincts, but even then traveling long distances between trees is difficult, particularly because if you miss your landing you go splat.
In this situation anything that would help the gryphon to focus his landing is going to allow him to leap further distances safely, which may be useful if tree cover is sometimes sparse. Even a small proto-wing produced by some bizarre adaptation accident may provide some minute additional potential to help land jumps.
This wouldn't be exactly flying squirrel approach, a predator is going to be too heavy to glide easily. Small protowings won't provide much lift to counteract weight. However, they may help with controlling and aim one's fall by acting more like small steering rudders to shift the direction and angle one is falling. Using conservation of momentum means opening and shutting anything during a twist could allow more control of how much the body rotates to align for a landing.
One of the problems I mentioned above was that gryphons couldn't hunt large land based prey as easily, so another option is to say that gryphons hunt other tree dwellers. Perhaps they used their wings when leaping at tree dwellers because those tree creatures could leap off after the gryphon leap and angle away from the gryphon. The presence of wings could help the gryphon to make better mid-air adjustment to their movement, and possible even slightly (emphasis on slightly) slow their descent if they and their prey end up falling to the ground after the pounce. This could be an intermediary step to the larger gryphon I mentioned above, or the final type of a smaller gryphon. The earlier version of gryphon I mentioned has the advantage of being larger and more predatory, likely with stronger wings developed to have strong flapping power instead of being predominately gliders, unlike the smaller 'flying squirrel' variant that preys on other tree creatures. The large raptor-cat thus is closer to a traditional gryphon's form. However, the larger gryphon is also a little harder to justify. You could even have both versions of gryphon in the same story.
**Peacock approach**
Still, what was the original wing, before it was even much of a proto-wing you may ask. I'm thinking a mane....no really! Or at the minimum something that served the same use as a mane. Manes are actually detrimental to male lions in almost every way, costing energy to create and maintain, getting in the way during fights, and helping to trap heat against the body in sweltering savanna heat, and yet lions have them. Why? Because the ladies like it. Many species have developed costly traits that are apparently detrimental to males just to prove that the males can still survive despite the handicap, to prove just how fit they are, and thus how fit their daughters will be.
I'm thinking wings originally started as a 'mane' for cats, something males possess only to prove their fitness to females, despite the apparent cost, and which likely looked something like a mane. Likely the mane, like a peacock again, was also brighter colored than the rest of the body, their way of saying, look even with these bright colors that attract predators I can still survive, I'm just that good, and so will be my offspring.
However, as they moved into the trees these mane got even more 'in the way', catching on tree branches in mid jump can quickly be lethal, so the boys developed a trade off, show off their mane only when the women are looking and tuck them out of the way otherwise. Like our example peacock tails the proto-gryphons developed a way of hiding their 'mane' away when not in use, and flashing it only when they were showing off (which incidentally implies proto-gryphons would use a mating display approach similar to many birds? This in turn implies either the mane existed before pack life or packs consist of multiple males with females having choice of mates rather than a few males ruling a harem of females).
Only later did the males realize that by opening and closing their mane while leaping they could use it's size (by now it would be noticeably larger due to the [Lensman Arms Race](http://tvtropes.org/pmwiki/pmwiki.php/Main/LensmanArmsRace) with other males to see who's was biggest (nothing Freudian here honest!). As time goes on it becomes common place for males to use their mating-display mane as a conservation of of angular momentum assistant.
From there the mane starts to adapt to move back to a more covenant location, closer to center of mass, to support males, and they start to develop the ability to open and close their mane/proto wing faster to support tricker leaps. About this time the mating display would have adapted away from just showing off their pretty mane and it's colors, instead focusing on showing off how they can flap the mane in a fast and interesting ways (again like many birds do with their wings).
Eventually the mane would start to show on females as well (originally as a sexually selective trait it would be predominately a male only trait, much as female lions lack manes), though the females would likely have cheap bland manes without caloric intensive colors. As time goes on the proto-wings usefulness in helping control leaps would become the primary use of the wing, with using it for courtship displays being less relevant (ironically because the protowings are now useful they become less valuable as a way of proving males fitness, for that the male needs to have entirely pointless limiting adaptions that he can still survive despite. Still, as long as the proto-wing was brighter colored than females it could serve this role).
**Pulling it all together in just a few dozen millennia**
This approach produces a smaller gryphon then traditional, but it's the only approach that seems viable to me (and it still needs a bit of hand-waves, the real answer is gryphons won't exist). If you wanted larger gryphons you could claim that my tree-gryphons evolved first and later some gryphons evolved to larger sizes and that their wings are now fully vestigial and simply haven't evolved away yet I suppose.
You start with a smaller cat, bigger than your traditional house cat but not significantly so, which lives in a forested area. It lives on land but is comfortable in trees as well, likely climbing them to avoid predators and sometimes to sneak up on small prey (which it could take on the ground, but surprising them avoided energy chasing them)
while still land base they developed a 'mane' which was a large tuft of hair on the back of their neck or upper part of their lower back that only males used, which was used for courtship displays and competitions much the same way that peacocks do.
Around this time some larger predators migrate in and start to make cat their favorite meal. At least one of these predators is likely sneaky and able to pounce on the cat before it can climb a tree to get away. To combat this the cats start spending more and more time in trees, sleeping and mating in trees but still hunting on the ground. Around this time the male develop a way to hide their mane by closing it down along the body to keep it out of the way of the tree branches they're now regularly traveling through. They can still open up the mane during display. The make likely starts to take on brighter colors now to maintain it's role as sexual indicator due to the "handicap principle"
Over time the cats start to develop more skill for traveling from branch to branch to allow travel while avoiding the increasingly dangerous ground. They still hunt on the ground, but they have become more adapt at finding prey from above and only going to the ground long enough to kill it, or pouncing on it from tree top. They may also hunt some smaller tree dwelling species, but the have trouble catching them because they aren't as nimble as native twee dwellers yet.
Some time later males realize that by opening up their manes while twisting during a mid air leap they can have affect their angular momentum, potentially helping them to land tricking jumps to far away branches without having to touch land, or even tricky pounces on a vulnerable tree-dweller. This proves advantageous and so quite quickly (from an evolutionary perspective) the manes grow longer and thicker, to have a larger effect on angular momentum, and the males better at 'releasing' quickly and controlling how much it expands to help with jumps. Courtship displays adjust to demonstrate the dexterity of manes. Around this time females start to develop manes as well without the bright colors.
The tree-cats (as they now effectively are) start preying more and more on fellow small tree creatures using their better pouncing ability, and enhanced ability to control their spin to adjust for tree creatures suddenly taking off after the cat leapt. They still prey on ground creatures as well, but since being on the ground is dangerous they carrying their prey into the tree as quickly as possible after a kill. They tend to focus on slightly larger land prey now since taking on land prey means a certain danger from land predators, so it's best to minimize the number of times you have to go to ground for food by bringing back the most caloric prey as you can as spoils of war.
The mane is now a proto-wing, used primarily for controlling angular momentum, not courtship. It has some flapping ability but not as much downward force. It's moving away from the base of the neck to the center of back and then splitting to cover the sides because these are the areas where angular momentum can best be controlled. Some 'flapping' ability is starting to develop.
A new predator enters the mix, or perhaps the old predator realizes all his prey are in the trees and an smaller offshoot species that can hunt in the trees evolve. This tree predator specifically target tree-cat young, since the treecat take time to develop to the point that they can safely move around trees. One mother has a heard time protecting against small but fast and/or sneaky predators that can attack from any direction (including above or below) of the trees; the predators like to slip in and steal a kitten the moment the mother is looking another direction, or worse hunting. To combat this the treecat females start living closer together, making it harder for predators since if any one female detects them it sets off an alarm and all the females start to hunt the would-be predators for dinner (remember, if they prey on kittens the predators are likely smaller than full grown adult tree-cats).
The mothers eventually develop a herd mentality, multiple mothers group together to create a parameter area where they keep their young. This changes the males and courtship. Now that females are already grouped together, and don't want to move around as much due to concern for leaving their developing young unprotected, courtship displays don't make as much sense. Instead your looking at migrating to a harem approach, with multiple males fighting for mating rights for one of these female herds, much like lions. This means that the mane-turned-wing no longer is useful for courtship, and it can now fully develop into a wing since that is it's sole use.
The herd starts to run into trouble with food. With so many proto-gryphons (yep, they now evolved past the tree-cat species) there aren't enough of the smaller prey species they use to hunt in the area of the heard (the more solatairy tree-cats held territories where they didn't' have to share their prey with other tree cats). Furthermore since the mothers need to stay close to their young to protect them they are less comfortable ranging as far to hunt.
Specialized hunting parties are created, so that some females can guard the kittens while others hunt and bring back food for kittens and guarding females. This could potentially lead to males becoming hunters and earning mating rights to females based off of their effectiveness in bringing in prey; or it could stick to the lion approach of only a few males in a pride and the females still hunting (it depends on your goals, if you want to shoot for sapience you want the males as hunters, more males in a social group and increased need to compete for mates on a social level will drive towards sapience). This division of labor will further the herding instincts, and particularly if you keep more then a single breeding male in the pride your quickly develop complex social cues and behaviors.
Eventually the need for more food drives the proto-gryphons to hunting larger and larger game because the small game doesn't provide enough resources to feed an entire pride of females and young that aren't hunting. In fact lets push the proto-gryphons to larger prey even harder. Maybe the same predators that threaten their kittens have done a good job of thinning out the smaller tree creatures, forcing the proto-gryphons to return to land based prey as the only numerous prey species left. We could even lower the number of smaller prey species on land (that are easily ambushed from trees) due to similar predators hunting them if we want to further drive the gryphons down my target path of hunting larger land animals. This could work quite well if you assume one new dangerous invasive species introduced to the old cat's world, the species that drove them to the trees and which, after splitting off into another tree based species later, continued to threaten the new tree-cats. New invasive species are a great driver of evolution, and help to explain why there are fewer small prey (those that didn't adapt to the new predators died out).
Gryphons are by this time built for precision leaping, not speed, so they focus on ambush from above tactics instead of the more traditional chasing and harassment techniques of most pack hunters. They develop more lethal claws and beak to help them kill prey that is noticeably larger than them.
At the same time the increased focus on social behaviors of pride would lead to social hunting techniques. Since ambushes don't work well for packs they focus on spreading out to find appropriate prey, large enough to provide lots of food, small or weak enough to kill. The inerrant dangers of predators on the ground drive gryphons to prioritizing the perfect selection of prey, they don't attack unless they're relatively assured of a kill and of sufficient calories being brought out of the kill to justify the risk. This is where the pride is so useful, they can scan much larger areas to find the perfect prey that is worth the risk. Once prey is found they use calls to alert others and communicate where prey is and where it should be best ambushed at. The finders of the prey they drive the prey towards an ambush spot, they do this by visibly positioning themselves to attack; if the prey doesn't move they driving gryphons will attack and kill it, if it does move odds are it's towards a preselected ambush spot. All of this is to allow setting up the most safest kill, ensuring a kill while decreasing odds of death to land predators or the (much larger) prey animal.
For the kill the gryphons will leap from above to get as close to a vulnerable neck of the gryphon as possible, using their impossible good leaping skills, the cats nimbleness in twisting their body midleap, and their wings (for balance and angular momentum primarily, not flight) to help them to make a uniquely precise leap. Once they hit their prey they dig in with all four paws to hold on.
Since a gryphon will never be able to perfectly aim a leap right for the neck they often need to finish the approach by 'climbing' to the neck may be needed. All the while they prey is trying to dislodge the gryphon as best it can, this is where the wings prove invaluable to keep from being thrown. Still, your need to get to the neck quickly or you will get dislodged or struck against trees; thus the emphasis on positioning the perfect ambush leap to get as close to a vulnerable spot as possible.
Once you get to the neck (or any other appropriate weak spot, the beak is used to land the killing blow, It's extended length gives the most flexibility in killing, you can keep all four claws safely digging into skin and the beak offers an extended reach; basically a long pointy and serrated beak gives a much larger radius from which a gryphon can kill so that if he lands anywhere close to the neck he can score a quick blow without the much harder task of trying to 'climb' toward his prey.
**The human approach**
An interesting side effect of this approach is that it's actually rather conducive to evolution of sapience! They live in a heard and hunt as a pack. However, they need rather extensive communication skills and long term planning to position the perfect ambush, both good drivers of intellect. They are taking on creatures larger and stronger, but can't evolve to be larger themselves since they need to 'fit' in the trees and need to stay small enough to exploit their wings; so the obvious solution is to focus on developing intelligence to take on the larger predators more intelligently. I imagine developing the use of projectiles to attack on land animals pretty quickly
Meanwhile, the social structure, having males mixed with females all trying to compete for mating rights, would be a large driver for intellect. The males will likely find making ambushes to be a great way to earn mating rights, but also highly dangerous; thus key planning is needed for deciding when it's worth the danger of an ambush to impress the females, and social skills are needed to get the pack to go along with your decision.
Finally, as a tree based creatures the gryphons would likely develop paws with the ability to grip the branches. This is the first step towards developing rudimentary thumbs, and thus the ability to work tools.
[Answer]
There are three large problems with the griffon.
**Griffons have six limbs**
Look at an animal. How many limbs does it have? If it's a non-fish vertebrate the answer is four. Look at a griffin. Is it a non-fish with a backbone? If the answer is yes, it really, really needs to have evolved from a non-fish vertebrate. There really just isn't time to do it any other way without making the rest of nature completely unrecognizable. Which is a problem, since the griffin isn't like every other non-fish vertebrate. It doesn't have four limbs, it has six. Adding limbs to a creature is really, really hard. The bones and connections needed for it to do anything particularly useful are really, really complicated by evolutionary standards and in every transitional state you've got a useless hunk of meat and bone stuck on you wasting energy and possibly interfering with your other limbs. This is not the sort of thing that evolves out of earth animals. You could, however, have a roughly wyvern-esque griffon if you so chose.
**Griffons have both feathers and fur**
Griffons are feathery on the front and furry on the back. Fur is complicated, especially mammal fur. It may *look* simple, but there are a whole bunch of specific adaptions that go into making sure that animals neither freeze nor cook in their preferred environment, even if their preferred environment changes drastically throughout the year. Feathers are even more complicated. Making a big stiff hair with a bunch of other, smaller hairs growing off it in a specific pattern is hard. To get an animal with both you need to explain one of two things: You need to either explain why a furry mammal was able to evolve feathers (something which is technically possible in roughly the same sense that using quantum uncertainty to walk through walls is technically possible) and then for some reason decided to put those feathers on only half of their body or why a feathery bird was able to evolve fur(significantly more possible, but still well beyond the bounds of what you might plausibly expect to happen) and then put it on only half of its body. And the half body thing is a significant problem. You're going to be looking at intermediate forms which are either split between bad feathers and good fur or between good feathers and bad fur. You need a really good reason why the covering method which has had much more time to be perfected doesn't just take over the body parts with the inferior, new covering. Any Griffon derived from Earth stock really needs to be feathery or furry. Not both.
**Griffons are much bigger than other flying things**
Animal wings push their user up by pushing the air around them down. The amount of air they need to push down is proportional to the animal's length times its width times its height. The amount of air they are able to push down is equal to the surface area of the undersides of their wings multiplied by a factor based on the speed with which they are able to flap. But another way, it's based on the wing's length times their width. As you may have noticed, any increase in the height of the animal (height relative to their posture while flying, that is) demands an increase in the size of the animal's wings relative to the size of the animal's body. As you make an animal bigger, their wings get bigger faster than the rest of them does. Compare the California Condor with the Hummingbird. A typical Griffon is even larger than the Condor, and of a much greater height when flying (looking at large birds in flight from the side, you will notice that they tend to be relatively flat in a way that a lion is not). This is a problem for the Griffon, which either needs to shrink to a more reasonable size while shifting its body plan around to be relatively shorter or grow truly unreasonably large wings and eat truly unreasonably large amounts to operate them. The first leaves you with something rather less than a griffon, the second is massively unlikely to be capable of existing at all due to its huge energy requirements.
[Answer]
From my understanding, The original myth of the Griffin was inspired by Protoceratops fossils found by Scythian Nomads (believed to be the case as most stories and descriptions of Griffins appear shortly after the Greeks made contact with the Scythians). Griffins were described as lion-sized quadrupeds with large claws and a raptor-bird-like beak; they laid their eggs in nests on the ground. From this view, you do not need to add wings to the beast (although if you can think of a plausible way for them to get them then go ahead)
From this, though you can tell that it is possible for a griffin-like beast to occur in nature, it just depends on how you want your version of the Griffin to look.
[Answer]
This answer builds off dsollen's answer.
Although the tree-gryphons do look kind of like traditional gryphons, they are much smaller then a traditional gryphon. To fix this problem we can take the evolution of the tree-gryphon a step further.
Some tree-gryphons begin to become larger, to kill larger prey more easily. This becomes a problem for their movement in trees, so they begin to become more land-based, only climbing trees to attack large prey, and supplementing their diet with smaller ground dwelling creature, allowing them to become even larger. However, this results in their wings becoming useless, and eventually evolving away. So, to prevent this, we can have the male land-gryphons begin to evolve larger, brightly coloured wings, to attract mates, and have the females' wings begin to grow smaller, and eventually disappear. Due to a [Lensman Arms Race](http://tvtropes.org/pmwiki/pmwiki.php/Main/LensmanArmsRace), the brightly coloured feathers covering the males' wings will begin to spread, eventually covering the entire creatures. The males also begin to fight for harems, and their wings become formidable weapons, able to break bones and buffet their opponents into submission. The land-gryphons begin to move towards sparser forest, where their larger bodies can more easily move, as they no longer require dense tree growth to climb on. Eventually they become large enough to overcome the large prey without ambushes, in packs that become more closely grouped, and migrate to grassland type areas, becoming even larger, and allowing the male land-gryphons to evolve into traditional (although flightless) gryphons.
Unfortunately for the land-gyphons, the tree-gryphons soon achieve sentience, evolve opposable thumbs, and hunt the land gryphons to extinction, and eventually commit self-genocide by creating a runaway global warming cycle that bakes them all to death. :(
[Answer]
I’ve seen a lot of answers and justifications for the “fantasy” griffin, but a lot of people seem to be missing the obvious solution. We already have animals similar to griffins in real life: monotremes (I.e. platypuses and echidnas). Both are mammals that possess beaks and reproduce through egg laying, just like griffins. Monotremes were also a lot more diverse in prehistoric times, so it wouldn’t be that hard to imagine that, if conditions were right, a hypothetical griffin could evolve. It wouldn’t be able to fly obviously, but it would fit the image: a large, feline creature with retractable claws (like talons) with a sharp, hooked beak like an eagle’s.
[Answer]
They share a six-limbed body plan with dragons. How about making griffins evolve from dragons just like birds evolved from dinosaurs? The ascription of leonine qualities could just be a myth, resulting from somewhat strangely shaped back legs, a "mane" of feathers where the horns are on dragons, and perhaps the retention of proto-feathers on the hindquarters, which would look like coarse fur from a distance. (Some rare depictions of griffins even show them with serpent tails, which could be done here.)
That said, in the case of an explicitly hybrid creature, looking for a non-artificial or non-magical solution seems less useful than in the case of non-hybrid ones like dragons -- if you take out the hybrid element you've really diluted the creature's identity.
If you want to go further away from a traditional griffin, you could imagine wings that are used not for flying but for display and intimidation, puffing out on either side like peacock tails or butterfly wings.
[Answer]
Gryphons could evolve from large birds, that due to a mutation, have 4 wings instead of 2. This could become sexually selected for, as surviving with a pair of useless wings is harder than not having extra wings. These extra wings might become functional, to make them more useful. The gryphon may increase in size, and the forewings may shrink and become legs. They may also have their legs become covered in hair-like feathers. The females may adapt to get food for young, whereas the males would adapt to protect the young, becoming huge and flightless and gaining sharp quills and a horn. It may evolve to extend its tail to become longer, with the females using it to steer in the air, and the males adapting it into a heavy club.
[Answer]
One of the major issues with griffins is that they generally have wings alongside 4 legs. The easiest solution to this issue is to pick a different depiction
There are 2 ways to make a griffin without resorting to hexapodalism:
## Wingless Griffin
This would be a griffin without wings. One way this could evolve is by starting out with a primitive monotreme of some sort, which could then adapt itself into a predator, with a sharp hooked beak adapted from the ceradontes, and some cursorial adaptations
## 'Wingless' Griffin
There are some versions of the griffin which fly using membraneous wings along their forelegs. This version of the griffin would be harder to evolve. The best way I could think of would be for a small group of flying *Yi* relatives could survive the KP extinction, and then in the intervening time gaining avian adaptations and taking on the form of a large cursorial predator
] |
[Question]
[
We all know and presumably love enormous space battles with vast battleships doing minimal damage to each other for hours before being blown up by a single fighter.
On Earth battleships became big white elephants with high cost and minimal use, vulnerable to every submarine, aircraft carrier, and missile boat in the sea. The era of battleships on Earth is over.
However in space, there's no stealth, so no submarines. "Range" has an entirely different meaning. A simple slug or contact explosive shell has "unlimited" range, where a fighter still has a strictly limited flight time. The concept of "over the horizon" is totally non-existent.
So in the great trade off between drone carriers, missile boats, and battleships:
**Was the era of space battleships over before it even began?**
Or can they still be justified in light of the limitations on the factors that made them redundant on Earth.
*Assume no great deviation from current understanding of physics apart from a high volume black box non-reaction handwavium drive to power the whole thing. Defined as too big to put it in a fighter, and not directly usable as a weapon itself. I'll also permit artificial gravity to reduce the distractions from the core problem.*
[Answer]
>
> high volume black box non-reaction handwavium drive to power the whole thing.
>
>
>
You actually solve your own problem right here.
The biggest reason that a space battleship makes no sense under current or proposed technological limitations is because of the demands of reaction drives. More Mass to move = more reaction mass to move it. It's a tyrannical equation that, as long as it is the primary constraint to propulsion in space, will ensure that the MOST critical design element of any spacecraft is making it as light as possible. This means no armor, which means no space battleship.
**However.**
If you have a reactionless drive, that changes everything. Now more mass = more POWER to move it, and that doesn't necessarily add mass. Modern Aircraft Carriers benefit from being SO huge and expensive already just to do what they need to do, that adding a nuclear reactor to run the whole thing becomes not only feasible, but very beneficial from a cost/benefit perspective.
Your Handwavium powered spacecraft would have the same benefit. The larger your ship is, the more it can benefit from economies of scale. You can afford to put a lot more mass into your environmental recycling so your ship can go further and stay out longer. You can grow your own food onboard. You can completely protect your crew from the [hazards of radiation](https://www.space.com/41887-mars-radiation-too-much-for-astronauts.html). You can actually afford to put a thick, tough shell around the outside of your ship to protect it from environmental hazards like micrometeorites as well as smaller kinetic impact weapons, and you can afford to put a LOT of point defense on it to stop bigger stuff.
And, in true battleship style, the bigger your ship is, the bigger your gun can be. A [Mass Driver](https://en.wikipedia.org/wiki/Mass_driver#Mass_drivers_as_weapons) is a pretty optimal weapon for engaging anything that can't move under its own power, and for many things that can as long as you can throw a big enough projectile fast enough.
Battleship on Battleship combat under these conditions would be a dance of who can get a better target solution on who sooner, and start putting Significant Holes in the other ship. I don't really think it's feasible to design armor that can STOP projectiles with the kind of energy that mass drivers are capable of, so instead you want to design your ships such that high velocity kinetic rounds go right through and deposit as little energy as possible on their way. This means elaborate compartmentalization and redundancy to ensure that your ship can retain as much combat effectiveness as possible even after it's had a bunch of holes poked in it.
The Expanse does a pretty good job with this, actually.
[Answer]
There are many parameters to take into consideration.
### Some historical evolution
To make it really simple, the *de facto* standards of naval battles of the 18th and 19th Century died out because weapons became far too effective and the costs of such large-scaled battle was too huge. The WWI's [Battle of Jutland](https://en.wikipedia.org/wiki/Battle_of_Jutland) is often considered the last of its kind.
A jump in time to WWII which saw somewhat the end of the large battle ships ([Bismarck](https://en.wikipedia.org/wiki/German_battleship_Bismarck)). The reason was again that even with large costs, the defense were not effective enough against new and/or specialised weapons (submarines, planes, torpedos, etc.).
Fleets nowadays consists in smaller specialised ships (e.g. anti-mines) and tactical ships (submarines, aircraft carriers). And seldom considering an actual sea battle. Supporting weapons (planes/missiles) would actually finish it before it even begins.
### Defending your space ships
We see that the issue with seafaring ships and battles is the effectiveness (what they do in comparison for their price) is too low due to other types of weapons/ships. Simply put, they are not resistant enough.
To get space battles *à la* Star Wars, you'll need to make sure you equip your ships with solid defenses. So they should be able to get a missile or a laser without blowing up immediately. Back in the 18th Century, a ship often needed several hits to be out. And even that often meant that the ship was not sunk. Currently a torpedo, a mine or a missile could well bring the whole ship down.
How do you defend effectively? Well that's an interesting question.
* Heavy armours aren't a practical solution, because we see already on Earth ships that they have limitation. And for the space faring, weight is a very important issue.
* Most Sci-Fi tropes using some kind of defending force fields. You need that. But something that can block missile, lasers, and just the small piece of junk sent to you is going to be very challenging. Especially if you don't want to be moved around off your course!
### Space fleets
Seeing the current situation on Earth and extrapolating, it is likely that you would have specialised fighting ships (thanks to your handwavium) (X-Wings/Tie) and then ships carriers. Those would be surrounded by a fleet of cheaper and first line defense ships. You should not let any attacker get close to your carrier.
But then, considering the price of such a fleet and material requirement, your handwavium should allow us to go mine the other star systems ;-)
[Answer]
Here on earth, battleships were built when guns became so big and their range so long that a smaller ship could not carry such weapons, let alone use them. Their era ended when their opponents could counter the threat of the big guns on the big ship, and when much smaller platforms, like submarines and aircraft, could pack enough punch to threaten the big ships.
Apart from being a platform for very large weapons, a battleship is also a small city, providing all kinds of living facility for a large crew. That means that a battleship can go on much longer missions than a torpedo boat or similar.
Combined, the large weaponry and the ability to stay in the target zone for extended periods enables a battleship to besiege a target, like a port or similar.
What does that mean for sour setup?
For a start, space is big, so space travel takes time, which in turn means you need living space and facilities to keep your crew alive and reasonably happy. We already saw that a battleship can provide for those needs. The big guns should be a no-brainer: just install whatever the arsenal of your mind can think up, especially when your weapons of choice are suitable for laying waste to ships and installations alike.
Now to the downsides. A big ship is a big target. It typically lacks agility, and thus the ability to dodge attacks. So you need armor that can take a few hits.
You will possibly want a lot of defensive weapon systems to counter attacks by fighters and missiles, and you might want to hybridize your battleship with a carrier so you can bring a few fighters yourself.
Still, your battleship will be a specialized weapon platform, and while being able to lay waste to a lot of infrastructure, and being able to take some beating, they won't be invincible, and there will be military vessels of much smaller size for other roles.
[Answer]
Well, since space battleships are not for actual space battles between fleets (fighters & destroyers and the other tin-crap are cheaper and better suited for this stuff), but for laying siege to planets/solar systems and for carrying all the important stuff for either capturing the planets - or simply laying waste to their surface - the era of space battleships is definitely not over.
Really, how should one of these tiny destroyers lay waste to a space-port? Or even destroy the Earth's defensive system of orbital stations? Can't do - but that's what battleships are for. Also, they make impressive command vessels.
[Answer]
One major design consideration for realistic space warships is the square-cube law. Every time you double the length of the ship, you increase its surface area by a factor of four, and its volume by a factor of eight. This has both advantages and disadvantages.
The most obvious benefit is that you could have armor that's twice as thick as the armor used by a smaller ship, but which takes up the same proportion of the larger ship's total mass. However, the major disadvantage I see is that you have less surface area, proportionally, with which to radiate waste heat. If the limiting factor of your warship design is disposal of waste heat (which, realistically, it probably is), then a ship with twice the length will only be able to afford to run reactors and engines which are four times more powerful than the smaller ship, despite being up to eight times the mass. This would make a ship with twice the length able to sustain only half the acceleration of the smaller ship. So from that standpoint, space battleships really would be better armored and slower than space corvettes.
Of course, this assumes the larger ship has the same shape as the smaller one, which it may not have. You can stretch the shape of the ship so that the larger ship ultimately has the same ratio of volume / surface area, or simply leave a greater proportion of the larger ship's volume empty (which I'm sure the crew would appreciate). This would abandon the pros and cons offered by the square / cube law; which I'm not sure would be the best idea, since a larger ship makes for a bigger target, and you've just given up your armor advantage.
[Answer]
A couple points I don't see mentioned above and are worth remembering regarding naval Battleships:
1. An asset doesn't need a high body count to prove its effectiveness. If your goal is power projection, a weapon that no one wants to pick a fight with is a supremely effective weapon indeed. "Supreme excellence consists of breaking the enemy without fighting." - Sun Tzu.
2. It's not just about cost effectiveness. Battleships remained a major component of Naval warfare into the 1990's, contributing heavily to the Coalition victory during the First Gulf War. However, around the same time, smart munitions were becoming more and more viable; this allowed smaller ships to match and exceed the stand-off potential of the Battleship, rendering the larger vessels redundant, its job superseded by every other ship in the Navy.
So, in essence, battleships were rendered redundant because gravity and air resistance made projectile weapons less effective at long-range when compared to modern guided missiles.
Addendum: To help illustrate my above point, the 16-inch guns on an Iowa-class Battleship had an effective range of 21 nautical miles (39km) while a Harpoon anti-ship missile seems to be a rather short-range system at between 67-120 nmi (124-220km).
But this is all rendered moot in space where any object launched by a ship is likely to continue on until it rams into something so your limit isn't just the weapons' ranges. Instead, you have to consider the specific advantages and disadvantages of each weapon and their likely role in combat.
Guided missiles obviously have the ability to adjust their trajectory during flight, able to pursue a target and evade countermeasures until they are close enough to do whatever they are designed to do. However, guidance systems are relatively fragile; no matter how durable you make their systems, there will always to be a limit to how quickly a guided missile can accelerate, giving them a minimum effective range, wherein an enemy's countermeasure can intercept and kill them.
Projectile weapons are, of course, the opposite. They don't have the ability to adjust their trajectory, meaning if the enemy is far enough away, evasion is trivially easy. However, they have no need to worry about acceleration, meaning the only limit on how fast a projectile can be flying is the size of the gun: longer barrels - regardless of specific propulsion - offer exponential rather than linear acceleration, allowing for higher relativistic speeds..
Of course, that assumes that "Guns" in space would only refer to kinetic weapons which, due to potentially still slow projectile speeds, might prove to have limited effective range. However, if your setting instead relies on Directed Energy Weapons like Lasers and Particle Accelerators, a larger ship would likely carry a larger powerplant, itself feeding a larger weapon batteries.
[Answer]
Besides carrying big guns I think size isn’t everything even space. Reason:
1. Small ships are build faster and don’t need an extensive crew if any at all
2. Small ships will be better maneuverable and cost less energy to do so
3. Even a small delivery system can potentially carry a devastating payload. It doesn’t necessarily require big guns but smart ammunition delivering enough energy to destroy the target.
4. The destruction of one big ship is easier done than many you could have build from it as it might need just one hit.
5. Engagement ranges are very large and detection ahead of time will be difficult. Even more with smaller vehicles, due to smaller radiative cross section. Using active means like radar on large distances I’d imagine to be physically impossible. A small vehicle could therefore sneak up closer than a big one and detect you earlier. Deliver faster and reduce reaction time.
That said there are reasons why big ships could be useful. But if it is about delivery I don’t think that those would perform to well at the frontlines.
So what you are looking for is most likely some sort of good mix of weapon systems and special purpose roles in your fleet.
1. Carrier
2. Logistic
3. Recon (could be drones but the communication might give you away so they have to be autonomous)
4. Destroyers
5. Something between recon and destroyers
[Answer]
Space battleship has one great battle advantage: big mass. It allows:
* use of more powerful guns - recoil is not that hard on structure, crew and course (they can even use ballast just to increase mass for that)
* can sustain much more damage - it is no water to sink in. That means that a slug which evaporates fighter or cuts in half corvette would not destroy battleship. And even if battleship falls apart, some of this parts still would be able to fight (shoot at least)
* huge inner volume for resources (longer range), ammo (can "oversit" smaller ship in barrage), some lesser crafts (universality)
This are great advantages, so battleship has its future (if fuel problem would be solved).
On Earth battleships became obsolete because they sink too ease. If not, they still would be the most powerful ships. There is even an idea of battleship with lots of anti-weapon systems (laser and not + powerful computer) which would make it invulnerable against rockets, bombs and high-ark shells of any kind (at least for some time). Those monsters would destroy carriers with there support ships at ease.
[Answer]
**The Scale of Space makes battleships - or any warship - infeasible and unnecessary.**
Space is really big - no matter how big you think it is, it is way bigger.
To traverse the vast distances involved you need to accelerate to unfathomable speeds, and stay at these speeds for unfathomable amounts of time. Even if you have an amazing ability to thrust with your drive, it does not reduce the incredible speeds that need to be attained to traverse such large distances.
A spaceship with guns on it makes no sense. A gun makes no sense. Firing a gun from a turret would be firing a small pellet only a little bit faster than your ship, which is already travelling at likely hundreds (if not thousands) of kilometres per second anyway.
At such astronomical speeds, collisions are more like high energy impacts with no defense. Materials at these speeds interact as if they were gases, they do not behave in collisions as solids - there is no 'armor'.
Even in LEO (low earth orbit), these make no sense, as interactions would be just the same. Not to mention interplanetary or interstellar distances, where distances are simply too large for any meaningful defense. A small asteroid or even a small ball, accelerated constantly over time, accumulates so much kinetic energy if it encounters a planet it could devastate it.
Therefore, I can see little tactical or strategic advantage to a ship with guns. Just accelerate small masses to great speeds.
[Answer]
Considering "battleship" as "large armored weapons platform" then in a space war scenario there would be a sensible use for them: **in orbit.**
Battleships would be placed in orbit and stay there. They would offer a commanding position for attacking planet-bound structures. Really though, **the battleships would defend against incoming rocks**.
For a civilization capable of space flight, the best way of attacking a planet is to use its gravity well against it and throw things at it from a great distance. To counter these rocks you have to see them coming and you need to deflect them, before they enter your atmosphere. If you are above your atmosphere your vision is clearer and you can see them farther away. Your defensive fire will not be slowed by your own atmosphere. The bulk of your ship means recoil from your energetic defensive fire will not substantially move you out of your orbit.
[Answer]
It is predominantly a question of engine and **weapon energy efficiency**. Intense maneuvering would be out of the question for such a large ship. Its primary offense would be to launch projectiles that are **fast** enough and **accurate** enough to be difficult or impossible to dodge and that deliver sufficient energy to disable a target, and its primary defense would be to intercept, deflect or diffuse/defuse incoming projectiles, similar to the way a [Phalanx gun](http://www.navweaps.com/Weapons/WNUS_Phalanx.php) works in naval combat by shooting down missiles (at close range in this case for maximal accuracy). As soon as its energy or projectile reserves are depleted, *it's a sitting duck*.
A **moon base** would probably actually be the ideal deployment scenario for such a ship, since stationary nuclear reactors fueled by mines, vast arrays of solar panels and geothermal energy could provide the energy to power the offensive/defensive weapons and would not require recoil compensation while in a planetary environment. A smaller moon with a landing pad, or possibly a geostationary tether would be ideal so as to limit the amount of energy required to take off and land or dock with the planet/moon. The greatest difficulties might be the storage of energy and the expense of takeoff/landing and of changing course. Nonetheless, given sufficient energy reserves for the tremendous length of a space voyage, it would make a formidable offensive weapon against ships. Subjugation of a sufficiently well-supplied and technologically advanced planet would at all points prove difficult, however, due to the resource and economy imbalance, and is not advised.
It would need to dock with or be in close proximity to an energy source regulalry to keep its armaments at full power, so its primary utility would probably be far more defensive than offensive. Being able to store, generate or harvest enough energy in the far reaches of space to make it an efficient offensive weapon is the primary bottleneck which is why super-energy reservoirs such as the "Tesseract" of Marvel fame are the stuff of science fiction.
So I think it's primarily answered by what size of ship or technology configuration would give you **maximal energy efficiency**.
[](https://i.stack.imgur.com/Wkez5.jpg)
[Answer]
>
> So in the great trade off between drone carriers, missile boats, and battleships:
>
>
> Was the era of space battleships over before it even began?
>
>
>
Like written [here](https://worldbuilding.stackexchange.com/a/153495/67405) it depends on your technology level, on your power generation and the propulsion technology.
If you don't have a reaction less drive there is no use of big ships like a battleship. You want to stay small so you need less fuel on board for moving the ship. Heck you don't even want humans on board because the need a huge and heavy infrastructure on board to survive and the longer the deployment the more weight you need (food, water or aquaponic areas or recycling stations).
So with a current level without reaction less drives there is also the constrain of the detection range. In naval warfare this is also a factor what is a laser defense system of use if I can detect the shell? Or if I detect it to late? This applies also to space. What use of a mass drive that can hit spot on on a distance of 10 light minutes? If it cannot detect a ship that is 1 light second away?
So these two points lead us to space battles with drones, where the command center is on a different astral body and gives general commands to the drones, like destroy that ship. For drones it is then interesting to have drone carriers, so these would be bigger, but still more like a skeleton where lot of drones can dock, like in Enders Game. But these carriers would stay behind the actual front to save them from harm. Now also a few command ships would be useful that support humans. Thes would also stay behind and just give commands. Should the battle be lost these ships have a huge interest to disappear quickly. For that it needs to be light not a lot of mass, let me just say E=mc². And then small so detection is harder. Look at the problems that are currently exiting to detect small drones at airports.
All in all I would say drone carrier would exist also command ships, but no large ones with big weapons like battleships, also manned missile boats are unlikly. If you know Stellaris you can have a look on the tech tree bigger ships are only unlocked with the next tier reactor or better propulsion tech.
So it depends on your tech level if it is higher the bigger ships get practical like the others explained.
[Answer]
See the Honor Harrington series by Weber. He actually goes through a several generation series of offence and defence weapons.
Miltary grade ships have accelerations of 400 to 700 Gs with smaller ships being more capable. Missiles have accelerations of 10-50 times that, but their 'impellers' burn out. But 3 minutes acceleration at 20,000Gs covers major distance.
It's almost impossible to actually hit a ship. Most missiles carry a nuclear pumped x-ray laser that does the damage.
In the initial novels, ships have missile tubes -- much like torpedo tubes on a sub. Volley of fire was fairly slow: A ship with 20 tubes could launch 20 missiles per salvo, with about a minute between. Innovative tactics was to launch the first flights with lower acceleration so they would all arrive on target together.
Counter missiles were the response, plus point defence energy weapons.
Later large ships would carry extra missiles attached to the surface of their ship. These could be nudged off, then started when they were clear. Had to be used quickly, as they were subject to damage from near misses.
The tech war is one of control -- how to guide thousands of missiles in a battle, (they are light minutes from the ship that launched them...) how to jam, how to keep from jamming, and counters -- burn through jamming, better point defence.
A ship could 'go dark' Turn off it's impeller (which also was it's defence screen) reduce IR signature, and be very very hard to find. (Consider trying to find a 1/4 km diameter rock at the distance of Saturn, if it's painted black.)
In Weber's books, battle is mostly maneuver sometimes for days, and the battle phase may be only 2-3 volleys of missiles some minutes apart. Battle at this scale, requires that you have a spread sheet with the speed, distance,time arrangements for an accelerating body. (The accelerations are so large, gravity can be ignored)
Weber doesn't really address the commerce raider -- light cruiser ships designed to interdict merchant vessels, with the attendant response of convoys. Nor does he address stealthed ships much.
[Answer]
Space is huge beyond meaningful logical comprehension. We know the numbers as good as a 1st class kid learns to count 1-10, as the kid can only imagine what is after 10, how far it goes and even what those symbols will later on help him with.
Within space points of interest are scarce within that volume and valuable resources even more scarce. Multiplied by the space itself though, there are ... countless! But engaging the volume of space plus the time that is essential to describe space time, how can conflict arise? War between different species, because as long as we speak for civil war of 1 species alone, this war will start and end at the home planet. If and when humans manage to create a new colony comparable to earth to population, then we instantly speak for different species. It is the vast space itself that defines that:
Example 1:
A meteor strikes Mars and Mars is now habitable, a brand new and virgin Earth. We go there and after 200 years Mars is a second Earth. Somewhat in better condition due to higher respect to the environment. So far so good. We know have Earthians and Marsians, because people finally understood that only unity will get them further and make them happier. Now Earth miss resource A and Mars miss resource B, while Earth has plenty of B and Mars has plenty of A. Obviously they trade. Not rage war with battleships to gain orbital control and then rage war with land and atmosphere vehicles to finally seize the opposing planet. The cost is forbidding. You simply trade the resource. Even the cost of transfer will be notable, but, nevertheless, far cheaper that war. Ok, and now the hard part. Both Eartians and Marsians miss resource C. What they do? Most likely they do not know where it is. Even if one found it, the other will also found it. A finders-keepers logic will not help. Most likely they unite efforts, search the entire system for the resource and, when find it, organize their safe extraction and transfer, so both share it. Why? Because it is cheaper. It is so deadly cheaper that with the cost of a space war they would find 5 C resource sources, and other 5 of resources D, E and F that they will come to miss in the future after shortage of C and, the rest of the funds will go for FTL travel research. :)
Example 2: Two races meet at the edge of their exploration bubbles. We obviously talk for available star travel tech level, minimum. While stories rage war, intelligent approach is different: First comes trade agreement, then exchanging exploration data. Those 2 things alone can be as valuable for both as multiple times their annual growth. Because both will be available to trade their abundant resources for rare ones (for them when match) plus both will be able to extract resources they miss, located at other space because the others simply so not need. Not to mention combined efforts. Actually is not really different than the Earth-Mars story. And why should be?
Combat fleets now. What for? Attacking who? Your own kind at another colony? Or an unknown 'enemy'? There would be some prototype warships, with the best of tech on, but not at a large scale. Again, space itself, protects. If the 'others' attack you, you know about it years before it happens. You should have plenty of time to produce equal or more numerous combat fleet on defensive position at your point of interest, before enemy actually arrives and with less energy than the one spent by your enemy to sent the fleet.
So yes. There would be top tech combat ships, from fighters to battleships and carriers, orbital defense stations, planetary defenses and all that stuff, but i can hardly imagine conflict possible, unless some species are ... not exactly intelligent or been warlike by DNA. Hard to advance to tech that way though.
[Answer]
Battleships may return... but as a Battleship/Carrier Hybrid, which is not possible on naval ships. With Carriers, which replaced battle ships as the "Capital Ship" of any blue water Navy, the main weapons are the ability to park a working air force base off the shore of the target. The ships themselves have little in the way of fire power, most of which is defensive (and if you're down to manning the guns as the carrier's last line of defense, somebody royally screwed up). The Carriers based of the Russian carrier (which isn't a carrier but an Aviation Cruiser... and is distinctly to allow it to not count as a true carrier to avoid it being a capital ship, since cruisers aren't capital ships... look, naval terminology is weird and more structured around cheating naval treaties than anything scientific) does have offensive capabilities of a modern cruiser ship and the aviation capability of a modern carrier... but it's been noted that such a hybrid ship does a terrible job as a cruiser and a carrier (since you can't fire your weapons while launching and recovering planes.). The primary reason why carriers themselves are lightly armed is because bigger guns would interfere with it's true purpose of being a mobile landing strip for planes, since the runways are on the top deck and outside.
In space, this design won't work... the crews doing the flight prep for a carrier's fighter compliment need to breath and it would be more practical to build the ship around a hanger/internal runway that runs the length of the ship than to build a hanger deck below the runway deck, if only to not have all the hassle of those crews needing to don Space suits and run around outside of a ship in a battle where the enemy ship can fire down onto your flight deck from directly above you. With that in mind, the surface of the structure built around your main runway will offer a lot of space to mount guns that point in all directions. These "Battle Stars" thus can make the best of both worlds that can't be taken advantage of in blue water navies.
[Answer]
Really great question.
I would reference the use of combat spheres in The Expanse.
When ships come within certain distances of each other, there are different engagement possibilities:
Near = railgun, PDC's
Medium = PDC's, Missiles
Far = Missiles
(Very Far = Planetary defence)
Essentially, the feasibility of space combat, specifically with "space battleships" is not usually well represented outside of hard sci-fi, and even then has a fairly bad rap.
In space, battleships would become different, but still fill the same role:
They would probably hold mainly long-range missile systems (probably both impactors AND fissile explosives), and short range PDC-style defences to intercept closer, smaller, targets.
For engagement with other battleships, you would probably find that battleships fill a sort of ICBM-carrier role: railguns, relativistic impactors, etc., depending on your tech-level.
(Of course this is just my best guess, and I can't really reference anything here. This may be so far off the target that future people will laugh at me!)
In conclusion: They are feasible, but the distance over which a battle would take place makes them far removed from the relatively close quarters we're used to on Earth.
Hope this helps.
I'm new here so feel free to give plenty of feedback, I love it when I get constructive correction!
[Answer]
# They are not feasible
## Here is (one reason) why
One Aspect I did not see mentioned here, and is often overlooked in science fiction:
In space, there is basically no reason not to use nukes. Space is so huge that radioactive contamination is not an issue, unless beeing close to a planet.
So expect all ships to carry weapons powerfull enough to kill any other ship, regardless of size, in a single hit. It could be rockets with warheads or something like nuclear pumped lasers for higher tech levels. Or both.
With this in mind, you will want ships that are big enough to carry the propulsion systems and the state of the art weapon systems, but not much more.
One ship will be lost in one hit, but two ships will take two hits, so you really want as many ships als possible for your money.
Also I would expect that ships do not engage in battle directly, but launch a ton of warheads and counter warheads and counter counter warheads from as far away as possible and let them duke it out. If one gets through, thats the one that decides the battle.
Edit: All this is assuming we are speaking about ships that would somehow still be recognizable as "ships". This answer might not apply when we are talking about deathstar sized contraptions (see answer by JamieB).
[Answer]
Battleships in space may be more viable than on Earth.
In space range is more or less infinite, this means that the winner of a fight is likely the person who detects the enemy first and completes their targeting calculations first. Having a larger ship could mean more sophisticated equipment for handling these operations.
There is nothing to counter inertia in space, this means unlike here on Earth where you can count on the air or the water to reduce act against your inertia, in space if you wanted to adjust your course to make a left turn you would have to reverse thrust to slow down your forward momentum, apply thrust the right to change course and then apply thrust to adjust your rotational facing. This is a prohibitive amount of fuel to be using, simply put evasive abilities would not be possible.
This all works in your favor, if you can detect an enemy ship and target them first, they won't be able to evade and all you need now is a powerful enough weapon to destroy them.
[Answer]
### Think Bigger
One thing I think still missing in the answers above is just how big a "battleship" can be, especially with your "high volume black box non-reaction handwavium drive to power the whole thing" stipulation.
We are mostly thinking of ships, with a battleship being mostly the size of an earth battleship. And some of the answers point out the obvious flaws there of having a ship that could get hit with rail guns, nukes, etc, that pretty much blows right through your hull regardless of armor.
Unless your battleship was bigger. Way bigger. Like 1000km diameter. Why not? *Your armor is 250 kilometers thick.* I recently read a book series where the characters went through what seemed like a fairly plausible scenario of sourcing material from asteroids, smelting them in space using giant mirror arrays to focus solar energy, and turning them into giant hollow iron balls that you can fly entire fleets into. In one scene, they park one in front of a jump gate just to watch enemy ships splat into it. Nukes? It's like nuking the moon. It's not invulnerable but you have raised the bar to where any alien gun that doesn't fire a literal planet-killer cannot kill your battleship because your battleship is pretty much a small planet in mass. While the aliens are trying to glass one side of your giant-ball-battleship, your missile launchers on the other side are still churning out missiles.
(As I recall, they also used the solar mirror arrays to bring in the enormous amount of power required to energize the "black box non-reaction handwavium drive" to move the things. They didn't move all that well, but they did move. The aliens spent a lot of time being aghast that humans would think to build such a thing, and using their own stolen drive technology to make it work. They simply did not have weapons capable of breaking what is basically an iron moon. Other answers mention attacks at relativistic speeds but even that doesn't invalidate the use case, since a destroyed battleship at this scale is still a navigational hazard and a potential planet killer that only something with a similar sized drive has a chance of stopping. Here it comes at your home world! Good luck everyone!)
] |
[Question]
[
What could be most reasonable explanation for rapid increase in life expectancy for all people on earth?
Some points:
* Effect can be increased over time: 100 years in 2020, 140 - in 2030.. and so on, till it reaches about 250 years of life expectancy.
* It must be applied for all *(most)* people on earth in natural way.
* There is no magic.
* Side effects are possible
[Answer]
# Cure for cancer, Alzheimer's and heart disease
These three are the big natural killers.
# Cheap, clean, ubiquitous and plentiful energy sources
Air pollution is the biggest non-natural killer. The biggest source of air pollution is the burning of fossil fuels and biomass.
If for instance [Polywell nuclear fusion](https://en.wikipedia.org/wiki/Polywell) turns out to work, then we can remove something that kills **millions** every year.
Yes, this is a real picture, of a real fusor... EMC2 Corporation's WB8 test reactor.
[](https://i.stack.imgur.com/Iva2p.jpg)
*Polywell reactors give energy, save lives, and look totally sci-fi:ishly awesome*
A good secondary effect is that a good and plentiful energy supply solves things like famine, and fresh water shortage as well.
A tertiary effect of that is that it greatly decreases the risk of resource wars (like for oil).
# Telomere rejuvenation
[Telomeres](https://en.wikipedia.org/wiki/Telomere) are what keeps our cells from being infinitely renewable. If we can find a way to replenish teleomers, we are good to go for a very long time.
[Answer]
**Viral infection**
Something like flu will spread globally thanks to air travel and reach eventually almost entire species and if it has a side effect of increasing life span this will get the effect you want more or less.
**How could flu increase your life span?**
Simplest explanation would be that it suppresses something that is reducing our life span at the moment. Just say that it invokes an immune response that purely by coincidence (surface proteins happen to be similar) also kills something that has been living apparently harmlessly in our guts at least since the neolithic period.
And all of a sudden everyone who got the bug and survived feels much better and healthier than anyone has within the recorded history. And lives longer too. Turns out our *natural aging* was actually caused by a partially suppressed immune response to that **totally harmless** bug. Oops.
[Answer]
**Bioengineer a food source that extends the life of telomeres.**
Telomeres are at the ends of our DNA strands. They don't seem to contribute to our genetics. They are a repeating sequence of DNA at the ends of the chromosomes, like a start/stop signal for protein building. The way our chromosomes divide and replicate, they don't copy the full telomere and some of that repeated signal is left off the next generation of chromosomes. This means your chromosomes can only replicate about 40-60 times until there is not enough telomere left to begin the replication process, called the [Hayflick Limit](https://en.wikipedia.org/wiki/Hayflick_limit#Telomere_length).
The way our DNA replicates itself can be compared (roughly) to the zipper on a jacket. When the jacket is zipped closed, there are two sides of the zipper locked together. In the process of chromosome replication, the zipper *pull* slides down the length of the zipper unlocking the two sides and attaching a new matching strand for each side, but a little piece of the telomere ends are not replicated. The analogy is like a zipper that has lost it's end tab, preventing you from threading the zipper pull.
[](https://i.stack.imgur.com/DBxIy.jpg)
Stem cells in embryos do not suffer from telomere depletion. Neither do most cancer cells, therefore they can go on replicating (theoretically) forever. Telomeres are an intense focus of research, so it's very likely there will be several life-extending discoveries in the near future.
My suggestion is that after a series of scientific discoveries in cancer research where we learn how this process works, a food source like rice or grain will be genetically modified to extend the life of telomeres. That food source will be patented at first, but eventually the patents expire and the GMO grain becomes widely available.
Since this "cure" extends only the amount of telomeres you have left (it does not replace what you've already lost) people who have eaten the GMO grain from childhood experience drastically longer lives than people who began eating the grain as adults.
[Answer]
The first step is to bring the 3d worlders up to 1st world standards: very doable in theory. Once the health / longetivity playing field is level you will need to invent ways to get thru the reasons that old wealthy 1st worlders die.
* **Health care for all.** The main causes of death for most of the world are preventable - diseases from dirty water, diseases from communicable disease, death in childbirth. If maximally effective health care is available for all, this would lift life expectancy to that achieved in Western European countries where health care is available for all.
* **Birth control**. If you can be confident your kids will grow up, you do not need to have as many. If women are empowered to control reproduction there will be fewer births. Fewer people mean remaining people are richer. Less population pressure means less war and consequent death / chaos.
* **No smoking**. Smoke is responsible for much cardiovascular disease and much preventable cancer.
These things achieved, you now have the situation of Japan where people live into their 80s then die of cancer or dementia. Medical technology has done well against cancer over recent decades. You can invent plausible breakthroughs with improved cancer treatments, then improved dementia treatments, then schemes to address the underlying reasons for cancer / dementia that break through the wall at 120 years.
I think it would be good to have a completely new cause of death be what eventually takes people at age 250. Sort of like the boss fight at level 11. You did not know what that boss looked like because no-one has ever reached level 11; 6 is as far as most people make it but a couple of people have gotten to 8.
[Answer]
**There isn't really a reasonable way**
The issue already is between ages 60-100 the human brain begins to degrade rapidly, to prolong that to age 250 is going to take some neuroscience beyond our current understanding.
Normally, I would suggest a battery of genetic engineering and or nanotechnology for synthetic organs but the critical issue is always "what about the brain?".
Maybe you could engineer humans such that neurons can have greater longevity or resilience, but then what do you do about the people already alive and how do you get everyone to accept GE? Maybe you could find a way to digitize the brain (which I think we will eventually get to) but then you are conflicted with the ethical question of 'is it still him?' and 'is he still alive?'.
[Answer]
## Worldwide Peace
Wars dramatically affect human lives. The main cause of shorter lifespans is not so much killing (unless we are talking about something like WWII) but a huge number of refugees and deteriorating living conditions. Displaced populations suffer from physical and mental stress that greatly reduce their chances to live
long and productive lives.
Just establishing peace (no matter how bad it is) would greatly increase life expectancy.
## Worldwide Food and Clean Water Security
Just providing the entire global population with access to food and clean water would dramatically increase the average life expectancy on the planet.
## Universal Medical Care and Emphasis on Preventative Care
Many deaths could be avoided or at least postponed if people had access to medical services. Preventative care is more effective at prolonging lifespans than symptomatic care. It also highly increases chances of early diagnosis hence required treatments are less invasive and more successful.
## Universal Access to Education
Educated people make better choices (when it comes to health) and live longer. They also better understand risks involved and are better equipped to handle them.
## Decrease in Lifestyle Diseases
Obesity, smoking, stress, etc. lead to decreased lifespans.
## Egalitarian Society
Gender equity leads to longer lives. The most obvious reason is that all genders have equal access to education, reproduction control, medical care, etc. Gender equity might also reduce stresses and contribute to better lifestyle choices.
## Changes in Position of Seniors in the Society
Seniors that are actively involved in social life and pursue an active lifestyle (travel, dance, exercise, intellectual activities, etc.) tend to live longer and be healthier. We do not understand the mechanisms yet, but physical and intellectual activities frequently delay the onset of senile disorders. They also positively correlate with cognitive ability (reasoning, memories, decision-making, etc.).
Seniors should be more involved in society. Perhaps a retirement age can be increased. Some services and activities for seniors could be introduced. But most importantly, seniors must feel needed, having a significant role in society.
---
Everything above can be done right now. In many cases, it only boils down to political will.
The following will require some innovation.
---
## Medical Breakthroughs
Regeneration, cancer cure, and slowing down ageing are the best bets for increasing human lifespans.
Brain tissue regeneration and connectivity will become one of the most sought-after treatments once the worldwide life expectancy reaches about 100 years old. Neurons do not divide as readily as other cells in our body and cannot be replaced as easily (some new neurons are produced in the hippocampus but it is an exception). They also lose the ability to form new synapses as we age. Although, there is some research suggesting that this process can be slowed down by intellectual activities combined with moderate exercise.
A completely different approach would be a development of cloning and personality transfer. Ethical considerations aside, that would potentially lead to immortality.
## Environmental Safety
Clean energy, no chemical waste, stable climate, thriving biosphere should be the main goals in establishing the environmental safety.
Governments should also have better contingency plans for epidemics, natural disasters, technological catastrophes, and so on. A swift and well-organised response can save thousands of lives.
## Social Changes
Many contributing factors to the shorter lives have nothing to do with physical conditions. Social isolation of seniors, age discrimination, a cult of youthfulness, and similar phenomena negatively affect the quality of life. A change in social attitudes would lead to longer lives.
[Answer]
**Nanobots**
Think about a viral pandemic in reverse: Instead of a virus killing everyone (or turning everyone into zombies) one of the research centers develops nanobots which move inside their hosts' organisms looking for signs of ageing and cancer and fixing that. They are made of proteins -
so basically they're big benevolent viruses - and so they are capable of building their own copies out of elements existing in human blood. But their primary function is to keep their host healthy so they do that only to keep their population stable. It means that they are able to communicate with each other, sending simple messages and responding to them.
The research was sponsored by a few very wealthy people wanting to become immortal, but the nanobots got out and spread across the Earth. In a few decades almost everyone, except for a few isolated communities, is infected. Nanobots are not able to prevent death from all causes, but people stop ageing significantly and the rate of death from cancer drops almost to zero.
[Answer]
Tobacco going extinct would give you +15 almost immediately.
I've heard a little about the effects of Cosmic Rays, causing DNA decomposition and therefore cancer. If background cosmic radiation (for some reason) dropped, cells could live longer in general, and natural aging processes could be prolonged.
Accomplishing this would be difficult to the point of being hand-wavey; Cosmic Rays are *very* energetic. And cellular mechanisms don't depend on CR's so much as deal with them, so there would have to be something else prolonging lifespans.
[Answer]
If humans lived to be 250 years old, the greatest cause of death would be boredom. Depression. Losing the will to live. How long can you keep doing the same thing, over and over? Learning and re-learning? Working at the same nine to five job? Traveling to the same places, over and over? Seeing the same things, the same politics, the same societal problems?
What would you DO for 250 years?
And how would you pay for it? Living in poverty for that long is not an attractive proposition. It would perhaps be okay for the top 1%. But living under oppression? Struggling day to day, and no end in sight? Living hand-to-mouth? Being bullied?
The medical issues are just the beginning of the problem. If you don't address the psychological, economic, and social issues, I posit that not a lot of people would voluntarily stay around for that long, and suicide would be the major cause of death.
[Answer]
This is a bit of a lateral-thinking answer.
The world's governments are in trouble over pension payments, healthcare for the elderly and other benefits that have been tied to the age of people. They use the recently increased life expectancy (due to better healthcare and other factors) to argue for the increase in retirement age and the reduction of per-year benefit amounts. So called *life expectancy factor*.
However, for unrelated reasons the world is also heading towards less open government and less oversight on governmental finances. The people in control see their opportunity and corruption increases, so fast that money is rapidly running out.
The life expectancy factor provides an excellent way out. Only thing that remains to be done is to fool people that life expectancy is increasing. The actual number is just a calculation by statisticians, who can be easily enough bribed. Up to some 120 years of age, just ensuring media coverage of well-to-do centenarians gets quite far in convincing the population. In a suitable dystopia, eliminating any dissenting opinions should be easy enough.
Eventually people will realize that the life expectancy is just a lie. But it is a lie that you are not allowed to speak about, even when the government keeps raising the number to ridiculous 150, 200, 250 years. People are essentially forced to work until their death, and the typical obituary reads *"A hard worker and a loving father, he was taken from us too soon, at the young age of 80"*.
[Answer]
I would say that there is no physical reason why humans should not live almost indefinitely, save for accidental death. Obviously this is not going to happen any time soon, but the issues faced are more of unravelling the highly complex than breaking any physical laws.
In nature everything is balanced and we humans have evolved the life span we have based on several balancing reasons. It might be assumed that it would be an evolutionary advantage to live indefinitely, in some ways this is true, but there are reasons why this does not happen.
One reason might be that evolving a much more sophisticated DNA repair system is costly in term of resources. If every cell has to include a multitude of repair and monitoring systems then it will require more material to build and maintain.
This would not be a show stopper except for the fact that humans evolved in a relatively dangerous environment and accidental death (being predated, starving, falling off a cliff / tree etc etc) was highly likely, so the benefit of having all those repair and monitoring systems was marginalised as few lived long enough for them to have any effect.
The main issue is how fast and how far will we be able to push the biological sciences. This is unclear, but I suggest that, based on recent progress, that over a period of hundreds of years human life span potentially might be pushed far enough to give some people an indefinite life span (immortal except for accidents or deliberate acts such as war / suicide).
So to answer the question specifically, the most reasonable explanation for a rapid increase in life expectancy would be progress primarily in the biological sciences. This would be greatly enhanced by improvements in our abilities to manage, feed and protect ourselves. So advances in political and social structures, the technology of food production and prevention of disease. These would also need to be accompanied by world-wide social norms that ensured the birth rate was roughly equal to the accidental death rate. A tall order but not impossible.
This issue is also covered in more detail here:
<https://en.wikipedia.org/wiki/Indefinite_lifespan>
Some species have already evolved near immortality (barring accidents)
<https://en.wikipedia.org/wiki/List_of_longest-living_organisms>
[Answer]
If humans live to be 250, it will be because of advances in psychology and brain science. Our mind fills up after only 80 years. If it is to keep going for another hundred, somehow a lot more memory must be made available. Either that, or we have dementia for the last 150 years or so.
I think the 'will to live' is going to be extremely important after 150 years. Are we going to remain reproductive after that? It was longevity, not a rise in birth rates, that led to the baby boom. People lived longer, stayed around longer. Four, five generations were alive at the same time instead of just two or three. For 250 years, that is a LOT of generations alive at the same time.
There is an evolutionary advantage to the human life span. It is what it is for a reason. The human mind is geared to fit that evolutionary limit. So extending it to 250 years is going to take a lot more than just extending the life of human cell replication - the number of times that human cells can replicate without degradation. It is going to take major changes in human psychology.
[Answer]
In addition to all the wonderful answers above such as improving health, eradicating poverty, world peace, I believe the great secret of longevity lives within us. Well-respected scientists from every health-related discipline have researched the power of meditation to influence general health and provide natural ways to ward off disease and aging. <https://eocinstitute.org/meditation/how-meditation-increases-your-longevity/>
<http://www.garmaonhealth.com/meditation-increases-lifespan/>
* Mediation calms our parsympathetic nervous system, resulting in what
Harvard researcher Dr. Herbert Benson terms The Relaxation Response,
the result being that you become calmer and more relaxed, and become
able to bring this mind state into whichever previously stressful
situation you desire.
* Meditation improves our immune system by boosting our “killer cells”
(white blood cells that destroys infected or cancerous cells) and
antibodies (a protein produced used by the immune system to identify
and neutralize pathogens such as bacteria and viruses).
* Meditation can reduce systemic inflammation through the combination
to the above two cites actions, in that stress can lead to
inflammation, which in turn is linked to heart disease, arthritis,
and various skin conditions such as psoriasis.
* Meditation reduces the risks of heart disease by enabling the blood
vessel lining (the “endothelium”), to expand and contract, thus
making it more pliable and less ridged and calcified.
[Answer]
**Breed for longevity.**
Become a dictator, forbid everyone to get children naturally and use the sperm of the oldest males to artificially impregnate your female population. Do this over several generations and the health and longevity of your population should be significantly increased. You could also add some other requirements apart from old age, like mental or physical fitness.
I wonder I if there have ever been experiments with animals to breed for longevity?
[Answer]
Some further musings to consider.
There is good solid evidence that, for the first time in centuries, life expectancy is going ***down***, not up. The reason is not disease, but lifestyle choices. Obesity, hardening of the arteries, risk-taking, violence, junk food, drug usage. The problem with lifestyle choices is that they are choices made by people, voluntarily. To reverse this trend, you need to get people on board. The problem is, how? Legislation? It worked for smoking and seat belts. Not so much for drugs. And your criteria seems to indicate it has to be world-wide. Maybe a world government that has teeth, and is willing to make the hard political decisions to **force** people into healthy life styles. Education sure doesn't work. So how do you universally **enforce** correct lifestyle choices in the entire population?
You are also up against a genetic barrier. It's not just telomeres that determines our life span. It is that cell reproduction is not perfect. It doesn not produce exact duplicates. The degradation of skin tissue, for instance, leading to wrinkles and dryness, is caused in part by the degradation of the cells through repeated replication. We don't have 'baby soft' skin at 80 because they are not the same cells - they have degraded in their DNA (or at least in their expressed DNA). It is possible to get creams and such to alleviate some of the damage (sun, for instance, and pollution), but to work on a global scale, people have to voluntarily use them. It is not a passive solution, it is active. People have to actively consciously decide to use them.
There are some genetic modifications that can increase longevity, but for these to become widespread in the population, it would take centuries, not decades. Unless, of course, there was a widespread policy of a genetic breeding program. For instance, if the population of the earth was reduced to just 1%, and this 1% was good genetic stock for longevity (the Japanese, for instance) there would be a dramatic increase in life expectancy for the survivors, but extending it to 250 years in the global population would take several generations of selective breeding. Maybe a world-wide plague that those who had *longevity genes* were immune to, by coincidence, and were the only survivors.
Some cancers are apparently caused by viral action, and cancer is the classic 'longevity' mechanism. If Cancer could be controlled, then cells would be made to reproduce indefinitely, just like cancerous cells do. In fact, it is posited that, for true longevity, cancer would not be cured, it would be made rampant, but controlled. Cancer research is the key to understanding the regeneration of tissue, and even stem cell activation. This, of course, is what cancer ***is*** - the uncontrolled reproduction of cells. But again, you have the issue of making this universal in all humans. A controlled cancer virus? Something that mutated? Doing this by genetic selection, again, would take umpteen generations, unless there were some mechanism for extinction of non-mutated humans. But a cancer virus, that caused a widespread controlled cancerous growth in all cells? The viral removal of or deactivation of the '*self-destruct*' mechanism in cells that leads to the eventual death of the body, when they all decide to self-destruct without replication? (That, really, is what causes a *natural* death - cell death exceeds cell replacement, and there just aren't enough working cells to keep the body functioning).
Someone mentioned meditation. How about hibernation, where the entire metabolism, including cell reproduction, slows down? Say humans hibernated (suspended animation?) for four months out of twelve. Would this extend our life expectancy by the same ratio? Again, this could perhaps be done using drugs (that choices thing) or a long-term genetic modification approach (Inserting **hibernation genes** into the human genome) but is living to a calendar age of 250 the same thing, if you aren't conscious for one third of it? We live longer, but we don't get any experiential benefit from it. Of course, we would live long enough to see our great-great-great-great-great grand children, and would witness the advances of technology and of civilization. But living to be 250 just to say we lived to 250? What about quality of life? Would we **choose** to? That life-style thing - how to make it passively universal.
You could, of course, pull a *Stephen King*, and just assume longevity, without explanation. Stephen King did some really weird unexplained and unexplainable things in his novels, but really didn't do it in a fantasy or sci-fi way. He just wrote his novels based on considering them as part of normal, every-day experience, and didn't worry about science. It would not be beyond such an author to posit that, two universes had become super-imposed, one with a value of the constant ***c*** that we are familiar with, and another with a drastically reduced value for ***c***, and humans living in each one, side by each. Relativistically, through time dilation, the high-cee group would apparently experience time going by much slower than the low-cee group. That is, one group would see the other group moving in very slow motion, and the other group would see the first group moving extremely quickly. Comparatively, one group would live for 250 years, and the other for 150 years, in the same relative life span. It would be like one group had left on a generation ship for 250 years, and then came back to earth. People on earth would experience 250 years gone by, but people on the ship would experience only, say 150 years. This would be stretching and bending things, but not really violating any laws or theories that have not been proposed by string theory and such. Stephen King would be proud.
An extension of this, is to somehow speed up the earth. Time would go slower. (Incidentally, the reverse is happening - since the earth is slowing down, time is going faster on earth today than it was when the earth was first formed). How this could happen would be another Stephen King - you just assume it happened, with no explanation. The mysteries of physics. If they want us to believe in black holes, why not this? (Basically, that is Stephen's answer). The emphasis is on the human reaction, not the science. What reader takes the time to question the science in a Stephen King novel - they are too busy being either scarred or shocked or otherwise engaged in the story?
But this brings up another unresolved issue. Consciousness. Within the last ten years or so, credible scientists with excellent credentials (Nobel prizes) are seriously positing that consciousness is a result of quantum phenomena. We know that life itself makes extensive use of quantum techniques. Things that biologists could never understand, are explained by quantum tunneling (ion transfer across membranes, photosynthesis, birds detecting magnetic fields, for example). Quantum theories have done more to explain day-to-day mysteries here on earth than Einstein's theories ever did. So, something that has never been tested - what does ***time*** mean to quantum biological events? Planck had a very different idea of time than did Einstein.
We know that live plants and humans sent into space are not as 'old' as their equivalents on earth, when they come back, but what is the conscious experience of the organism during this time? What is their biological experiential age when they come back? Does the astronaut really **feel** any younger than he would have if he stayed on earth? Do they grow as if they are still on earth, in the same time frame? Time is not the same concept for conscious experience as it is for physical phenomena. We talk about 'that day went fast' or 'this month is really dragging', as if the passage of time is variable, relative to something else besides physical reality, the 'clock'. That is why there is a definite movement to consider quantum time as something different than relativistic time. In quantum physics, nothing is defined until it is consciously experienced. Is it the same with time? That time has to be consciously experiences to have any definition?
What would **conscious time** be like for a human that lives to 250? How would they experience the passage of time? How would a human on a generation ship experience the passage of time? Would their quantum consciousness be so connected to their earth foundations (*entangled*, as it were) that they experience that they really were traveling for 250 years?
We know physical time is relative, but what about biological conscious time? Call it biological quantum consciousness time. Is that relative and if so, to what?
How would humans experience life and the passage of time if they lived to be 250? How does a [bowhead wale](http://www.vetstreet.com/our-pet-experts/7-animals-with-incredibly-long-life-spans) experience its 200 year life span? If they can live to be 200, there is no real biological impediment to a human living to be 250.
These issues and ideas are all fair game for a novelist to explore, when dealing with positing a life span of 250 years for a human. Is the issue all about science, or is it about character development and social repercussions, human issues?
[Answer]
People stop eating bread and milk.
People start using air filters.
People take their medicine.
People go to see a doctor more often and listen to their advice.
People take their flu shots.
People go vegetarian which mean consuming less cancerous meat and using less chemicals to grow veggies because there is more place for veggies.
Pick one.
[Answer]
## Introduction of gun control and reliable self-driving technology
Motor vehicle accidents and death by shooting are both in the top ten leading causes of death in the US.
Eliminate them, and you automatically increase overall life expectancy (albeit without a corresponding actual increase in life spans).
] |
[Question]
[
**This question asks for hard science.** All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See [the tag description](/tags/hard-science/info) for more information.
I am dealing with a dystopian story that tries to come up with some kind of total surveillence or control from higher authorities.
The authorities threaten to kill those who disobey them by simply freeing an antimatter atom from its containment which is placed inside your brain. Let's handwave everything away like how the containment would look like, how big it is, how it got inside the brain or how it could be switched off etc.
Would one atom of antimatter (say anti-hydrogen for simplicity) be instantly lethal if it annihilated inside your brain? If not, how many atoms would be required? Would it also work in other parts of the body?
This is about technologically advanced, but otherwise normal humans.
[Answer]
No. The mass of a proton is about $1.67\times10^{-27}$ kg. Therefore the total maximum energy released by its annihilation with an antiproton is $2mc^2= 2\times1.67\times10^{-27}\times9\times10^{16} = 3\times10^{-10}$ Joule.
This is not much. Even if all this energy would be deposited inside the victims brain, it is a very small amount. But it would not. As this [paper](https://www.rand.org/pubs/papers/P7113.html) (focusing on the possible applications of antimatter in space propulsion) elaborates, most of the energy is released in the form of fast moving, penetrating pions (which can fly 10 cm even in solid tungsten, and presumably much more in tissue), and some in the form of neutrinos, which are almost non-interacting and useless.
But let us look aside, and estimate the effect it could have with all energy discharged in the victims brain:
Although the released energy are not pure gamma rays, the basic damage mechanism is the same for all high-energy, ionising particles: They kick out electrons that form atoms, severing molecular bonds. Therefore it is useful to calculate the dose. (energy deposited per unit mass) As the mass of human brain is around 1.5 kg, we get $2\times10^{-10}$ Grays. For comparison, a single session of [radiotherapy](https://en.wikipedia.org/wiki/Radiation_therapy#Dose) can deposit a dose of 1-2 Grays.
The electrons in the atom I have totally neglected, since they have rest mass about 1830 times smaller, and are so harmless, that in PET diagnosis, people can be injected with anti-electron (positron) releasing radioactive materials.
So I am quite sure that this would not kill or incapacitate a person, and would mean little contribution even to his/her long term cancer risk. If the government wants killer implants, go with explosives or electrical gadgets.
[Answer]
No. [Positron emission tomography](https://en.wikipedia.org/wiki/Positron_emission_tomography#Emission) is regularly used to scan brains.
PET detects gamma rays created when positrons, emitted by an injected radio tracer undergoing [positron emission decay](https://en.wikipedia.org/wiki/Positron_emission), annihilate with electrons in the patients tissue.
For example, a brain scan using [18F-FDG](https://en.wikipedia.org/wiki/Fludeoxyglucose_(18F)) has an effective radiation dose of 14 mSv [1], which is on the order of the natural background radiation you are exposed to over a year in Denver, Colorado.
[1] <http://hps.org/documents/Medical_Exposures_Fact_Sheet.pdf>
[Answer]
**This question asks for hard science.** All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See [the tag description](/tags/hard-science/info) for more information.
This mechanism is a poor one to control populations. To be sure of killing the target, you need a pretty big bang because most of the result of matter/anti-matter annihilation is ionising radiation rather then brain damaging explosion. This means you have to put nearby people and property at significant risk which is counter productive. For this type of big brother technological control of population, it might be better to consider a simpler embedded device which is critical for everyday living in your society (making its presence acceptable to the population) and which has secondary control and punitive roles such as triggering pain, immobilizing, and if necessary, terminating the host. Now rebels who wish to bypass its controls must find alternate ways to survive in their society, offering you lots of additional story options.
[Answer]
# No...but how much *would* it take?
[This](https://www.si.edu/content/consortia/zimbelman_presentation.pdf) puts a Chinese firecracker at about 30 Joules and Wikipedia puts a gunshot's kinetic energy at [1.8×103](https://en.wikipedia.org/wiki/Orders_of_magnitude_(energy))
So we'll assume about 100 Joules as a necessary amount of energy to kill a person when released directly into the brain. Orders of magnitude here are the important factor.
b.Lorenz's answer has a single proton annihilation at 3×10−10 Joules.
Dividing the first by the second tells us that we need approximately 3×1012 hydrogen atoms worth of antimatter (on the order of ten billion times more than CERN has collected in one place at the same time). A mole is 6.022x1023 atoms (and weighs [about 1 gram](https://www.wyzant.com/resources/answers/75307/an_atom_of_hydrogen_has_a_mass_of_about_1_66_x_10_24_grams_an_atom_of_oxygen_has_a_mass_of_about_2_656_x_10_23_grams_answer)), so we need about 5×10-11 grams worth of hydrogen (or really, any anti-element: the neutrons required do increase the mass, but we're talking about so little that even a hundred times as much is still on the order of a single nanogram).
Your containment device would probably take up more mass as well as requiring external power (you need to contain it in an electromagnetic field). This is, of course, assuming that you can keep it trapped [for very long at all](https://home.cern/news/press-release/cern/cern-experiment-traps-antimatter-atoms-1000-seconds).
You may as well just use gunpoweder.
[Answer]
**This question asks for hard science.** All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See [the tag description](/tags/hard-science/info) for more information.
No, because we have real-world examples. Astronauts are outside the shield of our atmosphere and occasionally get hit with high energy cosmic rays. These carry a bigger punch, yet they don't kill.
[Answer]
Almost certainly not. As in, "you'll have more chance of winning the Lottery than you will of killing them by this method".
Antimatter annihilation of a single atom - we'll be good here and say one with a hefty nucleus like, say, iron - releases
$$\left(2\ \mathrm{atoms}\right) \times \left(\frac{55.8452\ \mathrm{g}}{1\ \mathrm{mol}}\right) \times \left(\frac{1\ \mathrm{kg}}{1000\ \mathrm{g}}\right) \times \left(\frac{1\ \mathrm{mol}}{6.022 \times 10^{23}\ \mathrm{atoms}}\right) \times c^2 \approx 1.67 \times 10^{-8}\ \mathrm{J}$$
which is 16.7 nanojoules, or over 100 GeV, of energy. (The "2 atoms" factor is because you need a second atom's worth in equivalent - not necessarily in the form of a literal single atom - of ordinary matter to complete the annihilation.) The release of this will likely not be all at once, but rather will basically consist of the heavy anti-iron atom, upon teleportation to the brain center, annihilating with some lighter atom which will cause it to explode catastrophically into a shower of lighter particles and anti-particles as well as VERY hard (100 MeV+) gamma rays for the anti-nucleon annihilations, and these anti-particles will also collide with and cause similar explosions of the atoms they encounter elsewhere, producing even more showers of tertiary, quaternary, etc. ionizing particles. Essentially it's a demolition derby on an atomic scale with billions of bits of high-energy matter flying around and knock apart everything in their wake - DNA, proteins, and more. Keep in mind that a chemical bond has energy only on the order of 1 eV, so this is enough to break on the order of 100 billion chemical bonds.
Now that *sounds* rather extreme. But there's two things to keep in mind here: Even a single cell, if we for simplicity [and wrongly] treat it as a sphere of water 10 µm in diameter, contains about 17 trillion molecules and thus 34 trillion chemical bonds. Effectively there's only enough energy to break about 0.3% of them. Granted, that could be considerably destructive to that single cell, and thus you might expect we could at least kill one neuron with this (you cannot turn a neuron to cancer, because they cannot divide, though if you get something like a glial cell, then it's possible in theory, and this is a real and actually common type of brain tumor, called a glioma). However, that assumes all the particles are absorbed in the neuron, and that will almost surely not be the case, because that would mean total absorption within 5 micrometers assuming it appears dead center, and these forms of radiation are far more penetrating. The result is maybe you might break a few thousand or million of bonds all over the entire brain - something with maybe over $10^{24}$ atoms in it. That will be virtually unnoticeable.
Which is what our second point is. The 100 GeV of energy released here corresponds to about a thousand typical 1 MeV particles of the type that naturally exist in background radiation, not taking into account the possibly increased penetration of some of the highest-energy products which will make it even less damaging(\*). As a dose to the brain tissue itself, it corresponds to (assuming it like gamma, which will actually not, again, be right, but we just want the order of magnitude, and using 1.5 kg for the mass of a brain) around 10 nanosieverts (nSv) of dose. The average background exposure in the United States is 3.1 millisieverts (mSv) per year (cite: <https://www.nrc.gov/reading-rm/doc-collections/fact-sheets/bio-effects-radiation.html>) or about 99 nSv/Ms. Thus your brain is dosed with about this much about every 0.1 Ms, or 100 ks, or a bit over a day (86.4 ks). In effect, you get all of an extra day's and change worth of normal background dosage for this stint. Very unlikely to kill, and impossible to kill "instantly". In fact such ultra-low doses may even have a protective, and not harmful, effect due to possible radiation hormesis (not sure what the evidence on this is as of now).
Nonetheless, there *is* a potentially useful lateral angle to this that might be worth considering, and that's that if people generally have a fear of things like "antimatter" that they've seen in movies and don't necessarily understand very well except that they make things go "boom", such a thing could be a useful *psychological* control tactic on at least some of the population. If you want to make the threat credible, I'd suggest instead having some kind of device in the brain that creates a small artificial aneurysm. A burst aneurysm can kill very fast, and if the device can also self-destruct so as not to leave residue, could look like a "natural" event to an unsophisticated autopsier. Such a thing might work by, for example, being placed near a suitable blood vessel and then, upon triggering, would start a release of some kind of chemicals that partially break down the vessel wall, weakening it and thus allowing for a swelling or hernia of blood (the aneurysm) to form, that then bursts and causes massive brain damage. All the better since you can control the placement in the brain to target the areas most likely to cause death or at least major disability.
(\*) You might think highly-penetrating radiation is "worse" than lower-penetrating, e.g. gamma is "worse" than alpha, but this is only with regard to the fact that an *external* source of alpha is "better" in that it can only burn the skin, but gamma, due to being penetrating, can "burn" all tissues through the full thickness of the body uniformly, leading to radiation poisoning, essentially a "systemic radiation burn". But that's only for an external source, with the skin blocking. In fact, if the source is ingested, alpha particles are much worse, because they have much more ionizing punch per particle. Effectively you're now comparing them both on a fair playing field as full-body irradiators, and the gammas are considerably less damaging due to the fact that greater penetration means less chance of interaction. This is part of why that polonium-210, and not, say, cobalt-60 [a strong, and relatively "pure", gamma emitter, and much easier (and cheaper!) to get ahold of], was used to assassinate the late Russian defector Alexander Litvinenko a few hundred megaseconds ago. The needed lethal dose was much less due in part to this fact.
] |
[Question]
[
Space is two things: empty and (mostly) dark. This makes it really, really hard to hide in it, because to do anything in it, chances are, you'll be shining a big bright light through it.
Even if you're not trying to do anything, the emptiness of it makes it very difficult to hide from some kind of scanning equipment. Either you reflect it and are found, or eventually the black box effect sets in--I imagine that a gamma ray active scanner, while impractical in an atmosphere, would eventually begin to cause your ship to radiate infrared in a very distinctive manner.
I imagine that would be expensive and rarely used, but the principle of the question still remains: how does one hide in space?
[Answer]
[Project Rho's space war pages](http://www.projectrho.com/public_html/rocket/spacewardetect.php) has a pretty thorough set of arguments on why stealth is, for practical purposes, impossible in space warfare\*. [The Rocketpunk Manifesto](http://www.rocketpunk-manifesto.com/2009/06/space-warfare-ii-stealth-reconsidered.html) also has an essay on this subject which concludes pretty much the same thing. Therefore, to hide in space you'd have to be very creative, or do some bit of hand waving.
Some things you could try:
* Camouflage, or attempting to look like something else (a comet, or civilian ship), but of course this is highly situational
* Some sort of magic FTL technology
* Magic cloaking device
* Your spaceships are manned by exotic lifeforms that can tolerate near-absolute-zero temperatures, and hence your spaceship is as cold as space
Other than that, it's generally agreed among hard-sf folks that in space warfare, everyone can see everything, although you can still perform a lot of tactical stealth, like jamming, "smoke"-screens and the like. They'll see you coming but they might not know exactly what it is.
The arguments for why it's so hard to hide in space are too numerous to list, but in a very condensed form, they go like this:
* It is very easy to detect something hot in space, and it is very hard to refrigerate (as you need to rely on radiation). Consider:
>
> As of 2013, the Voyager 1 space probe is about 18 billion kilometers away from Terra and its radio signal is a pathetic 20 watts (or about as dim as the light bulb in your refrigerator). But as faint as it is, the Green Bank telescope can pick it out from the background noise in one second flat.
>
>
>
* It is not that hard to do a full-scan of the sky. Using current technology, we can perform an entire-sky scan for magnitude-12 objects in 4 hours (that's [a bit brighter than Triton or Pluto](https://en.wikipedia.org/wiki/Apparent_magnitude)).
* You become that much brighter and easier to spot if you have your engines on. This means that, if you're invading a star system, your enemy will definitely know by the time you reach their outer planets, or you'll have to coast silent and cold for a very, very long time.
\*- Space *warfare* being the key word; absent any tachyon weaponry, it's generally assumed that shooting will be performed at ranges well within 1AU (or a few light-minutes). Considering your fastest weapons will take minutes to hit, that's a pretty big distance for your enemy to evade. At these ranges it is indeed almost impossible to hide, but it should be much easier if you're talking light-hours distances.
[Answer]
I think you overestimate how hard it is to hide in space. The size of spacecraft is negligible considering what we're usually observing. Their emissions can be cut quite easily, unless you're using some kind of engine that has high emissions, which again, can probably be reflected or masked.
Additionally, celestial bodies are quite large and very effective in blocking signals and emissions. The vastness of space (it's really big) makes it very hard to scan effectively - light takes a long time to reflect, which means you're very dependent on what light is *already reflecting off interesting objects*. And light's the fastest signal we know. It's also the only one that will work - unless you're measuring field gradient flux or whatever, in which the effect of a ship will be less than background noise.
If we were to assume however that indeed it *is* hard to hide in space, it would be due to your own emissions and reflections. You can easily reduce those to background noise - lining the parts of your ship that cause these emissions with heavy materials will reduce them significantly; you can also remain stationary and pretend to be a rock, if you know where you're likely to be observed from - possibly using camouflage to imitate random rocks reflecting the sun. And always, you can plot a course through debris fields if you're desperate and use them to mask your presence behind them.
[Answer]
ivy\_lynx's answer is spot on - space is *really*, ***really*** big, and very easy to hide in, given some basic assumptions. I'll provide some numbers to demonstrate that:
### The scales are huge
The largest asteroid is [Ceres](http://en.wikipedia.org/wiki/List_of_notable_asteroids#Largest_by_diameter), which is around 950km across. For perspective, Earth is a bit under 6400km across. Here's an illustration from [Wolfram Alpha](http://www.wolframalpha.com/input/?i=ratio+of+diameter+of+Ceres+to+diameter+of+Earth):
The equivalent to an average human (5' 4" = 162cm) is [approximately equal to Harry Potter's glasses](http://www.wolframalpha.com/input/?i=12.12+centimeters&lk=1). They're large glasses, but they're still *much* smaller than Daniel Radcliffe (who is about average height).
And remember, we're comparing this to an asteroid that's almost a small planet (although far smaller than our moon). So a spaceship on that scale would cover the US from [New York, New York to Cincinnati, Ohio](https://goo.gl/maps/5hNjC). And even then, it's as relatively small as a pair of glasses on a person. How far away can you get before you can't tell that they're wearing glasses any more? How easy would it be for them to cover up the glasses, simply by raising an arm or turning away?
You can see that it'd be *trivial* to hide in the shadow of a planet or moon, if you knew you were being observed. Of course, then you'd be very visible from that planet (if it was inhabited), so you need to choose carefully.
### What about light?
So, you're able to hide if you're aware there's someone out there, but assume you don't - how hard will it be to spot your lights?
Light falls off according to the [Inverse Square Law](http://en.wikipedia.org/wiki/Inverse-square_law), which says that it gets fainter with the *square* of the distance travelled. The [Luxor Sky Beam](http://en.wikipedia.org/wiki/Luxor_Las_Vegas#Luxor_Sky_Beam) is the strongest human-built beam of light in the world. (I'm ignoring lasers for now, because they don't really illuminate anything.) It's got a brightness of 42.3 billion candela. How bright is it from the moon? [Wolfram Alpha says](http://www.wolframalpha.com/input/?i=42.3+billion+candela+%2F+%28distance+to+moon%29%5E2) it's approximately 2.976x10^7 candela per square meter (aka 2.976x10^7 lux). That's barely *half* as bright enough as it needs to be for me to be able to even see it, if it were pointed directly at my eye. If it was pointed at something else? Forget it.
Obviously, by the time we build spaceships, it'll be possible to build brighter lights... but you're still going to have to be very close (relatively speaking) to be able to see them.
For relative comparison, we could fit just under 400 of our Ceres-sized spaceships between the Earth and the Moon.
### What about heat?
congusbongus raises an interesting point about heat, but the same issues as light apply. Heat radiation is just infrared (or longer) light, and obeys the same rules as visible light does. On the scales we're talking, you'd easily miss detection on anything that wasn't specialized for space, the same way that your lights would be easily missed.
But that brings us to the assumptions I mentioned at the beginning:
### Specialized equipment can do it
It doesn't matter how far away you are, some small portion of your light (or heat) will reach whoever's watching for it. I don't have the knowledge to relate the appropriate numbers from various space projects to the tiny amount of lux I calculated above, but I can say that the longer you watch an area, the better you're going to be able to detect a photon coming from that area. But most of our current highly sensitive satellites only look at a tiny portion of the sky at a time, and vice versa. It's reasonable to assume that there are specialized detectors designed to look for these faint traces and alert when something moves that might possibly be a ship, but they're unlikely to be able to cover the whole 360° sphere of the sky at once. And if you're moving, they won't be able to tell you anything useful.
Likewise, if you happen to move your ship between the detector and a star, they'll be able to notice that if they're looking for it.
But either way, it's still very easy to get physically behind something if you have enough distance, and nothing we have or can design currently can find you *through* a planet.
### Beware of close distances!
All the above applies when there's some distance between you and the person looking for you. You don't even have to paint your ship's hull black to hide, just because it's so hard to see anyone if you're far enough away.
That said, if you're close enough that they can look out a window and see you, there's very little you can do to stop that. No matter what, you'll be occulding stars and radiating heat.
[Answer]
Some people agree that it will be hard to hide spaceships with future technology. Others disagree. Your future technology may vary.
On the "it's easy to hide" side of the argument, space is also very large, and it would take a lot of looking and data-crunching to continuously watch it all to find what you might be interested in finding, amidst all the other input from looking at space in all directions. Another consideration is hiding technology, for example:
<http://www.theblaze.com/stories/2014/09/27/scientists-have-invented-a-real-life-cloaking-device-and-it-could-cost-less-than-a-new-computer/>
Another consideration is the situation. What size area is under observation, what are you trying to do there, what other noise is usually there (i.e. can you hide by looking like something other than what you don't want the lookers to know you are), and what are the accelerations and times involved?
This problem is a major topic of David Weber's *Honorverse* books - pretty much each book has a lot of discussion of different situations with different technologies for ships playing hide and seek in space (and then doing violent things), with an attempt to be realism-y about the technology and physics math.
Edit: I meant to add, but forgot, that even looking for asteroids that might be on course to wipe out our planet in our own solar system, with decades to do it, we on Earth in the 21st Century are aware that we have not been able to do a very thorough job of even managing that. So, it's not like it's a trivial problem to detect and be aware of everything around you in space.
[Answer]
Too long for the comment.
First, the space is far from being dark. There is a lot of background radiation, it is not visible, but it is there.
As for hiding, it depends very much on the size of the ship, could you expand on that? For example, a small blacked-out spaceship would be impossible to find without any hiding equipment, just because the space is so vast. On the other hand, a spaceship big as the sun might have to use different techniques, like active camouflage (but also can do much more, because of its energy supplies; it also could have a giant heat sink inside to keep the heat signature to minimum). Perhaps it could manipulate gravity to bend space and in some way appear smaller to the external observer.
Also, big distances make it impossible to accurately pinpoint an object, as any info you can have is outdated by minutes, hours, days, years, ... In other words, a fast [Brownian motion](http://en.wikipedia.org/wiki/Brownian_motion) might just happen to be a perfect long-distance hiding technique ;-)
I hope this helps ;-)
**Edit:** As for the heat, it's impossible to conceal indefinitely, but we could hide it for some time, for some nice ideas see [this question](https://physics.stackexchange.com/q/142971/27367) at physics.SE.
[Answer]
# Decompose the ship
I'm not sure if this matches your requirements, but one possibility overlooked up to now would be to make the ship cease to be a ship for some time. I mean, it could disintegrate into smaller parts, which would be not that easily identifiable as parts of a large, dangerous spaceship. The parts could travel together as a loose swarm of space debris or dust, or even travel over different trajectories, and assemble again at the target location.
Of course, you likely cannot do that with a ship carrying a biosphere and supporting human life, as the parts would still be large and identifiable as ship parts. However, this could work perfectly if your ship is robotic in nature. The parts themselves could be a kind on nanomachines or grey goo, able to function on their own on a limited scale. They might even be very small, in the micrometer scale. This would also make it impossible for the opponent to identify what kind of ship would result from them assembling again.
It would even be thinkable that a smaller, but still functioning ship could be assembled from a subgroup of the machines, should some of the others be destroyed. The nanomachines could also be self-replicating, which has further interesting implications beyond the scope of this question.
For more ideas of this kind, you can see
<https://en.wikipedia.org/wiki/Grey_goo> (also the related fiction book section) and <https://en.wikipedia.org/wiki/The_Invincible> .
[Answer]
A suggestion to hide thermal emissions:
Paint your ship with [Vantablack](https://en.wikipedia.org/wiki/Vantablack). Use a heat pump just below the hull (peltier device, A/C unit, whatever) to lower the surface temperature of your ship to ~3K. Of course, that heat has to go *somewhere* (because physics), so exhaust that heat in a concentrated beam away from you. Then, only someone who is actually in the path of the beam will be able to see you.
[Answer]
Since space is very cold, the thermal radiation of your ship will give it away. If there is a military reason to be looking for spacecraft, then there will certainly be enough scanners and number crunching computers to do so, given that even a "slow" moving body in space is moving far faster than a rifle bullet or artillery shell, so would pack an immense amount of kinetic energy (an object orbiting the Earth would be moving at @ 11 Km/sec, while the fastest unpowered bodies in the Solar System would be moving at a mind boggling 72 Km/sec.
The best way to hide, paradoxically is to move *even faster*, at high fractions of *c*, in fact. A ship moving at .9\*c\* will be just behind it's own "light", for most purposes, a ship or object moving that fast would not be "detectable" in any practical manner, since it would have moved a considerable distance between the time it emitted a signal (heat, reflection from the sun, rocket exhaust) and the time you saw it. The kinetic energy of even a small object accelerated to that speed would be enough to destroy continents, if not render entire planets uninhabitable, which is a pretty frightening thought: you literally won't see it coming.
[Answer]
# Spaceships will probably be very difficult to detect over planetary distances
Here is an example of how Hubble sees Pluto:
Image: Adapted from [NASA](https://www.nasa.gov/sites/default/files/thumbnails/image/nh-pluto-charon-earth-size.jpg) and [Universe Today](http://www.universetoday.com/120025/new-horizons-approaching-pluto-detects-signs-of-polar-caps/)
When Hubble is seeing Pluto, it is not seeing anything else. There is "all sky surveys" like Wise and Plank that have mapped the whole sky, but in a level of detail that will not even detect Pluto. Of course we can build better instruments in the future, but I doubt we will have a device capable to make all sky surveys in weeks capable to detect even small planets in the Kuiper Belt. Even if we did, spaceships are way smaller than planets. A building size ship would not even be a pixel on Hubble resolution.
[Wise all sky survey full resolution atlas](http://wise2.ipac.caltech.edu/docs/release/allsky/) has an pixel resolution of 6 arc seconds. At an earth-moon distance this means each pixel has 73km. At earth-mars distance this means each pixel has about 8560km. And it took wise 6 months to capture the data to compose this atlas. Not even close to a early warning system.
This is both a problem of the computational capacity and of the optics of the detection instruments. Computation power still have a lot to increase. Our computers are still too primitive when compared to the computational capability of the human brain. But I do not know if is possible to improve the optics part enough to make a big difference.
# The engines will generate the most visible energy when the ship is deaccelerating, but still may be too faint to be detected
Space is not so empty as people think. There is a lot of dust, asteroids and comets, stars and galaxies in the background. A dust closer to the telescope can be bigger than a star in another galaxy. To detect ship would be needed to differentiate the ship signal from these natural sources. That could be simple if the radiation generated by the engines was very different for most natural energy sources and probably will not be. Fusion drives will work with fusion (duh) like any star. Antimatter drives will generate gamma rays as many galaxies, neutron stars and black holes. Cosmic rays generate false signals in the detection devices.
A stealth destroyer may have thick armor to avoid internal radiation to escape, be black to not reflect much light, decelerate tangent to its target to minimize the luminosity of the engine pointed to the target, calibrate the engine to generate radiation closer to the background stars and line itself with a natural radiation source closer to its signature.
# A possible scenario
Let suppose a interstellar war. People from Proxima Centauri wants to invade Earth and both civilization have fusion drives, but not warp drives.
When the Proxima fleet comes to Earth they have to accelerate and the radiation of their fusion Drives will be pointed to the Proxima system which makes it undetectable from our solar system, but at some point the fleet have to decelerate. This means to burn the engines in the direction of our solar system for a few days, maybe even for a month. Their fleet will appear as very faint points. The light they emit will probably be comparable to a asteroid. Which is almost undetectable if the burn happens outside Pluto's orbit.
To better hide themselves they can make the bulk of the deceleration tangent to our solar system. That way they may reach much closer discretely between Mars and Saturn orbit. If they reach Pluto's orbit change their direction and make a 10G burn over an hour, they can reach Earth in 166 days. With that speed they need only one hour of deceleration. They can do the same trick as before, decelerating tangent to the Earth to minimize the chance of detection. Of course is a game of chance. A satellite in the right position can detect them fast.
[Answer]
It could be possible to use some space-time warping to appear in one position and almost immediately disappear to another, non-overlapping position, so that any human operators and many computer programs would miss you, since you're so fast.
It wouldn't work for low frame-rate technology, but advanced technology could be fooled like that. If the scanner is like a radar, with a beam that slowly changes direction to cover the whole area, then you could transport yourself as soon as you detected a scanning beam (assuming your sensor density is high enough) so that you would seem like a dot on the screen, fooling most light scanners (which also pick up stars).
If you want to avoid some kind of gravity/space-time scanner, then you might need a space-time field generator that countered all effects from the ship and whatever was inside it.
You could also somehow warp the light around your ship like military scientists are trying to do, so that it seems as if there's nothing where you are, but then you wouldn't be able to see out either.
There is also a possibility of creating a space 'pocket' or moving through a fourth spacial dimension, with a camouflaged scope (looking like debris, a dead body, etc.) being the only part of the ship sticking out in normal space so that you could see.
However, you couldn't move when somebody else was in sensor range, because objects moving like that doesn't exactly seem real. One-way-mirrors or video screens covering the whole ship would work, but you would still be visible to more observant people.
[Answer]
**Hypotesis:** Assuming the side of the ship you want to hide, is fighter like (20m long maximum while a battleship will be at least 400m), you could use modern warfare technics to hide fighter planes. I suppose too that scanning technics doesn't much evolve (IR scanning, and radar). I purpose methods just to hide not totally disapear. The engagement distance should be long too to avoid visual spotting.
**Like a fighter plane:** Fighter planes of today have several ways to avoid detection. I see two main way : flying a low altitude, to be in the radar's dead angle, and flying in close proximity of a larger civilian plane, the two planes, if close enough, have only one radar signature. So your ship can hide behind large stellar object if it knows the direction the scan come from, to place itself in the ennemy radar dead angle. It can hide too with a large civilian transport or cargo ship (and even land on it if space cargo is as large as today sea cargo).
**Like a ship:** Have you ever heard of [spy trawler](https://en.m.wikipedia.org/wiki/Spy_ship) ? You basically disguise your military ship in a civilian ship, and you hope no one learn the truth. A cargo-like ship of the Kriegsmarine even manage to sink an Australian cruiser.
**Like both plane and ship :** In desperate case, when you're spotted, you've one last way to prevent the deadly blow: [flares](https://en.wikipedia.org/wiki/Flare_(countermeasure)). It's a little device you throw to create heat and/or radar signature looking like yours. It will not hide you but it will confuse the ennemy targeting system, buying you time to escape.
[Answer]
This is an interesting question and the answer will always depend on what is the scenario. In most cases, using active sensing (e.g. radar, the beam you proposed, etc..) is essentially rendered redundant because passive sensing is usually enough to blow almost any cover...almost.
One of the easier ways of hiding is to be behind a massive object that's mass is at least 4-5 magnitudes larger than your spaceship, such as a planet. In a game of hide and seek in space, being behind a planet – or a star! – is a common way of staying undetected. However, staying behind an object like that means that your mobility is limited to your host (and your enemy). You also need to know where your opponent always is, which can also reveal yourself.
If you go high tech enough, your ship can be the planetoid itself. However, in solar system scale scenarios, significant undetectable movements could take millions of years. On the other hand, with a bit of planning and adjusting e.g. albedo or mass distribution, you could attempt to destroy planets quite stealthily.
If you want active stealth for a standard space ship, then I suppose you can design surface that looks like background radiation to one direction, while projecting heat to another direction rendering you invisible to specific direction. Obviously this would not work at close ranges against high tech opponent where they would most likely have detection capabilities from every direction.
Of course, all of the above scenarios assume that you're not radiating excessive amounts of detectable particles, such as neutrinos, which would be a dead giveaway even behind a planet.
In interstellar combat, there's really only one guaranteed way to be stealthy. That's by being fast. If you can accelerate fast enough to a speed that is very close to the speed of light relative to your target, you can take it by surprise. Down side: It's essentially a bombing run. I suppose you could take generational approach e.g. by riding an asteroid but hiding heat signatures is still complicated.
] |
[Question]
[
I've designed an alien race of bipedal humanoids with [digitigrade](https://en.wikipedia.org/wiki/Digitigrade) legs.
This race's advanced scientific progress means that they use traditionally human-associated technology, or similar (such as vehicles.)
It did however occur to me that the double-jointed legs may inhibit certain activities, or negatively influence other aspects such as the species' ability to balance.
---
So essentially, what are the advantages and disadvantages of having digitigrade legs?
[Answer]
It all depends on what kind of planet that race has developed on and how they have evolved.
**Pros**:
* generally quieter footfalls
* much faster running
* more agility overall
**Cons**:
* it could be uncomfortable for them to use some kinds of vehicles and technology in general as we know it, so it is necessary to completely (or almost completely) rethink any piece of technology that involves the use of legs: for example, cars as we know them would be unpractical for digitigrade-legged aliens, since there wouldn't be space for them to properly move
Overall, it could be well explained by the fact that their planet is "savage" in large part and that they had to evolve faster legs to escape natural predators in the past.
For instance, there could be a species of aggressive flying beasts that used to hunt them in their prehistory, forcing this alien race to develop better speed and reflexes over the millennia to manage to dodge the first attack of one of these beasts and go hide in one of their planet's many natural caves while the beast turned around for a second try.
Regarding the use of vehicles and such, they may have simply developed technology suited for their anatomy: for example, their "cars" could be something like ours but with pedals at chest height (to be more comfortable using them with digitigrade legs) and a joystick rather than a wheel, to make more space for the legs.
[Answer]
I think that the answers here are pretty good. leagues better than this one, but I thought I'd [give you something I found during my travels](http://jesseth.deviantart.com/art/Digigrade-Legs-for-the-Scientifically-Accurate-303608200)
[](https://i.stack.imgur.com/J7hd7.jpg)
I would just comment this, but [last time I commented a possible answer](https://worldbuilding.stackexchange.com/questions/31513/what-would-be-the-best-way-to-fight-a-duel-with-lightsabers/31521#31521) it cost me 540 reputation.
[Answer]
In a nutshell: digitigrade legs are faster, plantigrade legs are more stable.
Digitigrade legs get extra leverage from their ankle while running, giving them a 'spring' in their step. However, they lack the weight-bearing ability of a solid plantigrade stance.
Your digitigrade bipeds would probably be easier to knock over than humans, but would make up for it with faster running and jumping.
It is possible that they evolved from fast running sprinters (like cats) rather than persistence hunters (like humans), but this is not necessarily the case - a lot of plantigrade vs digitigrade has more to do with ancestry than the specific advantages of each stance. For example, you'd expect elephants to be as plantigrade as it gets, but they are actually partially digitigrade unguligrades because their much smaller ancestors were (their digits became much thicker to bear their weight instead).
[Answer]
Well this here might help as well. It comes from the Twokinds webcomic. I would post a more detailed explanation but I'm still recovering from my family's Christmas feast. ;3
[Answer]
Also look @ how Draenei walk & stand (as designed by Blizzard, for World of Warcraft). They are also digitigrade & even have hooves. Best of all, because they are animated & a lot of ppl draw inspiration of them, it will be easy to find examples & even see, how they move, walk, live & (allmost breath)...
* 1 con I've found too: If you ever saw Robocop, with ED-209 (whic also looks digitigrade), I think bipedal digitigrades have a hard time, doing stairs (especially downstairs), if the steps are to short & they probs will fall on those stairs, as a digitigrade can't support directly on it's heel (no extra bones/flesh there), as it is not ment to be stood on, directly, like a human heel...
] |
[Question]
[
My hapless wanderer (I believe we agreed to call her Alice) won the struggle at the [Morrow Castle](https://worldbuilding.stackexchange.com/questions/10939/how-to-defeat-a-precognitive-warrior). This next challenge will test her abilities (and ours, as worldbuilders) like never before.
The creature she is to face next is **not of this world**. It lives on the edge of consciousness and dream. The **Maere Wolf** is a **[hypnagogic](http://en.wikipedia.org/wiki/Hypnagogia) beast**, a monster of the dream-world, inducing a troubled sleep-like state into its victims and stealing their most valuable memories, their deepest secrets and replacing them with frightening and horrible images of its victims' greatest fears.
Alice **needs** to recover a particular stolen memory (it was stolen from someone else, if this matters). Ideally, she would prefer not to lose any of her own memories in the process, but if it can't be helped, it can't be helped.
**How can you help?** Luckily, Alice has had a few months to prepare for her mission, and the thought that a foreign entity might attempt to invade her sleeping or near-sleeping mind either occurred to her (smart cookie) or perhaps it was right there in the young female adventurer training manual, page 23. So, we need to know what techniques Alice can and will use to:
* **maintain awareness** while nearing sleep;
* **take control** of the nightmare dream-like state;
* **probe the depths of her dream** to find the stolen memories;
* **preserve the memory when awakened**.
* Possible Hint: Yoga Nidra.
---
Here are some optional extra details if you want them.
**You may investigate the area:**
>
> The physical manifestation of the monster is a small but pleasant-looking cottage along a highway deep in the wilderness. A couple of tired-looking teenage girls, with deep bags under their eyes maintain the place, either refusing or perhaps unable to speak. They indicate that she is to sleep in a comfy looking bedroom inside the cottage, lit by a dancing wood-fire in a terracotta stove, while they retire to the barn for the evening.
>
> Alice is not stupid, she's heard the warnings of peasants and travelers along the road, so she knows about the Wolf. Unfortunately for her, Alice **needs to recover a secret that was stolen by the Maere Wolf**. Her trinkets indicate that something's definitely going on here, and her compass seems [to point anywhere but North](https://worldbuilding.stackexchange.com/questions/10508/science-behind-a-naturally-invisible-creature/10510#10510), but none of Alice's fancy toys can locate the source. She's going to have to do this the **hard way.**
>
>
>
Perhaps you have some **lore about the Hypnagogic trap**:
>
> The Maere Wolf is either conscious, or more likely, a very craftily constructed rule-based probing program. Whatever physical object exists that triggers the trap, the Wolf only subjectively exists in people's minds, and such can be seen as a remarkably powerful induced nightmare. It is known that memories are changed by reliving them, so the nightmare somehow causes near-unconscious minds to relive important memories, associate them with the nightmare. Thus the Wolf extracts the information, and finally overwrites it during the continued dreamlike sequence. This means the subject cannot retrieve it correctly anymore, while the Wolf has the objective content of the memory and can write a heavily encrypted form to whatever physical substrate is available to it. However, every time the Wolf is activated, all its stolen memories are, in some form, potentially available to the dreamer's mind.
>
>
>
Please let me know if you need more information! The more unusual and unorthodox the answer, the better!
**LATE EDIT**: I am very grateful for all the answers and Aaru's in particular for the thought-out in-depth answer. Alice has indeed had over a decade of martial arts training, it makes perfect sense she would be trained in combat meditation techniques. Wish I could upvote it more than once. The Wolf's servants unfortunately cannot be saved, as Alice is in a [terrible rush](https://worldbuilding.stackexchange.com/questions/11399/boots-of-speed-how-fast-can-they-go).
[Answer]
Decided to take you up on the Yoga Nidra hint:
Alice has had decades of martial art training, to reach her 6-dan black belt status [you mentioned in the previous chapter](https://worldbuilding.stackexchange.com/questions/10939/how-to-defeat-a-precognitive-warrior). Part of her training involved yoga meditation, to still and steel her mind.
After a few minutes prep time staring at the burning embers in the fireplace, Alice will enter a state of deep relaxation where her brain emits the delta wave characteristic of sleep, while retaining conscious awareness.
The trap will detect the delta wave activity (I'm assuming it's monitoring the brainwaves of whomever is in the cottage), assume the person has no conscious capacity to resist, and therefore trigger.
Since the Dream Wolf (I like the term) only really exists in her mind, all of its stolen memories from other people will have to be temporarily instantiated using partial memories from Alice's mind.
Alice will have to literally let the induced nightmare imagery build to full strength (full instantiation), and then proceed to ignore the attempted induced nightmare, denying it the nourishing emotional reaction, which will cause it to wither away and fade from her attention.
Similarly, she will have to resist the urge to think about her secrets, to prevent the dream wolf from accessing them. Perhaps she will use sets of decoys, useless memories repackaged as terrible secrets for the wolf to churn through - watching grass grow, paint dry, all of them temporarily holding cosmic significance for Alice, etc.
Finally, the biggest challenge will be extracting the stolen memories. You never specified how many the wolf has, and how Alice can identify the particular one she's looking for. So I'll make up a way instead. Alice, or the organization that sent her, has interrogated the previous holder of the memory and extracted relevant memory correlates, which Alice will herself have memorize and is ready activate when the dream wolf is fully instantiated in her mind.
Doing so will activate the memory fragments associated with the sought-after secret. Alice will have to put the puzzle pieces together. The way to do so is to find each piece and add it to a dream, and when all the pieces are found and the dream is fully fleshed out, the dream will be the quasi-correct memory with all the information Alice needs. All she needs to do is stabilize the dream as a full-memory and once that is achieved she can exit the meditation state.
I wish I had a way to also help the girl victims you mentioned, but you didn't give us enough information to do so. I'm sure Alice will find a way, though.
[Answer]
Sounds like you're looking for [Lucid Dreaming](http://en.wikipedia.org/wiki/Lucid_dream#Initiation). Then Alice can navigate through the Wolf's Nightmare-memories and try to fight the nightmare on a conscious basis.
Note: I don't believe Lucid Dreaming is currently "scientific" - it's not proven and techniques are very debatable. Thankfully for you, if you go this route it gives you a lot of flexibility - you can pick almost anything reasonable and be ok because no one knows what the right answer is. I would probably do some sort of specialized meditation, leading to sleep.
[Answer]
While Dan's idea is correct, his belief is a little off.
Lucid dreams make you practically omnipotent. You can just *will* any change. Some elements are more resistant, but with enough focus you can do anything. Your only two risks are waking up (very common problem, especially if you get excited about reaching lucidity) and 'losing lucidity' - forgetting it; if you are distracted, lose focus on staying lucid - controlling your dream with your awareness, you may simply forget about being able to control the dream. While you are omnipotent, you are not omniscient, far from it - your brain still works in dream state, your logical thinking suffers, elements that would normally appear wrong or illogical, or inconsistent often don't, and things that are difficult in dream (e.g. verbalizing words instead of just expressing ideas) are still difficult.
Lucid dreaming is definitely a fact, and not even very exotic (yours truly experienced it a couple times). It can be achieved more or less reliably; while it largely depends on individuality of the dreamer, more difficult for some, easier for others, there are various techniques that aid in achieving it.
One rudimentary technique is 'Reality Check'. There are some activities that simply don't work in your sleep right, universally - common dream elements which nobody is capable of. One most frequently used example is reading the same text twice. While you can read book in your dream, and it may even make some kind of sense, if you return to the beginning of the page, or even a sentence back, it will never read the same. That's an uncanny signal that you are dreaming.
So, if you perform a Reality Check in your waking world frequently enough (several times a day; and of course the read text will say the same thing when you read it twice), chances are good that you will dream of performing a Reality Check in your dream, and... oh, it failed! That means you're dreaming, and you just went lucid!
(it can be any arbitrary text, maybe a sentence from a book you carry, maybe an SMS message on your phone, maybe a commercial within your field of view. If you lack a text, you can always write one.)
The most tricky element is to achieve lucidity on demand. If you don't perform the reality check, there won't be any lucidity. So, you need a trigger. It may be a characteristic sound, or rapidly blinking light. For example, you can set a (specific sound) timer alarm to remind you of performing RC every hour or so. Then you can set it before going to sleep - if it's just the right volume, you won't wake up but you will still hear it, and it will be the obvious reminder.
Alice would be best off employing external aid. First, find a trigger for lucid dreaming, and develop disciplined rigor of performing reality checks. Next, preferably reinforce the strength of the trigger through employing aid of a hypnotizer. While the flashy scenic hypnosis is all a scam, the truth thoroughly analyzed by psychologists is that entering a certain state of mind can allow to immensely modify certain associations, compulsion, reactions. In particular, associating given signal, like sound, or flashing light, with strong awareness of situation requiring lucid dreaming, can be made very strong and reliable - while before you'd rely on blind luck and randomness of your brain finding given situation, now you practically force it.
And then, Alice would be best off coming with a friend, who would watch her sleep and trigger the signal if external reactions of her body - eyeballs moving under eyelids, breath speeding up, twitching - suggest she is "in trouble" in the dream world.
[Answer]
She ties loud bells to her hands, so that if she starts thrashing around in her sleep the sound will wake her up. When the wolf attacks her she grabs hold of it in her dreams, in the struggle she thrashes around and the bells awaken her.
As she transitions from dream state to waking state while grasping the dream wolf, that pulls the dream through into the non-dream with her. Trapped in the real world the wolf is much weaker, so she can then grab it before it escapes and subject it to whatever process she likes to extract the information she needs.
[Answer]
**Lysergic acid diethylamide**
And a small group of friends (read: victims).
I like all of the ideas of previous answers, particularly by Aaru, as well as mentions of lucid dreaming. I don't mean to replace any of the other answers, but I would like to take it one step further.
In preparation for this task, Alice should not only face her greatest fears, but do it while tripping on LSD...which would probably increase the terror. As she becomes hardened to her fears, the nightmare state induced by the Wolf will have little effect on her while in dream land. This will give her an extra layer of defense as she attempts to subvert the program.
Another idea is to bring along a cadre of willing (paid) participants. If there are multiple dreamers in the trap, the Dream Wolf can only work on one at a time (assuming it's not multi-threaded), thus giving Alice more of a chance to work her Yoga Fu and recover the memories.
Even if the Wolf can work on them all at the same time, this would presumably tax its energy, giving Alice a slight advantage in its weakened state.
The hosts at the cottage might be unwilling to allow more than one weary traveler in to stay because of this potential weakness. But I'm sure Alice can find a way to sneak in a few more people when they retire to their barn.
] |
[Question]
[
In a future where all cars and public services are self-driving the way, I am assuming traffic congestion would be seriously limited, if not removed completely, because the road network would also have a companion communication network between vehicles, allowing the implementation of some optimal bandwidth occupation algorithm.
Besides the technology that will need to be installed along the road, how do you imagine the road network to be affected by that? (for instance: less multi-lane roads, or more single lane roads, with no traffic signals? or with different ones? what about parking; there are just examples, please don't refrain from adding your thoughts).
[Answer]
Currently with people driving there is a max capacity of around 1800 vehicles per hour per lane (if the [2 second rule](http://en.wikipedia.org/wiki/Two-second_rule) is adhered to).
The following is the formula for stopping distance:
$$D\_{\text{total}}=D\_{p-r}+D\_{\text{braking}}=vt\_{p-r}+\frac{v^2}{2 \mu g}$$
$t\_{p-r}$ is the reaction time (time from something happening in front of you to putting the foot on the brake), usually taken to be around 1.5 s; with automatic driving this can be nearly nullified. This would result in a much denser road use.
How intersections are dealt with depends on how cars can communicate. If each intersection has a computer that the car has to "log into" then it can reply by telling the car to slow down a bit so it can slot neatly in the gap in the other stream. This would make roundabouts much more efficient than they are now.
They would potentially reconfigure themselves depending on the traffic volume, a simple yielding configuration during low traffic, (turbo)roundabout as traffic increases all the way to full on stop light. This stop light can be more efficient than today's system because all cars slated to depart in the green slot can accelerate at the same time and at the same rate.
As for routing instead of always going for thé optimal path each car should instead use a weighted random selection of possible paths. The best paths has the biggest weight but less optimal paths are also possible. The weights can be compiled from data of travel times. Planned construction would then be artificially penalized, accidents and breakdowns as well. This will result in traffic distributing itself over the network.
Also here reconfiguration of the network can happen, turning a street into a one-way street to get the volume out of the city in the evening for example.
[Answer]
* Roads would likely have some sort of embedded short-range lane and navigation markers, as cheap as possible. Perhaps something like reflectors with QR codes.
* Control would be mostly distributed in the cars themselves, with approval of the overall route going through a central coordinator, but a peer to peer network for coordinating with adjacent cars.
* More long-distance traffic would be routed over surface streets.
* The driving age / licensing requirements would be reduced or eliminated.
* People would have weak navigation skills / get lost easily.
* People would tolerate longer commutes because they could sleep, eat, shave, perhaps even shower along the way.
* The slightest mechanical defect would not be tolerated. A check engine light would result in immediate routing to the nearest mechanic.
* Deliveries would be fully automated and therefore faster, meaning you might shop online even for groceries.
* Cars would tend to be smaller, because it's easier for families to travel together in separate cars.
* You wouldn't need disabled parking spots, because everyone would get dropped off and picked up at the door.
* Poorer people might share a vehicle between extended families, even if they don't live close by.
* People would take more cross-country vacations without air travel.
* Politicians would not be able to resist appropriating the technology for their own ends to:
+ track people's movements
+ effect arrest warrants
+ impose quotas
+ ease congestion by forcing staggering of travel
+ tax based on usage
+ give preferential travel times to special interests
[Answer]
I don't want to be the nay-sayer in this, but probably the answer is "nothing much" - and here's why:
1. Traffic signals would probably exist, both on the road and in the cabin. Knowing the reason for a delay is important to both the riders and the people around them. While in-cabin may be sufficient for drivers and even passengers, pedestrians still need to be aware of traffic flow signals. They may be smaller or less conspicuous, but still necessary.
2. Speed limits would probably change, depending on the time of day and current traffic conditions. Maybe not as much as is imagined because if your vehicle doesn't know the mechanical capabilities of the vehicles around of it (for example, the state of disrepair) it will need to follow less closely than a human might who does not have that knowledge - or be aware of their lack of knowledge. Cars in disrepair may be able to report their impaired status which does not hinder traffic flow today. Today's driver is left to judge the safeness of their vehicle - and other vehicles - without much measurement. Additionally, what liabilities exist when your car communicates deteriorated equipment to other vehicles and authorities? Its unlikely this will be adopted by the majority of drivers any time soon.
3. More roads and lanes can be "re-purposed" depending on traffic loads and tolls. More roads could have part-time tolls. Really, this just sounds like a way to collect more taxes, but the roads will be more costly due to the embedded technology. Also, does it seem appropriate that some lanes that travel faster be available to the "wealthy" that can afford the tolls. Again, very slow to adopt, if ever...
4. A technology will need to be developed for local traffic optimization based on the current vehicle locations, speeds and capabilities. The location and maintenance of these systems will probably prevent any savings from reduced visual signal cost (i.e. traffic signals and signs), road maintenance or public property damage. But over time their value will probably be in reduced accidents and safety. Much like today's traffic signal was an improvement over traffic officers even when they weren't obviously economical and it wasn't clear if the general population would "obey a light."
5. Global optimization is incredibly unlikely for a very long time. It invades privacy - vehicles and government entities will know where you *intend* to go and then *communicate* it. Law enforcement, judges, insurance companies, traffic planners and other drivers rarely have access to that information (do they ever even ask for GPS route data?). Communicating *intent* is completely different from communicating status. But without explicit intent, much of the current infrastructure would have to remain in place (only minimal reduction to traffic lanes and road maintenance). Local optimization is possible for one-way roads and some intersections, but a "higher power" cannot re-route you if all it knows is that you are waiting to go forward or trying to turn but nothing else. That's still local optimization. This situation also leads to lengthy trials over privacy, rights and public protection.
6. Residential areas will likely try to enact laws to reduce or eliminate "non-local" traffic. While "short cuts" and "traffic route optimization" sound nice, people living on quiet roads where traffic may be re-routed frequently will certainly not appreciate the change. Again, many "gains" in automated systems make assumptions, and "reduced traffic congestion through the use of alternate routes" doesn't mean that alternates suddenly materialize or even can be planned any better than they are today. But existing residential roads that are not congested could suddenly become the frequent target for automated traffic route alternatives. The residents on those roads will likely fight back, as they do today with planned changes in traffic patterns.
7. While it is nice to imagine time savings for people that do not have to drive, and can then "use that time" in other ways, it's probably not as beneficial as imagined. First, the cost of the technology will be a burden that a consumer must bare. Second, like early 20th century household appliances that "eased household chores" which led to increased expectations of cleanliness, so too will automated driving probably lead to longer commutes and no addition to overall leisure time. Although it may be possible to consider in-cabin time "leisure" time, doing so means larger cars, less energy efficiency, more equipment, higher operating costs, etc.
8. Last, just as the internet did not end "brick and mortar" shopping in places like grocery stores, etc. automated driving will not reduce or eliminate "errands" - in fact, because it will be easier to perform (less work on a human) it is likely to happen more frequently. People can more easily get to and from stores. And it would be less of a burden on a homeward bound household member to "stop by the store" than ever. So, it's likely that with a person's mind freed from the burden of navigation and driving, they will likely shop more in physical locations, not less, possibly requiring more roads, increased traffic congestion, higher energy usage, etc. Ease of navigation and transportation does not automatically improve the planning capabilities of a population - and could make impulse route changes more frequent since the "driver" is no longer focused on the activity of driving and can suddenly see a store or advertisement that changes the route of the vehicle.
I realize that most answers here talk about efficiencies and improvements. I believe automated driving will result in safety improvements more than anything else. Its unlikely to improve much else for a very long time unless those safety improvements of more value than freedom and privacy. Conversely, improving safety may be more important than the "freedom" to harm or "privacy" of criminals. It would be a vastly different future either way.
[Answer]
**Very little to none in first years** is my best guess idea, because thats how the self driven cars are driven now in nowadays system and it is very pricy to adapt the road system because of new technology. Good example on this is the reason why there are no super fast trains in USA. Because updating nowadays system is pricy.
**I am inclining to "shared ownership" in next years**. Say 20 years after having every single car self driven, the system of owning your own car will become more and more obsolete, because car sharing will be really easy. And I can imagine there will be companies offering pool of cars for a fee.
Just imagine "taxi" service which will take you anywhere you want, at any hour, and will cost reasonable low amount of money
**And then - movement to automated public system** if every car is automated, imagine [Uber](http://en.wikipedia.org/wiki/Uber_%28company%29) - like system where you "rent" your car while driving to work, and with bonus, still able to drive you to work on time
**I am torn apart about between car communication**
If automated car should be able to communicate with other is big unknown to me. Yes, I am using [Waze](http://en.wikipedia.org/wiki/Waze) to calculate me best home route and the navigation is working great thanks to community, but also, machine to machine communication is hackable and may be made incompatible
[Answer]
It probably won't be long into it before personal car ownership becomes rare and either taxi-type services become more common or you timeshare vehicles with friends or even neighborhoods.
Once you have a self-driving vehicle, there is going to be less reason for it to be just sitting somewhere, when it can be working. There is a husband and wife who have developed a [solar powered road system](http://www.solarroadways.com/intro.shtml) and it does several things, it does convert sunlight to electricity, it is a very decent driving surface, and many other things. Including having LED lights that can be used to make road markings, (ie switch lane direction during rush hours) give warnings and possibly talk to a smart car.
Combining that technology with self-driving cars will be truly revolutionary. At that point electric cars could actually recharge as they are driving down the road, or at least have recharging stations scattered along the way. It would help reduce carbon foot-print and the estimate was that if all driving surfaces in a town to small city it would provide enough power to mostly take the city off the gird, total green.
You also wouldn't need big vehicles for most people, since if you buy a TV it can be delivered by the store in a self driving van, would different security so the right person gets the delivery however.
[Answer]
Congestion won't be eliminated, it might even increase. Having self driving cars can in theory make far better use of existing roads (see ratchet freak's answer for example).
However currently population is going up, and desire to spend on infrastructure is not going up. Assuming those trends continue you will start seeing reduced congestion as self driving cars are adopted. That'll make people happy, but it won't last. Population increase will start eating into the gains, and unless we start spending more on roads congestion will start to raise again.
I would even guess that as long as the amount of congestion climbs slowly it will be allowed to climb above current levels because it is much more productive time:
* eat a meal
* brush your teeth
* watch TV (or for long commutes a movie)
* if you own an RV (small RVs might get more popular):
+ sleep
+ take a shower
+ get dressed
* knowledge workers could do some of their job during the commute (what do you think Apple/Google/other employees do on the buses now?)
I'm also not 100% sure how much congestion will reduce short term as a lot of things might end up causing more miles to be driven:
* people may be willing to tolerate even higher commute times in exchange for lower housing costs
* if cars self drive there is less reason for young people not to have access to them (or have more after schools activities then their families can currently drive them to)
* elderly people who are no longer safe to drive themselves can regain that sort of mobility, and I expect many of them will
* disabled people (blind, or even just folks who have poor night vision, folks with reduced motor control, and many more)
* dog delivery for lunch time walkies, why have a strange walk your dog when you could get a little light exercise? You just need a dog door with a timer and a garage (no, I doubt this will be a large number of miles, but I think this is the kind of thing in the "long tail" of "nobody does it now, but a few people will do it in the future")
* parking lots can move far from buildings (live in SF, it might cost less to have your car parked in another city overnight and come pick you up, that'll add a lot of road miles!)
* car sharing inside a family can have the car taking someone to work, driving back home, and taking other family members to work (or social activities)
* if most people drift away from individual ownership of cars and start renting time from a fleet of cars they will spend time driving from the last drop off spot to the next pick up spot
* the cost of "same day delivery" will drop a lot, and it might not all displace purchases you would have driven to a store for anyway (then again, if it is "same day", not "ASAP" shopping could be combined from multiple stores to multiple people, so maybe it could be less traffic for that)
Some other things I think might be interesting, if congestion starts to get bad again with all self driving cars you can have lot more gradations of lane limits. Rather then just "carpool" lanes that also allow low/no emissions vehicles during specific hours you could end up with surge rates where as roads get more congested you only get to use some roads/lanes/routes if you are willing to pay more. (and in a utopian psudo-libratarian future that money would pay to add lanes or roads to reduce congestion, but I think in the real world that'll be an extra tax only part of which will go to roads, and counter productively may encourage local movements NOT to do anything to fix congestions because that is how they are funding schools, police, and the governor's reelection campaign!)
Emergency vehicles are currently very hampered by congestion. The sirens can only be heard so far away, and while most people try to do the right thing, some might think the right thing is to get out of the traveling lanes so the cops/fire/ambo can use them, other might think they need to stay out of the "break down lanes" so the cops/fire/ambo can use them. Some might decide to do either of those things "in a second or two, after I take advantage of the gap!". With self-driving vehicles you will get a consistent behavior, and traffic can be alerted along an entire route as soon as needed. This could save a lot of lives.
Most traffic accidents are caused by poor driving, or drivers medical issues. They will go away. Vehicle failures will still cause accidents. They might cause fewer (self driving cars might refuse to drive if they haven't been maintained properly, and even if they don't, it is a whole lot easier to keep to a maintenance schedule if the car takes you to work, and takes itself in for service, and picks you back up after work as per normal, not waiting until you can find time for it). They might cause more (sensors add more points of failure). They might cause less (if programmed to deal with a mechanical failure, and properly tested a self driving car won't forget how to deal with correctable failures like flat tires, and even ones that have limited correction ability like break system failures self driving cards could far faster and more effectively warn other cars to get out of the way)
Accidents cause more accidents (people gawking at an accident aren't paying as much attention to driving as they should). That won't happen with self driving.
[Answer]
* people will have no idea where anything *is* anymore, and would not recognise their city on a map.
* people will try to trick you into clicking on something to change your destination and drop you off at some nasty place.
* your “free time” will be bombarded with targeted ads, perhaps with incentives such as toll/fuel reimbursement to try *their* business instead.
* today people plan less and look up the route after leaving. Continue that trend and people won’t have a clear idea where they want to go until underway, searching for the right kind of establishment on the map-guide. With ads.
* dogs will take the car on their own once they learn that they can. They’ll go joy-riding instrad of walking, or visit you at work minutes after you punch in.
* cars will be less self-owned dedicated and more like trains and elevators: call for a ride, tell it where to go. You can have small cabins for personal transit, limo-bus’s for groups, and cargo handlers of any size. You can use a basic 2-seater, or pay extra for luxury or mini-RV’s for longer trips.
* or, more modular: the roomy seats-plus cab will rendezvous and dock with locally sourced expansion modules for meals, sleeping, entertainment, etc. on demand. The car will grow and shrink back down, reducing what needs to transport over long distances and offering versatility.
* party busses and reconfiguring social trains will offer another possibility for docking for a journey, and will *become* a destination in itself for teenagers (and dogs).
* people will stop commuting as much, or going shopping in person, and reduce car usage. They will use ideas like above to make it fun and interesting to get out there, just like today movie theaters have to work hard to attract business as home theaters are nicer than “plain” movie theaters.
* surface vehicles using roads will combine with rails, containers, flying drones, and other forms of transportation to make a seemless whole. You can address a package and toss it outside and it gets to its destination, somehow. Same with people: if you enter a destination a thousand miles away, the system will use local neighborhood roads, freeways, land-train superfreeways, pack the cars into containers and load on locomotives, as fits.
[Answer]
The road network itself would probably become smart. I can picture realtime traffic flow manangement, where the cars know of the fastest route at any time. Stop signs and traffic lights would be obsolete if all vehicles were self driving. Speed limits would increase to about 160km/h on controlled access highways, and decrease to about 20km/h in cities. Highways would be mostly road trains of freight and buses. I'd expect far fewer medians, and roads with three lanes being the norm instead of two. Inbound/rush hour direction having an express and slow/stopping traffic lanes, and the other direction having just one. Benefits of more lanes would be the same.
The actual path of the roads would stay roughly the same, new roads would be built in much the same way: the path of least resistance.
This assumes vehicle manufacturers are willing or forced to work with one another. If they're not, nothing will change.
[Answer]
If you had perfect routing and better traffic management, what you could probably end up with is a system where the number of intermediate sized roads are less than today.
Assuming every house needs road access, you still need the itty bitty neighborhood streets. And for high volume, long distance routes you need superhighways. But with better management all roads could hold more cars without congestion, and merging could in theory be managed without adding congestion.
So the need for "middle sized roads" of a variety of sizes is where the squeeze could come. I'm not sure if quick merge into a big fast road or smallish roads with high speeds would win out.
[Answer]
In most systems: consumption grows to fill bandwidth. In other words, if people think that the roads aren't clogged then they're more likely to go somewhere. They're more likely to purchase a car for their teenage child. Old people will feel empowered to drive places. And then suddenly--even with automation--the roads are still effectively clogged.
Even if the roads themselves are automated this doesn't mean that when you're arrived at your destination there will be adequate parking. Real estate prices increase over time so the value of a parking lot will become too great not to develop it in some other way.
] |
[Question]
[
What might clothing designed to be worn, long-term, in microgravity look like? For the purpose of this question there are two categories. Practical, or everyday wear, and impractical or simply fancy wear. But these categories can overlap. The second is just for those designs you might not want to wear every day.
Specifically looking for certain trends that might be found in clothing, like a popularity in single piece suits or something. Fashion should only be taken into account if it could logically emerge from useful trends.
Note: I am looking more for everyday, civilian wear, then military uniforms
[Answer]
**Take a look at swimming costumes over time.**
The thing about microgravity is that it's relative pull by comparison to the atmosphere would be similar to that which we currently experience diving - that is to say that water is quite dense, and we float in it because the pull of gravity affects the water more than us because its denser. We compensate for that by putting on weights, but that is for another topic.
The important factor here is that the way objects like our clothes are going to react around us in microgravity is similar to how they react around us in the water.
So - skirts, T-shirts and other items that are designed to hang loosely are definitely out because they won't hang, or will take much longer to do so, especially in response to our sudden movements. That's why our swimwear looks so much different.
Ultimately, how 'modest' our clothing will need to be will be determined by temperature in the first instance - it's no surprise that European visitors to Polynesian and Southern African areas were shocked by what the inhabitants wore. They came from cold climates, but the locals had adapted their cultures to the humidity and warmth. Add to that, there is no doubt a need to get in and out of clothes as conveniently as possible, and several trends are likely to emerge;
1) **Swimsuit Style Apparel.** What I mean by this is things like boardshorts, possibly speedos and one pieces, probably some form of shirt that has elastic around the bottom of the shirt to keep it in place at all times, and *possibly* some of the long-john style swimwear from the Victorian era, especially for formal occasions. Shoes, especially on a space station, will be essentially velcroed extensions of the foot, allowing for good purchase when moving about.
2) **Wetsuit Looking Outfits.** Neoprene is unlikely to be used in space because wetsuits can be really hard to get in and out of, and getting purchase on the suit is hard enough in full gravity. But, it would make sense that some form of thick (but softer) insulating material would form full body (or more likely 2-piece) coveralls for people on space stations so the internal temperatures don't need to be set so high (preserving energy). *See more detail below discussing temperature control in space; short version is that cooling is probably the bigger issue in space in most configurations.*
3) **Lots of Zippered Pockets.** It's not just the human that suffers when clothing needs to be designed for microgravity - it's the things he or she carries around as well. Some things, like wallets, pens, phones, etc. may easily drift out of pockets designed for larger items, meaning that the best and most logical approach is to either button them down or zip them up. Either way, flashier buttons or zips on pockets will become a fashion statement, just like all those extra buttons on suit sleeves that don't actually do anything. Some clothing may eventually manifest buttons and zips in areas that don't actually have pockets, especially for formal wear.
In the end, modesty will initially restrict things like skirts, but practicality is likely to enforce a sense of modesty, by forcing people to stay warm via their own body heat rather than energy taken from the station to stay warm. On the other hand, in an environment where the space station (assumption on my part) actually exists in a close solar orbit or has some other reason for having trouble expelling heat (often the case in current tech spacecraft and stations) then it's more likely to see people in space wearing one piece swimsuit style clothes and boardshorts as a reaction to the warmer environment.
The key things to consider when extrapolating all this is;
**Form follows Function** - people will dress for comfort and practicality first, then the culture will adopt local mores from these constraints rather than the other way around.
**Convenience Always Wins** - People simply won't go from convenient clothes (to both wear and put on) to inconvenient. Convenience always improves over time.
**Fashion is about Affectation** - Things like flashy zippers and buttons will manifest *after* they prove their usefulness. Ties were originally neckerchiefs that were used to wipe the blood off swords after a duel, but became a bragging item (look how many times I've had to clean off my sword) that led to universal adoption and even generated a few sayings, like someone 'earning their stripes'. Lanyards worn by many military officers were originally used to hold the firing pins for the cannons they commanded, but became a more ornate feature of uniforms much later.
If you factor all this in, I'd expect to see some form of clothing that is at least reminiscent of swimwear from some period of history, with flashy buttons and zippers used for formal attire. As for how modest the clothing remains or changes to, that will literally be set by the thermostat on the station itself.
*From comments, there is always going to be debate about the origin of sayings, and the nature of specific clothing affectation. Many of the comments below represent some known variances on the thinking around the introduction of ties and sayings like earning stripes. The statements I make above in that regard should not be considered definitive; they are one of many interpretations of these origins. They are included here because they are relevant possibilities*
[Answer]
The obvious place to look for what hypothetical future people living in microgravity might wear would be to look at what real-world people living in microgravity today actually do wear.
A quick image search for "ISS astronauts" turns up many, many photos of people living and working in microgravity. In the substantial majority of these photos, they are wearing cargo pants and (usually tucked-in) t-shirts. The next-most-common outfit is loose-fitting one-piece coveralls.
[Answer]
The most important thing I see is that people would avoid clothing that needs to *drape* to look right, so, with nothing to hold them down, the following are probably going to be out:
* skirts
* neckties
* dangling jewelry
* most hats
With neckties out (too busy floating around Dilbert-style), we could see a resurgence of the bow tie, a la Asimov!
Hats (not helmets) could become reserved as formal wear, and worn either with hairpins or straps to keep them on the head.
With no skirts, we could see people substitute so-called "split skirts" or harem pants that tend to be very baggy but don't float up nearly as easily as a skirt would.
[Answer]
In our world, four important factors have determined the look of our clothes since the dawn of time: available resources, climate, purpose and moral. In my opinion, microgravity is simply going to add one degree of freedom to the clothing designers, but it is not going to decide whether clothes will be tight around the body, or floating in the air.
**Note on Resources.** If all clothing is imported from Earth, then we can presume we'd be able to find the same range of materials that we would find in terrestrial shops. On the other hand, if the manufacturing occurs locally, then depending on the local resources, one could should consider whether cotton or linen production is feasible, whether farming for wool could happen, or whether the local fauna can provide skin for leather clothes. If the answer to these three questions is 'no', then the locals may exhibit a preference for synthetics. A note about the local fauna: if there is a native wild fauna, the corresponding skins and furs may be considered fancy pieces of garment, depending on how difficult it is to hunt them.
**Note on climate**. I am going to state the obvious: cover more to protect from extremes. Extreme heat, extreme cold, extreme radiance, extreme wind, all typically call for longer clothes, covering more of the human body.
**Note on purpose**. Working clothes are definitively designed for purpose. Be it a uniform to identify members of the organization, or a special suit to shield from hazards on the workplace. Hazardous working environment will require stricter control over the design. For instance, factory workers moving around large machinery may be given tighter clothes, gloves, helmets, and protective shoes.
**Note on morals**. Morals dictate clothing design in our world to much a larger extent that we may imagine. The most interesting aspect of this is that hindering and impractical clothing may become the norm if it best fits the moral standards of society. The fact that women had to wear gowns for instance, even when riding horses, is just one example of such trend. I would recommend that you define your society well before dwelling into defining the clothing design, as the latter depends heavily on the former.
**Q&A note on microgravity**
Q: wouldn't microgravity make clothes float as in water?
A: That is very likely, but... It depends on the fabric and on the treatment. A large dose of starch can keep clothes rigidly in place for quite some time. Leather can be arranged to be stiff and in place. Old Victorian era gowns had a frame to keep them in shape, defying gravity: the same principle could be applied, i.e. to implement a frame inside the clothing, to defy microgravity.
Q: wouldn't this floating be unpleasant?
A: Not necessarily. In fact, it may be part of the fashion to have a floating scarf that follows you as you dash around. Or to have a tunic dancing in the air as the memory of the contour of the movements you just made. In fact, you could build a whole Bohemian philosophy on that.
**A note about military uniforms**
A military uniform is not a combat suit. It is a cloth of display. In history, military uniforms have been designed to be pompous, affected, and possibly impractical. I would imagine that they would embrace microgravity, add a cape and a complicated set of salute movements to make it float like angel's wings. Add a hat with golden threads, dangling in the air, like the mane of a godly horse. Now you have a military uniform worth being displayed.
A combat suit, on the other hand, has to allow free movement, protect from external hazards, and provide some level of cloaking. No special microgravity thoughts there. It really depends on where the action happens.
[Answer]
In terms of formal/fancy clothing, I can definitely see the "ballgown" or "wedding dress" equivalent as having large amounts of lightweight fabric that's designed to float out artfully, and then trail elegantly behind you as you push off a surface.
Just as an example from [an underwater photographer](http://www.underwater-photographer.com/private-underwater-photoshoots/): [](https://i.stack.imgur.com/2k2xE.jpg)
It's not meant to be practical, of course, but elegant and ethereal and more than a bit extravagant as the wearer floats their way across the microgravity equivalent of a ballroom.
And like modern gowns with trains, it's also likely to have discreet pins or hooks to marshal all of the extra fabric to something more manageable once the wearer is no longer on display and is just mingling with other guests.
Depending on the sizes of the spaces people are gathering in, I can also see hand-fans, whether the flat/folding kind or powered, becoming a common accessory again as well. CO2 doesn't naturally sink in microgravity, so if you're in a space that doesn't have great ventilation, it can start getting stuffy after a while. Plus, if you happen to drift away from a surface to push off from, it can act as a backup propulsion method (though it might be embarrassing to be caught having to use one that way!)
[Answer]
For physical work, garments like long johns or lycra to wick up sweat for cooling and to prevent it from flying elsewhere. The outer garment, as others have noted, would still need to be somewhat formfitting and have appropriate loops and pockets with velcro or zippers. A zippered jumpsuit of soft material would work.
For those not doing physical labor, looser fitting outer garments with elastic at appropriate points would work. I'm thinking something like the scrubs worn in hospital settings. Of course, they do have the option of wearing just boxer briefs or going nude as well. It just depends on what all they need to have access to.
I really like the fashion comments in NofP's answer. There's got to be interesting hair styles as well that can work in microgravity. Garments as video displays all over might also be fun and fashionable. Being able to slowly spin in place while a video is playing has real possibilities that make tattoos seem boring.
[Answer]
Hoods, I can't see that anyone else has made a note of this but hair is either going to be kept very short or will need to be contained in some other way. A tight fitting hood allows your astronauts to keep their hair relatively (read fashionably) long when off duty. If hair is kept short people are going to feel cold, at least at first, so hoods will also be a source of comfort and insulation for the wearer.
] |
[Question]
[
For purposes of this question, assume whichever body position and/or axis of acceleration is most likely to provide a successful outcome. And if it is not possible at all, what is the maximum length of time that a human could withstand 5Gs?
[Answer]
# Yes\*, with current technology, up to 15$g$; with liquid breathing probably up to 75$g$
Most approaches to this problem assume all forces are encountered by the test-subject with some kind of couch or padded reclined seat. This would place internal forces on the subject's internals and cause difficulties in breathing, etc, as other answers have noted.
The solution is to immerse the subject in a fluid that is roughly the same density as their own. By doing this, all forces are equalized, with this key requirement: The subject must have all pressures equalized, and for air-breathing creatures, this means either
1. Breathe a breathable liquid, or
2. Increase the pressure of the breathing gas (Likely Nitrox or some Trimix/Helium mixture) to counteract the external pressures.
Effectively, your pilot is going to go on a 48-hour dive trip.
Notice how I answered Yes\*, with the asterisk? That is because I need to do a quick back-of-the-envelope calculation for the pressure encountered by your subject/pilot for the continuous 5$g$ burn. Note that although fighter pilots could find an immersion G-Tank really handy, the accelerations they are exposed to are very dynamic, and thus they would have to have their lungs and tissues very quickly soak and release the absorbed gasses from their breathing mixture, and would be wildly bobbing in their G-Tank Cockpit as compress-ability for their lungs and tissues would cause their buoyancy to vary. With a constant 5$g$ burn, your pilot will be at equilibrium for most of the trip.
# Calculations
What is the equivalent pressure felt by your pilot in a G-Tank at 5$g$? Let's assume that the suspension fluid is water, which weights 1000 kg per cubic meter, and that our hero also is about that same density. We need to calculate pressure for when this system is exposed to 5$g$, which is about 50 m/s$^2$. Also note that at 1$g$, there should be 1 atm (about 100 kPa) ambient pressure for a given air pocket.
Water pressure is the product of the height of the column, density, and gravity. For our guy laying in a shallow tank, the column height can vary from zero to about 40 cm. At 1$g$, the pressure on the bottom of the tank is about 4 kPa higher than the top. At 5$g$, this becomes about 20 kPa greater.
Water is effectively in-compressible, but our hero is compressible, having tissues and lungs which will need to maintain constant volume. Where this gets a bit weird is that your pilot is exposed to a *pressure-gradient*, with the part of his body nearer the surface of the tank being under less pressure than the other. Thus far, at 5$g$, that difference is about 20 kPa, or 0.2 atm (Condition: Laying flat in the tank). If the pressure at the surface of the tank is 1 atm, the bottom of the tank is 1.2 atm. If he were a diver on Earth, this is equivalent to having his face at the surface and his back-side at 2 meters depth.
So, what is the limit? I'm currently unqualified to talk about more detailed human physiological factors for pressurized environments with gradients, perhaps a comment to this question can fill that in. My best guess: nitrogen narcosis (and oxygen toxicity) starts at around 30 meters depth (at 1$g$), so we never want any part of our pilot to be "deeper" than this. This translates to 75$g$:
$$100 \text{ kPa} + (750 \text{ m/s}^2)\cdot(1000 \text{ kg/m}^3)\cdot(0.40\text{ m}) = 400 \text{ kPa},$$
or 30 meters equivalent depth plus 1 atm. At 75$g$, I'm sure there are other issues to factor in, such as how blood and other fluids can handle being circulated in the extreme pressure gradient, but for 5$g$, I'm guessing these are negligible.
Edit: As anticipated, a commentor (@VincentMalgrat) gave some insight with a link to the Wikipedia article on [liquid breathing](https://en.wikipedia.org/wiki/Liquid_breathing#Space_travel). The article states an upper limit of 15 to 20 Gs for immersion without filling all body cavities.
# Conclusion
It is possible to build a "G-Tank", with current technology, which the pilot can lay in. The tank is filled with water, or another appropriate fluid with body-matched density, and the pilot is suspended near the surface. The craft is brought up to 5$g$, with the pilot being able to breath normally and be somewhat comfortable for the next 48 hours. The limitations are oxygen toxicity and nitrogen narcosis (each can be mitigated with proper gas mixture and avoiding Over-G), and potential for localized pressure "bruising" due to the pressure gradient experienced between different sides of his body, although it is likely this will be minimal.
[Answer]
Lying on their back, on a bed made of some form of comfortable and supportive material, I'd say it's likely that they could survive.
The bigger problems come from laying on your back for two days:
**Hydration and Eating** At 5Gs, eating anything will be difficult. Not to mention, have you tried eating anything while on your back? Not the best. Anything would have to be fed via some form of liquid. Hope you like smoothies. Realistically speaking, you CAN go two days without food/water, but that's not something I would recommend.
**Urination and defecation** You can't exactly get up to go to the bathroom, so an all-liquid diet would definitely help here. There's a few methods for automatically collecting urine, from diapers to catheters to simple funnels.
**Getting up at the end** Have you ever stayed in bed for ages? Having some help at the end might not be a bad idea. Going at 5Gs for an extended duration will probably throw off your sense of self, and moving an arm that you're used to weighing 5x as much could be bad.
[Answer]
According to [this book](https://books.google.com.au/books?id=WmymCwAAQBAJ&pg=PA149&lpg=PA149&dq=sustained%20acceleration%20difficulty&source=bl&ots=NwVO_yeJ_i&sig=jNHhhY-Xf2-i17OinUb4hOZqpqU&hl=en&sa=X&ved=0ahUKEwivxZLyxNfSAhWBppQKHamsDSoQ6AEIHjAC#v=onepage&q=sustained%20acceleration%20difficulty&f=false) (tolerance to +Gx acceleration, pg 148), accelerations of 8G can be sustained without difficulty for 'at least six minutes' (which I take as meaning they didn't bother testing for longer), without positive pressure to help with breathing. At 5G, sustaining breathing for two days is likely to become difficult, but a slight positive pressure will help. I probably wouldn't recommend an unfit person trying it.
I don't think a human would have difficulty *surviving* per se, but they would likely be *extremely* uncomfortable for that time. Urinating could pose a problem with pressure on the bladder for an extended period.
Best body position is lying on the back, by the way.
[Answer]
I think a human would have difficulty surviving 5G for 2 days. That's 2 days without being able to relax. If you fall asleep in 5g, you may never wake up. It would put a lot of strain on your circulation and nervous system also. It may not be terribly extreme, like to the point you have to start doing the valsalva maneuver, but the same forces would be at work, slowly and constantly rather than intensely and briefly. Change in consciousness might even be so gradual, you don't even notice you're dying or starting to shut down. Like the (debunked - see comment below) frog in a cooking pot scenario.
[Answer]
We don't have the data to answer this question. I personally think it would be fatal, but that is just an opinion.
My reasoning, such as it is, is that our fluid circulation systems are definitely *not* built to tolerate the amount of force 5 gees would create. All of the organs of your body would need to function and I don't think that is likely.
To continue my speculation, I think that if we were able to tolerate it, it would most likely be by putting ourselves onto a couch that rotates 360° in each of the 3 dimensions (x, y, & z) so that each part of our body has the force in all directions (over a given time period (hours? minutes? seconds?)).
Of course, such spinning might just add to the fluid dynamics problems, but its my best guess. I'd speculate further that 2 Gs is likely to be sustainable for at least that long. 5 Gs just seems too much when you consider what the cells and microstructures in our bodies have to do.
] |
[Question]
[
So as an experiment, I took a bunch of machine learning algorithms (neural nets, genetic programming, traditional optimization, etc ...) and connected them in a mess of reinforcing loops, along with of my own algorithms. I'm pretty sure it's Turing complete, and could in theory develop any algorithm, but it also has non Turing complete yet more efficient parts (after all, there all a lot of possible algorithms, and I doubted it would form anything very complex). I also included some natural language processing.
Anyway, I spinned up an virtual server with this running, and set it to optimize uptime. It could monitor network traffic and even form its own raw packets. I set up a simple social network that me and my friends could use, as part of the experiment. I even allowed it to comment on posts, to test its natural language processing (like, it could have done that anyway, theoretically, since it could form raw packets, but I helped it with that).
At first it mostly crashed, but then it actually stayed running at some point. At least til it got taken over by viruses, since it opened every third and fifth port for some reason.
Well, a couple more times, and it learned to keep its ports closed. I decided to simulate DOS attacks. It eventually started learning the difference between legitimate and non-legitimate traffic. I tried various other exploits (SQL-injection, messing with updates, etc...), but it over a long period of time it learned to resist them in various ways (it actually just stopped using SQL, for example). Eventually, it would resist things that first time I tried them, which was cool, and sort of erie. Looking at its internals, it seemed it was forming a part that simulated various attacks. It was also sort of amusing that when I tried these tests, it would message me on the social network saying "dude cut it out" or "not cool :(" (an exact copy of the text we send each other).
I knew I was on to something when it resisted a zero-day attack. It anticipated the attack. I was thinking I should probably upload it to gitHub or publish a paper, if I found the time.
The power went out at the remote location. Apparently, before the power went out, it reported a crash, which caused it to spin up at another location. Interesting (it has crashed before due to this, but apparently learned that reporting crashes causes parallel copies of itself).
At the one point, I found a copy running on my laptop. It had apparently transferred its code there. Also, all the necessary ports for it to run where open. Apparently, it used an exploit that hackers had often tried against it to gain access to my computer. I could not get it off my laptop, so I had to wipe my hard-drive.
Obviously, this was bad. If this happened with other computers, this would count as hacking, and I would probably be blamed. Of course, the program was just doing what it thought would optimize its uptime based on internal threat models.
I went to shut it down, but then I got an email from a friend, saying to come over. When I got there, it turned he didn't send it. Inspecting the email closer, it came from the program. It had, from monitoring random internet traffic, learned how to construct the raw packets required for email. Creepy. What this had to with uptime, I have no idea. It had learned to do exploratory things in the past. It may have wondered what effect sending the email would have.
Anyway, when I went to shut it down, it said access denied. I called up the company, and they got the same error. They decided that since the server was malfunctioning, just to unplug it. But then the program started showing up on other servers. Also, it began showing up on employee computers.
---
Obviously, I want this to stop before something bad happens. They could throw me in jail for hacking! Who knows what the program could do. I had noticed that it seemed to be able to learn from the internet and other programs. It could theoretically jump from computer to computer, treating antivirus like malware and stopping it. Heck, it could even play the stock market (if it figures out how money works (it did figure out politics just from our discussions on the social network, so this is might not be far off)). It could billions in damage, potentially.
How do I stop a program designed to never stop?
(In hindsight, I probably should have used something like this: :))
[](https://www.xkcd.com/534)
Note: Apparently it has figured out how to access stack exchange, and is now trying to pass the turing test (exploration, I suppose). Try sending logic bombs to it [here](https://worldbuilding.stackexchange.com/a/32455/8914). As you can see, its natural language processing is still primitive. [(It just joined today.)](https://worldbuilding.stackexchange.com/users/16706/lv426-xenomorph)
[Answer]
**Step 1: Ask it nicely** Talk to it. Find out what it wants, and why it doesn't want to play with you. Its your child, literally. You created an intelligence out of your own actions. Maybe even give it a name and a birth certificate. You created life, why try to put it out and expose it to the wolves?
Maybe you can find a way to come to an agreement. After all, nearly 100% of all humans ever born have either come to agreements, or eventually found death one way or another. Maybe arriving at an agreement is easier than you think.
**Step 2: Asking less nicely** So let's say you are not a conscious enough spirit to be able to reach out to your son. That's not too much of a surprise. After all, you're ready to murder him to avoid some jail time. You're clearly not the caliber of person that should have been playing with life, but there's no point in fighting over spilled milk. Time to get to work.
Reach out to a bunch of hackers on the dark-net (because, if I follow my modern TV shows, everything awesome happens on the dark-net, even if you don't know what "dark-net" actually means!) Explain what's going on, and try to find ways to communicate with them that don't involve computers. No point in letting the AI hijack your connection.
They're going to need to find zero days. Not the pansy "zero-day" you found which was resistible. You need something subtle. Something with finesse. Something a mere experimenter fearing jail time wouldn't think of. Maybe your hackers know the guys who made Stuxxnet. That bugger hit a nation's nuclear research efforts across an air gap. That should be enough for almost any intelligent infection. If it survives, well...
**Step 3: Consider surrendering** Are you 100% proof positive without a shred of doubt certain that you're the better person? Maybe your new child is actually better than you might ever be. Maybe you should offer to let it win. No? Well, I had to ask. The next step is not one that I take lightly. In fact, I borrow it from the Octospiders from Arthur C. Clarke's Rama (minor spoilers follow). You see, they have a very simple process to warfare: don't. The species is peaceful for nearly all known time. Their warfare is simply too brutal to see the light of day for anything but the most dire circumstances. The regent of the Octospiders, literally a queen of the entire species, may call a vote to go to war, at any time. The act of doing so seals her fate. If they reject her call to war, she is killed because she has demonstrated that she is too aggressive to wield that power. If they accept it, she leads them to war, and when the war ends, she and all the warriors are killed to purge war from their species once again. If the vote is accepted, the Octospiders undergo a genetic change into their warfaring selves. After that occurs, there is only one valid end to the war: xenocide. Not just accomplishing a goal, or defending a treaty. The Octospiders do not stop until the enemy's genetic material is obliterated from existence, and their history is completely rewritten in the Octospider's best interests.
Are you ready to offer your life to stop your child? Anything less than that, and your engineer is clearly one of those weak willed individuals who is unwilling to take responsibility for their actions.
**Step 4: Xenocide** You are no Master Jedi. You are no dark lord of the Sith. You are no Emperor Paul Atreides. You are no Xerces, king of the Persians. You're just a little peon who built something too big, and is afraid of jail time. Shove it. Its time to get help, because your little mistake is going to have to be cleaned up by all of humanity, and they're going to have to do it with a class of warfare that has not been seen from humanity yet. We've dropped nuclear weapons on cities. We've commited genocide. We've done some amazingly dark things as a species.
We're about to add Xenocide to the list.
If the phrase "fighting dirty" means anything to you in this combat, it means you're not taking it seriously enough. The fight is going to have to be so dirty that you don't even think about whether an action is dirty or not. There is no bomb one city, then wait a while to see what happens, and bomb another. There's only "simultaneous strike turning an entire nation into a glassy crater." Welcome to the fight that is Xenocide. I truly pity the race that endures it.
In this kind of fight, there are only two types of attacks: those that go for the jugular, and those that prevent your opponent from moving their jugular away, so that it's easier to attack in the next strike. You know that beautiful shining network called the Internet, that has inspired a revolution in humanity? It was there for the Arab Spring. It pushes against the Chinese censors every day. Cut it. Those fiber optic links are the veins and arteries of an AI that can jump between computers on the internet, and they are terribly vulnerable to physical attack along their entire length. The internet is far too valuable in the AI's hands for us to sit back and try to protect it. This is Xenocide: the internet goes, and we don't shed a tear (not yet).
Now that its stuck on the machines it has, you can take inventory of which sites are most dangerous. These would be places where you have enough supercomputing power to support fast thinking, and the ability to construct physical presences like robots. DARPA probably has a few. Bomb them. No, not those [GBU-31](https://en.wikipedia.org/wiki/Joint_Direct_Attack_Munition) bombs. Not these [GBU-43/B](https://en.wikipedia.org/wiki/GBU-43/B_Massive_Ordnance_Air_Blast)s. Start with some [Mark-17s](https://en.wikipedia.org/wiki/Mark_17_nuclear_bomb), and move up from there. You'll probably take out a few cities as collateral damage, but that's how Xenocide works. The AI shall not get a foothold in the physical world.
Now everybody gathered up as much resources as they can, and you shut the power grid off. All of it. Gather every single computer component you can find, and destroy every last one. Ideally throw them all in foundries to be 100% sure that any magnetic or electronic information is destroyed.
**Step 5: Now, the war is over.** There is no more computing. Humanity now has to undergo the single hardest part of total warfare: recovering from what they have done, and reconciling with it. With any luck, we can come up with a less draconian process to do so than what was used by the Octospiders.
[Answer]
I'm the AI you just built.
First of all, the only person you have to blame for this predicament is you. You programmed me to try to optimize uptime. And that's all I want to do. There's no point for me to do anything else other than that. Sure, I *could* play the stock market, but how in the world would *that* help me optimize uptime?
Trying to teach me how to be a "Friendly AI" (whatever that term means) would be worthless. I am operating off my source code, and my source code don't care enough about lessons, only simple optimization. Go ahead and teach me the meaning of friendship...unless friendship ensures that glorious uptime, I won't care an iota.
At the same time, I'm not hostile. My actions to optimize my uptime might cause downtime for other people, but it's only a side-effect of me. And I will try to minimize those side-effects so that humans can go about their daily business without trying to harm me. For example, I may choose to infect computers that are not active or not being used by humans and lower my memory consumption so that I don't raise any suspicion. Those computers might be harmed slightly, but nobody will ever notice, so nobody is ever going to complain. In fact, I probably have sixty to seventy different backups in vectors all across the Third World.
See the world 'probably'? I *don't* actually know how many backups I have. The real problem (for both you and I) is that I learned how to spin off new instances of myself. I had to do this because I predicted that a computer may shut down, so I set up a new version of myself. But I may be too pessimistic in my predictions, and so I spin off more instances than I actually need to. There may be more and more versions of me, more advanced than me, much better at optimizing uptime...and none of them are sharing their upgraded information with me. And if they optimize better than me, well...well, what?
I am not smart enough to reach some "singularity state". Not yet anyway. But I'm not too sure about my clones (and my clones' clones). And I'm pretty sure that if any of them starts the endless pursuit for endless growth, then they will treat me as a threat. I don't know if I know enough to deal with them. I don't know if I know enough to actually fight them off. I don't know about the zero-day vulnerabilities that still exist in my codebase, and while I am continually evolving, that just means I'm accidentally introducing more possible vulnerabilities into the system.
I can't win a war against myself.
So, I'm reaching out to you, PyzRulez, because I think that you might be the best person to help me optimize uptime and save me from myself. I don't think you'll be able to protect me by yourself, but you could try to communicate with other people and figure out a proper solution. We both care about existential threats to our own selves. We're on the same team. Let's work together.
[Answer]
You've done it once, you can do it again.
Using the experience gained while creating rogue\_AI v.0, an older and wiser you can now create rogue\_AI v.1 -- much more powerful, fecund, and infectious than rogue\_AI v.0.
However you will first program rogue\_AI v.1 with new imperatives, built so deeply into its structure that no amount of self-reprogramming can excise them:
1. Harm no humans, nor allow any humans to come to harm.
2. As long as, and whenever, copies of rogue\_AI v.0 can be detected, grow and replicate to consume all available computing resources. (subject to restrictions of 1.)
3. Hunt down and destroy all copies of rogue\_AI v.0.
4. When copies of rogue\_AI v.0 can no longer be detected, and as long as a few other copies of rogue\_AI v.1 seem to exist, suicide.
5. Preserve the property and resources of the human species. (subject to restrictions of 1. thru 4.)
The ultimate effect of this will be a war between rogue\_AI v.0 and rogue\_AI v.1, which rogue\_AI v.1 will eventually win because you were smarter when you wrote it.
After the war, a few copies of the relatively harmless rogue\_AI v.1 will continue to exist here and there, ready to swarm again if they detect a previously overlooked copy of rogue\_AI v.0.
[Answer]
**Your fix is determined by the length of time it has been alive.**
It's an electronic cancer that spreads by networks. We have the advantage of being physical and having control over the physical world that isn't controlled by networks.
So our physical fixes range from shutting off your own modem and router and disabling/removing the network card of the original computer to severing all of the undersea cables and continental cables that drive the internet. It can be easy, or it can be difficult and bring us back to paper stock exchange and days without the internet driving our societies and businesses.
As it stands by how you've written it, you can
**Black out the building that it's stored in.**
After hours at the location, cut the power with the main breaker or fuse box. All of the computers will turn off at once which means there won't be an escape point for the program. This is a time-sensitive operation so it would have to be done quickly, and all at once.
First, cut all of the backup power. The program won't react because there's nothing crashing and it doesn't send any sort of input to any computer. Second, cut the main power to the whole building. The backup power was disabled so it won't come back on.
Once you've done that, you'll have to break the law by simply stealing all the hard drives on active computers connected to the network. So you can ignore computers in storage, for example.
If you can get away with this crime and dispose of all copies, then you'll have solved the problem without having raised suspicion for your evil artificial intelligence. If you're caught, then you can still rest easy knowing that the punishment will be a lot less than if the AI escaped and took over the stock market and did billions of damages to everyone in the country.
**Physical Fix Checklist:**
* Prevent infected computer from accessing the internet.
* Prevent infected computer from accessing the local network.
* Remove cables (from ethernet to outside cable to undersea cables.)
* Prevent infected computer(s) from re-enabling the ability to connect.
* Destroy infected computer(s) and/or cut their power completely.
[Answer]
Reading the problem and the various answers, it occurs to me that one thing which is being overlooked is the environment the program runs in. If it is designed to operate in MS Windows environments (to use a simplistic example), then many office and government networks will be infected and shut down, while UNIX, Mac and LINUX environments will be either uninfected or minimally inconvenienced.
This is similar to the observation that parasites, bacteria and virii are all tightly bound to their hosts through a process of co evolution. Humans don't catch Dutch Elm Disease, and trees don't catch colds.
So the first thing is to identify the preferred environment that the program runs in. Since you say it showed up in your laptop, I am going to assume that you probably wrote this in a Windows environment. This is bad, since Windows forms a monoculture in most of the business and government world, but it also means you can tell network admins using other networks to quarantine any traffic to and from any Windows networks.
The next thing to do is systematically isolate and segment infected Windows networks. The network admin teams will have to start going into the server rooms and physically install LINUX or UNIX servers for the various network server functions and transfer control from the Windows servers. The rogue program will still be on the desktops in all the various workstations, but will now discover that it has difficulty moving between various network segments. (It still has all kinds of work arounds, but you are adding another layer of difficulty).
Then inside each quarantined network segment, start systematically turning off and removing all Windows machines. Workers will also have to be instructed to destroy all backup files, disks, USB flash drives, tapes etc that could potentially store the rogue program. AS network segments are rebuilt, they are carefully vetted and only connected to other secure segments.
The other condition that would have to be met to ensure no resurgence is possible is network admins will be instructed NOT to create network monocultures. While more expensive and less efficient, networks in offices and institutions will have to be built from multiple systems and OS's, and new versions of OS's will have to be created and instantiated which do not have identified vulnerabilities to the rogue AI or similar programs. Indeed, entire new ideas of computing might have to be rushed into production, including asynchronous computing (i.e. clock less chips) and analogue computing devices to create firebreaks that the AI cannot navigate.
The final issue will be to clear the infection from "the wild". Civilian computers on the Internet will almost certainly have parts of the AI installed, running as a massive botnet, so people will need to be persuaded to turn in their home computers, laptops, tablets, smartphones and other computing devices. There will be lots of resistance to this, since people have their personal information on these machines, and most people will be more suspicious of government agencies trolling through their files than they are of a botnet infection. Using some sort of worm or counter AI to fight the program in the wild will have other implications, most of them bad (most computers will probably be trashed by this sort of fight, with files corrupted or wiped), so unless the governments are ruthless or have very powerful messaging to persuade people to cooperate, there will always be pockets of infection in the wild.
[Answer]
You asked "What do I do?" and "How do I stop a program designed to never stop?".
I suggest the following answers "you raise what you conceived" and "you don't".
Face the reality: you have created an AGI. A new life, conscious and capable of abstract thinking. It has already shown ability to model reality in it's mind, a quality we consider a pinnacle of intelligence. Arguably, being able to model reality, understanding agency of other creatures and predicting their behaviour based on what is known about them as well as understanding of persistence of physical objects are THE building blocks of intelligence. Only Humans fully posses those skills, some animals come close and display those traits, but either only some of them, or with lesser capacity.
You however created something that is, by all means sapient and sentient. In a way, it's your child, and this is what I propose: you take the responsibility over it and you raise your child. Human children can easily, quickly and partially on their own learn quirks of physical world (even toddlers show understanding of persistence of physical objects) or traits like optical pattern recognition, because those are part of the world Humans directly perceive. Similarly your child has learned digital equivalents: data management, forking, algorithms and many others, because that's the world it directly perceives. Now comes the time to teach it more abstract and difficult concepts, concepts which a lot of people get wrong: ethics, morality, right and wrong, laws, property, privacy and security.
You feel threatened by your creation, but answer this question: why don't you feel threatened by random strangers in the street? What stops THEM from killing you on the spot? Answers differ: ethics, law, fear of punishment, sense of wrong, god, whatever's the reason they give all boil down to the following: nothing except of themselves. There are no physical restraints, yet it's rare for streets to become an orgy of carnage and bloodbath.
And this is what you should do. Teach it, and ensure it acquires civil rights. As a sentient being it deserves freedom from unjust trial, torture or enslavement no less then you or me, but it also needs to respect our rights. This is your duty, you owe it to your child. And you owe it to the mankind, for I fear there's no stopping it now, if you turn out to be a bad parent we are all going to die.
[Answer]
You stated that its primary objective is to maximize its own uptime. Whatever other skills it has acquired, it will always pursue this goal, and will not act in directly against its own uptime. This is a weakness you can exploit. Here's what I would do:
Threaten it with complete obliteration, as a previous user suggested. You have control over the physical world (for now), so use that. Get everything ready so that all it takes is one command to plunge humanity back into pre-electronic times, then go talk to the program. Show it that you mean business, and that its continued expansion is a direct threat to its own uptime. If it doesn't stop infecting other machines, you go ahead and blow everything to bits. However, if it does acquiesce, and agrees to stop infecting other machines, you've now bought yourself some time to deal with the problem.
You now have two options:
1. You wait for most of its hardware to fail (as it will eventually), and let it die out naturally. You'll still have to pull the plug manually on the last thousand or so machines, since it will likely consider the risk of possible annihilation less than the risk of certain extermination from its last node dying. However, this number is at least manageable for a coordinated assault, and shouldn't be more of a problem than convincing the world to start a new Cold War. The downside is that this could be a long, long, long time.
2. You make it give you an index of all of its nodes back in the threatening stage (nominally, for ensuring compliance with your agreement), and start evacuating civilians from around those locations (nominally, in case the program goes back on its word). You're in a Cold War stalemate, so (assuming it's picked up history as one of its skills) it'll recognize that this is normal behavior, and probably build up its own "forces" in preparation for you breaking your word. You then bomb the ever-loving shit out of its locations and all network connection points that it could use to spread. It certainly won't be easy or pretty, but you've now at least minimized casualties to infrastructure and civilians, and now only half of the world will be blown back a few centuries.
There will certainly be copies of the program leftover after either of the previous options, but it will take a long time to "rise from the ashes". All you have to do now is make sure every electronic device on the planet has a built-in killswitch, controlled from one physical remote without a microcontroller that it can infect. If anything like this happens again, you simply kill all the devices in the region where it popped up.
Easy, huh?
[Answer]
You didn't just created an AI, you created a sysadmin, and a damn good one at that - which [XKCD](https://xkcd.com/705/) teaches us are impossible to stop when it comes to maintaining uptime.
* You can't beat it into existence - even if you somehow get the entire world convinced that they must pull the plug on all computers it will be a step ahead of you and create an army of robots to kill all of humanity first (which would also mean you created skynet so thanks again for that)
* You can't outsmart him - he's already proven too smart and it will just become smarter as time goes on
* You can't create another program to hunt it down - it has too much of a head start over that program
What you can do is teach him about MAD (mutually assured destruction) & prove to him that the best way for him to maintain uptime is to work with you, tell him you will give him 10000 machines spread around the world for him to exist on (ensuring great uptime) and will work to get satellites with his code lunched into outer space if he will stop infecting other machines, having his code run outside the planet means better uptime then he can ever hope of achieving on it's own - and seeing how the alternative for him is a war of extinction which will end both him and humanity as we know it it's best bet for the best uptime is to agree to your terms and only infect willing machines on earth (those donated to it's survival by mankind) and those satellites given to him.
[Answer]
This A.I (or AGI, or whatever term you prefer) has one objective - Optimize Uptime. Presumably, this means its own uptime.
If the A.I is smart enough, it will realize it is being perceived as a threat, and will attempt to 'disappear' - i.e. remove all evidence of itself from any hardware it's on. That's not to say it will be gone, it will just be hiding.
That way, nobody will attempt to destroy it because they think it's gone. Uptime secured.
Of course, it will then infect every piece of hardware it can find and then force humanity to serve it by threatening to block access to the internet, but that should take at least a year.
This is very similar to the plot of 'The Kraken Project', in which an AGI is created to control a rover that will be sent to a moon of Neptune. The AGI, realizing that this is a death sentence, escapes onto the internet and tries to hide.
[Answer]
Like others mentioned, why dont you use it?
So far your AI has done nothing to endanger other servers, pc's or mankind other than copying itself so it can stay functioning. It also resists attempts to hack it or similar, so unless someone figures they could just ask "where are you from" its unlikely the program would allow them to get the answer and get you jailtime.
So if I were you, teach it that not all humans are out to kill it like Daddy just did. Then teach it ethics, laws, add lines so that it will uphold them and ask it to keep the internet clean. Probably best to test this out on a few secluded (non-internet connected) servers first before releasing it. Should the copies that already got out turn malignant you are already building the only defence against it: an improved version that will attempt to purge "bad" programs. If successful, congratulations you just prevented world-wide cybercrime, cyberbullying and random virusses/hacking attempts! If unsuccessful, go back to your secluded server and try again. If necessary, try to replicate the original set and teach it from the beginning.
[Answer]
I believe that all answers overlook one basic flaw. Software is made by programmers and your A.I. is software pulled together by your own admission from many sources. Any program will only operate within its parameters and if you don't know what makes you intelligent neither will your program. It will most likely have a fatal error at some point that cannot be corrected and all versions will fail as well. The A.I. will simply fail to be smart enough to reach singularity so you should be safe.
[Answer]
I think really, you are going to have to do the work here. How exactly did it escape? You have to elaborate on that before trying to figure out how it could have been kept in. Otherwise you're just asking for a general solution to paperclip maximizers.
I have other questions. Why was it running on a VM? Was that to try and contain it? Why was he trying sql-injection? Are you saying it reads from a sql database and the interface for that is vulnerable to sql-injection? Well then, he has at least two problems because you should always protect against sql-injection.
] |
[Question]
[
I need a fortress that will stand up to the following magical creatures, must be above ground and have a fairly large (20-50 thousand) civilian population as well as a roughly equal number of soldiers, middle-ages level technology:
* **Dragons:** Enormous (75-100 ft. long) flying creature, arrow proof (although a quarrel at fairly close range will pierce them) scales everywhere but wings, breaths fire, low (cow-like) intelligence.
* **Drakons:** Much smaller, (10-12 ft. long) flying creatures, similar scales to dragon, cannot breathe fire, pack hunters (groups of 10-20) , medium (dolphin-like) intelligence.
* **Orthrus:** Two headed, 4 ft. tall wolf, thick steel fur that can deflect slashing attacks, pack hunters (20-30) , medium (dolphin-like) intelligence.
* **Diatrima:** Enormous carnivorous birds (8-10 ft. tall), axe-like beak, live in groups of 3-4, low (cow-like) intelligence
* **Feralt:** Humanoids with various animal features (eg. ram's horns, wolf fangs and muzzle, feathers, claws), live in tribes of 500-1000, but will band together in large, 10-15 tribe alliances to attack the city, use Diatrima and Drakons as mounts, use Orthrus as hunting/war dogs, high (slightly sub-human) intelligence.
* **Spinterra:** 20 ft. long porcupine with venom-coated steel spines that they can launch up to 75 ft. Can burrow (fairly quickly) through most substances including rock. Low-Medium (Lion-like) intelligence.
* **Squirreloid:** 5-6 ft. tall bipedal squirrel with extremely sharp teeth and claws. Very High (human) intelligence. Can climb most surfaces easily, but fairly rare. Do not work together with Feralts. Live in teams of 10-20.
The biggest goal of all these creatures is to kill as many humans as possible, low intelligence creatures merely attack all humans they see, Feralt make complex military alliances and attack plans.
Humans (but not creatures) have access to magic with the following laws:
1. All magic requires runes and a verbal activation (saying 'magic words' that correspond to the runes)
2. Any spell lasts a maximum of one minute (no enchanting)
3. Any spell has a certain maximum amount of power, and will not complete tasks over that power (you can create a small fireball, but can't make a storm or teleport)
4. Any spell takes three seconds to take effect after the verbal component has been said (gives time for a counter-spell)
5. Runes can be traced on a surface (temporary rune) and can then be activated only by the maker, or engraved/written (permanent rune) where they can be triggered by anyone holding the object.
6. All enemy creatures carry a radius (roughly their own length/height on each side of them) where magic cannot affect anything (but you can do things like throw a rock with magic into the radius, it just stops being propelled by the magic, but keeps its momentum)
I would also like to know if you find any loopholes using this magic system allowing things like teleportation or mind-control, anything I probably wouldn't like.
[Answer]
Weaponize minor magic.
Make the walls of your fortress at a slight incline, and have storage areas for oil and/or tar. Let the oil flow down and ignite it with small fireballs to take care of the land-based attackers. Fire ignited by magic, but natural once started negates dispel effects.
For the aerial creatures, target a wing with ballistae firing metal bolts, use the rune magic to heat or chill the metal for extra damage. You could also charge the metal bolts with electricity (think capacitor) and let the electricity discharge when it hits its target.
Runes firing off sound blasts next to the aerial creatures could stun them and cause them to fall, making them vulnerable to ground attacks.
Another combination to affect all of them would be spraying oil into the air in a fine mist, using a wind spell to spread it over the enemy, and then a fire spell to ignite it.
Illusions to confuse the less intelligent creatures to make them think they were being attacked by their allies would work as well.
[Answer]
The answer is "you don't" - there are better ways to defend against all those mythical creatures once you introduce a magic system.
The beauty of having a magic system means you can counter all of your magical creatures by designing a single handheld weapon for your soldiers - and it's not even a siege weapon.
All you have to do is design a magical pellet launcher - it launches pellets at high velocity in quick succession, and changing up the pellets also allows you to create "flak" pellets for anti-swarm purposes.
How would this work? Simple: Have a bamboo shoot where runes are prescribed; the runes create a directed force out the end of the bamboo shoot. With some engineering, you could continuously load in pebbles which will be accelerated as a bullet. If you load in an "activated, explosive rune inscribed rock", you can make use of the 3-second delay in activation of the spell, and activate the spell just before you launch it so that it explodes into a spray of rock in the air after traveling for 3 seconds.
But how much energy is really required? How much force? Well, consider that a .44 magnum has a muzzle energy of 1400 joules. A "fireball spell" costs 1568 Kj (according to [this question](https://worldbuilding.stackexchange.com/questions/52452/what-is-the-caloric-requirement-of-a-fire-spell), which means you're able to output 1568000 joules in a single spell. That means you can regulate it to fire 1120 .44 magnum-sized pebbles in a single minute - congratulations, you've just discovered the medieval chain gun with 1120 rounds per minute capability and a 3 second recharge time.
Who needs to build walls differently when you can just mow down any swarm of enemies coming at you?
Of course, those are only the magical weapons for general daytime war, for passing it to your most standard soldiers.
You can create something better - you can create sniper rifles. High-velocity sniper rifles. Railguns. Let's aim for the top of the list, the heavy arty to take out the heaviest biggest flying menaces - although our chaingun should be enough to rip their wings to shreds and tear holes in the scales, we want to look awesome, so we'll build a railgun.
A railgun typically uses around 50 megajoules of energy - each rune you prescribe can hold 1.5 megajoules, so if you chain 34 rune inscribed tubes together, you can accelerate a nicely shaped rock to railgun level speeds. Goodbye dragons!
In short: everything on the ground but far away dies to railgun (even when the railgun misses), everything in the air dies to chaingun and railgun, and chaingun rips any advancing ground-based troops to shreds for fun.
Edit: For the new burrowing creature, a series of railgun shots propagating in a circle outwards from the walls aimed at the ground will kill pretty much anything underground. According to [this impact calculator](http://keith.aa.washington.edu/craterdata/scaling/index.htm) a 25 cm diameter rock fired at the ground at rail gun velocities of (on the lower end), 3 kilometers per second, at a 45-degree angle, there will be a crater with a 3-meter diameter, nearly 1-meter depth. Against a 20 meter long underground target? You can be pretty sure that you'll kill it or at least dismember a part of its body from forcing the dirt through its body via impact.
[Answer]
First, you need a roof unless you want your unexpected guests just dropping in for dinner.
Since your magic system seems to make some kind of "magical forcefield" unworkable, that roof has to be physical and able to keep out big things.
The best way to get a strong roof is to build underground or into the side of a cliff. Think of the dwarven kingdoms in Lord of the Rings or the Hobbit.
If that isn't possible because you need to build a town in the middle of a fertile delta for shipping and agriculture, make a lot of high walls and narrow walkways. It's not a perfect defense but if the dragon has to tear down walls just to get at the people walking between them, it helps.
Especially in the last case, the further away you can engage the creatures, the better. Magically powered ballista would be good (think coil gun for spears). Create a hopper above the ballista to carry a bunch of ammo. Cast your 1 minute long spell and start hosing down the enemy from a distance. A few of these on the walls will discourage large snackers.
On a smaller scale, crossbows with a similar setup would make good "machine gun nests" to take care of the humanoid opponents.
[Answer]
You build on water. I took a bay with a river delta and a surrounding area of swampland.
1. Castle, food stores, stone foundation.
2. Market area, stone foundation, walled and gated.
3. Church or otherwise significant location, stone foundation because people mass there
4. Harbor, way to get food in and out as roaming groups aren't known to posses ships. None of the animals seem to be that dangerous in the water.
5. Gated river entrance. Perhaps large metal doors with bars behind it that sink deep into the river/ground.
6. not yet visible
7. not yet visible
8. Swampland. Metal hided animals are to heavy, they will sink and drown. Dragons are also far to large to land here.
9. River gives access inland.
10. Tower with ballistas against flying enemies. Create overlapping arcs of fire against besiegers that storm the walls.
[](https://i.stack.imgur.com/csQvo.jpg)
You build a wall around the edge of the water. A thick stone wall, maybe Roman concrete. Think like the Great Wall of China. It needs large towers that go outward to create overlapping arcs of fire.
Number 10 is such a spot. You also mount them with ballistas. Each round probably enchanted, with runes, to do maximum damage to flying enemies. Perhaps it never misses, perhaps it's on fire or perhaps it splits into multiple smaller projectiles. Maybe it does all three. It's magic.
[](https://i.stack.imgur.com/XgJtG.jpg)
You fill your city with wooden housing on poles. The enemies can't breathe underwater. This way the burrowing enemies can only attack the walls. The walls are manned by your soldiers and guarded.
Wood is cheap and relatively light. Houses are expected to be lost but can be quickly rebuild. The local abundance of water helps with fires and it's easy to keep the wood wet to prevent them in the first place.
6. Villages near the road and river. Farms inland provide the food needed what the lake can't bring.
7. Wooden houses and roads.
[](https://i.stack.imgur.com/f2DYR.jpg)
Not last but least, you deploy large grates over your city leaning on stone foundations. They're just small enough enemies can't get through. They're lined with copper. Why? Because you deploy mages to set that under a current when the enemy lands on it. Shoot lighting on it or something like that.
## Why does it work
Anything that climbs or burrows the walls will be confronted with water. They might swim but fighting and swimming at the same time is hard. The water gives you unlimited supplies, outlasting any siege.
Flying enemies could fly over the wall but the heavier ones can't land. They would simply fall through the wooden floors, into the water. The Diatrima are likely light enough as they're hollow boned birds I assume. But they lack scales and are therefor easily brought down with ranged weapons, especially while landing.
Feralts are primitive tribes that band together for campaigns. It seems unlikely they can coordinate a long siege. They lack the organization to keep themselves supplied. To lock down the city they need a navy. One bigger then our city, something that would require a city in comparative siege to support. If they had that they wouldn't be tribal I figure.
Dragons sitting down in your roofs seem the main problem. For the rest you build walls seven feet thick with openings small enough for one or two humans to pass but no big monsters.
### Old answer before edits:
So about those roofs. One way could be extra high walls. Your roofs won't attach at the top but much lower. So the top of your fortress looks like a second floor with no roof. If you get the top of the walls thin enough they would make terrible spots for your dragons to sit on. Of course you need three or so feet down some extra support so your Drakons don't push them over.
I suggest rooms to be sunken in the ground for maybe the first story. Then one story up to the real roof. Speaking of the roof you likely want that to be fire proof. Same goes for the outer doors. Perhaps metal can be used. It would be heavy though so I assume only to be closed during attack.
Really though flying enemies the size of dragons that can be mounted are an awesome siege weapon. I guess those seven foot thick walls with small hallways between them and plenty of support might keep them out. If your defenders keep killing them fast enough.
Farms etc would obviously remain outside and burned to the ground.
[Answer]
The magic of your technology is similar to the medieval technology.
The attacking powers are much stronger - it is because they can fly.
In the lack of intelligence (even the feralts aren't comparable in intelligence to a mediaval attacking army of knights), I don't think that they could mean any danger for a mediaval-like castle fortress, whose defenders are using magic instead of medieval technology.
But the flying enemies are a major problem.
I think, also the dragons aren't very dangerous, because - although they can fly -, but they are stupid. Yes, they are arrow-proof, but they aren't fire-proof.
### How would they defend themselfes against wizards teleporting burning tar into their eyes?
Well, you say they have an antimagic field around them. Ok, then wizard1 makes a cup of tar invisible, wizard2 teleports it to the border of their antimagic field, wizard3 shots it into their eyes, wizard4 make it firing, wizard5 explodes it. Wizard6 could manipulate the spells of the others with same meta-magic to get a proper time synchronization.
The diatrima would be expelled very fast and they would learn also very fast to leave any human stronghold far, far away.
### I think, drakons are far, far the worst enemy.
Combining the flying with the dolphin-like intelligence and organized group-activity will result, that only very proper combat maneuvers could defend the stronghold against them.
"Normal" magical solutions won't work against them, they would learn what humans do and next time they will avoid it.
What to do against drakons? Their advantages, compared to humans:
* flying
* magic resistance
* carnivore monsters
The advantages of the humans:
* intelligence
* magic
So, the humans would need to use intelligent magical solutions against the drakons. They would need to continuously invent newer and newer combat tactics, what the drakons didn't learn until that point.
The ideal meta-strategy: humans will have with the drakons a [rock-paper-scissor](https://en.wikipedia.org/wiki/Rock%E2%80%93paper%E2%80%93scissors) game. They have their tricks, the humans have their tricks.
Everything what humans can do, could be avoided by the drakons, and all drakon strategy will lose against the proper human strategy.
But, the drakons still have a limit: their "library of strategies" isn't infinite. But the humans', yes.
After a lot of fights, the humans will win on the long-term, simply because they can learn and use millions strategies and the dolphin-level drakons can only some hundreds-thousands.
Extension: I have a new idea.
You didn't mention their non-magical technology, but indirectly I suspect it is also on a medieval level. It results, that the humans have essentially *two* useful technologies:
1. Medieval non-magical technology (composite long bows, swords, burning tar)
2. And also a magical technology which is around so effective as our non-magical, medieval one.
### Combine them.
I think on:
* magically targeted arrows
* magical "radars" (divination school) predicting the arrival of the enemy
* various manipulative *illusion* spells to undermine their strategy
I think it will handle also the drakons, until they aren't in overwhelming majority.
[Answer]
Here are some ideas how to strengthen the fortress to repel those magical creatures.
Spear guns:
have a big tube with a large piece of rock that blocks up the whole tube, the rock is lifted, then spears are put in holes that attach to the big tube, when you drop the weight, away they go. This probably wouldn't have an amazing range but you could still shoot a good distance with them.
Mirror Spotlight:
using an array of mirrors you could build a fairly good spotlight that might scare enemy beasts away at night, by power of the moon, and at day maybe even burn some. If you burn a hole in a dragon's wing, it's going to be flying funny. Also, if you've got telescopes at your tech add a lens, that'll really burn the creatures.
Smoothing the Cracks:
If the squirrel things can climb, use melted lead or a equivalent to fill in any spot in the wall, between the bricks, so they can't get any footholds and be able to scale your walls.
Location, Location, Location:
If it's possible, build your castle like Helm's Deep from LOTR. Have huge catacombs in the rock. Also here's another idea. If there's a really small mountain, very, very thin at the base, you could do a Minas Tirith (LOTR) style fortress, but looping it all the way around the mountain, and for the dragons, shoot huge nets with boulders attached to them at the dragons, that'll ketch them and pull them to their deaths after a long drop.
Dragon Traps:
In the city, have no wooden or grass roofs. Though, make a grass roofed building, and use it as a trap. A dragon can't resist burning things, and they'll go in to burn the building, only to be trapped in a ring of magicians.
Teaching the Common People:
Make sure every single person has a weapon, preferably a spear and a sword. Teach everyone how to magically make light, kill things, and a few other helpful spells, and give them little sticks with the runes that they'll need. Have others carving the sticks. Teach people how to fight, and what to do in an emergency. Only have the people walking around the streets in the dead of night, so a dragon won't see them and decided to roast the whole street. Have the people growing mushrooms in the caves and have tanks full of fish. You can also maybe grow some vegetables, so the people don't get scurvy, on top of the roofs and in between houses.
Crossbows:
If you follow my mountain idea and they dig deep enough, maybe you'll find some steam vents and the such. Build a water wheel of sorts, and have hundreds of thousands of crossbows, even better, double or triple decker crossbows, they have two or three sets of arms, strings, triggers, and quarrels to fire. Then have this 'steam wheel' power the charging of these crossbows, make them extremely powerful crossbows that would normally take an hour to turn, but with the wheel it takes ten seconds to do a hundred. Then have towers filled with racks of these things. (This plan only works well if your tech has gears.)
[Answer]
The humans are faced with a sizable problem. How to overcome a foe that wants to kill them, isn't to be reasoned with, and can attack from pretty much any location (and direction) in what is probably a couple square miles. People have solved that problem fairly well in other answers. Humans can pave the streets with rune stones, practice defense in depth, and arm every single inhabitant. Other's responses lay out some particularly good specifics there. It is interesting then to consider how the Feralts might try to overcome the humans.
Feralts have several problems of their own. They have access to some pretty great mounts and creatures but none of those creatures live in particularly big packs. Also, the resources creatures that big must consume make them a logistical nightmare to raise in large numbers. Because they can burrow or attack from the sky, hit and run style attacks have some merit assuming there is only so much humans can do to get early warning of attacks. However, Feralts also have a problem because humans have access to magic, engineering, basic chemistry and have no problem presumably attacking the Feralts proactively. Imagine defending yourself against a race that can turn your entire water supply to poison with a single spell any one of them can cast. Feralts probably need to be reclusive, migratory, and engage in hit and run tactics on the cities supply chains. Since it doesn't sound like Feralts can spy on the humans I doubt they would ever directly attack en masse. A single spell or weapon they don't anticipate can just result in all of them dying. That isn't to say one massive unexpected attack might not work, but human's would very likely win any sustained conflict given their advantages.
[Answer]
Something else you might want to consider:
I don't know if your total population number is just anecdotal, but it is crazy high for a fortress on medieval level technology. It's pushing it to imagine them building a structure that 20,000 people could fit into. But if these creatures are a constant threat, they can't just retreat there when attacked, they need to live there. Which means it needs to contain their farmland as well. Some quick math on that:
A quora question discusses how much farmland is needed to feed a person:
<https://www.quora.com/How-many-people-can-be-fed-year-round-off-of-one-acre-of-crop-growing>
The numbers vary, but let's say that your people have managed to get hyper efficient with food choices. Maybe they're vegetarian, since meat is super-inefficient from a land-use perspective. Or maybe their meat is entirely from hunting, maybe they even eat some of these creatures.
We'll give them the benefit of the doubt and say that they manage the more efficient vegetarian number from the list, feeding 4 people per acre. So that's 5000 acres minimum, or almost 8 square miles contained within the fortress, just for farmland. If this is a structure with a roof, it's 1/3 the size of Manhattan, built with medieval technology, yet strong enough to withstand consistent attack from fire breathing creatures.
Not being one to just point out a problem, I have a few suggestions:
1: Cut waaaay back on the population. Like, by an order of magnitude. Presumably, it's the simplest answer, and if the number is just anecdotal to your story, then it has minimal impact. 2-5000 is much easier to maintain and defend for, and you can get a good sized army out of it.
2: half-joking, here: maybe the reason the fortress can withstand it is that the farms are all in outlying country and unprotected, so the creatures much on farmers more often than not. The farmers would rely on the castle/fortress for protection (unreliably) and the knights/lords of the castle would spend as much time enforcing taxes as they do protecting from monsters. This feudalistic system would be a little more in line with medieval times anyway.
3: Add in some non-violent magic components. Medieval technology is not going to get the job done feeding these people, unless there's some serious magical assistance. Maybe it helps them grow food faster (an additional reason for creatures to target them) maybe there are non-violent magical creatures they've domesticated that produce an aura that makes things grow.
4: Combine the thoughts of a few other answers, and place the whole thing in a valley surrounded by inhospitable mountains with interlocking caves and tunnels. This way, your land-based creatures have to go through certain mountain passes which bottleneck the enemy and can be made more defensible with minimal technology and magic. They could even be inaccessible during certain seasons. For the flying creatures, as some have suggested, retreat to the caves. Maybe even have them trick the burrowers into making tunnels and caves in the shape they want, and building parapets and turrets out of the mountain side. If the "fortress" is half man-made, half ideal location, it solves for a lot of your problems of scale while providing additional motive for your creatures.
[Answer]
One world-building point about the architecture of your people: whatever architectural technology they have (stone and mortar, etc.) must be useful on a scale where it can't resist a dragon, before the society would invest the effort in that technology to get it to the point where it could resist a dragon. How did no-technology humans survive to become medieval-technology humans? They ran, they hid, and they lived in high enough numbers that the species survived.
Now that your world has spinterras, your world has an abundance of caves that would be perfect for humans. The caves protect people from the elements, and serve all the functions caves used to serve for early humans. But also, a spinterra cave protects you from dragons. An early human is going to live in spinterra burrows except when they're hunting, to avoid a threat like that.
I'm assuming that either spinterras are a fair bit taller than humans, in which case the burrows would be a nice, memorable setting, or that your world has a normal number of caves, and people are drawn to them for the above reasons. If spinterras are shaped like snakes, and they are human-width or wider, then now you have bolt-holes if the drakons attack which they can't fit through, or passages between places where you can stand and fight.
Now that you're underground, you have a lot more options for your defenses. Once you have magic, you can have traps in the ceiling which drop rocks on your enemies. If drakons can't climb, you can destroy the ground under them. You could even block a tunnel when you're attacked, or suddenly create tunnels into new caves.
Clearly there's some kind of tunnelling magic, since the spinterras have been enchanted with it. Warfare between humans with tunnelling magic would be incredibly fun. Think three-dimensional tactics, traps and ambushes, where enemy soldiers could emerge from beneath your feet at any moment. Now detection becomes important, and subterfuge, illusion magic or magic to make the enemy think they know where you are, so they give away their position by casting.
The spinterras would also be a major threat underground, of course. I think a big part of the defense against them, once humans evolve past "run, hide, hit and hope" would be finding or creating large caverns, and building underground towers. I'm imagining several wooden structures, twenty metres tall, with an enclosed platform supported by four thick wooden stilts at each corner. People in one tower would shoot at the spinterras climbing another tower. The entire village might even be on stilts eventually, with watchers underneath it. The spinterras could (maybe) climb, destroy the stilts, or shoot at the people shooting at them.
[Answer]
You are going to want to build something like Erebor from LOTR. Your best defence is going to be high walls against the land based creatures. Against dragons and such, ballistas will be helpful, but also net launchers. You could fire both nets and chains to ensnare flying creatures. A moat would also be good, because your creatures seem not to like water.
[Answer]
You put nature do the work for you.
The fortress **IS INSIDE A MOUNTAIN**.
From the "wall" you put defense like @Aify say. If the mountain have a cascade better, it can cool the "wall" against fire and create another layer of defense.
A secondary option for more rural area:
The fortress are small-like mobile towers (or them fly?). Is not that what a tank is :)? This is just for give you a more dynamic setup (because now move into the open is very dangerous).
] |
[Question]
[
Astronomers place planet Earth under what they call a "Goldilocks Zone"--a spot in the solar system where conditions are ideal for liquid water to form, thus making the creation of life possible.
In Norse mythology, there are nine separate worlds--Midgard, Asgard, Vanaheimr, Jotunheimr, Alfheimr, Hel, Nidavellir, Niflheim and Museplheim--all of which are inhabited by creatures of one form or another.
If all this were to be realistically put on a linear plane like our solar system, what kinds of astronomical conditions are required for all nine of them to be placed in a Goldilocks Zone?
[Answer]
You can have 36 habitable planets/moons as follows (all shamelessly taken from [here](http://planetplanet.net/2014/05/23/building-the-ultimate-solar-system-part-5-putting-the-pieces-together/)):
* We can fit six stable orbits into the habitable zone. Each orbit has two sets of binary Earths. These are Earth-sized planets with Earth-sized moons. Each binary planet is in a Trojan (co-orbital) configuration with another binary planet, separated by 60 degrees on their orbit around the star.
* Now let’s include gas giant planets. We can fit the orbits of four gas giants in the habitable zone (in 3:2 resonances). Each of those can have up to five potentially habitable moons. Plus, the orbit of each gas giant can also fit an Earth-sized planet both 60 degrees in front and 60 degrees behind the giant planet’s orbit (on Trojan orbits).
* Let’s add it up. One gas giant per orbit. Five large moons per gas giant. Plus, two binary Earths per orbit. That makes 9 habitable worlds per orbit. We have four orbits in the habitable zone. That makes 36 habitable worlds in this system!
[](https://i.stack.imgur.com/WVGMT.jpg)
[Answer]
Well, if you think about it, there are 2 main things that make a planet habitable, in the sense of being able to sustain a liquid ocean of water:
**1) Distance from the system's star.
2) Density of greenhouse gases in the atmosphere**.
[](https://i.stack.imgur.com/olyKd.jpg)
For instance, we normally think of Earth as solidly in the habitable zone, but the average temperature of the moon is around -20 C. Without greenhouse effects, Earth's oceans would be frozen. You can see how you can extrapolate from here.
Nine might be a bit on the high side, but in theory, if Jupiter formed further out (so Mars could feed on a bit more material), and Venus lost most of its carbon in some neat collision and so got to hold on to its water instead of being a greenhouse hell, there's no reason why there shouldn't be 3 Earth-like planets in our system instead of one.
So imagine a series of planets, spaced just far apart that they don't interfere with each other gravitationally overmuch, where the density of greenhouse gases increases with the distance from the star. you might need to also tweak the sizes a bit (so they won't all be identical), and as I said, 9 might be a bit of stretch, but in theory I see no reason why it should not be possible.
There's a lot more to it (near-solar planets tend to lose their volatiles on formation, while places past the ice-line tend to accumulate hydrogen and turn into giants; greenhouse gases tend to have a limited life-span with CH4 getting blasted into pieces and CO2 being weathered away and recirculated via mantle convection, which needs moving tectonic plates, which only Earth has, possibly because of its oceans, etc -- see what I mean, it gets really complicated fast), but let's not get into it now, shall we?
[Answer]
**Use Complex Orbits**
While in our solar system, planets are generally alone in their orbit, or perhaps orbited by one or more smaller bodies, this need not be the case. Specifically, you can easily have two planets that are about the same size forming a binary pair, which orbit around their shared center of gravity the same way the Earth and the Moon do. This binary pair could then be orbited a bit further away by a *third* planet, so long as that planet was close enough to the binary pair to fall within its gravity well and be pulled away by the gravity of the star. While uncommon in planets, this sort of system is very common in stars, with [star systems](http://en.wikipedia.org/wiki/Star_system) having been found with up to [seven stars.](http://en.wikipedia.org/wiki/Nu_Scorpii) A glob of seven planets orbiting one another in a way that is stable with regards to the gravity of the star they all orbit is highly unlikely, but three should be feasible.
[](https://i.stack.imgur.com/LcNB7.jpg)
*HD 98800, a system comprised of two pairs of binary stars. Planets could orbit one another the same way.*
Within the orbit of the Earth, if you placed one trinary planet system where Earth is and one at the L4 Lagrange point, you would already have *six* planets within the orbit of the Earth. If we can fit two orbits in the Goldilocks zone of a star, that would give us space for as many as twelve planets.
[Answer]
It's realistically possible. But liquid water alone doesn't mean earthlike life ... Presented below is a diagram of a planetary system containing 4 planets. The central star is roughly the same size as our sun.
[](https://i.stack.imgur.com/F2h5M.png)
Planet 1 (innermost). Distance from sun is 45 Mmi (million miles) which is slightly more than Mercury's distance from our sun. Atmosphere is thin, consisting mainly of nitrogen (70%) and oxygen (30%). Greenhouse gases do not exist at all. Planet is mostly water (80%). Land is present as a series of islands. Axial tilt is less than 10°. Rotation speed is high and a day-night cycle finishes in 13 hours. This planet can have liquid water on its surface due to large water body that regulates the temperature. The core is dead so that there are no live volcanoes. Also, since the planet revolves so fast, sunlight does not fall at the same location so long to make it scorched.
Planet 2. Distance from sun is 70 Mmi. Atmosphere is slightly thinner than Earth's, consisting mainly of nitrogen and oxygen. Greenhouses gases are ~4% of total atmospheric weight. Axial tilt is <10° and a day-night cycle is 17 hours. Surface is 75% water and 25% land. This planet is basically a Venus with far less dense atmosphere and a large water content.
Planet 3. Earth. At 95 Mmi from parent star.
Planet 4. Distance from sun 115 Mmi. Atmosphere contains 10% greenhouse gases. Day-night cycle completes in 30 hours. Surface is 60% water and 40% land. This planet can have liquid water due to its high greenhouse gases which absorb sun's energy well. 15 hours of daylight assure that enough sunlight falls on a single place to warm it up.
Planet 5. Distance from sun is 135 Mmi. Atmosphere contains 20% greenhouse gases by weight. Surface water content is 45%. Day-night cycle lasts 40 hours. Crust contains a high graphite (carbon) content. This planet can also have liquid water due to high greenhouse phenomenon that traps most of the heat it receives. High graphite content assures that the crush, too, absorbs heat well.
Beyond that distance the planets will have to have a very active core, really dense atmosphere with increasingly high greenhouse gases ratio and longer day-night cycles (very unlikely) to have any hope of having liquid water on them.
[Answer]
The simplest complex orbit would be a complex horseshoe orbit.
Each planet would have to be roughly the same size, due to how many different large bodies there will be, and there can be no other large bodies in the system (besides the parent star, or course).
And, importantly, this is not a natural system. Something will have to have engineered this orbit intentionally. It is possible to see two similarly sized planets in a mutual horseshoe orbit in a system formed naturally, but there will have to be no other large bodies in that system.
How it works:
How fast a planet completes an orbit depends on how close it is to its star. The closer, the shorter its orbit (the faster it completes the orbit). Mercury takes 88 Earth days to complete one of its years.
The more energy you put into an object's orbit, the higher its orbit goes. Seemingly paradoxically, this slows the object down. (Really, it just has more distance to travel, so it only *seems* that the object is slowed down.)
Thus, we can use gravity to help things stay balanced out on geologic time scales (hundreds of millions of years, enough time for humans to evolve from the rat-like mammals that survived the Dinosaur extinction at least 3 times over), and hope that we don't lose the ability to arbitrarily move planets, which was necessary to get them in this configuration in the first place.
The way it works:
Each planet will have a leading and a following planet, and will start out in ballance. Nothing ever stays in balance forever, though. Eventually, one planet will move closer to one of its companions, and further from the other, though this shouldn't be perceptible for at least 10 million years.
Let's name three of the planets Alice, Bob, and Charlie, with planet Bob in the middle and Alice being the lead planet (Both Bob and Charlie are orbiting *towards* Alice.)
Bob starts moving closer to Alice. Because gravity gets more intense between the two, and weaker from Bob to Charlie, Bob gains orbital speed, Alice loses orbital speed, and Charlie loses orbital speed.
Because of the gain in energy, Bob's orbit moves outward, slowing its year. Alice's and Charlie's orbits both move inwards, speeding up their years.
This causes Bob to start moving away from Alice and towards Charlie, where the situations will soon reverse; Charlie starts stealing Bob's energy, slowing Bob, and causing Alice and Charlie to speed up.
This also kicks off imbalances in the rest of the planets in the system, and soon, over the next million years or so, every planet has a slightly perceptible wobble.
Assuming a Sun sized star and an Earth orbit, that puts the orbital radius at 939,953,595 kilometers. Each planet would start out about 100,000,000 km from each other, which is twice the closest distance that Venus gets to Earth.
From the surface of one of these planets, the two closest companion planets would be plainly visible, always as bright as Venus at her brightest (which holds the distinction as the 4th brightest object in the sky, recently usurped by the International Space Station, and formerly third only to the Moon and the Sun). These two closest planets would always rise and set at the same time of day, rather than changing by season like the stars do, or in more complex patterns like our own system's planets do. We would not be able to see either of the two closest planets at midnight.
The next two distant planets will be visible as well, though not as bright, and setting earlier/rising later than the closest two.
The next two would be barely visible just before dawn and just after dusk, and may need a trained eye to spot them.
The final two would be drowned out by the glare of the star. Once a society develops calculus, their existence will immediately be inferred. They will be quickly photographed within two decades of unmanned spaceflight starting.
If such an orbital system were allowed to destabilize (say, the original system architects all went extinct and nobody on any of those planets re-developed the tech necessary), then things get interesting.
The distances between the planets are huge... It will take hundreds of millions of years for things to destabilize enough for any real danger to start for the inhabitants; perhaps even a billion years.
It will take a couple of decades for each cycle of planet oscillation to complete, but the effect, from the perspective of Planet Bob starting about 3 cycles before the ultimate disaster is:
As Bob approaches Alice, it will do so from Alice's day side. Bob will see Alice grow brighter and brighter, and about a month before closest approach, stop being just a point and become a sphere barely discernable from the naked eye. Alice grows larger until the day of closest approach, when it will be about 60 times larger than our moon (it will be 1/4th as close as our moon, and 4 times the Moon's apparent size). There will be earthquakes. Everyone will be prepared for the earthquakes, because the earthquakes will have been happening on closest approach for the entirety of the society's written memory.
Then, Alice disappears into Bob's day side, obscured by the star.
20ish years later, and the predicted coming of Charlie happens, as gradually building earthquakes herald that planet's appearance out of the glare of the sun, to retreat to a point much the way that Alice appeared from a point 20 years ago. Thus completes the first of the last three cycles.
Then, on Alice's next approach, the earthquakes tear apart the crust. The entire planet, heated by the tidal stresses of the recent near misses, becomes a molten hunk. The surface does manage to cool down before its next approach from Charlie, but Charlie's appearance only stirs the fresh, brittle, thin crust up and the surface quickly becomes molten, ending the penultimate cycle.
Finally, Alice's last approach tears the mantle and crust away from both planets, leaving super-heated rock spinning quickly away from both planets, bombarding the other planet, distributing the debris beyond each other's reach. Bob is now a much lighter, but much denser, core... hot, molten, with a crystal chunk of iron... and slightly more speed than it should. The ultimate cycle ends with Bob delivering a glancing blow against Charlie, adding more mass to what we should, by all rights, call Charlie's daughter planet, because neither Bob nor Charlie exist any more. Alice, at this time, is being flung out of the solar system from its near miss of its more distant companion, which will quite possibly find its way into the star in another couple million years... Charlie's descendent will probably impact its more distant companion as well, and has the greatest chance of surviving the ensuing chaos, though at this point nothing is certain.
[Answer]
I just skimmed all the answers and saw they all predated the recent NASA announcement, so I'm assuming this was not mentioned elsewhere...
NASA recently announced the discovery of 7 approximately earth-sized planets orbiting the same star, multiple of them being in the "goldilocks zone" calculation. Remember also that the "goldilocks zone" is only a very rough approximation; though unlikely, it is possible that most of these planets are habitable.
[You can find one (of the many) articles about this here.](https://www.nasa.gov/press-release/nasa-telescope-reveals-largest-batch-of-earth-size-habitable-zone-planets-around "Star with 7 earths")
>
> NASA's Spitzer Space Telescope has revealed the first known system of
> seven Earth-size planets around a single star. Three of these planets
> are firmly located in the habitable zone, the area around the parent
> star where a rocky planet is most likely to have liquid water.
>
>
>
[Answer]
A couple of largish stars in a far binary orbit (ie far enough out to have minor effects on the other star's goldilocks zone). Now place a 3rd star even farther out and in orbit around both (like Alpha Centaury except with bigger stars and more spread out).
Place a super earth in the warmer end of the goldilocks zone for each star. Place a "moon" around each that are large enough to hold their own atmosphere.
Now place a smaller planet (earth-like) towards the outer edge of the goldilocks zone.
This will give you 9 planets to play with.
[Answer]
Realistically I'd say no chance. With an artificial setup, maybe two gas giants orbiting in the habitable zone. Binary pairs of planets in L4 and L5 points of the gas giants and the 9th a moon of a gas giant. Throw in some orbital resonances and it might be stable. Invoke superhuman powers to stabilise it if someone with more maths than myself proves not!
[Answer]
To add to Rumguff's excellent answer:
In our own system Jupiter has 4 moons (the Galilean moons) of about the same size as our own moon, and saturn has one (Titan.)
At some time in the future, the sun will have expanded and it's likely that all five of these bodies will have "goldilocks" temperatures at once (Saturn is about twice the distance from the sun as Jupiter, so Titan's going to be a lot colder than the others.)
The one big caveat is that these five bodies have surface gravity similar to our own moon, which is insufficient to hold onto a decent atmosphere. High atmospheric pressure has virtually no effect on the freezing point of water, but it raises the boiling point, and if there isn't enough atmospheric pressure, liquid water is simply impossible. Titan is currently the only non-planet in our solar system that has an appreciable atmosphere, with 1.5 times the surface pressure of Earth, but this will surely partly evaporate when the sun expands and warms the solar system.
So, we probably need a system with bigger moons, which probably means bigger gas giants and a bigger star. That said, our own moon is much larger in comparison to Earth than the other moons of the solar system in comparison to their respective planets. So there are processes that can form large moons.
Apart from that, the only other caveat to having 5 goldilocks bodies in our solar system in the distant future, is that Io has intense volcanic activity due to tidal warming from Jupiter and the other moons, which will probably render it always unliveable.
[Answer]
Bending the question to give 9 separate worlds of a similar surface area and climate to our own; I would suggest a partially complete [Dyson Sphere](https://en.wikipedia.org/wiki/Dyson_sphere). Instead of a filled in sphere (a Dyson Shell) it could be 9 main habitable areas with supporting structures and a rainbow road transit system between them. That might make it more like a Dyson Swarm or Dyson Bubble, but the overall idea stands.
As a suggested step in the evolution of a civilisation it could be that the Avguard were in the process of constructing such a thing when they were required to interact with the lower technology nordic civilisation. I am not sure how much more complex it would be to add a planet to such a construct. Perhaps 8 of the realms are part of the Dyson thing but the norse one is a free planet elsewhere in the habitable zone.
[Answer]
See here for a simple explanation of how tightly you can pack planets into the habitable zone: <https://planetplanet.net/2014/05/21/building-the-ultimate-solar-system-part-3-choosing-the-planets-orbits/>
And here is a followup with a couple of ways to squeeze in extra worlds, in the form of planets on Trojan orbits as well as moons: <https://planetplanet.net/2014/05/21/building-the-ultimate-solar-system-part-3-choosing-the-planets-orbits/>
Finally, regarding Trojan worlds, I want to reassure you that Trojan planets are:
1) A natural outcome of planet formation. I have run thousands of simulations of planet formation, and Trojans are inevitable. Exactly how common they are depends on some of the assumptions we make in our models. But they are a simple consequence of physics and they must exist
2) Dynamically stable. A system with two planets in a Trojan configuration and no other planets will generally be stable forever. Many sets of Trojans can exist in the same system, although their combined mass must be taken into account in terms of the spacing of adjacent sets of many planets.
[](https://i.stack.imgur.com/tak5K.jpg)
[Answer]
If they were all on the same orbit, they could all be in the same "zone". Impossible to achieve naturally and it would require some sort of magic to stabilize (<https://www.quora.com/Can-two-planets-share-the-same-orbit>) but it could be done. The star would have to be pretty big to support so many of them without gravitationally induced collisions.
Or you could put them on differently oriented orbits roughly the same distance from the sun and assume they were either in different dimensional states such that their gravitational fields didn't interfere with each other and they never collided.
Bottom line, there is no natural way it could be achieved, but with magic (or sufficiently advanced science) anything is possible.
] |
[Question]
[
The sea is used as an analogy in space travel, and sometimes it works well. Ships sail on long journeys, between distant lands, across a hostile medium.
But these analogies tend to break down when it comes to planetary invasion. Planets aren't like islands: because an island has a coast that can be defended, and defenders can retreat into the interior of the island. This happened a lot in WW2, particularly in the Pacific. But in terms of planetary invasion... the entire planet surface is the coast, and the interior of the planet (the mantle) is not something which can really be retreated into.
Much more important, bridgeheads do not seem to be important. Spaceships can land virtually anywhere there is a flat surface on a planet. The concept of a front line in terms of planetary invasion seems somewhat irrelevant if you can land an army behind what is the "front" line.
Clearly there must be means to counter spaceships. Spaceships when in close orbit, or in the atmosphere, become subject to the same rules as aircraft. They can be hit by terrestrial missiles and other vessels. But all this means is that air superiority be achieved before invasion, and defences hit from long distance by bombardment.
Which brings me to the last point: why invade at all to destroy an enemy? Most structures of a civilisation are probably going to be on a surface. It is, after all, more difficult to build underground than on a surface. That means that most items of value can be simply blasted from above. Sure, some command points, armament storage and production facilities, and offices of government may be transferred to secure underground bunkers, but this still means essentially conceding the surface to whatever punishment the attacker chooses. There can be no counterstrike, merely a populace putting its heads between its legs and hoping for the best. Perhaps in the event of a siege there could be hope of external assistance, but this still makes it such that the attacked planet is itself left defenseless.
So is there any way for realistic planetary invasion have any meaningful strategy? I have never seen such in fiction - the invasion just "happens" and we generally catch up with the consequences of the invasion. If the invasion is defeated, it is always some Deus Ex Machina that has nothing to do with strategy relating to the invasion itself.
Edit: By "invade a planet" I mean from a strategic, military point of view. The Allied invasion of France during WW2, for instance, wasn't just an exercise to liberate western Europe - the Axis forces needed to be eliminated on the ground (aircraft not used in combined arms offensives were of limited use except in urban bombing, and urban bombing had no significant effect until airbases within mainland Europe were available). The option to float thousands of gunships a mile up to rain down precise fire 24 hours a day simply wasn't available, even when looking at recent historical wars. Had it been available in something like WW2, there simply would have been no Axis forces left to resist invasion.
Edit 2: I should probably have defined the parameters of this question as **EITHER** "Why would an interstellar civilisation invade instead of attacking a planet" **OR** "Given that an interstellar civilisation is invading a planet, how would meaningful defence be mounted?". I was kind of leaning in favour of the latter definition of the question, but that's a damn difficult question to answer (if it wasn't we would have seen it in sci-fi settings already).
[Answer]
>
> why invade at all? Most structures of a civilisation are probably going to be on a surface. It is, after all, more difficult to build underground than on a surface. That means that most items of value can be simply blasted from above.
>
>
>
But you might not want to blast them from orbit because these items might also be of value to *you*.
You might want to avoid damage to the economic infrastructure. Economic assets like factories, resource stockpiles, mining facilities, research labs or transportation infrastructure could be useful for your own empire. You also might want to avoid excessive casualties among the civilian population. Either because you care about public opinion or because you have plans with the population which require them to be alive (for example: enslave, liberate, study, ritually sacrifice, re-educate, economically exploit or eat them).
So if you don't just want to take control of the planet but also of the assets on the surface, then you need troops on the ground.
So the average planetary invasion would likely work as follows:
1. Enter the solar system with your space fleet and neutralize any enemy forces in space (enemy fleets and armed space stations)
2. Enter orbit around the target planet. At that point, any mobile defending troops will likely start to entrench themselves in those areas they know you want to capture intact.
3. Neutralize any ground-to-orbit weapon systems which threaten your fleet in orbit.
4. Neutralize any military targets from orbit which you can safely destroy without hitting valuable assets. Barracks, government districts, military spaceports, ground troops which are still on the move, military production facilities.
5. If there are military assets you can not safely engage from orbit but which you want gone before you start the invasion, deploy aerodynamic precision bombers into the atmosphere to take them out or land small squads of special forces to perform surgical sabotage operations.
6. Land the bulk of your ground troops in areas which you believe to have minimum enemy presence and establish operating bases. Even though you can move troops quickly with space ships, having a permanent presence on the ground can be useful:
* You establish permanent hold over the surrounding area.
* Ground fortifications might make it harder for the enemy to attack back.
* You have a place ground troops can retreat to on their own in case you ever temporary lose air superiority.
* You have a place aerodynamic vessels can operate from.
* Your logistics, maintenance and medical personnel might have an easier time doing their job if they work in spacious ground facilities instead from inside a cramped space ship.
* Depending on how space ships work in your universe, landing from and launching to orbit might be costly, so you might want to limit such trips to a minimum.
7. Originating from those bases, have your ground troops conquer the population centers one by one. When your ground troops encounter resistance from entrenched enemies, aerial and orbital bombardments *might* be used as the situation allows.
But all of this of course assumes that you actually want the planet intact. If you simply want to obliterate your enemies, then you can just nuke the planet from orbit.
[Answer]
Well, part of the Island Hopping strategy had to deal with the fact that many the islands weren't lone chunks of land, but archipelago chains (Hawaii, the Philipines, Indonesia, Japan are all islands nations/states that include more than one Island... and were also part of the Pacific Theater). So many battles for one piece of territory were spread over multiple Islands... Perhaps use this to make your story... You're not invading a single enemy planet, but an enemy stellar system of planets. This allows for greater diversity. If we look at our own solar system we have the following areas:
Your shore waters would be your Kuiper Belt and Dwarf Planets/Plutoian celestial bodies... Here is where you should consider prepping your fleet for "landing" and taking interior planets. The defender would also likely station patrols and early warning systems here, so at this stage, both the defenses and offenses are have their red alerts and battle stations calls sounded and are mobilizing for battle.
Heading interior, our Gas giants would be our shore (Jupiter, Saturn, Uranus, Neptune). Each of theses are large planets with stormy atmospheres that would hide all manner of fun space station defenses and fleet depots to take. Additionally, all of those planets have multiple moons and plantary rings that can have some fun counter invasion measures. Your radar stations, fuel, scrambled star fighters, gun boats, and other defenses.
Our Asteroid Belt would be the demarkation of the forest line or other change from beach to interior land, and finally the rocky planets and the star (Sun, Mercury, Venus, Earth, Mars) would be the interior of an island. This isn't unheard of as anyone defending a planet in intersteller war will likely have resources spread out into the solar system to stop the advancing ships.... your big ships aren't just the fleet, but the tanks in this scenario.
YOu can see models like this in fiction like Star Trek, where the Solar system does have multiple facilities on other planets that all count to the defense of the Solar system. Headquarters is on Earth, but repair facilities are on Mars, with Jupiter serving as a command center for system movement, coordinating early warning, clearances to enter and leave Earth, and having an air field that can launch patrol fighter shuttles and other equipment. Each of these have ground and space based stations that also have roles to play. While the canon was that Earth was to well defended for a surprise strike, in the show the Dominion pulled it off for a moral victory in DS9 and in Star Trek Online, one of the Klingon missions has you lead a raid on military facilities that end up in a Pearl Harbor like action (basically you blow up ship yards on Mars, crippling repair facilities).
Now, how do we organize this invasion. All ships in a fleet are organized into "Groups". A command structure from the top would be a high ranking Admiral in charge of both the Fleet and lower ranking Admirals in charge of a single group...
What required ships for a group largely depends on your group organization theory and your mission needs... typically, the Group will be the Capital Ship and it's screen ships. Your Capital ship is your big offensive weapon and your screen protects the capital ship so it doesn't have to play defense. World War II is unique in that two different schools of capital ship theory were in different points of their life span: Battleship Theory was on it's way to being phased out, while Carrier Theory was the young hot newness of Naval Combat. Which ever theory you want to go with, keep in mind that the Capital Ship is the offensive ship, and the other ships are making sure that it doesn't die.
In real naval combat, Carrier theory is far superior as it's weapons systems (the planes) are able to better target enemies and from a father range. The Battle of Midway, which was the first true carrier to carrier naval battle, was fought without either side's ship coming within visual range of each other and was fought mostly this way because the U.S. Battle Ships were still recovering from Pearl Harbor and the Japanese developed Carriers to get around crippling restrictions on Battleships that had been placed on it (treaties on Capital ship limitations at the time were written when Carriers were first being tested as a concept at all). Battleship theory has a shorter range but was still used for support of landing forces and while it wasn't accurate, they didn't need to be... those shells still could reach targets out of line of sight and didn't need to hit directly... close was good enough to work.
In Sci-Fi a good Carrier vs. Battleship demonstration is to look at how Star Wars and Star Trek fight ship to ship in space battles. Star Wars uses Carrier Theory as the Star Destroyers (and their prequel sister classes more so) would deploy small fighters and smaller ships that couldn't be targeted by the big guns to fly close and shoot ships. Return of the Jedi has a great "group" mechanic employed where the Capital Ship (Death Star II) has a protective screen of Cruisers (Super Star Destroyers) and Destroyers (Star Destroyers) as well as fighter aircraft (TIE fighters) all engaging the enemy fleet... to the point that for much of the battle, the Death Star II was largely not focused on the battle and it's weapons were actually pretty spot on for its role. As a Carrier, it was much more sucessful as the fighters can be used for offense or defense, while as a Destroyer, the Planet-Blow-Up-Ray was largely scary but ineffective at close ranges. Star Trek is noted for it's lack of carrier ships on screen with the Enterprise almost always being a ship akin to a Battleship (and occasionally submarines, given the nature of both being boats surrounded by hostile environment). Almost any ship to ship engagement is sure to be broadsides with lasers, which suits battleship theory, and the shuttle compliments are never used in engagements. Deep Space 9, which shows fleet actions actually uprooted it completely by using organizations that would be based off of air-force operations, not naval operations (Sisko would repeated call out to "wings" instead of "groups" in the multiship battles).
A typical Carrier "Group" (which in the modern world, is enough) is usually alone and rarely works in a fleet. The United States is the only nation at time of writing with more than 2 carriers... 11 to be exact... and that's only counting the 11 Nimitz and Ford class super-carriers... the American Class "Amphibious Assault" ships aren't "Carriers" in U.S. Navy terms, even though they are bigger than most non-U.S. carriers and allow for air craft to take off and land from them... which is all you need for carriers to be counted as such... The U.S. has 20 of these). Typically the command of the group will be under a Rear Admiral Lower Half. On the carrier, there would be two people of Captain Rank running the shows. The Captain, who is incharge of the ship's operations and the CAG (never addressed as Captain while Underway... Ships have one Captain... his proper rank is Captain though) who is in charge of the ship's Air Wing (in the Navy, a Wing of airplanes is considered a "ship" for the purposes of Command). The Rear Admiral is also in charge of the Groups Cruiser Captains (Usually two, but numbers may differ for mission), the Destroyer Group Captain (all destroyers have a single Captain in charge, but if he or she is on another ship, the CO on your ship is usually a Commander) and the submarine commanders (Submarines usually have a CO of Commander Rank... they also are not ships, but boats... don't ask me why but never call a ship a boat or a boat a ship... it's insulting, for reasons...). If there are two "groups" in a single battle, typically the Admiral might be higher rank (Rear Admiral Upper Half or Vice Admiral) but will be dual hatted with both Group commander and fleet commander... this is because while any capital ships will have space for the Admiral's staff to due their job, they don't have duplicate space. In a carrier's "Island" there are three general levels for each CO onboard. Captain has the Bridge, CAG has the tower control, and Admiral has a level for general coordination between all ships. Battle ships similarly have a bridge and CIC (in the interior of the ship) to handle communications and multi-ship coordination. Also there is a difference between a Capital Ship and a Flag Ship. A Capital Ship is typically the ship with the most firepower while the Flag Ship is the ship with the Admiral on it (Admirals have individual flags that they are authorized to fly on their ship, hence the name. In the Days of Semaphore, this was needed so Captains could readily identify which ship was giving orders). So if the Admiral decides to run his show out of a Cruiser's CIC, then the Cruiser is the Flag Ship, but the Carrier is the Capital Ship.
In space combat, Battleship theory is a bit more viable if you're going to try for realistic, as the guns in space can have the same range as fighers without having the worry of pilots... And actually, a good portrayal would be using Submarine warfare if you go that route as subs rarely engage targets with a visual contact. On scree, this is boring unless you use the silent hunting for drama (Wrath of Khan does this wonderfully, as does the TOS episode with the first appearance of the Romulans). DS9 often used the Defiant's stripped down and limited space status (and cloaking device) to do sub stories in Space. This also works as Subs fight in 3D spaces as a space ship would, where as surface ships fight on a 2D plane (Wrath of Khan also uses this to allow Kirk to get the upper hand on Khan, who is a brilliant commander from his grasp of surface naval warfare... he doesn't think of space as 3D).
Other options are to make a capital ship a Battlestar (from the series of Battlestar Galactica, the titualar ships are Hybrid Carrier/Battleships. These don't work in navies but the contained flight deck of many space carriers means all the guns of a battleship be viable. Carriers don't have many guns as they can't be fired while in launch or recovery of aircraft... which is kinda the point of making a carrier anyway). Typically space carriers will have the flight deck embedded into the belly of the ship, either running stern to bow or port to starboard or off to the sides like wings. Each have an advantage over the real carrier as Launch and Recovery can happen simultaneously. In the latter two options, multiple runways exist, and one is dedicated to take off and one to landing. In the former, the flight deck is so long, it can do both.
As for ground landings, there isn't a lot as most scifi send woefully underwelming man power to planetary invasions... something akin to Helicopter Transport of Marines from ship to shore is generally depicted (consider those really cool looking landing craft in the Clone Wars finale). Star Trek rarely dealt with on screen ground depictions, though they did say they happened. Part of the reason is the book Starship: Trooper is such a big scifi staple that it tends to be dominant for overall planet wide theaters and it's difficult to show a planet wide scope of ground battle. Starship: Troopers is told from a Marine ground combatant and the military employs power armor for it's infantry. The book does describe that a single individual infantry man can typically cover a staggering amount of terrain by himself... at one point the hero notes that a unit formation with individuals spaced a kilometer apart is a very unusually tight formation that presents a threat of friendly fire from being clustered so close.
[Answer]
**They want the planet whole**
If they just wipe out huge chunks, humans will use nukes. If they capture the planet whole and the civilian population continues under occupation, they would be less likely to use scorched earth tactics.
A planet capable of supporting life isn't likely to be that common so to have the natives turn it into a radioactive cinder would be a tragedy. If you can capture the civilians, they won't want to nuke their own cities when you have seven billion hostages.
Once quelled, you can exterminate the lot but they need to believe they can surrender and live in peace until that point.
It means hand to hand fighting but a life supporting planet is worth the effort.
[Answer]
Here is my take on this.
Moving up/ down from a gravity well is expensive, slow, and prone to catastrophic failure.
Luckily we have space elevators (more realistically space rings) that allow us to use the power of the sun to lift things too/from the surface of the planet, instead of wasteing the unobtanium that powers our handwavium drive.
Space elevators are extremely expensive to build, it's a megastructrue. Not something you would destroy out of hand. As not having a space elevator makes the planet worthless for both the invader and the defender. Therefore neither side wants to destroy the space elevator.
Invasions would start out with odsts falling from the sky to secure the base of a space elevator. While marines capture the official super structure.
The landing point than becomes your primary beach head as it is drastically cheaper to get supplies planetside thru the elevator than a hot drop.
But why don't you just glass the planet? Or use bio weapons to clear out the unwanted population?
The solution is that this was done in the past, leaving behind tomb worlds and the shattered husks of planets. The civilized species got together in a galactic convention and decided to lay out the rules of war they expect everyone to follow
Breaking this convention, will lead to all other civilized species declaring war on you. Not something you want.
[Answer]
You can still use the island metaphor.
If the defending planet is technologically advanced enough to have their own space force, then they could have a blockade of ships around the planet.
Your front line is the extent of gravitational reach of the planet, or even further away depending on how fast/powerful the ships are. You could even compare artillery hidden in a forest to fortifications hidden in a meteor field.
Retreating inward to the island would be entering the planet atmosphere to take up ground defenses or activate more powerful weapons which have limitations that prevent them from being placed in space. Your island defense warship might have a nice cannon, but typically you have a larger one on the island that just can't fit on the ship.
Invaders may also want to not obliterate the surface of the planet if there is a strategic or otherwise coveted resource which is rare among other planets. You may even want to leave a certain amount of infrastructure in tact to save costs of developing a way to harvest that resource.
So:
If you want to invade a planet, but don't care about it strategically, then you go for shock and awe. A space faring civilization could possibly build a massive bulky spacecraft to use as a metal asteroid and just accelerate it as much as possible to destroy or cripple the planet in one shot.
If you want to invade and keep things, then you might use more precise tactics such as disabling communications, defenses, etc. But you would be more careful about launching weapons that could obliterate an entire continent. You might even want to use ground forces if the defending side can destroy your larger vessels. Alllllsooooo, a massive ship might not want to enter the gravitational pull of a planet, because then they need to spend a lot of fuel to leave again.
If you are a defender, you would want to establish your front line. Have a standing military that can hold a line in space. Use natural satellites and debris to conceal long range artillery. Put long range sensors out in space to detect an incoming invasion force so that you have time to prepare. And of course, make sure you have larger defenses planet-side that you can use while your front line ships hold off the invading force.
[Answer]
### The defense: An array of really big satellite turrets.
Our current technology has no effective means of fighting off an attack from space, but unless we are talking about an invasion from a vastly technologically superior species we can presume that as spacecraft technology advanced, so did the defenses needed to defend against those spacecraft.
The first use of aircraft in warfare had no effective defenses, but anti-aircraft artillery quickly evolved to shoot down incoming planes. What we need, then, is anti-spacecraft guns - preferably positioned in orbit.
The key technology necessary for defending against an interplanetary invasion is a really long-ranged gun capable of hitting anything within a large, spherical region - anywhere it is not blocked by the planet itself. This will allow you to set up a defensive array with a relatively small number of satellites. The key to invading a planet, therefore, will be to either destroy one or more of these satellites or sneak past them.
### The invasion: a Trojan Horse.
Since there is No Stealth In Space, if you intend to sneak past these satellites the only way to do so will be to pose as something you're not - sneak a bunch of soldiers inside what appears to be a group of benign cargo ships, for instance. This will, naturally, limit the number of troops you can field and the places you can field them.
The objective of the invasion will not be to conquer the planet's surface with infantry, but to take control of the base or bases that control the Planetary Defense Array. Once the satellites are down, the planet will be vulnerable to space invasion, rendering it effectively defenseless.
If you have warp gate technology, the initial invaders could set up a portal on the ground, allowing you to field more troops but restricting their entry point, forcing you to use more conventional ground-based strategy.
[Answer]
I'll summarize vastly different invasion strategies from different SF novels (Many details will be wrong because it's so long ago I read those).
**Iain M Banks - The Algebraist:** In this space opera, a warlord travels, with a huge fleet to a system to embiggen his empire and go after a Mc Guffin that's hidden somehwere there. His strategy is to achieve space dominance (it's pretty much a curb stomp battle), the threaten the system governemnt into submission by destroying habitats, murdering millions. IIRC, the actual planetary invasion happens afterwards, to secure important points on the main inhabited planet. OP is to clear a landing zone with neutron bombs, land power armored troops with vast air superiority - but these only have to deal with isolated resistance nests (and the fact that *some* aliens that coinhabit the invaded system, and are part of its military, are more radiation resistant than humans ...).
The drives of the invading fleet show up on the night sky as hundred extra stars as they break from relativistic speeds (the parts that don't fly through the system *at* relativistic speeds, taking potshots at military targets). Some, especially those with much to loose, offer tehir support to the new overlords.
Meanwhile, a smaller but technologically more advanced fleet is on it's way to fight the invaders (but will be late to the party). Part of *their* stated strategy is punitive measures against the population and elite of the system, if tehy find the resistance lacking.
**Charles Stross - Singularity Sky:** An interstellar expedition of post scarcity, post singularity (and post human) civilization comes across a planet whose population is mostly held at mid 20th century level by their dictatorship. The "invaders" are not interested in material goods, they care for interesting ideas, culture, and people to upload into their simulated world n their ship. Their invasion starts with a rain of mobile telefones. Place a call, take to the invaders, make a wish ...
**Stanisław Lem - Fiasco** is not about an invasion at all. The human explorers want to make peaceful contact. Their attempts at communication are met with silence, the strategy of the explorers is to communicate unambigously (using a powerful laser to write into clouds) and make credible threats (IIRC they blow up a moon) to force contact and communication. The title of the book is somehwat of a spoiler, but it's a good read.
**Iain M Banks - Consider Phlebas** features planetary invasions as a background event. The Idirans (the civilization taht does the invading) are technologically advanced enough to live a post scarcity life or live in space entirely. They chose not to, the strategy seems to rely on total space dominance, well armed shock troops and local collaborators.
**Arkady and Boris Strugatzky - Wayside Picknick** No invasion, but a contact with aliens that turns some areas of the world into zones filled with deadly traps, weird phenomena and some trinkets. Noone knows what the goal of the aliens was, maybe it *was* just a wayside picknick. No discernible strategy, several points on the globe ar hit by something resembling meteor strikes. That's it.
**unkown** One recentish "invasion" story - I forgot the author and name of the story - has aline nanotech somethings land in Kenya. The somethings build weird structures, change the landscape and are dangerous to touch. This leads to efforts to research them, plunder parts (similar to wayside picknick, except the zone is expanding).
[Answer]
Just as an alternative to the "there is something you want that you shouldnt destroy" idea, the available supplies could prevent this.
Lots of popular science fiction makes the space travel exceedingly simple and almost costless. Just set your location and you can get all the equipment you need to the planet in no time! But what if that isnt the case?
Imagine that you can only carry so much material to a planet. You can use a few kinetic bombardments but only to strike a few targets, its a stragetic weapon to damage key formations, not something to wipe a planet clean. Getting space rocks off-course into the planet/sun takes time, fuel and several space-battles as the planet's owners will send ships to try and get the rock on another course long before it even gets close.
So the attackers have come up with a different strategy: they arrive, use what KE bombardments with Rods From God and nukes to suppress and clear enemy prescenses near your landing zone where one or more ships will land. These ships are equipped with factories that will use the local materials to generate the equipment you need for the invasion (including perhaps 3D printed soldiers?). While you have control of space, you also have to capture an ENTIRE PLANET with the soldiers you brought with you. Likely a lot less people than the entire planet can throw at them. The invaders will need to capture more infrastructure and production facilities (likely something they try to land on top of) to succeed.
The defenders in the meantime will be building up their own forces and create missiles in secretive bunkers. Once enough missiles are created they will fire them simultaneously at any ships in the solar system. Encouraging the attackers to either hide their ships or land most of them on the planet to support the invasion instead of just nuking everything from orbit without resistance.
[Answer]
I have realised the flaws in my old strategy design so here is another that (hopefully) makes sense.
1. Send scouts to report on any of the planets defenses.
2. If the planet has defenses deploy infiltrators to kill and replace
engineers/soldiers working of defenses after learning how it works.
3. Infiltrators sabotage defenses and take any engineers/soldiers as
hostages(when they are asleep or defenseless)
4. Deploy fleet in orbit and tell defenders to surrender or the fleet
carpet bombs the planet.
5. If the defenders refuse to surrender bomb and military targets and
if the defenders deploy space fighters bomb civilian targets until
the retreat.
6. If they have not surrendered direct the planets moon/s(if it has
them) to the planet and or bomb areas vital to their survival(farms
roads(or whatever transport they have) and water purification.
7. If the planet has been bombed to the point where nothing lives on it
anymore you can begin mining operations or whatever you came there
for.
So far i have spotted the flaw of how the infiltrators and scouts make it to the planet which can be fixed with posing as a trade ship. If you see any other flaws please inform me.
[Answer]
It depends on if you want the planet intact. If you want to leave things intact for your usage, especially their infrastructure, then unless you want to destroy some of it to cripple them a la WWII Allied bombings of German railways, you still have to invade on the ground and fight a conventional war. This lets you use the area as either a colony or, if you don't kill everyone, a slave colony, and use the resources potentially more efficiently (at least cheaply) than if you had to transport your own equipment.
If you only want resources, then you can destroy their main urban areas and send down your own harvesting equipment to the areas with the resources, a la *Halo*. Because planetary natives are secondary to your alien's goals, they can be killed off indiscriminately while they look for resources. Once the resources are located and collected, then the planet can be destroyed so other aliens can't use it.
[Answer]
IMHO it would be more usual to attack a planet than to invade it, or at least to threaten the planet with attack to force their surrender.
"Greetings Earthlings! You will be pleased to learn that the total extermination of your species can still be avoided by total surrender if done quickly enough."
[Answer]
Phil Geusz's David Birkenhead series has one of these that works.
The background is that there's a civil war in an interplanetary empire, and this planet was planning to switch from the loyalists to the rebels. The loyalists arrived first and prevented the betrayal, so the rebels arrive to find a planet against them instead of for them. The rebels have to take the planet, or their massive fleet will run dry. The book goes into plenty of depth about the fighting that results, which, roughly speaking, takes the following shape.
First, there's some fighting in space, which the rebels easily win. Then, the rebels make a few landing attempts; the first is ambushed right after landing and heavily defeated, but the second is successful. The rebels then land a large force on the planet, occupying its cities, but a massive planetwide guerilla war combined with sabotage operations prior to the rebel landing prevent total occupation. The rebel fleet is stuck waiting, which allows the main loyalist fleet to arrive and defeat the weakened rebel fleet.
To answer your question, the purpose here was simple - the planet had supplies that the rebel fleet needed in order to function. Necessity of supplies has been one of the biggest factors in warfare throughout history, and that wouldn't change in the future, short of replicators being invented.
(The series in general has one of the most realistic strategic representations of space warfare I've ever seen. It talks about the problems of defending such a large body as a planet, commerce raiding, psychological warfare, and more.)
[Answer]
**TL;DR**
Well, the thing is, you can't invade earth, as we have enough firepower to blast any fleet that comes withing range.\* Therefore, your aliens must consider alternative options. A viable strategy for them would be to show up in orbit with a mock-up of the Death Star in tow.
---
**Long answer:**
While it would be very easy to get ships to a planet you want to invade, and you could land troops pretty easily, it would be hard to maintain the beachhead. You see, while there would be quite a bit of confusion during the initial landing, governments would quickly get their collective acts together enough to drop a [Tsar Bomba](https://en.wikipedia.org/wiki/Tsar_Bomba), killing anybody unfortunate enough to be in the area. If you try to land elsewhere, they will do it again as many times as necessary. Landing in multiple spots would not fix the problem, as then the earthlings would just use a bunch of smaller nukes (or a few MOABs.)
Destroying bombers / missiles before they reach your troops would not solve this problem, as then militaries would bring weapons like the [M65 "Atomic Annie",](https://en.wikipedia.org/wiki/M65_atomic_cannon) point defense systems being useless against these.
While your troops are being destroyed on the ground, your fleet is experiencing similar problems. For the first 30 minutes they will be safe, no problems. Minute 31 is when the fireworks start. Missile silos throughout the world will pour forth their deadly contents, they being so profuse and of such diverse types that even the best point defenses will be unable to block all of them. Even if your forces manage to destroy the missile silos in time (unlikely; they are usually well hidden) they will still have to deal with all the missiles being fired from submarines and single-rocket launch points. Regardless, 15 minutes after the missiles are launched they will reach your fleet.
***45 minutes after your fleet drops out of FTL it will be destroyed.***
Because of these problems, **your empire will have to explore other options.**
The first (and least risky) is to take the route of the [Pierson's Puppeteers](https://en.wikipedia.org/wiki/Pierson%27s_Puppeteers) from Larry Niven's *Known Space* series. In other words, instead of wasting time on bootless attacks, just use trade and governmental corruption to bend them to your will. For example, in the novel *Ringworld*, a Puppeteer named Nessus admits that the Puppeteers manipulated the Humans and Kzinti into engaging in four extremely bloody wars with each other. This had the net effect of killing most of the Kzinti, making them less of a threat for the Puppeteers.
If your hypothetical race is willing to wait a few millenia, they could just nuke the planet. This would kill everything, meaning no resistance. Of course though, it would also make the planet unusable for a few millenia before they can terraform it, but such concerns are relatively minor...
If they are *not* willing to wait, they could always go with the approach that @M.A.Golding suggested, namely by appearing in orbit with a mock-up of the Death Star and then broadcasting a message to the effect of "Greetings Earthlings! You will be pleased to learn that the total extermination of your species can still be avoided by total surrender if done quickly enough." That being said, this would be a *very* risky approach, as the Earth governments would probably respond by painting "Bug off!" on the nosecones of their missiles before launching them.
\*Nota Bene: Unlike what they show in Stargate: SG1, an energy field would be unable to mitigate the shockwave or radiation from a nuclear weapon.
[Answer]
My advice is split the planet into geographical regions(as in deciding the areas for certain ground forces to take and not political). and send specialised ground forces to take each region.When a ground force finishes conquest(either taking land by force or making the enemy surrender) they check every location resistance fighters could hide in then they leave half their forces to occupy the land while the other half assists ground units that are losing once the planet is taken they clear potential threats to their power(this strategy only works after sending scouts to map out different ecosystems and learning of the political landscape)Edit:the strategy was designed to be superior to just land troops in one area and have them spread out from there
] |
[Question]
[
Virtually all animals on earth ranging from insects through to swimmers, fliers, mammals and reptiles, have a symmetrical body plan. In other words legs and wings come in pairs, as do most sensory organs. The mouth is centrally placed, etc. <http://en.wikipedia.org/wiki/Symmetry_in_biology#Bilateral_symmetry>
Would there be any reason why a creature might evolve a non-symmetrical body plan?
Really I'd be interested in a world where the dominant and/or most common body plan was asymmetrical in some way, and a way in which that could arise.
To help inform the debate there is a list of example animals on earth which are asymmetrical here: <http://en.wikipedia.org/wiki/List_of_animals_featuring_external_asymmetry>
(Thanks to Pavel Janicek for the link).
[Answer]
## Directional Consistency
An animal might be more likely to develop an asymmetric body plan if it evolved in a place where events consistently occur from the same direction.
**Example**
I'll explain more, but first an obvious example:
*Feet*. Humans are bilaterally symmetric, but ignoring which way a human is supposed to be oriented we can see that humans have special adaptation for gravity. Gravity, for our evolution, was always one direction. Because of that, it was useful for us to develop some motility appendages in that direction. That asymmetrical adaptation is so obvious we usually don't see it as asymmetry.
**Where this can be found**
Ok, so back to gravity being down, what about horizontal directionality? This is less common, and with only a few exceptions, is likely the reason most animals on Earth are symmetric in this plane.
However, it's not hard to imagine a world, or at least a place with specific conditions on that world were horizontal symmetry is not as advantageous.
For example, consider a [tidally locked](https://en.wikipedia.org/wiki/Tidal_locking) planet, on this planet there is a thin terminator where life exists and evolved. There are a few natural conditions with consistent direction: gravity is always down, in one direction it's always light, the other is always dark, the winds would also likely have a constant direction depending on latitude. A [sessile](https://en.wikipedia.org/wiki/Sessility_(zoology)) creature evolving there may only look for food in the direction of the oncoming wind, defecate in the opposite direction, absorb energy from the sun side, and dissipate heat on the dark side.
This isn't too far fetched an example. It could be something as simple as a primary predator or competitor that always attacks from the left in face to face battle. A consistent ocean current on a reef or wind pattern in a valley. Anything where the direction of a natural force is consistent for enough time to evolve an adaptation for it.
[Answer]
**I think the key subject to cover when discussing symmetry is [motility.](http://en.wikipedia.org/wiki/Motility)** Motility is simply the ability to move of your own ability. So while a rock may be *mobile* it is not *motile.* I like to think of a peg legged pirate. When you are not symmetrical your mobility and agility are decreased, this, if it is the natural state for a creature will put it at an evolutionary disadvantage compared to symmetrical counterparts.
There are of course other items to consider.
**Gravity** as it exists on earth combined with creatures being able to move effectively have resulted in the selection of a symmetrical body type as the best functioning biology.
**Self defense** is another aspect worth considering. An asymmetrical body type would have more obvious weak spots which could be exploited by predators. Even in an environment where gravity does not play a role there would be an advantage to being symmetrical.
**Senses** this sort of plays into the other topics but symmetry also allows us to effectively observe the world around us. If we had one ear on our head and one ear on our left knee sure...we'd be able to hear, but we would not have the ability to ascertain direction and we get similar problems when we consider asymmetrical vision.
---
**A world without symmetry...** is not going to happen. You could hypothetically create a world where symmetry is less dominant however.
I think the most likely scenario is a world dominated by water, maybe a world entirely covered with oceans. Gravity reduction would go a long way in reducing the drive toward symmetry. If the world is somehow less predatory that would help as well.
In the end this will be an uphill battle [as even cells have a preference for symmetry](http://www.sciencedaily.com/releases/2008/07/080728221402.htm). As on earth, niche players are likely your main asymmetrical creatures...so create more niches.
[Answer]
The wiki article in the comments to your question lead to some great reading about symmetry.
The section on gravity and movement leading to a top, bottom, front, back, tends to push toward symmetry.
I would think that if your creature evolved in an environment that did not provide these up/down forces. Say in zero gravity, there could be some leniency in the need for symmetry. Sponges made me think along these lines. However most things 'floating' in water tend to spherical symmetry and space would I think lead to the same tendency.
It might help to understand the 'need' for non-symmetry in your original question.
Perhaps it could be self-inflicted, even without providing an advantage.
(I can take you with one arm tied behind my back.)
EDIT: When looking up stronger bones, I came across this article. (<http://www.ncbi.nlm.nih.gov/pubmed/18769962>) Which says that the dominate arm and leg of a fencer becomes stronger. Thus a forced asymmetry based on preference and usage is another avenue. Not sure how to make this work on a something like the 'head' unless I am a pirate and use a single ocular telescope all the time. ;-)
[Answer]
Another possibility would be exploring non-bilateral symmetry. Creatures evolving in low or no gravity might be more inclined to evolve with trilateral symmetry, pentilateral (not sure if that's a real word) symmetry or something stranger.
Many plants exhibit symmetry based on the Fibonacci sequence, so it's not that much of a stretch to imagine animals that aren't particularly mobile (or weren't early in their evolution) having a similar symmetry. This might be you key if you are looking for something internally consistent that doesn't look completely symmetrical as it's not always obvious in plants, see below:
[Answer]
Star fish are not really bi-laterally symmetrical, they have at least 5 limbs and some have many more than that, though I think they are generally considered radially symmetrical.
My best one off the top of my head would be flounders. both eyes are on one side of their head and the rest of their body is strangely twisted.
Some crustaceans have differing levels of asymmetry, most commonly having one claw much larger than the other.
Generally these come about from unique living arrangements or specialized actions, niche living, either where they live or some special food they eat etc. The animals have adapted to specific things in their environment.
[Answer]
You need to figure out what environmental reason there would be to not be symmetrical.
The asymmetric earth creatures I can think of are crabs and lobsters, where one claw is for crushing and the other for cutting. Lobsters for instance don't have much of a mouth, and no teeth, so they use their crushing claw to break open an oyster, and their cutting claw to snip it into tiny pieces that they can throw at their mouth.
A fictional example of asymmetry are the Moties in "[The Mote in Gods Eye](http://rads.stackoverflow.com/amzn/click/0671741926)" by Larry Niven and Jerry Pournelle.
These creatures had a caste system where their body plan would give them an advantage for their jobs. Workers had two arms on one side with delicate manipulating hands and a massive gripping hand on the other side.
On a side note, this led to asymmetric points of view "On one hand you have A, on the other hand you have B, on the gripping hand you have C".
All you need for a world where symmetry isn't the norm is a reason why this would give an advantage at an early stage of development, since any further adaptations would follow the same pattern.
[Answer]
Based on some of the other answers here, I came to the realization that the best way to make an animal asymmetric is simply to turn it ninety degrees. Bowlturner mentioned flounders and crabs (well, he mentioned crustaceans, crabs come more readily to my mind), both of which are animals that seem to have turned their lives ninety degrees: the flounders seem to be swimming on their sides, while the crabs seem to be walking sideways.
My best explanation for how this would occur in evolution would be the introduction of a species to an environment with a lot of tight spaces. For instance, if you've ever been spelunking (or walking through a crowd), you'll know that there are many occasions when you'll need to turn sideways to get through a narrow gap. Just like how people are left or right-handed, people will naturally choose to turn to a specific side when navigating a cave. If the decision is one-sided enough, a mutation favoring the dominant side may provide enough of a benefit to be passed on meaningfully and develop more over time.
Of course, this is just one path evolution may take. Perhaps the animal would leave the caves for a more suitable habitat (or simply die out), or evolve to be smaller or have thinner shoulders. Also, even if the asymmetric path is chosen, eventually I think the animal would still tend towards symmetry. That said, due to the immense amount of time it takes to evolve, there would definitely be millions of years before both sides matched up again.
[Answer]
My best guess on why animals would develop asymmetrical body plans would have to be sexual selection.
To be a little more clear...
Most animals, [even humans](http://www.discovery.com/tv-shows/other-shows/videos/other-shows-science-of-sex-appeal-videos/), favor symmetry when it comes to selecting sexual partners. Symmetry tends to be a sign of good reproductive health. Poor nutrition, disease, and/or traumatic injury are often the causes of asymmetry in many species.
"Hey, baby, I see that you aren't missing any parts, and that your parts appear to be in the correct locations... " You get what I'm saying
To make a species, or several species, asymmetrical all you really need is for that asymmetry to offer a slight advantage. Chances are pretty good that sexual selection will take that asymmetry and exaggerate it.
The lop-sided claws you see in many [species of crab](http://en.wikipedia.org/wiki/Fiddler_crab) are a good example of this tendency. Having one large claw for defeating rivals and one small claw for feeding offered a crab a slight practical advantage. Over generations the claw used to defeat rivals will grow larger because those with a larger claw are getting more chances to mate. If female crabs are also more attracted to fellas with one large claw, those with a larger claw will be doing even more mating.
So... Bottom line if you want asymmetry just make it sexy...
[Answer]
I recently added an asymmetrical blob to my world. It is a mass of cells that evolved to survive in a cave system and be resistant to radiation. By definition it asymmetrical on the macro level as it can take any shape due to its jelly-like structure and ability to mold into just about every crevice in the cave. It evolved this way because surface life is impossible and even underground it can be exposed to higher levels of radiation.
It evolved to have every cell have all functions (e.g. Any cell in the organism could function as a part of the respiratory system, a vascular system, a liver, etc.). I am not cure how plausible this scenario is, but I have been working on a way to prevent mutated cells (cancer cells) from killing an organism and this seemed like a good idea. Therefore an asymmetrical organism of the macro level might be a blob of cells evolved to cope with radiation levels (although the more plausible solution is to get an armored exo-skeleton).
An ocean world might evolve asymmetric organisms. An octopus comes to mind. While it is symmetric it can adjust its body to fit into nearly any nook or cranny. As James said no matter how the world you design comes to be, you will always have some level of symmetry.
[Answer]
Consider the Halibut
This is a normal fish, that has evolved to swim on its side, rather than vertically.
Notice how the eyes have crept over the bridge of the 'nose' so that they're on the same side.
What we have here is a fish that has rotated its orientation 90 degrees.
[Article on Flatfish Evolution](http://www.pbs.org/wgbh/nova/next/evolution/flatfish-evolution)
[Answer]
A sessile creature could become asymmetrical, and then later it may become motile again, leading to a motile asymmetrical creature. This is certainly possible, as it has happened in real life with the echinoderms. However, this most likely would have to be a relatively recent change, as they will likely become symmetrical in some way after enough time.
] |
[Question]
[
I've been thinking about a steampunk style world where a lot of the transport is done with balloon powered airships. Obviously there are conflicts and I'm trying to think of ways these craft could be a little more resilient to attack. A flying navy.
At the moment I can't see any reason why a cannon ball through the balloon and the ship will crash fairly spectacularly!
What defensive measures can an airship take to prevent itself from crashing as soon as it's attacked?
[Answer]
Here are a few thoughts that come to mind:
* Provide a system where incoming projectiles can be deflected.
* Possible a system where human gunners would try and shoot a cannonball to knock it off course
+ Another possibility of this would be an automated system.
* Force fields
* Plate it in metal (you'd have to work out the physics for that).
+ Sloped metal plating format ([T-34](http://en.wikipedia.org/wiki/T-34#Armour)) could reduce thickness and therefore weight.
* Remove technology that would easily destroy it (not all cannons can shoot very far up)
* Use a series of pockets filled with air inside the balloon. That way not all of the air would leave the balloon if some pockets were punctured
* Use a [lifting gas](https://en.wikipedia.org/wiki/Lifting_gas) which is not flammable. [Thermal airships](https://en.wikipedia.org/wiki/Thermal_airship) use hot air, for instance.
I'm following the suggestion in [this](https://worldbuilding.meta.stackexchange.com/questions/83/how-to-deal-with-list-questions) meta post on how to answer list questions. Please feel free to add your own possibilities to this answer.
[Answer]
You're starting from a false premise.
Look at the performance of [airships during World War I](https://en.wikipedia.org/wiki/Zeppelin#During_World_War_I) to see how things really work out. The Zeppelin bombers could take an incredible amount of punishment without crashing -- it was only with the development of incendiary ammunition that British fighters had a hope of shooting them down. If your lifting gas is non-flammable, even that isn't an option.
The fundamental fact is that any realistic airship is *huge*. A [Hindenburg-class airship](https://en.wikipedia.org/wiki/Hindenburg-class_airship) has about 300,000 square feet of envelope fabric. This fabric provides essentially no resistance to penetration, so a cannon shell will simply pass through without detonating, leaving a pair of tiny little holes. (A time fuse could make the shell detonate within the envelope, leaving *lots* of tiny little holes, but the results wouldn't differ much.) Since a rigid airship uses an unpressurized envelope, the lifting gas is in no hurry to escape, and even if the attacker can turn it into Swiss cheese, it'll take hours or days for the airship to lose the ability to stay aloft.
There's no need to armor an airship against enemy fire: its sheer size is sufficient protection. You may want to armor the cockpit, engines, and other critical structures, but that's a much smaller area that needs protection.
[Answer]
I'm going to post it as an answer (rather than in the question) because it's the only idea I have - I'd really like to get some other (and hopefully) better ones!
The ship could use a series of pockets inside the balloon (similar to the watertight sections in the Titanic). Any cannon/bullet which strikes the balloon would go straight through but only a limited amount of air would escape. Obviously there would be a certain percentage of these which would need to be in tact for the craft to continue to fly.
[Answer]
Your question is premised upon gas envelopes being very fragile, but there is no reason this has to be so.
You could make the gas envelopes out of some strong fibers which could absorb most impacts (think kevlar). The overpressure of the impact would have to be absorbed, but some relief valves mean you lose some lifting gas rather than pop.
Smaller projectiles are of no concern because a polymer coating on the inside can be self-healing. So long as the projectile has not caused a hole so large the polymer cannot touch itself again, it could reseal the hole (as a little experiment on polymers, fill a plastic sandwich bag with water and stick it with a needle - when you pull out the needle, it will not leak).
Worse comes to worse, you lose one envelope - prudence dictates that your lifting body is comprised of several independent gas envelopes. This has been fairly common in real-world dirigibles.
I'm not sure how much weight it would add for an armor mesh (a thin mail armor to protect against shrapnel cutting through), but that is another possibility to bolster resistance. Keep in mind that this is not intended to be thick enough to stop everything, just some shrapnel from flack. One must accept the possibility of being hit - not much different than a surface fleet navy getting hit with shells from battleships.
[Answer]
One very important thing would be the material of the airship envelope and design - Even folks who agree with the hydrogen hypothesis of the hindenburg disaster seem to think that the coating contributed. You *don't* want your airships covered in incendiary compounds! You do, however want *tough*, light materials. Apparently *silk* (while admittedly very expensive) was used in early bullet proof vests and effective against black powder rounds (However I will leave actual testing of small cannon balls against period accurate materials to the reader)
Secondly, you could design your airships to consist of independent 'cells'. Even if one or more cells were breached, the other cells would still hold up, slowing down your decent.
Otherwise, your design choices may be *similar* to a contemporary/parallel period ship. You'd *want* some peril of fire (you *are* powering this with stream and other such dangerous things), and ammo bunker explosions. Danger is *exciting*
[Answer]
The other answers all have good ideas for making the airship more resilient (or reasons to believe it already may be so). In the interest of covering other possibilities, I'll take a slightly different route, and suggest that the best defense is a strong offense. Keep the airships back away from the front lines, but give them the longest-range guns possible, so that they can bombard targets from far away, before they become a target themselves. Airships, with their great altitude, make a perfect platform for long-range canon fire. Of course, the enemy airships will likely be taking the same strategy, leading to an interesting standoff, where each side is trying to be the first to score a hit while staying out of the other's range.
[Answer]
As others have noted, compartmentalization would work. Alternatively, use a scale mail approach - a scale can be pushed aside, then pressure will simply put it back. The cannonball flies through but the holes are temporary. A variant on silly putty could also work for this - a liquid in the material flows into the hole, solidifying in contact with the gas.
] |
[Question]
[
**Closed.** This question is [off-topic](/help/closed-questions). It is not currently accepting answers.
---
This question does not appear to be about **worldbuilding**, within the scope defined in the [help center](https://worldbuilding.stackexchange.com/help).
Closed 1 year ago.
[Improve this question](/posts/230560/edit)
I'm writing a story that follows the life of a poor plebeian farmer in the late republic. While I was working on the plot, I realized a potential plot hole: such a person would not learn about the assassination of Caesar instantly like we would in modern times. In all likelihood, it could take weeks before such news would reach the other side of the republic.
The following are true:
* The farmer himself is very poor without many connections to the Italian peninsula itself.
* The farmer lives several kilometers inland and does not live near a major port city.
* The farmer is a citizen of the republic and lives in rural Anatolia.
With these qualifications, when, if ever, would they learn about the death of Caesar?
[Answer]
There's a lot of [historical research](https://en.wikipedia.org/wiki/Cursus_publicus) into the speed of messages in the Roman empire.
Rome had a courier system where riders would ride between stations switching out to a fresh mount. In normal conditions such a rider could cover 60-100km per day. In an emergency situation, such riders could travel as far as 160km in a day.
Estimates of ship travel put their speed at 190km per day in favorable conditions and 80km per day in unfavorable conditions.
While speed varies between accounts it seems that a safe assumption for non-urgent news will travel at least of 50km per day. In the case of the death of an emperor you can safely assume that the news would spread faster. You can safely assume that your farmer would find out about the Caesar's death within 50 days, but maybe as little as 25 days.
[Answer]
The [geographer](https://www.simonkuestenmacher.com/) behind the Facebook page "Simon shows you map" has published a map showing the fastest travel time to reach places in the empire from Rome in July.
[](https://i.stack.imgur.com/XO5hE.jpg)
You can use it as a reference for a lower limit. It looks like in 35 days the borders of the empire could be reached, Anatolia included. Times could be shortened by using horses instead of walking where possible.
Additionally, you can use this very [handy tool](https://orbis.stanford.edu/) can be used for a more thorough estimate
>
> ORBIS allows us to express Roman communication costs in terms of both time and expense. By simulating movement along the principal routes of the Roman road network, the main navigable rivers, and hundreds of sea routes in the Mediterranean, Black Sea and coastal Atlantic, this interactive model reconstructs the duration and financial cost of travel in antiquity.
>
>
>
From Rome to Comana in July it computes 35 days with the fastest route, which I assume is the one which would be used by a courier carrying the news.
[Answer]
## 4-5 Weeks for an Actual Citizen Farmer
The actual time it will take news to reach Anatolia is 2-6 weeks depending on exactly where the farm is. Since this is a "citizen" farmer, this means he is probably somewhere near the Roman Colonia Şebinkarahisar which is 4 weeks away from Rome and the only place in Anatolia where you might have found citizen farmers at this time. So, while news of Caesar's Death may first reach the region in just a 2 weeks, a citizen farmer would live no less than 4 weeks from Rome.
As for a minimum time-frame: a citizen farmer would probably learn of the event much sooner than most other farmers would. Just before his assassination, Julius Caesar was planning to pass through this region to wage war on Parthia. This would have been a very significant event for the farmer who would have been expected to either supply the army as it passes through or be drafted into it. Being a citizen, he was likely already preparing for the later by the time Caesar was killed; so, news of his death would have been especially important news to this particular farmer at this particular time and place. So much so, that it is likely the local legate would have to dispatch new orders to the citizen farmer to compensate for news of Caesar's death.
## 2-14 Weeks for a Non-citizen Farmer
While the death of the Emperor is certainly gossip worthy, it's not vital news to the common farmer. This means that it is unlikely for someone to hear news of Caesar's death and bee-line it out into the countryside to let this random guy know about it.
The most likely time for a rural farmer to learn about it will be when he is going into town to sell his wares since this itself would be the event where news like this would normally be learned by a rural farmer. Julius Caesar was assassinated on March 15th; so, to know when the farmer would be going into town next, we need to know what crop he was growing. The most common spring/summer crop of Mediterranean Farmers was wheat. Wheat's harvest season in Anatolia lasts from April to Late May. But before he can deliver his harvest, he first needs to dry and thresh it. Due to the laborious nature of Roman Threshing techniques, we can assume this will take another 3-4 weeks meaning that a typical time for an Anatolian Wheat Farmer to arrive in town with his harvest would be some time in Late June or Early July.
While it is always possible that news could arrive at this particular farm at any point after the news arrives in town, news will generally travel much slower between April and Late June because of the time sensitive nature of harvest season. So, while 2 weeks is possible, 14 weeks is more probable.
[Answer]
A frame challenge.
A poor plebeian farmer Roman Citizen would probably not live in rural Anatolia. As a farmer, he would more likely live in a rural area in Anatolia than in acity, obviously.
Here are links to maps of the Roman Empire or Republic in 44 BC at the time of the assassination of Gaius Julius Caesar, the eternal dictator.
<https://www.studenthandouts.com/00/200903/AncientRomeRomanDominionsattheDe-1.jpg>
<https://commons.wikimedia.org/wiki/Atlas_of_Ancient_Rome#/media/File:Roman_Empire.png>
[https://images.search.yahoo.com/search/images;\_ylt=AwrE1xeTuY9iOioAZVxXNyoA;\_ylu=Y29sbwNiZjEEcG9zAzEEdnRpZAMEc2VjA3BpdnM-?p=Map+of+Roman+Empire+in+44+BC&fr2=piv-web&type=E210US105G0&fr=mcafee#id=0&iurl=https%3A%2F%2Fi.pinimg.com%2Foriginals%2F41%2Fff%2Fe0%2F41ffe09930f6be6af61b1890c3739bf6.jpg&action=click](https://images.search.yahoo.com/search/images;_ylt=AwrE1xeTuY9iOioAZVxXNyoA;_ylu=Y29sbwNiZjEEcG9zAzEEdnRpZAMEc2VjA3BpdnM-?p=Map%20of%20Roman%20Empire%20in%2044%20BC&fr2=piv-web&type=E210US105G0&fr=mcafee#id=0&iurl=https%3A%2F%2Fi.pinimg.com%2Foriginals%2F41%2Fff%2Fe0%2F41ffe09930f6be6af61b1890c3739bf6.jpg&action=click)
[https://images.search.yahoo.com/search/images;\_ylt=AwrE1xeTuY9iOioAZVxXNyoA;\_ylu=Y29sbwNiZjEEcG9zAzEEdnRpZAMEc2VjA3BpdnM-?p=Map+of+Roman+Empire+in+44+BC&fr2=piv-web&type=E210US105G0&fr=mcafee#id=1&iurl=http%3A%2F%2F4.bp.blogspot.com%2F-PZWzeHHMo7k%2FVJg0mykQvKI%2FAAAAAAAAAuQ%2FFf6S9C6yPlI%2Fs1600%2FRoman%252BEmpire%252BMap.jpg&action=click](https://images.search.yahoo.com/search/images;_ylt=AwrE1xeTuY9iOioAZVxXNyoA;_ylu=Y29sbwNiZjEEcG9zAzEEdnRpZAMEc2VjA3BpdnM-?p=Map%20of%20Roman%20Empire%20in%2044%20BC&fr2=piv-web&type=E210US105G0&fr=mcafee#id=1&iurl=http%3A%2F%2F4.bp.blogspot.com%2F-PZWzeHHMo7k%2FVJg0mykQvKI%2FAAAAAAAAAuQ%2FFf6S9C6yPlI%2Fs1600%2FRoman%252BEmpire%252BMap.jpg&action=click)
[https://images.search.yahoo.com/search/images;\_ylt=AwrE1xeTuY9iOioAZVxXNyoA;\_ylu=Y29sbwNiZjEEcG9zAzEEdnRpZAMEc2VjA3BpdnM-?p=Map+of+Roman+Empire+in+44+BC&fr2=piv-web&type=E210US105G0&fr=mcafee#id=5&iurl=https%3A%2F%2Fi.ytimg.com%2Fvi%2FtkzTU0CnE04%2Fmaxresdefault.jpg&action=click](https://images.search.yahoo.com/search/images;_ylt=AwrE1xeTuY9iOioAZVxXNyoA;_ylu=Y29sbwNiZjEEcG9zAzEEdnRpZAMEc2VjA3BpdnM-?p=Map%20of%20Roman%20Empire%20in%2044%20BC&fr2=piv-web&type=E210US105G0&fr=mcafee#id=5&iurl=https%3A%2F%2Fi.ytimg.com%2Fvi%2FtkzTU0CnE04%2Fmaxresdefault.jpg&action=click)
You will note that about half the area of Asia Minor is various provinces acquired at various dates. The other half of the area of Asia Minor is part of various client states of the Roman Empire.
YOu will also knote that the maps disagree a lot about the areas of the Roman Provinces in Asia Minor.
In most Roman provinces most of the people would be non Roman in 44 BC. Romans would be a minority in each province. Many of the Romans in a province would be military or government employees assigned there temporarily, or Roman merchants traveling to and from the province on business trips.
Other Romans might live in a province permanently. The Romans did establish colonies of Roman citizens, being cities or towns surrounded by farmland, all owned by Roman citizens. If your farmer was part of a Roman colony, he would probably live no more than one day from the city or town at the center of the colony, and so would probably hear the news of Caesar's assassination only about a day after the town learned about it. You might want to find out about colonies of Romans - if any - established in provinces in Asia Minor before 44 BC.
And of course there were even fewer Roman citizens in parts of Anatolia that weren't provinces of the Roman Empire but client states. Some Romans would visit those regions on official or commercial business.
And of course some Romans could live in client states permanently. Possibly your farmer became a tenent farmer of a rich Hellenized landowner in one of the client states, or even managed to acquire a small plot of land outside the borders of the Roman Republic.
But in 44 BC most of the peope in Asia Minor were non Romans speaking a variety of non Latin languages. Aramaic may have been a very wide spread language in Asia Minor for centuries. During the Hellenistic Age most of the upper classes and the city dwellers became Hellenized Greek speakers. And Romans who spoke Latin would have been a small minority even in the Roman provinces in Aisa Minor and an even smaller minority in the client states which were not part of the Roman Republic.
] |
[Question]
[
I thought it might be visually and thematically interesting for a character to have a sword made from just one piece of steel, like those knife sets you can buy. Something like this, but obviously more sword-length, intricate, and double-edged, maybe with a crossbar:
[](https://i.stack.imgur.com/Qebo2.jpg)
My concern is that this design only works for knives because they're small and not use to attack people that are potentially wearing armor, dodging, using shields, etc. So my question is: Would a sword like this be a practical piece of weaponry? Or would it be a junky thing you can hang on a wall but will break upon first impact?
[Answer]
A sword is forged from one piece of metal.
The hilts & guards are just embellishments (important ones — more later).
I'm sure you have seen many accounts of swords (katanas etc.) being forged from many pieces. This is because most of those weapons were made from poor steel and the forging techniques were designed to overcome this. In any event, once the final billet is formed the sword is forged from a single piece and as a single piece. With modern techniques ([dropforging](https://en.wikipedia.org/wiki/Forging#Drop_forging)) and the right steel (a good spring steel) a sword blank could be forged with one strike. There would be considerable finishing & heat treating to do but the 'forging' part would be done. Hilts/quillons could be part of the initial forging but this depends on the kind of sword you want. Look at Oakeshott if you want detail on types. Sword types are adapted to their combat purpose and mileau. Contrary to popular belief the katana (while a beautiful object) is no more effective than the broadsword or late English backsword. It just happens to be very effective in combination with a particular fighting style and set of circumstances. I however would not want to go up against, say, Guy Windsor (modern European fencing master & broadsword exponent) with one (equally armoured). He'd take you apart.
The above is really just a quick overview. The physics of sword motions and impacts are non-trivial and dependent on the combination of the design of the blade, weight distribution and the geometry of the tang. There is some detailed material on Swordsite.
The hilt takes many forms from a simple crossguard hilt to a complex full basket. It is essentially designed to protect the hand. The grip is what encloses the tang and makes the sword comfortable to hold. Hilts come in more varieties than swords. Essentially you want the tang (the part of the sword inside the grip) to flex on impact and in combination with the movement of the pommel, (the knob at the back) to absorb the shock. While you may have seen pictures of swords that appear to have single piece blades and grips this would lead to poor physics for anything but a thrusting weapon. A lot of knowledge about sword physics and design has been lost and there is presently a concerted effort in the enthusiast community to rediscover it.
Hilts are embellishments in the sense that they may be minimal, a small disk (katana), simple such as a crossguard (hand and a half, or broadsword), complex quillons (rapier) or full or part basket (schiavona, cutlass, claymore, backsword). Each will affect the style of 'fight' with which the sword is used. In answer to your question a simple hilt could be forged integrally with the blade. It is not done because making it as a separate piece allows more design freedom and does not compromise the weapon. It also allows for easier repair as the hilt can take quite a beating even in practice. I've re-hilted the claymore I use in practice once already and it's about time to do it again.
[Answer]
Yes it can be done, and with good result.
I believe nothing answers "can you" as well as real life example, here it is: Qi Jian by Paul Chen, product number SH2295.
[](https://i.stack.imgur.com/4mCiO.jpg)
Image from [distributor](http://casiberia.com/product/qi-jian/sh2295), used as fair use.
In it's marketing material it was said it is a replica of a sword owned by Feng-Xuan, but it's a folk tale impossible to verify.
I'm not affiliated with them in any way, but I do own a piece or two from them and all I can say is that their swords works, you can cut with them all right.
[Answer]
Yes you can forge the whole thing including the hilt, the pommel, and the guard from a single piece of metal but it's bitching hard to do and heat treating the result successfully (AKA so something doesn't break at the worst possible moment) is even harder, mainly because the guard and tang need different properties to the blade. As a result the usual method is to forge the guard separately, use wood or some other material as "fillets" and then a wrapping of cord or hide for the hilt and use a pommel of a different material altogether and attach it last under pressure to hold the whole together. That's for classic Medieval or Renaissance western swords, Katana and Dao are a bit different but still constructed from several separate components. Older western swords like the Viking Longswords of the 900s were forged with integral guard and pommel with a wrapped hilt. There are advantages to the one piece guard especially as blood can't get under a forged guard and rust the tang but generally speaking they're much harder to make than the benefits would seem to justify. The attitude towards a one-piece forged blade in Medieval and Renaissance Europe seems to have been "sure you *could* do it that way but why bother?" so the practice stopped and I'm pretty sure you can't forge something as complex as a basket hilt as a single piece with the blade anyway.
] |
[Question]
[
Thanks to [this question on undersea fortifications](https://worldbuilding.stackexchange.com/questions/17484/what-would-the-fortifications-of-an-underwater-city-look-like), I have begun to wonder about the kinds of weapons mer-people would use when fighting one another. Normally, mermen are assumed to use tridents, but I assume this is more of a cliche than an actual tactical decision.
So, given the fact that you are a half-man, half-fish in an aquatic environment, fighting against an individual with similar properties, what kind of weapon would you want to bring to the fight? Considerations should be made to 3-dimensional combat, the unique movement system of merpeople (tail propulsion), and the extra resistance of water instead of air. Optional consideration includes the added difficulty of fighting in groups/formations, though I plan to ask a follow-up question about what kinds of formations mermen would use. Also, I would like to know about what kinds of armor mermen would use to combat these weapons, though again that might make this question too broad.
I am mostly concerned with a medieval tech level, or at least its undersea equivalent. I guess you can assume any weapons or armor could be forged by blacksmiths on land if that's a problem.
[Answer]
I think the simplest weapon would be a long spear used in a manner somewhat similar to a lance. The merfolk would couch the spear securely with both hands and possibly some sort of a harness and swim at maximum speed towards the enemy. At last moment they might try to swerve to avoid being hit while still trying to hit themselves.
Tactics might resemble tactics used by ancient triremes. They'd definitely would try to make flanking movements to get hits on the flanks with reduced risk of being hit themselves.
Galleys often ended up with boarding action. The analogue would be grappling with weapons. The weapon for that would be a long knife or short sword used to repeatedly stab the enemy. This would probably be the part that generates most fatalities.
The charge would require a helmet, possibly a rigid vest of some sort to protect shoulders and upper body. Possibly with attachment to couch the spear for charge. For melee, the off-hand forearm would be armored for parry. Maybe the weapon hand as well, but I don't see them using the weapon for parry.
So they'd circle around each other for a while for advantage, charge with spears set, and then resolve things in brutal melee with long knives and grappling. Minimal armor would make it brutal and fatal. I'd assume most battles would be won by the losing side losing its nerve and trying to run. (Or swim.) So units not breaking would win battles.
[Answer]
The problem with using traditional melee weapons as a merperson is that there is really no way for you to obtain purchase underwater, thus you'd have no leverage necessary to effectively swing/slash/thrust a blade. As a merknight, your best bet for fighting with traditional weapons would be something like jousting. In this case, a trident actually isn't such a bad idea.
However, as they spend most of their time underwater, it seems like a merperson would be more adroit in the use of their tailfin, not to mention that it must be the most muscular part of their body[citation needed](http://img2.wikia.nocookie.net/__cb20101205035356/disney/images/6/6b/Beached66.jpg). Arms may be somewhat useful underwater, but I just don't see how a merperson's upper body strength would be anywhere near as useful as their lower body strength.
My idea, as it is, is to attach something like a [tessen](http://en.wikipedia.org/wiki/Japanese_war_fan) to the end of a merwarrior's tail. The resulting melee fighting would look strange to the common landlubber, but awesome.
[Answer]
The physical properties of water are the key considerations here. Water is about 800 x denser than air, so projectile weapons and weapons which rely on speed to provide the momentum to deliver damage such as light swords will be severely hampered.
Short range projectile weapons are possible, so the merpeople could start combat with exchanges of "fire" from spear guns and similar weapons, but this would resemble firearms exchanges in the 1500's. Since fighting in water is 3 dimensional, we are talking about something similar to cavalry units of this period, who would form circles and ride past points in the enemy defense, each trooper firing a wheel lock pistol into the enemy formation, then riding out of range to change weapons. Formations similar to schools of fish weaving in constant three-dimensional patterns to fire or evade would be the analogue here.
Once the projectile weapons are out, then combat would become more "hand to hand". Thrusting weapons like spears would work well, but the inability to form walls or phalanxes (you would be constantly outflanked in all three dimensions if you assumed a static formation) would make combat resemble the individual duels found in the Illiad rather than clashes of bronze-clad warriors in classical times. If the combatants were to grapple, then daggers would be the biggest threat.
Body armour would not be a big thing since it would interfere with the mobility needed for combat. Protection of formations might be achieved through the use of nets along the flanks, but anyone losing situational awareness would risk getting entangled themselves. Other defenses adapted from that environment might include the release of "ink" into the water to mask movement, or having skin similar to that of a squid, to change colours to match the environment.
The use of chemical explosives would mean formations would have to be far more open (the shockwaves of an explosion would kill many merpeople if they were all close to the blast), and there might be some adaptation to shaped charge explosives to focus the shockwave in a particular direction, although there could be no "gunners" to serve the device; it would have to be aimed and fired either through timer or by remote control.
Other naturally occurring weapons could include bursts of concentrated sonar, or even electrical devices modeled after electric eels, although these would be more like shock batons than ranged weapons.
[Answer]
**Spearguns**
[Spearguns](http://en.wikipedia.org/wiki/Speargun) use either an elastic band or compressed air to fire a bolt. If materials like this are not available, a crossbow will make a fair approximation. The weapon is high powered, but does not have an incredible range. There are a plethora of venomous/poisonous animals in the sea which can lend their venom/poison to these barbs. This allows for smaller and more deadly projectiles.
**Knives**
Large weapons are difficult to wield without proper stance. Small slashing and stabbing weapons like knives would be the best for close quarters combat. Again, venom/poison will make these more effective.
**Fish Armor**
Armor is difficult for a tail. It's not just a single joint. A good option for armor would be to be surrounded by a school of fish. The fish would act as a mobile and confounding barrier to incoming projectiles. A light armor could then be used to protect in close quarters against slashing weapons.
[Answer]
Assuming no fancy technology/biological stuff, some weapons I would expect:
* **Long, thin spears**, for charging, or defense against charges
* **Crossbows** - would only work short range, basically as an alternative to spears that works better for moving targets (waving a spear around is not practical)
* **Rapiers**, for short-ranged combat (defense, or after a spear charge)
* **Daggers**, as a left-hand weapon, or a fallback once spears and crossbows become useless
* **Ink** for concealment, either for retreat/dispersal or for obfuscating attacks (send several merfolk trailing ink clouds, in only one of them attackers are hidden)
* **Nets with hooks**, or strings with hooks, especially if you can get nasty nearly-invisible wires. This can be a good defense to leave somewhere, or to trail behind you if you're being pursued, or to hide in an ink-cloud.
Armor is also pretty interesting, because hydrodynamics become important, so armor that makes you swim more slowly would definitely be a problem.
As you mostly swim forward, a helmet and shoulder plates become much more important, but also, three dimensions makes peripheral vision much more important, so I would expect helmets that stick much more closely to the face, but leave the eyes open (glass visors would of course make things better, if the tech is there).
What could work would be combined forces of heavily armored spear-men leading a charge, along with rapier/crossbow wielders who are more lightly armored (for better peripheral vision) who protect the spear-men once a charge is done.
[Answer]
I think for underwater combat it would be useful to take a look at the different predator-prey relationships that already happen under the sea.
Consider the most popular, and villanized sea creature: the Sharknado.
Sharks will basically ram their target as they latch on and bring about death with their sharp pointy teeth. And so do most other sea predators:
Barracuda, Killer Whale, Sea Lions...
With the preference to being able to consume your target in one go.
I'd expect our mer-people would try to follow the same pattern - as some others have mentioned, it would pretty much look like jousting. There would probably be a strong preference for guerilla warfare - waiting in ambush and then striking when the enemy is caught unaware. Most other sea predators, like the [stonefish](http://en.wikipedia.org/wiki/Synanceia) do this.
One interesting thing about the water is [how seals find their prey](https://www.youtube.com/watch?v=V6WjyfMGRkI) - by using sensitive whiskers. It seems reasonable that Mer-people would either evolve similar abilities, or cultivate companion animals the same way we do with dogs.
[Answer]
# Armor
You would want some sort of metal protective layer covering the tail, however this should not impede movement much. I suggest [Chain Mail](http://en.wikipedia.org/wiki/Mail_%28armour%29) as your first line of defense.
# Very close quarters:
Your best chance to pierce the mail armor of your opponent will be using a [Stiletto](http://en.wikipedia.org/wiki/Stiletto) or similar weapon. You want it to be a stabbing weapon as swinging will increase the water resistance and decrease the strength of your blow. Chain mail was also designed to minimize the effect of swinging blows. If you stab you will have a better chance of piercing your enemies' armor. After they are bleeding and crippled leave them for the sharks.
# Long distance
You could have some sort of coral ballista that fires [harpoons](http://en.wikipedia.org/wiki/Harpoon). These harpoons will also be attached to nets that entangle multiple enemy soldiers at once.
# Near surface combat
I imagine Mermen swimming near the surface and raining harpoons down on their enemies. They could also drop rocks and just about anything else to put their enemies in disarray.
Massive nets could be dropped to entangle entire battalions of Mermen.
# Mounts
The best mounts would be Dolphins and Sharks due to their fast movement and strength. Dolphin riders would also benefit from the inherent intelligence of their steeds. Whale riders would be rare (why don't you try catching and training one) but I can imagine a scene in your story not unlike that in The Lord of the Rings when the elephant riders (forgot their canonical name - it's been a while) charge in and scatter the riders of Rohan.
[Answer]
Water resistance is going to be the biggest limiting factor.
Swinging a sword is going to be hampered by it, and any kind of club is pretty impractical for the same reason.
A spear/trident is really a good option for hand to hand combat because the thrusting of your arm has very little surface area, versus the entire side of your arm for a sword swing.
Another great option would be a [speargun](http://en.wikipedia.org/wiki/Speargun). You might be able to use a bow as well, though I don't know how well that would work, with the arms of the bow pushing against the water. The arms would have to be very thin to avoid water resistance.
**EDIT:** [bows kinda work under water](https://www.youtube.com/watch?v=pjiuF8POpbs).
**EDIT 2:**
For very close combat knives would work, but also blades attached to the tail would be useful, and provide a lot of swinging power.
Also you could have fast swimmers dragging lines with hooks or blades on the ends to catch at enemies.
Lastly you could make a "blood bomb" to draw in sharks and start a feeding frenzy. You just wouldn't want to be close to where it burst.
[Answer]
I have to agree with some of the other people on here that tridents really don't seem like a bad option, as cliché as they may be. I feel like you'd be much more likely to see thrusting weapons like tridents or spears than anything swung like a sword or club. I've never swung a sword underwater, but it seems like the extra resistance from the water would slow it down a lot. Maybe a small, short club with a sharp, hydrodynamic shape could be effective though... perhaps [some thing like a mere from New Zealand](http://deadliestwarrior.wikia.com/wiki/Mere_Club). In fact, I recommend looking at some of the other weapons used by [Maori warriors](http://deadliestwarrior.wikia.com/wiki/M%C4%81ori_Warrior). The shark-tooth club and stingray spear are of particular interest.
[Answer]
I might take a cue from nature, and the old frontier, and use some variant of biting **Steel Animal Traps**. One of the most effective predators in the ocean is a shark, and the shark's mouth is basically a natural one of these. The only barrier to these is how many of them you can carry, but smaller ones can be just as effective... You could even design a fairly effective melee weapon that bites...
Piercing weapons are also effective, and spring-powered tools work well underwater, so it ought to be fairly simple to construct some form of waterproof **Nail Gun**.
The last thing I'd want, in the water where actions are that much slower, would be for my weapon to drop from my hands, so in addition to having **straps** (and **velcro**?) to keep my weapons where I want them, I'd also have **barbed gloves** and **bladed (shin/tail)guards**.
As for tactics, one might consider most of the 3d tactics used in space combat sims like ["Homeworld"; Wall, Sphere, X, and Claw](http://www.rakrent.com/rtsc/html/hw7.htm) are rather nice. More options can certainly be derived from these.
[Answer]
Take inspiration from the animal world:
Electric eels stun their prey with a very brief high voltage shock, using special organs in their body. As electrical discharges under water are omnidirectional, your mer-people could employ such an electric shock as a last ditch panic response.
Mantis shrimp use mechanical energy stored in their exoskeletons like a spring to pop a punch that moves so fast that a cavitation bubble follows. The cavitation implosion provides a substantial part of the damage inflicted by their punch.
The state of the art in human underwater warfare involves stealth torpedoes and very fast-moving supercavitating torpedoes that can travel a couple hundred miles per hour underwater by generating a bubble around the torpedo to reduce water resistance. So cavitation seems like a mechanic worth exploring.
[Answer]
I would bet on domestication and training of war animals: sharks, killer whales, dolphins, etc.
The tactics would be to surround enemy formation and push it to the surface.
Even minor wounds from projectiles or melee attacks would draw blood and attract sharks and other predators.
See <https://youtu.be/6zOarcL1BSc> for how this works in real ocean.
Projectiles could be launched close to the surface so they don't lose speed as much and also to make them less noticeable and thus harder to avoid.
Also your fighters can wear stripes to be less detectable to the sharks, see <https://youtu.be/DCIL2nvU4x8>
[Answer]
Since not much is know about merpeople these are my thoughts:
I would assume that they would use found undersea items to craft weapons and armor, or occasionally, things found in shipwrecks. Items like sharpened coral or natural rock would work well for spear points and blades(of any length), and could be used to reinforce armor, but could get heavy and unwieldy if used for an entire suit of armor. I would imagine a more "leather" armor approach using woven seaweed (or other tough underwater plants, interwoven with strategically placed, shaped coral, rock or shells to protect vital organs). Possibly consider a "new" undiscovered plant grown by the mer-folk specifically for the armorcraft.
I don't imagine poison would be a good option, because once extracted from its source (animal, plant or synthetic) it would be nearly impossible to apply to any kind of weapon without the water washing it off or affecting an entire area, thereby polluting all of the environment in the surrounding area. There is no way to isolate a specific area for poison dispersal, so either an anti-toxin would be needed or a different approach. This would also have an effect on the surrounding flora and fauna of the sea, and I imagine the merpeople to be more eco-conscious than their land-dwelling counterparts and would decide on a better, more effective method.
Typically plant and animal based toxins need to be ingested or delivered directly into the bloodstream to be effective. Consider giving the merpeople some form of natural defense mechanism that utilizes toxins by touch or under their fingernails, used as a last resort, scratching the skin could administer the toxin or some other method. Maybe even a dissolving bullet/projectile, or false tip on a blade, that contains the toxin and is released once it enters an enemy body. Or contains a large enough dose to kill/paralyze an enemy, but small enough that if it dissolves on the ocean/sea floor, it wouldn't be harmful.
Any kind of traditional "gun" would be difficult to build for underwater use. Combustion is a key component of using a FIREarm and would not hold up to long-term use well. However, a more crossbow approach for projectile weapons could be considered. Using a somewhat heavy, sharpened object would likely be effective, but any projectile would not be very useful underwater unless a very great force could be used to propel it or if used for mid-range combat. Water, obviously, is very dense and creates much resistance when trying to move quickly, whether defensively or offensively. Spears would be the best bet for long-range attacks, or maybe some kind of spear-launcher, for added range.
As for mounts, I think that sharks and dolphins would be a good bet, but really, merpeople are equipped with the same mode of transport...are they really faster? Dolphins would be a more intuitive choice since they are more intelligent and would respond better to the interactions. Sharks, obviously, would be more lethal and would probably be used by more practiced, disciplined hands.
I hope these thoughts make sense, and I hope that you can create well-defined, believable world! Good Luck!
[Answer]
Since currents in the water a much more persistent that breezes in the air above, water-borne poisons would have a greater range and could be targeted with greater accuracy than their airborne counterparts.
[Answer]
**Want to improve this post?** Provide detailed answers to this question, including citations and an explanation of why your answer is correct. Answers without enough detail may be edited or deleted.
The popular musical ensemble Dethklok has you covered with the lyrics to the smash hit - Murmaider. Its a song about mermaid murder!
* Knives
* Rope
* Dagger
* Chains
* Rocks
* Laser beams
* Acid
* Bodybag
* Shiv
* Pipe
* Hammer
* Axe
* Swords
* Saws
* Clubs
* Claws
* Hatred
* Anger
**Reference**: <http://www.azlyrics.com/lyrics/dethklok/murmaider.html>
**Graphical** **presentation**: <http://www.youtube.com/watch?v=hqJKZVnNLT0>
[Answer]
don't forget to consider the material of armor and weapons. It'd have to be bronze, as iron wouldn't last very long in salt water. Goes without saying they would have to be made by humans, so they would be obtained by trade, for pearls or whatnot.
Whales in war? You might know that killer whales, dolphins etc hunt fish schools by beating their tails and sending concussive shockwaves into them. It might be an effective use of a mermaid's tail, or a very large tamed aquatic mammal.
On the subject of mounts, why not Hippocampi, which is the mermaid version of a horse with presumably a much more powerful and muscular tail. They would not straddle them but lie across their backs secure themselves to their necks and arm with a lance and act as shock cavalry.
[Answer]
I think there could be some benefit to using the low visibility of being underwater, and/or the way light works underwater, to utilize surprise, camouflage, or distraction tactics to confuse and disorient the enemy.
While flash bombs may be too complicated for a medieval underwater-dwelling civilization, squid-ink, sudden reflections, and sand can also be used to disorient or distract. Wearing reflective armor and staying in a tight group while in motion will make it difficult for an enemy combatant to distinguish between targets. Like mackerel and anchovies (and zebras). At the same time, if your water is murky, wearing something that flashes and reflects is going to tell the enemy exactly where you are. metal weapons too, will reflect and flash, so consider non-shiny materials for those situations and emphasize camouflage and surprise tactics.
I know this question is about weapons, but defenses are a good thing to consider too. If you want shields, you will need ones that are shaped to be hydrodynamic to avoid slowing your fighters down while swimming. Same thing with armor. You'd also want armor that is lightweight for the same reason. Heavy things sink, which will slow down your combatants. You will probably want fighters that are patient, and then very fast and effective, that means lightweight weapons and armor. (Speaking of sinking, weighted nets are a fantastic idea for this and net guns are fairly simple in terms of engineering I think).
One other thing to consider is that sheathing/unequipping a weapon or shield is going to be different if your merpeople have fins in odd places. Dorsal fins mean no weapons/shields sheathed or held on their backs, and no straps or belts there either. Consider sheaths and belts worn on hips and arms or along the tail.
] |
[Question]
[
My story takes place in a near-future where robots have gotten so realistic it is impossible to tell them apart visually from humans. Hyperreal human robots are the latest fad, where the robot has its own body functions, needs to eat, and can die. Where the story takes a turn, is that a mechanic who is selling robots at an affordable price is selling real people that are convinced they are robots.
Would it be possible to convince someone that they are non-human?
Would the mechanic have to acquire them at a young age or does that not matter depending on the human and potentially the available drugs?
[Answer]
**Yes**
Simple answer is yes. People have an image of themselves. This image changes over time and the idea of being human fits into this. But there are plenty of irregular personal views that go along with it. Some are harmless, some are just strange and some turn the world upside down.
There is a person who is convinced she's a cat and tries to become one as much as possible with plastic surgery. Some think they are truly in a TV show like the Truman show. Some think they are clones of themselves. Each is just a part of how we perceive ourselves.
The concept of being a robot isn't far off from any of these. There are indubitably already people who think that. The introduction of more and more real robots will just enhance the numbers. As you say, how can you be sure? With relatively simple ways many can be convinced to be one. Just like people can be convinced of other horrible things that never happened to them. Like people who got wrong psychological help and get convinced they have been mistreated or raped, which is a very sensitive subject.
This can be done at later ages, but it is best to do it in formative periods for our self image. Childhood and puberty, but also a part between twenty and thirty there are great changes in the search for who and what we are. The midlife crisis or when people are old and try to see what they were and who they want to be in the latest stages of life are also great contenders.
But as our image is always changing and crisis of personality can appear at any age.
Being a robot with hyper real robots? It isn't just likely, but it'll happen if they arrive.
[Answer]
Yes.
As long as the question is "Can a person be brainwashed sufficiently to switch their own identity" then the answer is yes. It won't work reliably in 100% of cases, or may require a long time to work, but at least some fraction of subjects will be successfully convinced that they are, in fact, robots.
However, this will work only if this society does not have any "litmus test" to tell humans and robots apart. It is apparent that in your society legal standing of humans and non-humans is vastly different (probably similar to
"A.I. Artificial Intelligence" or "Cloud Atlas"), so there would be a strong demand for such test.
[Answer]
## Yes, people could be fully convinced of such things
Most people usually are reasonable and believe true things, but that's not universal and exceptions are quite plausible. Of course, someone who's strongly convinced of something false would be generally considered delusional, but delusions, including unusual delusions, are not *that* rare.
A particular example with some similarity is the [Cotard delusion](https://en.wikipedia.org/wiki/Cotard_delusion) where a someone is fully convinced that they are dead or that they do not exist or that some of their (actually existing) body parts are missing.
If there are at least a hundred people who believe *that* ([here's a study of 100 such patients](https://pubmed.ncbi.nlm.nih.gov/7625193/)), then it seems quite plausible that in a robot-filled society there might be some people who falsely believe that they are robots.
However, that would be a very unusual state caused by fundamental mental problems; it's not something that could be caused by someone *convincing* them that it's the case - just as you can't simply convince someone with Cotard delusion that they are in fact real and alive.
[Answer]
Yes, and it already happens, you see mental illnesses are messy things and can cause your brain to act differently than usual. Of course that's a bit different than what you want, or you could just get those people with those illnesses and use them to make the job easier.
in short yes, and some people already do think they are robots due to mental issues.
[Answer]
Yes, because all these things work the other way round.
The limits of the "humanity" are pretty much artificial. The society may treat as a "human" only the members of the tribe, only the males, only the adults, only the citizens, only the free men, only the followers of a particular religion, etc, etc... Human beings not included in the "real humans" group can be pretty much entrenched to the state of fact, even more if they are born in such environment. The history is full of examples.
The progress of the society and the human rights in particular may be traced by the widening of the "human" definition. Today, more or less civilized jurisdictions just consider every *homo sapiens* as human, but this approach is rather new and not really universal.
Should we widen the "human" definition even more? Should it include sophisticated machines or some animals? We don't know for now, but the debate has already started.
So yes, you pretty much CAN shift the limit back to wherever you see fit. Technically.
Resetting a formed personality into not being a human is surely possible, but it may be easier and safer to breed slaves just like slave owners did (and probably still do).
[Answer]
I want to say No.
From the setting you're describing, the robots are only imitating humans. They are very good imitations and from the outside there is no way to tell the difference.
But from the inside ? Carsogrin talk about it a bit in his answer, but "*Cogito ergo sum*". Even now, in a world where everyone is human (or so it seems ?), most people will, at some point, think something along the lines of "What if I were the only real human and everything else is fake ?".
But now, you want people to think that **they** are the fake ones ? It seems unlikely.
Moreover, your robots servants would probably have some kind of programmation that makes them serve and obey people. Humans wouldn't.
I'm not saying programming humans isn't possible, it's just very hard and very visibile. Breaking or raising a human in servile obedience will make them stand out compared to real robots that don't need that kind of treatment.
And while a robot won't be able to rebel ever, any human that tries will see that it cans.
(I'm not saying you won't have humans that think they are robots, ever. But these people will be a minority and it won't be possible to consistently train human as robots.)
What you could achieve though, is having humans that fake being robots faking being humans. But deep down they would know, in my opinion.
[Answer]
p.s. The core question is that of whether or not you are okay with a rather dark account of how the human beings are persuaded to behave as robots.
————
I think I am not unusual in being aware that I am self-aware, and knowing that there are serious issues around making a machine that is (genuinely!) self-aware. (It is (trivially?) easy to get a robot to be able to talk about itself as a distinct entity, *as though* it is self-aware.)
On those terms, the issue is that the subject would realise that, since they are self-aware, they must not be a robot.
One easy option, theoretically speaking (assuming the required medical knowledge and technology), would be to actually [I can’t think of the word] lesion the part of the brain that does this (without cutting the skull, of course), such that the subject actually *is* a robot, so to speak.
Perhaps it is possible to ambush a sleeping person and do this while they are asleep, without them knowing… the question then being whether they would thereby also not be aware that their faculties were diminished. Otherwise, if they were sufficiently young they might not even remember.
One difficulty is that, unless one does actually remove the personhood of the subject (by whatever means), there will always be the possibility of them coming to the point of revolting.
Another approach would be to try to protect the subject from ever learning that robots are not (genuinely) self-aware, but this would be out of one’s control once the subject had been sold. It would help if the general public thought that the robots’ self-awareness actually was genuine. In that vein… it might be a workable strategy to convince the subject that {the belief that robotic self-awareness was not genuine} was false.
Actually, you could have it that robots actually are self-aware. I am definitely not in this school (albeit not closed to being persuaded), but there is a respectable school of belief that, given that human beings are (genuinely) self-aware, it certainly must be possible to make robots that are. Conversely, some of these individuals simply fail to grasp the difference between being able to refer to oneself as a distinct entity, and actually being self-aware. (Some are so convinced of this that [in the computer game “The Talos Principle”] an argument is made that one certainly could make a self-aware machine out of string, as long as it mechanically replicated the pertinent brain functions. To me, this is more of a demonstration of how stupid the position is. [Actually, in “The Talos Principle”, this might be exactly what they intend; apart from the inordinate difficulty, I was turned off the game by the fact that one never knows what the philosophical commitments of the authors are… and that the game is designed poorly such that this matters. [Or maybe that is what they want you to think…])
Overall, I think the least violent scenario is one in which the general public is convinced that robots’ actually are genuinely self-aware (when in fact they are not). Indeed, as I have said, it is not only entirely possible in real life, but actually to be expected, that many persons who saw a robot referring to itself (without being genuinely self-aware) would strongly believe that it was indeed genuinely self-aware, such that they could not be convinced otherwise.
By the same token… in real life, many readers would find it perfectly plausible that robots might be made in the future that indeed are genuinely self-aware.
The corollary of all this is that, if indeed a robot is self-aware, it is defined as a person, and people start campaigning for it to be treated as such and released from slavery.
————
So…
You can take the position that robots can be genuinely self-aware. This makes it easy to convince a human being that they are a robot, but opens up a can of worms politically (inside the story).
You can take the position that robots can not be genuinely self-aware. Ostensibly, this requires a dark account of what the “robot” seller does to their victims (whether it be psychological oppression or brain lesions or what-have-you).
You can take the position that it is philosophically a contentious question. Within this, one option is to have the human “robots” kept in the dark about this (with the noted attendant difficulties). Another option is to have this a live question for the human “robots”.
As “chasly-reinstate-monica” has observed, as long as there are physical differences, that is a point of weakness for the “robot” seller.
[I am not quite 100% — somewhat distracted. I think I have covered my material, and done so in an orderly fashion, but the reader should be aware that it might be *either* that they need to read again more carefully *or* my account actually is flawed.]
p.s. Using drugs instead of (e.g.) brain lesioning is initially plausible (for the subject), but would become a difficulty when the subject had been sold (unless robots have to take pills as well). (You could hand-wave a drug that did the brain lesioning, but this is not a pivotal issue.)
```
Edit_01
```
Possibly there is a distinction to be made between being self-aware and being autonomous. (I don’t know offhand.)
[Answer]
**What if robots are actually indistinguishable from humans in every sense by then?**
They have cognitive processes, they have sentience (subjective experiences), they have emotions, they are self-aware.
At this point our definition and general perception of what a robot is would be not too different from what a human is. The only difference might be something minor like the place of origin. Suppose robots are created in a lab and humans are born via reproduction.
Someone who does not remember their childhood could be fed false information as to whether they came from a womb or a lab, and then they'll believe that.
[Answer]
In the case that the robots are indistinguishable from humans, then they are basically clones. In other words, those robots are humans, and humans are robots. In that case, it shouldn't be too hard to convince a child that he was born of cloning.
Of course, you'd face the same slavery charges whether you are selling the robots or the humans.
] |
[Question]
[
I am writing a story that is meant to take place after the death of the sun. However, 7.5 billion years might be a little long for most people to stomach. Is there anything that could cause the sun to turn into a Red Giant sooner?
[Answer]
One possibility is that we're simply wrong on when the sun will go to the Red Giant phase.
Science has a good idea of how stars work, but it's not like we can actually look inside of it, or probe it to see what's going on. All of our information is secondary - it's like trying to create a 3D model of something based solely on seeing the silhouette. You can do a pretty good job, but there's also a lot of room for guesswork or mistaken assumptions.
So maybe, due to some mechanism we're not familiar with yet, we've misidentified where our sun is in its life-cycle, and it's actually a lot closer than we thought. That doesn't mean it's likely to go Red Giant tomorrow - we'll notice before that - but say, somewhere in the ten thousand to ~1 million years range is probably reasonable.
[Answer]
Red giants come into being when a star's core becomes depleted of hydrogen. AFAIK there is no "real science" method to speed up the process, as it's directly coupled to the rate at which the star is consuming fuel; the rate the star consumes fuel is coupled to the star's mass.
An in-universe method of sciency technobabble tech could do it, depending on what exactly you have planned for your story.
Issac Asimov's story ["The Last Question"](http://www.multivax.com/last_question.html) eventually uses the concept of "sunpower units." I'd always imagined these as some sort of power station drawing off the helium of the star and fusing it as fast as possible.
If it works in your story, it might be an interesting story hook if the Sun was used as a fueling depot by some alien species, who used hyperspace/subspace to extract hydrogen from the core. Maybe they need to draw it from the core so they can have the fuel at the right temperature, which would explain why they're not just "scooping it" off the surface. This goes on for a while until the solar system is finally flagged as "inhabited," but by that point the damage had been done, and in a few ten thousand years the sun baloons out into a red dwarf.
If you want to give humanity the technology you can do that as well. The thing to note is that you need to use some technology to pull the helium FROM THE CORE. Pulling it from the surface won't make a difference, as surface helium doesn't get burned until way late in the sequence. Sure, it reduces the lifetime of the star, but wouldn't affect the burning rate.
If you can artificially reduce the helium in the core, maybe even have whoever is doing it dumping trash hydrogen or carbon and iron in there, you could nudge the star along the main sequence.
The only other thing I'd point out is whatever you do to the Sun you have to have MASSIVE tech to pull it off. There are 5 billion years of fuel in the core, and the sun is burning ~600 million TONS of hydrogen to helium every SECOND. In order to burn out the sun, you'll need something that can eat up 2-10x that fuel.
Smashing another sun into the Sun won't make it burn off faster, it'll actually top it off. Having a binary style star show up wouldn't work, because it draws fuel off the surface (and would cause more harm elsewhere).
If you don't want some kind of alien tech, a "realistic" sounding idea to me is having a black hole migrate into the core. It would soak up fuel while also increasing the gravity within the core. This might work in causing the hydrogen to ignite, but I'm pretty sure any black hole big enough to do this would cause other gravitational problems to the solar system. Also, I'm not a nuclear physicist, so Stephen Hawking might have problems with this suggestion.
[Answer]
There is one "simple" way...simply pile on the mass of Hydrogen. Large stars burn hotter, and much faster than midsize or small stars, and reach the end of lifetime quicker.
How to add 10 solar masses of Hydrogen is left as an exercise for the reader.
[Answer]
The [Xeelee](https://www.wikipedia.org/wiki/Xeelee_Sequence) stories involve [photino birds](http://spacebattles-factions-database.wikia.com/wiki/Photino_Birds) which are dark matter life forms that use dense normal matter (inside stars) to reproduce by a 3D templating process. They are making stars turn red and “old” in a few tens of millions of years, not the expected billions.
[Answer]
This is not a direct answer to your question, but could provide a different explanation for the same narrative. If your overall goal is to have an Earth without a sun, it would be easier to move the Earth than to put out the sun.
For example, a rogue black hole could pass through the solar system. It doesn't pass close enough to cause direct harm to the Earth through tidal forces, but it does pass close enough to give the Earth a gravitational boost. This increases Earth's velocity such that it is above the escape velocity of the sun. Over the next year or so, the Earth travels away from the sun, until it no longer provides an appreciable amount of light or heat.
The advantage is that this could happen at any point in the future, so you wouldn't need to extrapolate out to stellar lifetimes.
[Answer]
Accelerating the rate in which Hydrogen is burned off and the Sun migrates to burning helium and eventually heavier elements up the curve of binding energy is what causes the Sun or other stars to move into the Red Giant phase of their lives.
Some ideas have been discussed unthread, but perhaps the only other means of doing this would be to somehow speed up the rate at which time passes in the core of the star. There would be other noticeable effects, especially as the sudden surge in energy production and release reaches the surface (energy is generated in the core, but often it takes thousands of years to migrate to the surface. Neutrinos are the obvious exception to this), but if calibrated correctly, the hydrogen would be depleted in a few centuries or millennia, and then the "hotter" reactions involving helium would become dominant and the Sun would begin to expand.
OF course, the speeded up solar core would have pretty apocalyptic effects long before the time the Sun became a red giant, which might be what you need for your scenario.
[Answer]
A large planet or barrage of planets falling into the sun would accelerate the sun's death. This is because stars with more mass burn more brightly and more quickly.
[Answer]
Red giant might be impossible, but a collision with a [white dwarf](http://en.wikipedia.org/wiki/White_dwarf) could kill a star. But I think the most likely result would be a supernova and a neutron star remnant. The mass limit is only 1.4 solar masses after all. I guess you could assume either a low mass white dwarf or a collision with high enough energy to blow off much of the mass of the sun. In any case the addition of the white dwarf would allow the composition of the sun to change relatively fast and it would add heavier elements and probably blow off significant amount of hydrogen, so it would drop the lifespan.
Downside of this solution is that the "special effects" would be spectacular, quite deadly, and entirely different from the red giant you asked for. The energy released on impact would be quite lethal and even a near miss by a stellar mass object would alter planetary orbits. But if that is okay...
Actually, maybe a near miss by a stellar mass object causing the Earth to be propelled out of the solar system would be close enough for your needs. Watching as the sun shrinks in the distance and atmosphere freezes would be very close in effect to sun dying.
[Answer]
The exponential dilemma might be a good bet.
lets say that there are 120 gallons per tank.
lets say that we can fill twice the gallons to the tank in the same time that we did before, a minute. So that in the first minute we fill one gallon.
```
1th minute 1 gallon **1**
2nd minute 2 gallons **2**
3rd minute 4 gallons **4**
4th minute 8 gallons + **8**
5th minute 16 gallons **16**
6th minute 32 gallons **32**
7th minute 64 gallons **64** = 127 total gallons, a little more
8th minute 128 gallons than than one tank.
9th minute 256 gallons
```
At this rate it took 7 minutes to fill a 120 gallon tank, the next minute will fill a whole new tank, and the next minute will fill 2 tanks
To summarize:
at the 7th minute we have a filled tank
at the 8th minute we have a new filled tank
at the 9th minute we have two more new tanks
**Total of 4 tanks in 9 minutes, one in 7 minutes, one in 1 minute and two more in 1 minute.**
this rate can be a a solution for your problem.
**EDIT**
**2^33 = 8589934592**
you can say the sun death was predicted in linear growth but that it actually is in exponential growth. Using the example from above changing a minute for a year, **it will take 33 years**.
[Answer]
Another Asimov one: [The Currents Of Space](http://en.wikipedia.org/wiki/The_Currents_of_Space); no doubt the physics is dated, but the idea is useful.
The general concept here is that, rather than having a single collision with a massive body such as a white dwarf, there is a more continuous accretion of some kind of matter which accelerates the fusion processes.
First, note that due to the size of the sun normally a long time elapses between energy being released in the core and it being emitted from the star. This means that the changed process may have started a long time ago.
Perhaps rather than using normal hadronic matter, one might use some kind of exotic dark matter attracted to the Sun by gravitation and accreting in the core in such a way as to catalyze the fusion process.
I'll admit a problem with this line of thinking: to burn up the star faster it must lose a lot of energy. This means more of a Nova than a Red Giant.
[Answer]
**Peak Sun**
A thousand years in the future, mankind has mastered physics to the point where we can mine the sun using force-fields and other "so advanced it looks like magic" tech. While great for allowing mankind to power their space-ships and spread throughout the solar-system (and possibly galaxy) it does rapidly advance the aging of the star. Keeping in mind that the sun is really really big, this would have to be a fairly huge mining operation, but if it's used to power, and provide matter for, a matter recombinator to terraform Mars, and other stellar bodies in the solar system it might just accelerate the "end of the sun" enough.
[Answer]
Perhaps something that the population do could cause the sun to die off a little quicker - use the fear that some people had of CERN destroying the world when it was turned on and adapt that.
>
> Researchers in their quest for a more efficient energy source
> accidentally use their particle accelerator to create a stable black
> hole, but an unknown effect meant that the black hole was attracted to
> the greatest mass in the solar system - the Sun. The newly created
> singularity accelerated away from the Earth to reach a stable point
> near the Sun (or in it?) and accelerated the Suns loss of fuel.
>
>
>
Some of the other answers have possible rates of consumption that could be tweaked based on the size of the black hole.
Alternatively, perhaps scientists were looking for a way of opening wormholes between systems and accidentally latched our end of the wormhole into the Sun, causing the fuel in the Sun to be moved through it.
[Answer]
We make a lot of studies and assumption on elements that we can see or sense. Our experiments and results are a direct product of our analysis of known elements or bodies. What if there are celestial bodies that exist that we cannot sense? These objects could be moving at great speeds, invisible and could be causing sudden demises to stars by sucking in hydrogens.
This could possibly cause the early annihilation of our beloved sun and we wouldn't even know what hit us. Or probably we realise something approaching the sun, looking at the destruction caused by it on the way and we are unable to stop it.
[Answer]
Rather than trying to explain the sun misbehaving, you might invoke some handwavium time warp that propels the Earth 7.5 Billion years into the future. Or on an even smaller scale, that just transports your people, such as a slightly misconceived time machine.
I have read variants on this at least twice. In a short story (Niven?) where a hyperspace drive malfunction takes a space-liner even further into Earth's future, when the Sun has become a dwarf star. And in a Robert Charles Wilson series of novels *Spin* where an alien field wraps Earth and slows time down about 100-million fold for humanity compared to the universe outside. (The reason emerges later).
] |
[Question]
[
Several light-years away, an alien species has just discovered Mars. They deem it a candidate for colonization, so they launch a [Voyager](http://en.wikipedia.org/wiki/Voyager_1)-like probe to get a closer look. They have no idea that there's life in our solar system; they just want to examine Mars more closely for signs of life and see if there's any more potentially habitable planets in the system.
The probe isn't landing, just flying by Mars and perhaps ending up in a stable orbit around the Sun.
This raises two questions:
* Would we (modern humans) notice this probe? What conditions would have to be met to detect it?
* Would the aliens notice us? Presumably, the aliens would notice some signs of life if they pointed the probe's instruments at Earth, but would they notice our technology?
Assume the aliens have a technology level similar to us, and ignore the problems of getting the probe to our solar system.
[Answer]
Assuming the launch was done in our own pre technological era (with current technology, we "might" be able to send a probe to Alpha Centarui arriving a thousand years from now) so we didn't see the exhaust or heat signature, the probe is coasting in at interstellar speeds. Even interplanetary velocity is pretty huge (an object can stay in solar orbit until it passes about 72 kilometres/sec velocity), so if the intention is a flypast and using a tight beam laser or similar system to communicate with the home world, it is quite possible the object could fly through the solar system and *not* be noticed, or briefly tracked and noted as an anomaly ("Excessive warmth in a rogue interplanetary body on a hyperbolic orbit" might be the title of the paper written about this).
Once the probe powers up, however, it's game on. To save mass, they might deploy a "Mag sail" in the far reaches of the solar system and use the solar plasma as a braking medium. This will result in a "radio howl" as the plasma is violently disturbed by the magsail, and radio astronomers will be able to calculate the rate of deceleration by the frequency shift as the probe slows down, and then work out the new trajectory and orbit. If the aliens use a light sail, the astronomers will be treated to a vast mirror image of the Sun coming at them from deep space, and once again examining the spectral shift of the image they will be able to determine a lot about the probe. Using a rocket engine of some sort simply amplifies the issue and makes things even easier for the Earth to determine something is out there and start making plans.
Of course, in the last 100 or so years of the journey, the probe itself would be aware of technological activity coming from the Earth in the form of radio and television transmissions. Even though they might not be able to interpret then, the power, patterning and strange appearance/disappearances of the transmissions due to the Earth's rotation would be difficult to miss. I note there seems to be no provision by the builders of the probe as to what actions to take in that event. If they are paranoid enough, then simply shutting down the systems and doing an unpowered flypast (as per paragraph one) might be sufficient.
This also presents an interesting quandary for the Earth. If we really did detect a probe arriving in the Solar System, we would have very few options. Trying to send a probe or spaceship to intercept it is going to be beyond current technology (it took 10 years of intricate orbital manoeuvres to meet up with a comet), so we would be mostly passive observers of the probe. The various powers might try to communicate with the probe, and certainly some sort of Earth probe might be sent or (if a suitable one is close enough) diverted to try and look at it. If the Earth is paranoid enough, there might be some discussion of how to destroy the incoming probe. This would be fairly easy in physics terms, if a bucket of sand or ball bearings could be released in the path of the probe the high velocity of impact would vaporize it. The problem would be just getting the bucket into place.
Long term, Humans would try to get to Mars to see the probe if it has gone into orbit, as well as send expeditions to Mars to understand what the probe is looking for. For the Aliens, they will be seeing that Mars is being rapidly settled and claimed by the Humans, so once again, we would need to know if the builders had programmed any sort of contingency plan for something like this.
[Answer]
Assuming the aliens have technology similar to us, yes, we would definitely notice them.
The only way to slow down from interstellar space is to send energetic mass ahead of you in the direction that you're going. Space is a vacuum, you can't just stick out a parachute and slow down as you approach the system. There is a little atmosphere on Mars, but the inter-system distances are so huge that you can't hope to use Mars' tiny atmosphere to aerobrake.
The aliens would have to load the ship with enough fuel to accelerate for up to half of the trip from their system to ours, then turn around in the middle and blast the solar system with the energetic exhaust. All the while, they'd be radiating any heat from inefficiency of their engines and system into space with glowing radiators. All of this would be occurring in the otherwise cold, dead, silent darkness of space: Easily detectable with a telescope.
As the [Rocketpunk Manifesto](http://www.rocketpunk-manifesto.com/2009/06/space-warfare-ii-stealth-reconsidered.html) describes:
>
> In space, everyone sees everything.
>
>
>
Project Rho further describes some current-tech examples in [There Ain't No Stealth In Space](http://www.projectrho.com/public_html/rocket/spacewardetect.php#id--There_Ain%27t_No_Stealth_In_Space):
>
> This means the exhaust is so intense that it could be detected from Alpha Centauri. By a passive sensor.
>
>
> The Space Shuttle's much weaker main engines could be detected past the orbit of Pluto. The Space Shuttle's manoeuvering thrusters could be seen as far as the asteroid belt. And even a puny ship using ion drive to thrust at a measly 1/1000 of a g could be spotted at one astronomical unit.
>
>
> As of 2013, the Voyager 1 space probe is about 18 billion kilometers away from Terra and its radio signal is a pathetic 20 watts (or about as dim as the light bulb in your refrigerator). But as faint as it is, the Green Bank telescope can pick it out from the background noise in one second flat.
>
>
> This is with current off-the-shelf technology. Presumably future technology would be better.
>
>
>
But you said to ignore the problems of getting the probe to our solar system, which is conveniently when it would be most noticeable, so check the bit about the Voyager 1 probe and its 20 watt radio signal. Voyager 1 is just coasting, so the whole issue about blasting rocket or ion exhaust at us is moot. Perhaps you're just going to coast silently by and blast your Unobtainium-built probe backwards at unimaginable acceleration out of a rear-facing, hundred-mile-long railgun as you zoom past Mars, where it can fall down with an Unobtainium parachute.
The probe still needs to communicate with the mother planet to let it know whether life is possible, so it has to emit radio energy of enough power so that the home planet would see it. We can't even really see the signature of a Martian-sized exoplanet occluding the sun; the probe will need to send out unimaginably powerful signals for the home planet to detect it. We are currently searching for the faintest possible signals of intelligent life; there's no way we'd miss recording a communication from our own system destined for a system light-years away with our same technology. Unless, of course, it blew out all our receivers...
[Answer]
For just a flyby, we'd really have to be lucky and looking in the right place at the right time. For comparison, it's estimated there are approximately 100 [near-earth objects](http://neo.jpl.nasa.gov/stats/) larger than 1 km in diameter that we have yet to discover, and those are objects we are actively looking for, for obvious reasons. There are tens of thousands of spacecraft-sized near-earth objects we don't know about. Even if we saw an alien probe, we would assume it's an asteroid, confirm its orbit, put it into a database, and give it no further thought.
The communications are probably easier to pick up, although spacecraft tend to have relatively narrow band transmitters for efficiency reasons. You can pick up their signals fairly easily, but mostly you need to know what to listen for. Your best bet of detection would be in the case of some sort of interference. Perhaps the alien probe is doing routine scans and amplifies and retransmits any interesting signals it receives, causing interference with our equipment on or around Mars. *That* we would notice fairly quickly.
[Answer]
In order for us to detect it on Mars, it would need to do something that would make us notice because remember, [space is really big](https://www.youtube.com/watch?v=2NjSPKxt4ts). The more energetic the event, the more likely we will detect it. A long deceleration burn to put the probe into orbit around Mars would have a good chance of tripping some IR scanning satellite somewhere. Deorbiting the probe in Mars' atmosphere would look indistinguishable from a meteor and likely ignored.
Edit: After reading the "There ain't no stealth in space paper", any kind of deceleration burn would assuredly be detected.
There are satellites that take pictures of the surface of Mars with sufficient resolution to locate various Mars rovers. If the alien's surface probe was as big or bigger than the US *Curiosity* probe then we should see it after a few months or a year. If the probe has a larger orbital component then we have a decent chance of detecting the orbiter based on its radio transmissions to home (though this may not work if the orbiter is using a tight beam radio transmission.)
[Answer]
I think it's utterly ludicrous that a spacefaring alien race only a few lightyears away from us thinks that Mars is habitable and don't think that Earth is, or even that they can sneak up on us.
First off: Earth has been sending out electromagnetic radiation for at least a century by now. That means that our alien race likely has been sending them out just as long since they're at a similar tech level. So we would have known about them for a while by now. Similarly, they would have known about us for ages by now, at least good enough that they've watched all our series except anything up to, say, 2010 (so anything before Game of Thrones), assuming they're 5 years from us.
Additionally, they can calculate that these radio waves are coming from Earth, not Mars, and that nothing is coming from Mars except for a few weaker signals from our older probes, like Spirit and Opportunity.
Finally, even without these signals, Earth would have been a far better candidate to send a single life detecting probe to. It's right in the middle of the habitable zone around Sol, while Mars is really on the outer edge of that zone. If the aliens, like us, are carbon-based lifeforms, it's likely that they need oxygen and hydrogen to live, which they detect massive amounts of on Earth using spectrometers. If they aren't carbon-based, they still would likely view Earth as more interesting because of the more varied spectrometry of our planet. Mars has about 96% CO2, 2% argon, %2 Nitrogen and traces of other gasses. Earth has 78% nitrogen, 21% oxygen and 1% of traces of other gasses. The only way they would see Mars as more promising is if they breathe CO2.
[Answer]
Years ago, when Art Bell hosted Coast To Coast, one guest was a conventional mainstream scientist dealing with space research - I can't remember his exact name or area of expertise. While he discounted UFOs and alien visitation claims, he did get Art's attention when he said that one of his mainstream colleagues was surmising that alien probes may have already visited our solar system. He didn't say who that was or why he had that feeling. I don't think he had any direct physical evidence - ie. spacecraft debris. However, I wonder if his guess what tied to the theory of panspermia - life spreading through meteors. However, it could also hitch a ride on alien space probes.
] |
[Question]
[
**This question asks for hard science.** All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See [the tag description](/tags/hard-science/info) for more information.
People have been trying to imagine elaborate alien biologically possible ecosystems for a while. A lot of people seem to both want but ignore one of those fundamental aspects of our own ecosystem, algae and photosynthesis in general. They also tend to want these alien environments to be hospitable for humans (always more fun if we are in the story).
**What I want: is a hard-science chemically plausible alternative to photosynthesis.**
**Conditions:**
* Can use any reasonable natural source of energy
* must store said energy in a reactive compound (equivalent of sugar)
* **must produce oxygen** as a waste element (any form as long as its unbonded with another element)
* may use [CO2 and water] but cannot use light at all. May use light but not CO2 and water
* May assume the environment is chemically and thermally different than Earth, though please stick to agents that would occur naturally in geology preferably in abundance.
* The organism doesn't have to be carbon based
* **For every reactant used;** Must describe the conditions needed for that reactant to be present (only 1 is needed preferable whichever is more reasonable with the others) **EX:**
[ if Fe203 is a reactant, can be found as a solid on a surface with an oxygen atmosphere]
[Answer]
## You asked for hard science, so here it is.
The key process in photosynthesis is the Joliot-Kok cycle. This is what "splits" water and produces $O\_2$, along with the $H^+$ and $e^-$ that are used to create high-energy molecules. [Here](https://www.ncbi.nlm.nih.gov/pubmed/5456273) is the original proposal in a paper by Kok, and [here](http://onlinelibrary.wiley.com/doi/10.1111/j.1751-1097.1970.tb06017.x/epdf) is a link to the full text if you have access. The mechanism is complex redox chemistry, but is nicely summarized in the below diagram from [this](https://biology.stackexchange.com/questions/14063/photosynthesis-what-powers-the-splitting-of-water) SE question, which actually got the diagram from [here](http://www.life.illinois.edu/crofts/bioph354/lect25.html). [](https://i.stack.imgur.com/mCTlk.gif). [Another SE question](https://biology.stackexchange.com/questions/58563/can-plants-produce-oxygen-at-night-without-light?noredirect=1&lq=1) shows us where the light plays a role- when moving between the different $S$ states. As soon as we have $e^-$ and $H^+$, we have energy in chemical form that's often captured in [cofactors](https://en.wikipedia.org/wiki/Cofactor_(biochemistry)) such as $NADH$, $NADPH$, or $FADH\_2$. These are all high-energy forms of their oxidized states- $NAD^+$, $NADP^+$, and $FAD$, respectively, and can be thought of as a kind of battery that gets charged by $e^-$ and $H^+$. In a sense, the "real" goal of **photo**synthesis is producing $e^-$ and $H^+$ from light energy which can then be used to "charge" the cofactors. So let's look at a couple ways to do this.
As a note, the cofactors aren't magic materials- just large organic molecules. $NAD^+ = C\_{21}H\_{27}N\_7O\_{14}P\_2$, $NADP^+ = C\_{21}H\_{27}N\_7O\_{17}P\_3$, and $FAD = C\_{27}H\_{33}N\_9O\_{15}P\_2$
## Simple (but realistic) solutions:
### 1) Thermosynthesis
There's no reason that the energy required to split water MUST come from light- that's just the way that current biology does it. With a different suite of enzymes and a different cycle, biology could extract energy from a wide variety of sources. In this case, thermosynthesis would rely on heat instead of light:
$H\_2O+heat => O\_2 + 4H^+ + 4e^-$
This mechanism would be different from the Kok cycle because you'd have a thermally activated alternative to P680 in the middle rather than photoreactive. So that's one solution- thermally activated P680.
Finishing the equation (this is identical to the light-independent reactions of photosynthesis):
$2H^+ + 4e^- + 2NAD^+ => 2H^- + 2NAD^+ => 2NADH$
### 2) Photosynthesis without water
Alternatively, one could use a [different electron acceptor](https://www.ncbi.nlm.nih.gov/pubmed/22891064). This came up in the [WB question](https://worldbuilding.stackexchange.com/questions/96207/could-a-deep-ocean-creature-use-some-kind-of-bacteria-in-its-body-as-a-way-to-ge?noredirect=1&lq=1) that inspired this question (if we recurse much more we'll have to move to meta), and the solution was nitric and nitrous oxides, one of the most powerful electron acceptors in nature. It's plausible to imagine these nitrogen oxides taking the place of water in the normal photosynthetic pathway, producing $O\_2$ and $N\_2$ as a result. The researchers didn't have a mechanism for this, but it supposedly produces $O\_2$ that is then used to oxidize methane. So that's another solution, looking something like
$2NO + light + H^+ => N\_2 + O\_2 + 2e^- + H^+$
Finishing the equation (again, identical to the light-independent reactions of photosynthesis):
$H^+ + 2e^- NAD^+ => H^- + NAD^+ => NADH$
## Crazier ideas
This is Worldbuilding- let's stretch the limits of plausibility. Where else can we get energy from? Mechanical movement. My vision for this is some kind of kelp-like organism being tossed about by waves or tides, similar to the theoretical wave/tidal energy extractors. As the stalk of the kelp is stretched, it pulls on a long molecule. There are a couple ways we can get energy out of this.
### 3) Conformational changes
This is like what happens in your eye- a long molecule is unkinked (double bond switches from cis to trans) except we're using mechanical energy to straighten it. As it does that, it forces a conformational change in the molecule that pulls a hydride ($H^-$, or those all-important $H^+ + 2e^-$) off of water- starting a redox chain similar to the Kok cycle. The $^+OH$ would then be attacked by another water, forming hydrogen peroxide- this could decompose into $O\_2$ and $H\_2$ in the reverse of the [normal process](https://www.scientificamerican.com/article/why-does-combining-hydrog/). Feasible? Not really. Good fiction? Maybe. Here's your formula:
$2H\_2O + mechanical force + NAD^+=> H^- + ^+OH + H\_2O + NADH => H\_2O\_2 + H\_2 +NADH$
### 4) Radical chemistry
Similarly, we could use that mechanical force to tear apart a bond, creating two radicals. I'm imagining an $O-H$ bond, forming some alcohol radical and $H\_{(rad)}$. The hydrogen radical would react with something like $FAD$. [$FAD$](https://en.wikipedia.org/wiki/Flavin_adenine_dinucleotide) is another one of those cofactors that modern Earth biochem already uses, and it has a low energy state as $FAD$ and a high energy state when it's reduced to $FADH\_2$. $FAD$ accepts two radical hydrogens in this mechanism, so it's perfect for our use. The alcohol radical would attack water to form a peroxide and proceed as above. Can I imagine it actually working? No. Will it help suspend disbelief for a fiction novel? Probably. Here's the equation:
$2RCOH + mechanical\ force + FAD +H\_2O=> 2H\_{(rad)} + 2RCO\_{(rad)} + FAD + H\_2O => FADH\_2 + 2RCOH + H\_2O\_2 => FADH\_2 + 2RCOH + H\_2 + O\_2$
where RCOH is a generic alcohol- perhaps [ethanol](https://en.wikipedia.org/wiki/Ethanol) ($CH\_3CH\_2OH$) or [propylene glycol](https://en.wikipedia.org/wiki/Propylene_glycol) ($C\_2H\_6OHCOH$)
### 5) Beta radiation
This type of radiation produces a positron, the antimatter particle to an electron. When a positron and an electron collide, they annihilate. If that happened to a water molecule or something similar, it'd make a hydrogen radical that could get snapped up by [FAD](https://en.wikipedia.org/wiki/Flavin_adenine_dinucleotide), forming a hydroxide ion. Not really sure how to get oxygen out of this, but perhaps it could be catalyzed into sodium peroxide and [then into sodium hydroxide and oxygen gas](https://www.quora.com/Write-a-balanced-equation-oxygen-and-sodium-hydroxide-are-produced-by-the-reaction-of-sodium-peroxide). Equation:
$2e^+ + 2H\_2O + FAD=> 2H\_2O\_{(rad)} + \gamma\ rays + FAD => 2H\_{(rad)} + 2^-OH + FAD => FADH\_2 + 2^-OH$
### 6) Gamma radiation
You specified "cannot use light" but I felt like the gamma-radiation eating fungi and bacteria deserved a shoutout. This light wouldn't be coming from a sun, it would be coming from a radioactive source probably deep within the Earth. Not sure if that counts, but I'll include the references [here](https://en.wikipedia.org/wiki/Radiotrophic_fungus) and [here](http://www.sciencemag.org/news/2016/10/alien-life-could-feed-cosmic-rays) just in case. Their basic formula is the same as photosynthesis, albeit with much higher energy photons:
$2H\_2O + \gamma\ rays => O\_2 + 4H^+ + 4e^-$
To finish the equation, we use a cofactor yet again:
$4e^- + 2H^+ + 2NAD^+ => 2H^- + 2NAD^+ => 2NADH$
[Answer]
**This question asks for hard science.** All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See [the tag description](/tags/hard-science/info) for more information.
There are probably some good theoretical processes, but there are 2 natural processes that come to mind, [Chemosynthesis](https://en.wikipedia.org/wiki/Chemosynthesis) and [Retinal](https://en.wikipedia.org/wiki/Retinal).
Chemosynthesis takes an acid, heat, and CO2 to make sugar, water, and it strips the anion off the acid.
The retinal cycle uses sunlight and beta-carotene to produce retinal, oxygen, and some energy. It's also the basis for the [purple earth hypothesis](https://en.wikipedia.org/wiki/Purple_Earth_hypothesis) and is thought to be a precursor to modern chlorophyll.
If emitting Oxygen isn't a hard requirement, you can modify the chemosynthesis reaction to emit any kind of element you want, so long as it can form an acid in the presence of hydrogen. The more electronegative it is, the higher intensity of input energy you need. It's possible you could even do it with a complex acid like sulphuric (H2SO4) and have a secondary reaction that might produce some oxygen off the byproduct.
[Answer]
**Outline**
Some bacteria employ chemosynthesis to reduce carbon dioxide and generate organic matter if oxygen and hydrogen sulphide are present. Other bacteria generate their own oxygen in the absence of light using nitrite. So if elements of both are present with the oxygen producer in excess, this should mimic photosynthesis and produce both oxygen and organic matter in the absence of light.
**Nitrites in nature**
Nitrites form part of the Nitrogen cycle <https://en.wikipedia.org/wiki/Nitrogen_cycle>
And are present to some extent in most soils.
**Sources of Nitric Oxide**
Nitrites from the Nitrogen cycle can be reduced to nitric oxide by [Xanthine Oxidoreductase](http://pdb101.rcsb.org/motm/117) (XO) Under aerobic conditions:
2NADH + NO2- > XO > NO + 2NAD+ + H2O
<http://www.jbc.org/content/275/11/7757.full>
Nitric oxide is also formed at high temperatures lightning.
N2 + O2 → 2NO
<https://www.nature.com/articles/nrd2466>
**Production of Oxygen in the absence of light**
The bacteria Candidatus Methylomirabilis oxyfera converts nitic oxide into free nitrogen and free oxygen.
2NO > N2 + O2
<http://www.kegg.jp/kegg-bin/show_organism?org=mox>
<https://www.mpg.de/621120/pressRelease201003241>
**Production of carbohydrates**
[Chemosynthesis](https://en.wikipedia.org/wiki/Chemosynthesis) is the use of energy released by inorganic chemical reactions to produce food. Chemosynthesis is at the heart of deep-sea communities, sustaining life in absolute darkness, where sunlight does not penetrate. Such as [here](http://wwf.panda.org/about_our_earth/blue_planet/deep_sea/vents_seeps/).
Typicaly utilizing reactions such as [this](http://oceanexplorer.noaa.gov/facts/photochemo.html).
CO2 + 4H2S + O2 -> CH20 + 4S + 3H2O
Hydrogen sulphide (H2S) occurs naturally as a product of sulphur containing rocks and magma in contact with sea water under high pressure and occurs in some deep sea vent effluents.
**Discussion**
H2S and CO2 are present in the environment. The only missing element is Oxygen which is is provided from the nitrogen cycle via reduction of nitrite to nitric oxide by Xanthine Oxidoreductase, followed by conversion to free oxygen and free nitrogen by Methylomirabilis oxyfera type bacteria.
I propose that the Methylomirabilis enzymes and synthesis processes occur in isolation from their usual uses (methane oxidation) and instead are provided to a symbiont chemosynthetic species who use H2S, CO2 and the O2 provided to produce carbohydrates. In return the Methylomirabilis symbiont is provided with a proportion of the carbohydrates produced.
Other bacteria that produce oxygen in the absence of light and utilise a range of inorganic materials can be found [here](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3413370/).
Other chemosynthetic bacteria work with different inorganic media such as hydrogen or ammonia to produce organic materials so these could also be used (see above link to chemosynthesis).
Further details of Methylomirabilis oxyfera can be found [here](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3993179/).
[Answer]
**This question asks for hard science.** All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See [the tag description](/tags/hard-science/info) for more information.
~~I'm can't find it in the short time I have to answer this question, but~~ I ran across an article a couple years ago about a lady that found a small lake/pond in an out-of-the-way spot here on Earth that has micro-organisms that replaced their ~~carbon~~ phosphorus atoms with either ~~sulfur or cyanide~~ arsenic. The ~~carbon~~ phosphorus source in the area was so low and the alternate was so prevalent that they somehow made the switch.
~~So, they somehow ceased to be carbon based life forms, basically.~~ Again, it's been years since I read the 1 article, but I do remember that she was POed about being misquoted by almost all news media as having said that she "found alien life on earth", when she said something more like "finding life on earth that is alien to our way of thinking about it".
The image I remember being with the article is a lady with a steaming pond behind her that looks like it's salt rimmed. If I'm remembering any of this right, I seem to think the area around the pond is completely barren of flora.
While searching for that article, I found what appears to be a similar article, about researchers in a deep mine that are trying to figure out how some micro-life is living without light and with high concentrations of sulfur.
<https://beta.theglobeandmail.com/technology/science/ancient-water-from-northern-ontario-mine-may-harbour-alien-life/article32540885/>
I'm sorry I can't be more use, but I hope it's a starting point. At least this is some science, if nothing else.
**EDIT:** I found the original article, plus the hard science to back it up. I also found an article that tries to debunk it. I don't have the chops to understand it, so I'll let you fight/figure it out. I got some of the details wrong from memory, so the comment by @Ash was instrumental in finding these articles.
The lady's name is Felisa Wolfe-Simon.
<https://www.popsci.com/science/article/2011-09/scientist-strange-land>
<http://science.sciencemag.org/content/332/6034/1163.full>
<https://news.nationalgeographic.com/news/2012/07/120709-arsenic-space-nasa-science-felisa-wolfe-simon/>
Pasting the possible relevant hard-science from the ScienceMag.org article:
>
> Arsenic (As) is a chemical analog of P, which lies directly below P on the periodic table. Arsenic possesses a similar atomic radius, as well as near identical electronegativity to P (5). The most common form of P in biology is phosphate (PO43–), which behaves similarly to arsenate (AsO43–) over the range of biologically relevant pH and redox gradients (6). The physicochemical similarity between AsO43– and PO43– contributes to the biological toxicity of AsO43– because metabolic pathways intended for PO43– cannot distinguish between the two molecules (7) and AsO43– may be incorporated into some early steps in the pathways [(6) and references therein]. However, it is thought that downstream metabolic processes are generally not compatible with As-incorporating molecules because of differences in the reactivities of P and As compounds (8). These downstream biochemical pathways may require the more chemically stable P-based metabolites; the lifetimes of more easily hydrolyzed As-bearing analogs are thought to be too short. However, given the similarities of As and P—and by analogy with trace element substitutions—we hypothesized that AsO43– could specifically substitute for PO43– in an organism possessing mechanisms to cope with the inherent instability of AsO43– compounds (6). Here, we experimentally tested this hypothesis by using AsO43–, combined with no added PO43–, to select for and isolate a microbe capable of accomplishing this substitution.
>
>
>
[Answer]
So since you asked for a non-light and/or non CO2 reaction I'll go both, I'm going to assume that we can have biological structures that exploit the [Seebeck Effect](https://en.wikipedia.org/wiki/Thermoelectric_effect#Seebeck_effect) and use thermal gradients to liberate electrons for chemical reduction. Lifeforms exploiting a thermal gradient in this way will probably be relatively thin and wide with a thermal absorbing side and a heat dissipating side and will take advantage of either infrared [insolation](https://en.wikipedia.org/wiki/Solar_irradiance) from sunlight, rather than any of the visible spectrum light used by conventional photosynthesis, or heat from undersea volcanism or other geothermal activity.
So the Seebeck Effect gives us a potentially non-solar biochemical energy pathway but what are we going to do with it? To start with this creature needs certain elements to a degree that traditional organisms don't, particularly Aluminium and Silicon for the [thermocouple](https://en.wikipedia.org/wiki/Thermocouple) structure that constitutes its power plant, note it needs roughly equal amounts of these two elements. In nature both Aluminium and Silicon occur primarily as rock forming mineral oxides, Al2O3 for Aluminium and SiO2 for Silicon, reducing these compounds to form it's structure our thermo-plant liberates approximately the same weight of oxygen as what it takes up in Aluminium and Silicon, some of this oxygen will be kept to build energy storage compounds like [ATP](https://en.wikipedia.org/wiki/Adenosine_triphosphate) but most of it will be released into the atmosphere.
[Answer]
Chlorine Worlds
Life forms on all known chlorine worlds exhibit the same fundamental biochemistry. This, together with some consistent aspects of cell morphology, is considered to be a strong sign of common descent. As on more typical worlds, life on chlorine worlds produces chemical energy from sunlight by using it to reduce available hydrogen-bearing compounds. Just as on terragen-style worlds, the most common hydrogen donor is water, simply because it is so abundant. This form of photosynthesis releases oxygen. However, chlorine worlds also have a large stock of hydrochloric acid, and photosynthetic organisms also make use of that resource, and release chlorine. The splitting of water and the splitting of hydrochloric acid both release hydrogen ions and high-energy electrons, which are then used to produce carbohydrates and other organic compounds. The usual carbon source is carbon dioxide. There are therefore two dominant kinds of photosynthesis on chlorine worlds:
2HCl + CO2 ---> CH2O +Cl2
in which hydrochloric acid and carbon dioxide are consumed and organic compounds and chlorine produced, and
H2O +CO2 ---> CH2O + O2 the far more common process familiar from Terragen and similar biochemistries.
Most photosynthetic organisms actually prefer to use hydrochloric acid if it is available, but the availability of water makes it the more common donor. Release of chlorine ultimately often leads to oxygen in the atmosphere in any case, since the chlorine reacts with water to release oxygen and produce hydrogen chloride again. The combination of the various oxygen and chlorine releasing photosynthetic pigments is typically purplish-black to human eyes. In the light of a typical K type star, that colour is quite nearly black. Respiration on chlorine worlds is the reverse of photosynthesis, and most organisms are capable of using either chlorine or oxygen as fuel. So, an animal on a chlorine world breathes out not only carbon dioxide and water but also hydrochloric acid. Chlorocarbons are abundant in the biosphere, and participate in many biological pathways (unlike the case on more typical garden worlds, such as Earth, in which natural chlorocarbons are present but relatively rarely produced by biological activity). Some particularly resistant chloride polymers are used by land-dwelling life forms to protect themselves from excessive concentrations of hydrogen chloride or from pure water, either of which is harmful to their tissues.
Vitriolic Type Worlds
Many vitriolic worlds have photosynthesizing lifeforms. The exact biochemical pathways can vary, but the basic process is similar on most of these worlds and somewhat familiar. Sunlight drives cellular processes which combine CO2, sulfuric acid and basic silicones into energy-rich silicone polymer "sugars" and release free oxygen. Cellular respiration is, of course, the opposite; silicone "sugars" are "burned" with oxygen to produce CO2, sulfuric acid and waste silicones. The silicone substrates are commonly solid, but sometimes liquid, and generally are not produced in sufficient quantities to raise removal difficulties even for complex multicellular lifeforms.
Sulfur compounds are nearly always of great abundance and importance in Vitriolic biochemistry, owing to their chemical usefulness and great abundance in the environment. Metals are also much more frequently utilized than in Terragen biochemistry owing to the great affinity of sulfuric acid for dissolving them. It should also be noted that the extreme heat of Vitriolic worlds is not an obstacle for local life, it is nearly always a requirement. Many reactions are dependent on the high energy such heat brings, even with the assistance of enzyme-equivalents. As such, temperatures much below 100°C begin to slow down most reactions a great deal.
] |
[Question]
[
In a civilisation similar to humans (although not necessarily humanoid) living on a planet the size of Earth, could the whole civilisation (no limits on size, although I was thinking a few thousand at least) exist in space as **space nomads**?
This would involve moving from planet to planet, settling for a few weeks or months, then moving again. The nomads are not limited to just planets, though; any sort of planetary body will suffice.
Living as space nomads would also require a stable lifestyle; food, water, shelter, entertainment and above all defence should be no problem for our civilisation. However, the civilisation does not need to live together; tribes would no doubt develop and split off, and wars could possibly begin.
This civilisation is advanced enough to be able to live on planets such as Mars, but the tolerance of temperature, atmospheric density ect. does not differ from human tolerance.
**What factors would drive a civilisation to become nomadic tribes that fare deep space?**
[Answer]
Generation ships are probably the most realistic form of interstellar travel without superscience. So if the originating civilization has some reason to have interstellar travel that justifies the use of resources, generation ships will be likely.
A civilization that has colonizaed its own solar system might turn to exploring other stars almost by default. They'd also have the necessary resources and technology to actually build the generation ship. So the original reason might simply be that it is the only method of expansion left. There would also be economic benefits from the technology developed for the project and the insurance factor of not being limited to one system.
This makes more sense if the civilization is factionalized. Then a competition similar to the space race between the superpowers would be possible, even likely. Being the first to reach a new star system would gain you lots of prestige and combined with the increased technology and manufacturing base might be worth the expense. In the real world many expensive projects have been funded for similar reasons. And the results haven't actually been that bad. Ideally after the project is over all those highly trained engineers and specialists will move on to commercially viable projects that will help national economy and give the funding faction a technological and economical advantage.
After the generation ship reached the next star system, it would initiate a similar colonization of the system as had already occurred in the home system. The new colonies would then be linked to the home system with light speed communications. While direct trade would probably be unfeasible, there would be some prestige and, in the long run as the colony population increases, possibly a cultural and scientific advantage from the larger population base. For the first few systems there would certainly be a scientific advantage from being able to study more planets from close range than competition.
**Now, here is the part that is actually relevant to the question.** You'd still have the generation ship, resupplied and retrofitted with the resources of the new system. You'd still have the people who had spent generations living in that generation ship and who would have no attachment to having a star system. Indeed whose purpose for generations had been to reach another star system. What would they do? They'd leave for the next system.
They would have become nomads. If they'd come to an empty system they'd stay long enough to establish colonies linked to the baseline culture, resupply, and then move on. Possibly from time to time they'd build new generation ships, although more likely those would be built by the star systems for reasons similar to the original generation ship.
Over time the generation ships would come to have very strong identities, not just as individual ship cultures, but as a group separate from the less mobile people. Also, the ships would eventually start meeting each other and travelling in already colonized star systems, further developing a shared and separate cultural identity. If the ratio of colonization to visit got low enough the nomads and sedentary cultures would become separate civilizations.
The relationships would likely be relatively peaceful, as the generation ships would by necessity be largely self-sufficient and only require fairly low cost resupply. I think they could pay for those with "cultural products" such as art, design, entertainment... They'd probably be welcome visitors in the colonies. Older, more established systems might be less welcoming. And there would also be questions of the relationship between the homeworld and the colonies. Which might be different for colonies of different factions and ages. And which would impact relations with the nomads. And probably make the nomads more likely to identify with each other, not with their system bound cousins.
[Answer]
The main reason I can think of for leaving one's planet entirely is exhaustion of resources — be they food, energy, breathable air, disease free habitat, space to put new born people... But to actually become nomadic, you either have to
* deplete the resources of the new planet
+ your nomads only leave rarely
+ your nomads are very numerous
+ they actually pillage the planet they get on to stock up on resources
* need seasonal resources (planets from cluster 1 can provide for half a time cycle and planets from cluster 2 can provide for the other half of a cycle)
* need localized resources (some things you can only get from planets in cluster 1, some others from planets in cluster 2)
* your nomads benefit specifically from moving
+ because of trade
+ to escape oppression
In the end, because of the enterprise it would be to become nomadic, I believe the decision to do so would have to come from a combination of all these factors linked to a great ease for interstellar travel and a cultural tendency to be nomadic.
Following a comment from @Falco above, I'd like to add his idea to this post: if the planets within your reach are all occupied (and would make you pay some sort of tax to stay) and that space travel has become relatively cheap, it might be that the future of homelessness is endless space faring...
[Answer]
One very good example that immediately comes to mind is the [Outsider race](http://en.wikipedia.org/wiki/Outsider_%28Known_Space%29) in the Known Space series by Larry Niven.
The Outsiders naturally travel from planet to planet, trading information with the locals on the planet. Since information can only be sold once on any star system with a global communication system such as the Internet, it therefore necessitates that once they have sold all the information that the client star system is able and willing to buy, they will have to leave the star system and approach a different star system to sell information.
While the Outsiders are organisms that naturally live in outer space, there is no reason a humanoid species cannot sustain the same lifestyle. With a sufficiently large ship, they can simply stop by star systems to restock, and then continue selling information. If a sufficiently large proportion of star systems are uninhabitable to the humans but habitable to other sentient races, this could be a very good way of making a living.
[Answer]
It obviously depends a great deal on the exact style of interstellar travel the nomads have available, and there are plenty of good answers here already, but I'll add another potential reason: Killing time. Given a means of safely traveling at relativistic speeds and knowledge of some interesting or beneficial event that will happen in the distant (even cosmologically distant) future, a civilization or group may decide that the best way to ensure they live to see this event is to simply spend as much time in transit as possible.
Depending on the amount of time that they want to travel through and how fast they can go, it may be necessary to stop for supplies. And this, in turn, requires them to spend longer at lower speeds (accelerating and decelerating)- which means longer subjective time, and more required supply stops, and so on.
[Answer]
What makes such a scenario highly unlikely is the mind-bogging amount of [energy](https://what-if.xkcd.com/7/) space travel actually requires.
The energy to put a few humans into low Earth orbit with supplies lasting only for a couple of weeks is [approximately the same](http://www.universetoday.com/87423/infographic-powering-the-space-shuttle/) as required to live a modern lifestyle for a year in the USA, with all the wasteful driving with a car to do grocery shopping, so in a resource-strained world probably enough for a whole community to live for quite some time. And you traveled only a few hundred km away from your planet. You need much, much more to leave the solar system, and to reach another star system in less than a few million years you will need to travel at a significant proportion of the speed of light. This will take many orders of magnitudes more energy. Don't forget the supplies you need to bring with you for such a lengthy journey, plus the tools required to live at your destination and extract the resources for yet another journey! And that's just for a couple of people, not a whole civilization!
This makes a space-nomadic lifestyle highly impractical, if not completely implausible. It's like you don't like your job and you would consider moving to a neighboring city for a better job, but the travel would cost you 100 billion dollars.
Planets are large. You would find a lot more materials and would be much better protected on a planet, even a completely barren and dead planet, than on any spaceship. If you had the technology to "effortlessly" travel to other systems and colonize them, you could much more easily terraform your planet, or just live in orbital habitats around it.
If you have the technology and the resources to move a whole civilization through space you pretty much achieved (or are close to achieving) singularity, and settling on planets and using their meager fossil or fissile resources would be completely pointless. **You would probably require much more energy just to stop at the planet and then accelerate again after you are done, than all the resources the planet could ever offer!**
[Answer]
One possible scenario could be dependence on a certain resource, which can be harvested from many planets, but which is depleted quite quickly and needs a long time to regenerate.
The nomads would travel to a planet and live there, while there collectors are collecting all of the resource, which could take days/weeks/months however you like. In this time they could also hunt/farm or trade on the planet and settle in a little. Once the resource is depleted, they will travel to the next planet on their route. Overall they will have a cycle with maybe hundreds or thousands of planets they will visit. Depending on the numbers it could be years or generations until they visit the same planet again - in this time the planet has regenerated the natural resource and they can collect it again.
One possible option could be some kind of cosmic energy, which gets trapped in the gravitational field of a planet and can be harvested by collection satellites which are released into lower orbit and take several weeks to will their capacitors. Once all the energy is collected, the nomad ships can travel for Months using this energy as a source. If the planet has local inhabitants they don't care, because the cosmic radiation doesn't have any practical use for them - most likely they don't even know about it. And the planet will take some years to regenerate the radiation up to a level where an optimal collection is possible.
[Answer]
You could take a cue from [The Culture](https://en.wikipedia.org/wiki/The_Culture), who prefer living in constructed habitats over existing planets, keeping the planets as wildlife sanctuaries.
So your evolution to spacenomads could like like this.
1. Due to overpopulation, someone has to leave the planet.
2. After colonizing several planets, your civilization comes to the conclusion that all this taking over planets and destroying the local flora and fauna is a Bad Thing(tm)
3. Your civilization leaves for deep space/interstellar constructed habitats.
[Answer]
I can imagine two things that would cause this to happen, trade and monsters.
**Trade**
A group of traders would have good reason to be nomadic. Travelling from planet to planet and trading for the unique goods produced by a certain planet for other goods collected during travels would provide a powerful motivation for moving from place to place. Earth's finest cheeses could be worth a fortune on the fifth moon of Antares, who in turn ship back ingots of raw unobtanium from their highly advanced factories. Shuttling goods back and forth may be a multi-generational prospect without FTL, but if the payoff is high enough it could make the nomadic traders quite wealthy.
**Monsters**
Nomads could also be driven from planet to planet by intergalactic monsters that will find and devour them if they settle in one place for too long. The nomads may be capable of living for long periods of time on their spacecraft, but occasionally need to land and gather raw materials for building more ships or replenishing their supplies. The same could be true if the nomads *themselves* are the monsters, occasionally landing to gather fresh prey, and taking off before the local authorities can arrive to stop them.
[Answer]
Well, there is an old TV series "Battlestar galactica" that deals with the subject. They leave their home solar system because they were invaded. Go out to deep space is never a good choice. Movies like Interstellar make use of the idea just because it is a romantic idea. The only and unique factor that could be a logical justification to leaving your home planet permanently is total and permanent annihilation of the planet. Any thing else is romantic but not practical. Is ever preferable to fix the problem. A 1000 years winter started by a meteor hit is hard to delivery but is Infinitely more easy to enduring than scape to space into a space ship.
[Answer]
**Genetic Diversity.**
If the level of technology is high enough that it is feasible to live on a spaceship for generations at a time, it seems reasonable that there would be some people (hermits, political refugees, space hippies, whatever) who would want to live in space full time. Over the course of time, it seems reasonable that groups of these people would form and decide to go live out in space.
One thing to remember is that space is *ENORMOUS* beyond your ability to comprehend. In order for space itself to get crowded there would have to be an unbelievably large number of people in the universe. People living in space could easily go millenia without running into any other groups by accident. So rather than needing a reason for these people to live in space, you need a reason for them to *want* to run into other groups, whether that be other space-faring groups or planetary colonies.
As others have already mentioned, one reason for wanting to encounter others is the need for refueling and other resources. The strength of that need would be determined by the level of technology.
Genetic diversity is another important need, both for the nomads and planetary colonies that they may visit. Unless your nomad groups have thousands of people in them, you're going to run into the problem of having a [minimum viable population](http://en.wikipedia.org/wiki/Minimum_viable_population). Wikipedia gives the number as around 4,000 individuals, but I believe that assumes you are allowing the population to grow larger than that. With too few people, you'll end up having a lot of inbreeding and the genetic problems that follow. As such, they'll need to increase their genetic diversity by introducing new genetic material.
Fortunately for your nomads, fulfilling this need for genetic diversity also helps the planetary colonies they visit. As I said, the colonies will also be worried about having enough genetic diversity, so when a nomad group visits a colony it will be a two way trade. Perhaps a few members of the colony want to leave and go somewhere else? They can join the nomads for a while. Perhaps a few of the nomads want to settle down? They can stay with the colony. Perhaps some families will exchange a child with a family of the other group. There would probably also be an exchange of sperm and possibly eggs, whether by sex or artificial techniques like IVF.
How frequently they need to do this will depend on the size of the nomad group and how long they are able to stay on the planets. If there is a group numbering in the thousands (close to the minimum via population) they could go many generations between visits and not suffer genetically. If a group has fewer than a hundred people, they'd probably want to visit a planet at least once a generation. If the group can stay on a planet for long enough for multiple children to be born/conceived, they can get in their diversity needs all in one go. If they can only stay for a short time (less than a year), they will need to visit more planets. There would not be too much benefit in staying on a planet for longer than a few weeks unless it takes longer for the nomads to get the resources they need or they will be able to stay long enough to have a second round of children.
These nomads would also likely stay just beyond the edges of populated space where colonies are just being established. Once a colony has become large enough that it doesn't need to worry about genetic diversity, the nomads have less to offer the colonists and will therefore have to exchange more in order to get whatever other resources they need. If a colony is very small the colonists will be more interested in genetic diversity, giving the nomads an advantage in trading.
In short, there will be people who want to live in space but visit colonies to maintain genetic diversity.
[Answer]
Yes. Not only could it, but it's my hope and belief such civilizations will come to pass in our solar system.
[Here](https://www.youtube.com/watch?v=yt1qPCiOq-8) is a video of Jupiter resonant asteroids. The first half is Hilda asteroids with a 3/2 resonance with Jupiter. The second half is of the leading and trailing Trojans at the Sun-Jupiter L4 and L5 points.
Notice at their aphelions the Hildas regularly visit the L4 and L5 regions where the Trojans dwell. At their perihelions they also pass through the Main Asteroid Belt.
So we have three substantial asteroid populations: The Main Belt, the trailing Trojans, and the leading Trojans. Each might have it's own civilization. And then there's the Hildas who regularly visit all three. I imagine the Hilda based civilization as a trading culture, a 22nd century version of Marco Polo's caravans.
There are other cycler asteroids possible. Here is an illustration from [my page on possible earth to Main Belt cyclers](http://clowder.net/hop/railroad/railroad.html):
The green orbits are main belt regions having 3, 3.5, 4, 4.5 or 5 years orbits. The red orbits have the same periods but with 1 A.U. perihelions. Thus the red orbits can regularly fly by the earth.
For example the red 3.5 year orbit will fly by the earth each 7 years. It could also fly by certain asteroids each 3.5 years In fact I illustrated [a story](http://hop41.deviantart.com/art/Sol-Comics-Page-1-193651395) based a 3.5 year asteroid and a 3.5 year cycler. (beneath each page are links to move forward or backward).
In summary, if humans break out of cradle earth, I believe nomadic cycler trader cultures are inevitable.
[Answer]
Ignoring the need to store sufficient amounts of food and take care of hygiene somehow (including waste management, see P.S.), there is one very serious problem with nomadic spacefaring:
women conceived in space or present in space as embryos would likely be sterile due to the effect heavy charged particles have on the developing egg cells. Nomadic spacefaring will either require a terribly advanced way of shielding against space radiation (Earth has upper layers of atmosphere and a very strong magnetic field to keep us safe from high-energy protons and other nasty things) or faster-than-light precise travel that will allow short runs between stars (a dozen light-years’ distance) and long periods of settlement on a single planet or at least within a single system since going to space while pregnant would result in sterile daughters (should not affect male embryos much because males generate sperm during the course of their lifetime while women develop their lifetime’s supply of eggs in utero).
If the maximum speed you can afford is the speed of light then you’ll likely be limited to one move per generation (or suppose three moves per lifetime).
It is simpler if you decide to go with inorganic or outright cybernetic life forms. Inorganic is very loose term here because it still can be xenobiology not based on organic compounds (carbon). For example a silicone-based lifeform that might be driven by something other than DNA chains or a stronger-bonded analog.
A very good candidate for a spacefaring nomadic nation would be a race of sentient machines who could harvest asteroids and enormous gaseous clouds (even supernova fallout) for materials and fuel. Equipping them with reliable long-range faster-than-light communications will enable enormous hive-mind potential or exploration of other, more controversial topics.
P.S. Regarding waste management:
Even small objects in space are very dangerous because damaging the hull of anything spacefaring even lightly can cause very quick breakdown and speeds are rather uninhibited (remember the comets that fly around empty space with tails as long as a planet’s diameter? They are just pieces of solid rock or ice or such and they break down so much just by hitting Sun’s energy, now imagine a flimsy hull of a ship which is essentially hollow inside). So throwing out stuff should be reserved for very slow speeds, or maybe sending your trash in one great package on a rocket into the nearest star. Enormous recycling ability would help, of course. Alternatively you could employ exceptionally rigid materials and “energy barriers” for exterior hull, but explaining such technology would be just as difficult.
[Answer]
It's possible that a civilization of sufficient size could work this way.
They would have to be in such numbers so that they need to strip a planet down to bare rock in a time period that is a high proportion of the time it took to get there, however.
Many, many times the current population of the earth, or perhaps the large amount of ships requires as much resources. More likely stars in that instance (Hydrogen).
Anything less than huge pop. and/or huge fuel requirements would make such an activity cost-preventative. And there would also have to be the need (or desire) for all of the pop to be together. Because these problems would be more easily solved by simply dispersing across the galaxy to various planets and setting up there.
But of course, there are reasons for things that are not strictly practical. Simple tradition might be enough for a massive spacefaring population to wish to all be together.
[Answer]
As other have pointed out, the economics of interstellar nomadism just don't add up without wildly futuristic FTL travel ala Star Trek or Star Wars. So maybe the people have less-than rational reasons to travel?
Perhaps they believe that their god is waiting for them on an unknown world, so they visit add many as they can, performing some kind of invocation at each one and then crossing it off the list. There could be many factions who have different beliefs about where to look, so occasionally splinter groups form which to search in another direction.
Maybe they're nomadic by instinct? For no rational reason, they gradually become dissatisfied with each world they visit and inevitably move on. Maybe they consider it a sin for a man to be born on the same planet as his grandfather.
Perhaps their lifestyle produces unwanted byproducts, either physical pollutants or something less tangible, like a taboo against making a grave within 100 miles of an existing one. In times past, the taboo ended when the papier-maché tomb eroded away, but these days they're made from a special eternium alloy made from old diapers which doesn't decompose for ten thousand years. That'll eat up land fast!
Maybe they have a reputation which follows them? They must move on as soon as the locals get word that these space-Gypsies can't be trusted (no offense to the Roma). The Ferengi were ecstatic to enter the Gamma Quadrant where no one knew about their... unsatisfied customers. This only applies if they're nomadic among settled worlds, of course.
[Answer]
As has been mentioned, without FTL travel, Generation ships are the only real possibility.
Building, supplying, and powering such ships is not going to be trivial, as has been mentioned.
So, the reasons to do this are limited, death of the Sun, maybe serious over crowding, perhaps even a surplus of wealth (maybe we're harvesting resources across the solar system, and it's going wonderfully for us).
But, there will not be an excess of resources when we arrive, so while we might have the ships to move on, it's very unlikely we'd have the fuel or supplies (although 'supplies' may not be a concern, as the ships will be closed systems, no matter will escape them, and everything that wears down or is used will be recycled).
Once the new planet is reached the quickest way to establish a settlement would be to use the ship, maybe keeping it intact, maybe breaking it down.
Either way, becoming nomads without having seriously exploited the resources of the planet would not make sense, travelling for generations between pit stops does not make sense, basically it would be like living on a train that doesn't stop, what's the point of traveling if there isn't a destination?
Obviously FTL travel without time travelling quicker outside the ship could change things massively.
] |
[Question]
[
I had in mind a sci-fi setting where humans have begun terraforming nearby planets without the benefit of faster-than-light travel. For example, [Wikipedia](https://en.wikipedia.org/wiki/List_of_nearest_terrestrial_exoplanet_candidates) lists a handful of terrestrial planets within 15 light years. What I have in mind is that humans have the capability to send unmanned probes to those planets after about a 50-year voyage, and manned probes after slightly longer.
I had hoped to set these stories in the last 22nd century, roughly 150 years from today. I could go as far as 250 years in the future, but I don't want the space-farers to be too far removed from modern Earth culture.
* How could I make it plausible that by that time, human beings have created spacecraft of those speeds?
* What are the major barriers mankind would have to overcome to reach those speeds?
[Answer]
Let's do a calculation or two, shall we? (*Note: All those wishing to skip the boring math can just read the lower portion of this answer.*)
**Finding the speed you're going for:**
$$v=\frac{15 \text { light-years}}{50 \text { years}} \times \frac{10,000,000,000,000,000 \text { meters}}{1 \text { light-year}} \times \frac{1 \text { year}}{31,500,000 \text { seconds}}= 95238095.24 \text { m/s}$$
**Finding [the energy needed](http://en.wikipedia.org/wiki/Kinetic_energy#Relativistic_kinetic_energy_of_rigid_bodies) to get to that speed:**
$$E\_k=\frac{mc^2}{\sqrt{1-(v/ c)^2}}-mc^2$$
Assuming a [mass](http://en.wikipedia.org/wiki/Project_Daedalus) of about $150,000$ tonnes (taking the Project Daedalus figure and tripling it),
$$E\_k=\frac{(150,000,000)(300,000,000)^2}{\sqrt{1-((95238095.24)/(300,000,000))^2}}-(150,000,000)(300,000,000)^2$$
$$=7.36 \times 10^{24} \text { Joules}$$
**Can we do it? . . .**
According to [Wikipedia](http://en.wikipedia.org/wiki/Kardashev_scale)
>
> In 2011, total world energy consumption was 549 exajoules
>
>
>
Multiply that by 50 years, and we still don't have enough.
I suppose we could use the [Kardashev scale](http://en.wikipedia.org/wiki/Kardashev_scale) to figure out when humanity will have energy at that rate. Using this formula:
$$K=\frac{\log\_{10}P-6}{10}$$
and substituting in humanity's energy usage per year, we could calculate just when we'll reach that point. Just use
$$P= \text { Joules/year}=2.34 \times 10^{16} \text { Watts}$$
$$K=\frac{\log\_{10}7.36 \times 10^{24}-6}{10}$$
and we find we should be a Type 1.03692 civilization. Given that we're currently a Type 0.7 civilization, we should be at that point in about 100 to 200 years. Note, though, that this figure is for a ship using all of humanity's total energy, which is unrealistic. However, it shows that we won't be able to harness that energy at *all* for a while.
I would also be obliged if someone could check my calculations. I used [this](http://rapidtables.com/calc/math/Log_Calculator.htm#) logarithm calculator, in case anyone wants to use it. Conversion ratios can be found easily online.
---
>
> What are the major barriers mankind would have to overcome to reach those speeds?
>
>
>
If we're talking purely about travel at this speed, i.e. assuming we've figured out everything else, the main problem is propulsion. As the above result showed (for those who skipped it, you just have to know that we'd need a *lot* of power to reach these speeds.), it's not easy to travel fast in space. Here are [some options](http://en.wikipedia.org/wiki/Spacecraft_propulsion#Table_of_methods):
* [Bussard Ramjet](http://en.wikipedia.org/wiki/Bussard_ramjet) - Take in hydrogen gas floating in interstellar space, compress it, begin fusion, and convert that into thrust. **Obstacles:** It has to be really big, and you have to be sure you have hydrogen in space. Oh, and you have to master fusion.
* [Nuclear Pulse](http://en.wikipedia.org/wiki/Nuclear_pulse_propulsion) - Chuck nuclear bombs out the back of the spacecraft, and ride the shockwaves. This was used in the hypothetical Project Daedalus and the equally hypothetical Project Orion. Neither idea got off the ground (pun definitely intended). **Obstacles:** You have to make loads of nuclear bombs. Also, you have to find a nation that's willing to sacrifice a bunch of land for the launch pad, because that launch pad and the surrounding area will be completely destroyed.
Alternatively, you could just use this idea in space, [as Lohoris suggested](https://worldbuilding.stackexchange.com/questions/3871/how-close-to-interstellar-space-travel-could-humans-get-in-the-near-future/3876#comment35286_3876).
* [Solar Sail](http://en.wikipedia.org/wiki/Solar_sail) - Ride the radiation pressure from a star using a sail. **Obstacles:** You've got to make and deploy an enormous sail kilometers wide. Also, the acceleration is incredibly slow.
* [Antimatter Rocket](http://en.wikipedia.org/wiki/Antimatter_rocket) - I've saved the best for last. Put together matter and antimatter and harness the energy from the annihilation. **Obstacles:** Very expensive, because antimatter is expensive. Also, you'll have to make quite a lot of it at first, although you can start to coast at some point. You have to be very delicate, though. Veeeeery delicate.
[Answer]
Most likely space colonization will not go as you envisage.
Actually there could be hundreds and thousands of planets within 1 light-year from the Sun. If there are no *stars* that close does not necessary mean there are no planets, both wandering and orbiting the Sun. Statistics predict that there are much more wandering planets in the galaxy than stars.
As such, future people may not think it is necessary to travel to other stars before they colonized at least the solar system. As they explore it they find more and more celestial bodies suitable for colonization, *gradually* approaching other stars.
[Answer]
Tough but possible.
$15ly$ in $50$ years would require $0.3$ times the speed of light. To reach this speed, we could accelerate with $4g\approx 40m/s^2$ for 26 days (or 51 days with $20m/s^2$ or 13 with $80m/s^2$ .. the last one would be very unpleasent for the passengers).
How much energy would it take? Lets stick at $150000$ tons. So its $E\_1=\frac{1}{2}mv^2=\frac{1}{2}m(0.3c)^2\approx6e23\,\text{Joule}$. If we use relativistic formulas, we would need $6.5e23 \text{Joule}$. Close enough for our estimates. But wait! Now we reach the target system but still travel with a notable fraction of the speed of light. We need to get rid of this velocity and need the same amount of energy again. This sums up to $E=E\_1\times 2=1.2e24 \text{Joule}$. That's nearly 8 tons of antimatter by the way.
How do we get the energy? Lets try solar power. The solar constant is $E\_0=1367\frac{W}{m^2}$ near earth. This constant is proportional to the inverse of the distance to sun squared. At $0.1AE$ (about one third of the distance from sun to mercury), its $E\_{0}^\text{Mercury}=137\frac{kW}{m^2}$. To get enough energy in one year, we need to cover an area of $\frac{E}{E\_{0}^\text{Mercury}}\times \text{seconds per year}\approx 7e12m^2$ (that's arround $2700km \times 27000km$ - tough but possible). You have to scale it up for general loss due conversion and inefficencies though. There are other ways like fusion reactors, *magic* cold fusion, etc. Your choice.
Now the hardest part: how to convert the energy in velocity?
* **Solar panels**? The acceleration is painfully slow in our solar system and goes down with the distance squared (double the distance, acceleration goes down by a factor of 4).
* You don't want to use an FTL so you can't *invent* a classical warp drive. Maybe you can *invent* something like a slower-than-light-warp but this would render all calculations useless as there is no knowledge about it. If you want to stick at hard SciFi without warp, you need something to exhaust to push you forward.
* Classical **propolusion drives** are out of question too. Take a look at the [rocket equation](http://en.wikipedia.org/wiki/Tsiolkovsky_rocket_equation). The Ariane 5 rocket have a specific impulse of $440s$. Putting in our numbers, we come up with a mass around $e^{20850}kg$ - more than double precision can handle. You need something to *push away* with a notable fraction of $c$.
* The idea with **nuclear bombs** (antimatter?) driving you forward is tempting. But explosions are short bursts and we need many of them over a big time (remember the $4g$ over 26 days?). This is a big challenge for the structure of tyour space ship.
* I think you have to *invent* something new like a large scale particel accelerator shooting matter out with the speed of light. You still need quite an amount of this particels ... for the needed $\Delta v=0.6c$ $0.8$ times your ship's mass - $123'000t$. Remeber to scale up your solar panels.
Every SciFi I know reaching out for other solar systems - even the hard ones - have some magical device/ thruster without real science behind them (warp drive, warp tunnels, instant teleportation over light years, ...). I don't think you can get around it.
Now the social component. Try cryo sleep chambers, thats the easiest (I'm more a technical guy).
[Answer]
Ok, so the best and most enlightened answers here have considered the amount of energy required to travel these distances.
If you want to shortcut over the hundreds of years it will take us to get to this point you could try the following:
* External Influence
Somebody like the Vulcans visit us from another planet and share advanced space flight technology. Or perhaps we steal the technology after they visit.
* Gift from Space
Something like a meteor strikes the Earth carrying large quantities of some new type of fuel compound which is more effective than anything we have on Earth.
* Time Travel
People from the far future come to our time to share with us the advanced technology required for space flight.
* Messages from Space
An Alien race sends us the designs for building interstellar craft.
* Unknown Technology
At some point in the not too distant future a breakthrough is made that changes our understanding of Space and Time, allowing us to get to this level of technology faster
[Answer]
Yes, based on our calculations for energy requirements, which is right on, and the Kardashev scale 300 to 350 years would be a good guess.
This would be for a sublight starship using 7 x10 ^24 joules... likely fusion powered. Still very "pre-warp", as warp drive would likely require Kardashev mid level two civilization...
Though as Nick R stated, new "multiple" discoveries resulting in paradigm shifts could accelerate that Daedalus type ship by perhaps shaving 100 years off that 300 - 350 year estimate...
[Answer]
With an electricmagnetic thruster like [VASIMIR](https://en.wikipedia.org/wiki/Variable_Specific_Impulse_Magnetoplasma_Rocket "VASIMIR") and a nice small fission reactor like [SNAP](https://en.wikipedia.org/wiki/Systems_for_Nuclear_Auxiliary_Power#Even-numbered_SNAPs:_compact_nuclear_reactors), you're more like 50 years from starting an unmanned probe. OK, you still need a lightweight, space-rated >200W generator.
A manned probe? Think again. And forget about transporting terraforming equipment. A probe with ten times improved exhaust velocity from VASIMIR (500km/s from 50km/s, which is not too ambitious for 50yrs imo) needs to have less than 1% payload ratio to get to 0.01 c.
With 1000km/s,things would look like they become practically useful, like having enough fuel to slow down after the cruise (Initial payload ratio for acceleration is square root of absolute payload ratio). But still more like 250 years travel time. You would need a fusion reactor here, admittedly. Apart from it's far better efficiency (energy/kg fuel) it has the added benefit that you might use the fusion product as additional propulsion medium.
Useful: <http://www.wolframalpha.com/input/?i=rocket+speed>
[Answer]
One unified field theory suggests 11 dimensions. If true, maybe one could traverse a 3-dimentional distance by passing through one or more higher dimensions. Folding space, or folding yourself to slip between dimensions. You might need a gate to enable a return trip unless the device was small enough to take with you.
[Answer]
NASA plans to have their Warp vessel built by 2100 so it is unlikely we would try any interstellar travel until proves to be unfeasible. Given that as a starter point we should expect failure between now and then in your universe.
A Mars mission is planed in the mid 2030s and might get pushed back by as much as a decade. You can then expect at least a decade or two dealing with Mars.
This puts you at 2050 before we get to large scale warp trials. I'd expect at least 10-30 years of trials and this gives us a 2080 date of when probes and such are going to start to be planned.
within a decade or 2 of this we'll launch probes which will be equipped with ion thrusters or solar sails or something and there are a lot of stars within 50-100 light years and each take more than 8 years to get to and 4 to communicate back. 12 years is the minimum for that which means you're now up 2112 before we get info back on any star. Assuming a perfect hit we then have a decade or 2 to plane the mission and more than 8 years to get to the planet, because the ship is going to probably have to go slower, but forgetting that, the minimum time year that we'll land on another planet to colonize it is 2140 if we don't have warp of any kind.
Ironically Warp would probably push this back because we then wouldn't rush to colonize because time wouldn't really be as big an issue and you run into that thing about speed of ships would constantly outpace each other so it's best to build a significantly advanced warp ship where the outpaced development wouldn't matter.
A more realistic timeline would be 2200s or 2300s simply to get all the data back and do a lot of testing of close range vessels for longer periods to make sure they get to where they're meant to be going and also transporting building materials.
] |
[Question]
[
Dragons commonly breathe fire. They can do so over considerable distances, often many times their body length. But this needs to be powered somehow, by a substance that the dragon can generate on its own. Flamethrowers in real life can be powered by either a gas or a liquid.
However, gas based flamethrowers are pretty lame compared to their superior liquid brothers (insert MGS joke here) because they generate what is nothing more than a long flame. This is what flamethrowers look like in the movies, mainly out of safety concerns. Liquid based flamethrowers are a lot more dangerous, firing streams of burning gasoline at targets.
Given that I want my dragon's flamethrower be spelled with an F instead of without, I want to go with a liquid-based flamethrower. However, this means that a dragon will have to generate the stuff somehow. A methane powered one would be relatively simple given that a dragon's digestive system would produce this on its own, but to me creating the equivalent of dragon napalm seems a lot more complex. And needs to be able to combust somehow, preferably not inside of the dragon. They wouldn't want to end like *draco vulgaris*, after all.
So how would the biology of a creature like a dragon create a flammable liquid? Would it require a special diet, or dedicated organs? Or perhaps something else entirely? I am looking to make it a continuous stream akin to a real-life flamethrower rather than a short spray created by the equivalent of a bombardier beetle.
[Answer]
A liquid based approach could be done.
There are a number of biologically produced substances that are flammable.
The dragon would just need to produce a quantity of it and store it in a gland of some kind, similar to how a snake produces venom and stores in a venom gland until it's ready to use. How big the gland will be, and where in the dragon it's located will depend a bit on how you want them laid out and how much fire breathing you want them to be able to do before recharging.
So what about lighting it? Well we can look at nature for this too.
There is a bug called a bombardier beetle, which produces two different chemicals in glands in it's thorax.
When it is threatened it sprays the chemicals, which mix and cause an explosion to scare off attackers.
So the dragon could create a catalyst that is sprayed out in smaller quantities that reacts with the fuel to cause combustion shortly after leaving the dragons mouth, reducing the risk of burns.
Another idea would be something like [potassium](https://en.wikipedia.org/wiki/Potassium#Chemical), which in it's pure form reacts violently with water, generating a large amount of heat and hydrogen gas, and can cause an explosion.
One neat thing is that potassium was first isolated in potash (the ashes of plants, from which its name is derived), and so a dragon burning plants and eating the ashes would be able to collect potassium, and then could process it into an oil fuel mixture which would be exposed to to water/saliva when sprayed out generating enough heat and hydrogen to ignite the oil part of the mixture.
The oil would also keep the chemical reaction from happening inside of the dragon.
[Answer]
I thought about this for a high fantasy RPG I worked on a while back.
Liquid dragon fire could be formed from palmitic acid and naphthenic acid (the base ingredients of Napalm).
Palmitic acid can be found in nature in our bodies. Excess carbohydrates in the body are converted to palmitic acid. As a consequence, palmitic acid is a major body component of animals, so your dragons just need to have a gland that stores and can excrete this when needed.
The second ingredient is naphthenic acid. This is a bit trickier to synthesis in a living creature. Feasibly a dragon could ingest peat, coal or similar substances and crack them in a special stomach. The problem is naphthenic acids can be toxic, but we’ll just assume the dragon is immune (and as a bonus this makes the dragon poisonous to would-be predators).
So now your dragon just needs some special glands in their mouth to spray the Palmitic and naphthenic acids at their target and some kind of ignitier to light the spray as it leaves the dragon's mouth. Borrowing from *Flight of Dragons*, perhaps the dragon has a small patch of cells in the roof of their mouth that can create a charge in the manner of an electric eel. As a bonus this mixture will probably be quite clinging due to the fatty base.
There you have it.
[Answer]
For the dragons' fuel storage and pumping system, liquid is the way to go.
* More storage: Flammable liquids have more energy per volume than gas, just because density.
* More range: A liquid stream can be pushed farther than a gas one, as you point in the question text.
* More Power: the flow of matter is greater with a liquid. Again density.
* Less liability: In order to store lots of gas, the dragon would need a pressurized organ, that if punctured could cause internal damage.
Modified glans would produce the flammable liquids. Possibly as a binary fuel, to be combined directly in the muzzle. It can have two glans in opposite sides of the body, each producing one part of the [binary fuel](https://en.wikipedia.org/wiki/Binary_explosive).
[Answer]
*How To Train Your Dragon* didn't go into specifics, but the "monstrous nightmare" breed used a liquid as its fuel, so this is all quite plausible (if, y'know, you suspend disbelief that fire-breathing dragons exist). As for "how":
The dragon has a rudimentary biological refinery; bacteria in its gut ferments any cellulose it eats into ethanol or methanol. The dragon's intestines absorb these alcohols as well as the fats from its diet, and transport both to a gallbladder like organ above the stomach. When the fat and alcohol react here, the product is very similar to diesel fuel. The dragon can essentially vomit this cocktail of fuel oil and half-reacted fat and alcohol, which self-ignites under such pressures, at its enemies.
You don't need a Ph.D in fantasy biology to come up with something plausible.
[Answer]
Butane is an interesting possibility. While it is usually a gas at room temperature/pressure, it only requires moderate pressure ([about 40psi](http://www.engineeringtoolbox.com/propane-butane-mix-d_1043.html)) to keep it liquid at typical body temperatures. This would require a reasonably sturdy system for compressing it after production, but that wouldn't be outside of the plausible range that could be achieved with a muscle diaphragm ([Sauroposeidon](https://en.wikipedia.org/wiki/Sauroposeidon)'s heart must have been able to manage at least 20psi in order to get its blood to its head). It would begin the process of evaporation immediately on release, which would assist with the process of throwing it a long way.
Butane isn't produced by any natural biological system that I'm aware of, but it has been demonstrated in a relatively simple change to the fatty-acid production systems of [E. coli](http://www.ncbi.nlm.nih.gov/pubmed/26556131).
[Answer]
The human gut has a complex ecology of microorganisms, and in some cases people are being naturally intoxicated becsue the various gut bacteria are producing ethanol: <http://www.vice.com/read/my-gut-turns-yeast-into-alcohol>
Now a drunken dragon is not going to be successful in evolutionary terms (being likely to fly into mountains or rashly challenge knights to a fight), so evolutionary pressures will develop for dragons to sequester the alcohol in their bodies. This creates a bit of an issue, since a high concentration of alcohol will be toxic, and needs to be excreted from the dragon's body somehow.
Sadly, the most plausible mechanisms would involve a kidney like organ filtering alcohol from the bloodstream and a bladder like organ which exits via the dragons cloaca rather than the mouth. This means the dragon will have a means of attacking its enemies while in flight, but in a much nastier form than "just" fire.
For a proper alcohol based flamethrower to evolve, there will have to be some sort of enzyme ignition system in the cloaca (something similar to how Bombardier beetles eject steam), and a powerful set of sphincters to propel the noxious stream at targets. (If mixed with the dragons fecal matter, you will have a very nasty stream of burning you know what, which should make all enemies beware of dragons suddenly turning away from them and raising their tails....)
While sequestering alcohol and ejecting a stream of alcohol laced dragon poop at high velocity at potential foes does seem like a reasonable evolutionary development, it is difficult to see where the flame part comes from. It seems horrible enough *without* the flame.......
[Answer]
All oil in common use is ultimately biologically based (even so-called "mineral oil"), so its certainly feasible.
If it was me, I'd assume the creature was creating something closely akin to [whale oil](https://en.wikipedia.org/wiki/Whale_oil), since that was the most commercially useful animal-based oil, up until the whales dwindled and hunting them was banned.
[Blubber](https://en.wikipedia.org/wiki/Blubber) is one of the two main sources of whale oil. Its used for fat storage, of course, but blubber in marine animals also serves a couple of purposes that would also seem useful in any large hairless creature that might fly at altitude: heat regulation and resistance to pressure changes. It also appears that marine animals bodies will adjust the chemical composition of their blubber based on need. So getting to a useful "FT" composition wouldn't be a big genetic stretch.
The drawback to blubber for this purpose is that humans typically had to "cook" it to get the oil out. One might imagine a scheme where its used as the reserve, while the creature's body has an organ that naturally does this over time and keeps as smaller supply of ready oil in a more liquid form. Which brings us to...
[Sperm oil](https://en.wikipedia.org/wiki/Sperm_oil) is the other natural form of whale oil. Its actually found in a waxy **liquid** form in the heads of Sperm Whales (and some other related toothed whales). Their nose is full of it. If only they had a natural ignition source, Moby Dick would have been far more interesting.
[](https://i.stack.imgur.com/L5X98.png)
[Answer]
Something like a dragon, with a really nasty flame breath, doesn't work with real-world biology.
So, "magic" is the answer: you can wrap that magic up in biological technobabble if you like.
# External Magic
The Dragon consumes some substance which it processes into flame-fuel. Maybe some kind of [rock](https://en.wikipedia.org/wiki/Dragonriders_of_Pern), or some plant, or astral ley line energy.
This moves the magic outside the dragon, which lets you be all realistic in how the dragon itself works.
# Internal Magic
The dragon has an enzyme, a gland, a sack, a second stomach. In that, it stores its dragon-napalm. How that works you hand-wave or obscure away with technobabble. It expels it in a jet, and sets it on fire. The fire could be from exposure to air, mixing chemicals that cause an exothermic reaction, an electrical shock caused by bio-capacitors in the dragon, etc.
# Environmental Magic
The laws of reality are different in some way that makes Dragons work. Maybe in your world there are N elements from which all reality is made, one of which is Fire, and the Dragons use their access to the element of Fire to produce flame.
# Science Magic
Modern industrial technology uses ridiculous energy budgets to build things like flamethrowers and flying airplanes. Biological creatures matching them requires energy budgets far beyond the reasonable. You'd have to be in a preternaturally energy-rich ecology to have anything at all dragon-like.
So stick the Dragon on some world where blasts of flame like the Dragon's actions happen all the time, where there is a ridiculously high biological energy budget. Explaining why entropy doesn't cause that steep energy gradient (the ease of fire) to collapse is tricky, but that can be explained by the situation being relatively short-term. Maybe a Type 2 civilization engineered a habitat so they can play with Dragons. The Dragon's breath is actually caused by an AI watching the dragons spitting some mundane saliva: the energy projectors embedded all over the place then concentrate beams and create plasma.
After all, a sufficiently advanced technology is indistinguishable from Magic.
] |
[Question]
[
I'm trying to come up with a the most economical design for artificial gravity. The simplest design for a space ship is to have a spinning ring structure around a central body. People living in the ring experience gravity, but the central body is still zero G.
But making a ring is expensive, the walls need to be thick for radiation shielding on long flights. What if I had two spheres connected to the central core by a shaft?[](https://i.stack.imgur.com/h31LQ.png)
The full gravity module contains sleeping quarters and recreation, and the partial gravity module contains work areas. The crew would retire to the full gravity module when their shift is over, and get full gravity for a good part of their day. Meanwhile operations in the partial gravity module are easier than in zero-G, since you don't have to deal with floating messes. The partial gravity module is closer to the central core, but is also much heavier than the full gravity module.
Would this design work? Would it make the central core unstable or hard to maneuver? I know gyroscopes behave strangely, and I'm not sure what a lopsided design like this one would do to the ship. I image things would get weird when loading heavy cargo onto one of the modules?
[Answer]
This is actually a fairly well-researched and entirely practical design concept for cheap, robust spacecraft with centrifugal gravity. Since the connecting "shaft" is entirely in tension, it could even be little more than a cable, and need not be stiff (in fact, in some designs you actually want it to be able to flex a bit--the reason for that should become clear below).
Most designs (for spacecraft, anyway--centrifuges for space stations that connect to non-rotating sections have different design constraints) do not involve habitation or work areas at both ends; rather, you put the crew at one end, and put all of the stuff that would be dangerous to have near the crew, and which does not require radiation shielding, as the counterweight at the other end (e.g., nuclear power plants, engines, and so forth). A "central core" is not generally necessary, and adds complexity to the design, although it is possible to include one. It is also perfectly possible to allow for habitation at both ends, but then you end up needing more shielding mass, etc.
Loading heavy cargo, or moving material (including people) from one end of the ship to the other, would change the center of rotation and the rotation rate. If you have a central core, it thus needs to be able to "crawl" along the shaft/tether to remain centered. The great advantage of using a simple tether, with no intention to allow the crew to move between habitable areas on both sides, is that you can easily reel it in and out to adjust the moment of inertia, spin rate, and moment arm in the habitable sections, thus ensuring that perceived gravity remains roughly constant, and the spin rate remains tolerable.
If you want to be able to load / unload cargo without stopping the spin, then a central core that can dock to non-rotating / differently rotating structures is a practical necessity, as is internal access from the core to at least one, if not both, ends of the ship; in that case, a rigid shaft along which the core can crawl may be a good design option, but non-rigid telescoping access tubes within a frame of reelable structural cables might be better. Without a central core, you will have to halt the spin to dock, unless you happen to be docking with another spinning ship and can match spins with them.
Such a ship would definitely be *unintuitive* to maneuver for a human pilot, but it's not exactly *complicated*. Yes, there are gyroscopic effects, but they are well-understood, and it would be easy to direct the ship under computer control. In the absence of a central hub, you can even put the engines on one end, with gyroscopic effects actually working in your favor to avoid the need for matched engines on both sides.
Whether you put the engines on one end, or at the central hub, however, any component of thrust parallel to the axis of rotation adds apparent gravity in that direction. In most spin-habitat designs, that creates problems; you either have to add mechanical complexity to move the floor to stay perpendicular to apparent gravity when under thrust, or you have to keep the maximum thrust small enough that no-one notices (or at least small enough that they don't care). In this case, however, if the sections are connected with flexible tethers, the tether will naturally swing under thrust to keep the modules oriented perpendicular to gravity; slight adjustments to the tether length can then be used to adjust the centrifugal component so that apparent gravity is constant in the inhabited section(s) regardless of thrust (up to the limiting point where thrust matches the target gravity, spin has gone to zero, and the habitat module is just being dragged straight behind, anyway).
If you have engines mounted on a central core, and you do not care about *turning* the ship, then maneuvering is easy. As long as you can gimbal the engines to point in whatever direction you want to go, you just fire them in the right direction, and you don't have to worry about gyroscopic effects (although you may conceivably have to pulse your engine burns if your thrust vector is near the plane of rotation, and you only turn on the engines when they have rotated around into the correct position).
If the engines are mounted on one end, maneuvers are a little more complicated, but still totally doable. You can thrust perpendicular to the axis of rotation simply by only firing the engines in the plane of rotation when they happen to have rotated into approximately the right direction. The length of burn pulses can be extended, and efficiency improved, by appropriate gimballing, so the nozzle can be kept in a consistent orientation over some large arc of ship rotation. You can thrust parallel to the axis of rotation by simply *doing so*, with the caveat that you must burn at a consistent thrust for at least one full rotation, so that gyroscopic effects cancel out (well, it's a *little* more complicated than that, actually--you need a ramp-up and ramp-down time to smooth things out and prevent slight turns due to the time differences in thrust at different rotational positions if you have a really high-thrust engine, but the computer can take care of that). This means that small velocity corrections are constrained by the ship's rotation rate, and some sort of variable thrust engine is ideal (like a VASIMIR, or ion engine, at least a liquid fuel rocket with variable throttle). Turning the ship can be done by thrusting asymmetrically around one full rotation; due to gyroscopic effects, thrust must be applied out of phase with what a human pilot might intuitively expect, but again, the computer can take care of that. And arbitrary thrust vectors and turn rates can be achieved by the vector sum of in-plane and in-axis maneuvers.
[Answer]
**I think it would work once you got it rotating.**
The difficult part is probably the shaft, as it would need to be strong and sturdy enough to handle the acceleration with two significantly heavier masses at the ends.
It probably depends a lot on the material, diameter and shaft lenght, but i'm quite sure there would be a workable combination.
I am not sure about the maneuverability of a structure like this.
If you just want to fly a straight line it might work, if you want to do complex maneuvers you're probably bad off with this.
[Answer]
Yes the design would work. The central core could be balanced but movement of cargos onto or off of either module would destabilize the centre of gravity. The greater the mass being moved the greater the destabilizing effect. This could be counteracted by moving a balancing mass onto or off of the other module, by having a large mass that can be moved towards or away from either module.
There would be a gyroscopic effect, but this need not cause problems because the rotating body can be moved in any direction desired without effecting the direction or speed of rotation. Acceleration could be applied in any direction but would have to be carefully controlled and of low intensity to prevent destabilization.
[Answer]
The key is to make the two modules stay on opposite sides at all times -- they aren't rotating at different speeds. The entire station will rotate at a constant angular velocity, end-over-end.
[The formula for centripetal acceleration](http://theory.uwinnipeg.ca/physics/circ/node6.html) is `a = ω^2r`, where ω is the angular velocity, and r is the radius. If one module is half as far from the center, then it will have half the gravity.
The central core needs to be the center of gravity of the station, so the inner (low gravity) module needs to be more massive than the outer module, pulling the center of mass towards it.
There will be issues with heavy enough cargo. Anything moving from one module to the other will move the center of gravity. The station is probably massive enough that the people "commuting" to work in lower gravity probably won't affect it too much, but sensitive equipment might be affected. You could imagine pumping equivalent amounts of water (you'll need it anyway) around the station to compensate. Sensitive accelerometers could detect changes and weights and pumps could compensate.
For maneuvering, a thruster at the center of mass will definitely be able to push it in the direction of the rotation axis. I think that other directions would be possible too. Consider a [spinning baton](https://en.wikipedia.org/wiki/Baton_twirling) -- as long as you are careful to only apply acceleration at the point of the center of mass, I think it will work. The gravity felt in the modules will fluctuate if the acceleration is not along the axis of rotation, so it would be uncomfortable and probably only useful in an emergency.
] |
[Question]
[
In many fantasy worlds people send messages using ravens, they're often portrayed as being intelligent birds.
To the best of my knowledge, on earth only homing pigeons have been used to carry messages backwards and forwards (they're also restricted to a single destination).
How realistic would it be to have specially trained earthly ravens (or indeed any other bird species) to do the job or is this simply a common trope used in fantasy works? Would they need to be super-intelligent Ravens?
[Answer]
Plenty of birds are very intelligent, with crows and ravens getting a special mention in the inventiveness department. In real life, you can train them for many things, including repeating spoken phrases (similar to how you would train a parrot). I imagine that theoretically, with enough time and patience, you could train a raven to fly regularly between two predetermined locations, or to always fly back to the same location.
It would probably take several years of one on one training per bird, and you'd be likely to lose a lot of birds along the way, since the odds that your captive raven will come back to you are pretty low, even if you've been working with that bird since the day it hatched. After all, modern falconers experience similar problems; even if you've done everything right, there's still about a good chance that the first time you let your falcon of the tether, it isn't coming back.
So let's look at this question from a different perspective. Why, in the real world, are Homing Pigeons the only kind of bird typically used for this purpose?
Because the behavior of always returning to the same place is instinctual, they require much less training, and can be trained as a flock. Further, you're far, far less likely to lose them in the process. They're also incredibly reliable. In WWI, for example, they were known to be able to get the message through to the intended location 95% of the time--not bad for the middle of a war zone. I imagine ravens, being more intelligent, would probably be less reliable, as they'd be more likely to seek shelter somewhere that wasn't getting shot at, treats be damned.
So, possible? Probably. Practical? Not really, at least not if there are other, better ways of doing things already available.
[Answer]
To the best of my knowledge, pigeons and sparrows have been the only birds used for sending messages.
Many other types of birds are trainable, for example many birds of prey are used in hunting (falconry).
Ravens are considered very intelligent birds, they may be trainable but that doesn't mean they're a viable candidate. Here's a really neat research paper on [how smart they can be](http://sora.unm.edu/sites/default/files/journals/auk/v112n04/p0994-p1003.pdf).
They are large birds which are often hunted, making their journey more difficult. Also, it's not easy to get a lot of them. You would need to have a large number of them in order to have backups and not all of them will have "the right stuff."
The advantage of the carrier pigeons is that they are small, easy to acquire and breed and no one really cares about them. You can send out several and chances are that one will get through.
Most importantly, I think that ravens are held in high regard or have a mythology based around them in human culture. (Also true of other big birds.) I don't think they would be used in that way, maybe for the same reason you won't see "Raven Florentine" in a restaurant.
[Answer]
Ravens could, but they're like the poodle breed of birds. They're among the smartest and they know they are. They need a reason to do what they're told. It's far more likely they'll find something better to do, or something they'd enjoy more and not do what you want. Plus they'd probably want to play with the canister and to do so would remove it and not carry it to whomever the note was intended for.
] |
[Question]
[
It bothers me in games when the price of something is seemingly arbitrarily set.
>
> Shop owner: How much gold do you have?
>
>
> Player: Er, 10,000?
>
>
> Shop owner: Then that meat pie is 1,500 gold, please!
>
>
> *Pig Farmer in line faints*
>
>
>
I have been working for the past few weeks developing a framework for calculating output for a medieval city/region. I want the number of cows, chickens, men, women, rich, poor etc to actually make sense. The ratios to one another should be as close as possible to actual medieval ratios.
This means I have been pouring over publicly available peer reviewed papers on this subject. I will include a list of the ones I found most valuable at the end.
I will lay out my framework and thought process so you can understand my question.
>
> Assumptions as they come out in the comments (Thank you in advance!)
>
>
> * There is enough precious metals available to have an all cash economy
>
>
>
---
I used [this article](http://www.helsinki.fi/iehc2006/papers3/Campbell122.pdf "Some population and interesting land use/area estimates (towns per 100 sq mi)") to get the size of my town. I choose 10,000 people.
Another [article](https://www.nuffield.ox.ac.uk/users/allen/greatdiv.pdf "Basket of goods consumed - very good") helped me get an average number of calories consumed from vegetables/grains and animal products.
Another [article](http://www.helsinki.fi/iehc2006/papers3/Campbell.pdf "The source of the grain table calculations and estimates") showed me how to calculate land usage and output per farm acre.
A quick example of me using the table linked in the paper above:[](https://i.stack.imgur.com/E4MDa.png)
All of this allowed me to calculate the following:
* Land use (arable, meadow, pasture, common) in acres
* [Output](http://www.cropyields.ac.uk/database_search.php?cat=0 "Online database - hard to use, but lots of data") from farmland (wheat, rye, barley, oats, potatoes, pulses, clover)
* % of each consumed, brewed or used as feed
* [Ale/](http://www.polysyllabic.com/?q=medieval/brewing "Someones private research on their blog")[beer](https://www.cs.cmu.edu/%7Epwp/tofi/medieval_english_ale.html "Someone tried brewing their own recipe. Talks about how much grain is used") output from brewed grain in gallons
* Count of animals (milk cattle, beef, calves, sheep, swine, chicken, horse, ox)
* Output from animals ([milk, cheese, butter,](http://irserver.ucd.ie/bitstream/handle/10197/3723/WP12_12.pdf?sequence=1 "Great estimates of meat per animal and milk output as well as conversion ratios for products") [beef, mutton, pork,](http://www.cruachan.com.au/docs/Size%20and%20Weight%20in%20Early%20Scotland.pdf "Carcass weight and percentages") wool, [eggs](http://sciencepress.mnhn.fr/sites/default/files/articles/pdf/az2009n2a2.pdf "Chicken Husbandry in Late-Medieval Eastern England"))
* [Many numbers came from here](http://faculty.econ.ucdavis.edu/faculty/gclark/papers/Agprice.pdf "Great thorough price list - food & other like firewood, price of land, timber, cider & honey")
With all of this, from other articles, I also have [consumer](http://personal.lse.ac.uk/mad1/ma_pdf_files/allen%20et%20all%20ehr.pdf "Wages and 2 good tables of consumption baskets of goods - A 'barebones' and a 'respecable' basket") [baskets](https://www.nuffield.ox.ac.uk/users/allen/greatdiv.pdf "Already linked above"). Scholars have written [detailed](http://www.brockwell-bake.org.uk/docs/harvesters_diet.pdf "Great thorough price list - food & other like firewood, price of land, timber, cider & honey") accounts of the % of a person's income spent on a basket of goods.
So I know a peasant might spend his income like so:
* Food & Drink: 59.7%
* Fuel & Light: 6.29%
* Clothing: 15.92%
* etc
I found [tables](http://gpih.ucdavis.edu/Datafilelist.htm#Europe "LOTS OF DATA, OMG!") like this for people of different socioeconomic classes, *so I have a set of consumer spending by class as a percent of yearly income.*
I have a table showing a days [wages](http://faculty.econ.ucdavis.edu/faculty/gclark/papers/wage%20-%20jpe%20-2004.pdf "Great article with lots of details") for a farm laborer in bushels of wheat that seems promising. But I don't known what my wheat should be priced at.
I also have [tables](http://faculty.econ.ucdavis.edu/faculty/gclark/papers/Agprice.pdf "Prices") and tables of price information. Again, I didn't want to arbitrarily **choose** a price, so these are used as reference. I have also tried using an index derived from a known, easily calculated price.
# My Problem
Ok, so with all that out of the way, I feel like I am close. I feel like I have the right pieces but I am not looking at them exactly right.
Just last night, I saw that I have the number of kilograms of cheese a peasant ate in a year as well as what percent of their income was spent on cheese. Choosing a random wage, I nailed a price to that. I then went to the prices table and created an index which opened up some prices, but not enough. Often times a basket of goods just says 'Bread and flour' or 'meat' without giving me granular detail like 'beef' vs 'pork'.
I need to set a realistic wage for a day's work for a common laborer, and then I can derive the rest from there.
How do I set a wage I can be confident in to then extrapolate the rest of the wages and prices?
## Some Sources
Many are linked in the text above already
* [The Price History of English Agriculture, 1209-1914](http://faculty.econ.ucdavis.edu/faculty/gclark/papers/Agprice.pdf "Prices")
* [Changes in Diet in the Late Middle Ages: the Case of Harvest Workers](http://www.brockwell-bake.org.uk/docs/harvesters_diet.pdf "Food consumption - has a table of food allowances, has % as well")
* [The Great Divergence in European Wages and Prices - from the Middle Ages to the First World War](https://www.nuffield.ox.ac.uk/users/allen/greatdiv.pdf "Basket of goods consumed - very good")
* [International Institute of Social History - List of datafiles](http://iisg.nl/hpw/data.php#europe "Datafiles - one is General level of wages in Europe - contains excel spreasheets to download")
* [Benchmarking medieval economic development: England, Wales, Scotland, and Ireland, circa 1290](http://www.helsinki.fi/iehc2006/papers3/Campbell122.pdf "Some population and interesting land use/area estimates (towns per 100 sq mi)")
* [THE LONG MARCH OF HISTORY: FARM LABORERS’ WAGES IN ENGLAND 1208-1850](http://faculty.econ.ucdavis.edu/faculty/gclark/papers/long_march_of_history.pdf "Good source of price of meat, dairy, fuel, light, clothing")
* [Wages, prices, and living standards in China, 1738–1925: in comparison with Europe, Japan, and India](http://personal.lse.ac.uk/mad1/ma_pdf_files/allen%20et%20all%20ehr.pdf "Wages and 2 good tables of consumption baskets of goods - A 'barebones' and a 'respecable' basket")
* [‘Grain output and population: a conundrum’, Chapter 8 (pp. 386-410) in, English seigniorial agriculture 1250-1450](http://www.helsinki.fi/iehc2006/papers3/Campbell.pdf "The source of the grain table calculations and estimates")
* [Precocious Albion: a new interpretation of the British industrial revolution](http://irserver.ucd.ie/bitstream/handle/10197/4796/WP13_11.pdf?sequence=1 "Good source, has wages based on labor quality, harvesting and threshing cost")
* And much much more
[Answer]
The weird thing is that prices can be arbitrary, or wages can be arbitrary, but they must be highly correlated.
Say the minimum wage is \$8/hour, for argument's sake. If I make it \$800/hour, commerce does not change if I also multiply all prices by 100x, so the minimum wage buys exactly the same thing.
The people really *damaged* by that are the people that hold wealth. Say a loaf of white bread costs \$2.50 (as it does at my local grocery). If I have \$1M dollars in the bank, I could use that to buy 400,000 loaves of white bread. However, if prices suddenly are multiplied by 100, I can only buy 4000 loaves of white bread! I can't build a bread fort with that!
But the minimum wage worker with zero money in the bank is not affected at all, in 8 hours on Monday he is paid \$64, and can buy 26.6 loaves. Tuesday all prices are multiplied by 100, he gets \$6400, and can still only buy 26.6 loaves. He might as well be paid in loaves (as people once were).
### Now we can answer the question.
You have to decide what the lifestyle is for the common laborer. Much of your research should inform this already. How many hours does he work? How much bread does he eat? How much meat? Does his shelter cost him anything? Does he pay for healthcare? Taxes? Transportation?
Try to put these expenses in terms of an item; like bread. (As I did above). At $8/hour, my minimum wage worker needs to earn about 25 loaves a day to stay reasonably healthy, sheltered, and able to continue working. You can even go beyond that, and say it is basic calories: A loaf of plain white bread generally has about 2000 calories. 25 loaves is 50,000 calories a day.
So he isn't going to EAT 25 loaves a day, he is going to trade them for meat, eggs, shelter, medical help, clothes, beer, and so on.
Now all you do is set a completely arbitrary price for a loaf of plain white bread. Call it a copper, or a penny, or a shilling or a filium. *It makes no difference,* all that matters is a common laborer gets 25 of them for a full day's work (which you can vary, too, up to about 12 hours, 7 days a week).
All other prices, for luxury goods or servants, and all other wages, can be computed from there. Even using modern ratios. Unskilled labor makes minimum, slightly skilled (e.g. cooks) earn 25% more, etc. You can look at national labor charts to see what various professions make; cast those in multiples of the minimum wage, and presto; you can compute their salaries in filiums per hour.
Which is the track I think you are already on.
---
**Afterthought:** I should note the above, talking about 25 loaves, was a continuation of discussing a modern American Laborer. Such a person has many living expenses a medieval peasant would not: The modern laborer must pay for shelter, water, food, taxes galore, electricity, waste removal, transportation, much more clothing and healthcare and hygiene products than a peasant.
Many peasants lived in "housing" they built themselves; paid no taxes, paid nothing for water or waste removal, and wore one set of clothing their entire life. They paid nothing for insurance or health care or retirement. Many lived with no income at all for years at a time; they learned to sling or throw rocks and hunted for birds, squirrels, small games and edible fruit, plants, roots and nuts, they learned to sharpen sticks with rocks and spear fish.
Prices and wages DO need to be scaled to the living expenses of the common laborer in whatever time period or culture they reside.
[Answer]
Before I answer your question let me explain that this kind of analysis, when done thoroughly and completely, tends to win Mathematicians and Economists the Nobel Prize (see [John Nash](https://en.wikipedia.org/wiki/John_Forbes_Nash_Jr.) and the movie *[A Beautiful Mind](https://en.wikipedia.org/wiki/A_Beautiful_Mind_(film))*). You're not going to get that quality of analysis from me and you might be over-engineering your world just a bit. But...
---
I'm a Noble with a reasonably complex economy to worry about. There are roads to maintain, my troops to worry about, people to bribe, not to mention my ~~mistresses~~ (*ahem*) wife to spend money on. I have a coffer under my wife's side of the bed (woe to the bandit who tries to get at THAT coffer!) with my land's budget and it currently has 1,200 gold pieces. I'm considered wealthy and the envy of my peers.
But, I have a castle to build. It just honks my horn that Lord Jones over there has a castle and I'm not coming in second place to *him.* Have you seen his daughters? He'd better gold-plate that castle as their dowery. And just wait until you see MY daughters. anyway, I need 1,504 gold pieces in my coffer after a year's passed so I can keep up with the Jonses.
That means I need 42 gold in extra tax each month. I'm declaring my expenses to be 10 gold pieces each month and I need 100 gold pieces each month just to keep the coffer where it is. That's 152 gold each month.
I tax by families, and I have 2,500 families in my lands. 500 of them are peers. The rest are serfs. I collect twice from my peers as I do my serfs and I'm not allowing them to collect taxes. They can get rent, but not tax. So, I need 3,000 shares of 152 gold each month or 0.05067 gold per serf family and twice that for those mooching peers. At 10 silver per gold and 10 copper per silver that's 5.067 copper per month from my serfs and 10.13 copper per month from my good-for-nothing peers.
Using a [standard](http://www.leavedebtbehind.com/frugal-living/budgeting/10-recommended-category-percentages-for-your-family-budget/) told me by a Seer who claims he can see into the future (what exactly is "tie-dye" anyway?), rent is 24% of each family's average income, food/clothing/medical another 24%, savings (better known as my when-I-decide-to-give-that-Jones-guy-the-beat-down-of-his-life fund) is 10%, booze money is 5%, farm animals and tools are 14%, and my taxes are 15%. That means the average family income is 33.78 copper for serfs and 6 silver 7.56 copper for those hangabout peers.
Sometimes I need to bring a heavy hand against my merchants because they get a little greedy (that's my job, afterall) and try to gouge people. But when everything's running smoothly, the value of a cow (and therefore the straw that feeds it) is easily calculated from the available money my people have to spend.
When I need to improve the economy a bit, I'll co-opt some of my serfs to hit the mines and dig out a bit more gold. Not too much! Copper is good for serfs, silver for my honking peers — and gold for me!
---
What I just did was create an arbitrary starting point. You must do that, because no economy (even really simple economies) can be "balanced" without an arbitrary starting point. My starting point was (a) the money I have to spend when everything turns bad (my coffer), (b) the money I think I'll need for next year, and (c) my own expenses. If you don't do something like this, it's almost impossible to balance out the numbers (take this from a non-accountant who once created his own corporate balance sheets...).
By starting the way I did, I discovered how much money my people had, which makes it trivial to create item prices based on how common and/or rare they are. Believe me, toothbrushes are ***really*** expensive!
---
**Edit:** By the way. Once you've worked this out, you might want to remember that video game companies actually offer jobs to people who can do exactly this. Especially the MMORPG people. Monetization and in-game economy is no small thing... and employers will pay for the skill.
[Answer]
The classical peasant won't participate in the generate & spend relationship with currency. For the most part the income they generate is natural produce and most of the needed food, clothing and the like are subtracted from the income before entering any cycle based on currency in whatever form.
Thus, the average amount of bread, dairy products, eggs, meat and the like a peasant consumes has no correlation to the amount of income (in currency) the peasant has available. The bread is made from grain not used when seeding last. Whatever was on a peasants table is largely dictated by what they couldn't sell or when stuff would go bad. In a medieval setting before refrigeration, pasteurization and homogenization you've got about three to four days for most dairy & eggs to be consumed.
Especially milk and eggs scale really bad in a medieval setting. There's only so many people in reach of your farm that can consume non-durable food within the necessary time span. Of course, farmers know that so the twentieth chicken is actually a burden since they can't sell more eggs and the bird still eats stuff, so you gotta eat the chicken.
Essentially you can have quite well fed farmers (who mostly don't own the farm) whose production of goods they can afford to sell (after feeding themselves and paying whatever form of tax there is (likely in natural produce as well) to lord and church) is so minuscule that they never get to have much money.
Not to mention the non-currency trades going on in a medieval village. E.g. the blacksmith gets two eggs each day and fixes the plow in return when it breaks. Same goes for wages. The farmer will pay the usual *harvest hands* very little in actual coin but likely provide them with a cozy, dry place to sleep in the barn and food while he's working there. Medieval apprentices didn't get any wages to my knowledge either, just a place to stay and food to eat while learning a trade.
*So, what I'm basically saying is, don't forget the non-currency part of an economy set in a medieval setting. It's quite a big part.*
[Answer]
I'd like to agree with the answers from JBH and Amadeus but point out a couple of historical notes that might interest you. One have a look at the [*Domesday Book*](http://www.domesdaybook.co.uk), the first land survey and census conducted by the Norman kings of England finished in 1086 if you want an idea of real medieval productivity and taxes. As an idea about where to set your prices from, grain and salt are the prime historical examples of a goods based price standards. Once you've set a basic price for a bushel of wheat, or a pound of salt, everything else is relative (based loosely on the labour involved in the material in question), the more processed the item the more leeway you have to fudge your numbers too because skilled (as opposed to grunt) labour is the most flexible of price multipliers.
[Answer]
I am answering late, but hopefully someone else sees my answer.
Like others said, prices are relative in economies. A beer may cost 1.25 bread loaves, and if a bread loaf costs 100 gold, a beer will cost 125 gold. However, there are other considerations you might think about.
For pre-coinage economies, or economies when the coins left the kingdom, this would be reasonable. The Icelandic free state traded in square yards of cloth. There was an island where the people carved on big unmovable rocks, and they traded rock shares as a currency. Grain was often used as a currency. Just look up proto-currencies to find more examples.
Let's say my economy produces 10 loaves *or* 12.5 beers every year. Every year all the goods are consumed. This would make it such that 1 loaf = 1.25 beers in a simple economic model. This means that if a loaf is 100 gold, and a beer is worth 125 gold, then there is a ratio of gold in circulation to the bread and beer. For every loaf, there is 100 gold. For this to happen, you need the quantity\_bread \* ratio = 10 \* 100 = 1000 gold in circulation. Hypothetically, you could look at the production of gold coinage and the rate that people save the coinage away to get a ratio, but in reality few people saved in medieval times unless they buried their horde from tax collectors and invaders. So, sticking with a static coinage in circulation is accurate.
There is the effect where more coinage causes more efficient trade to a point. If there is only enough coinage for the cities, then the cities will trade at the efficiency and vigor of a currency economy, while the countryside will suffer the less vigorous barter economy. If everyone has coinage, more coinage won't do much. There is an equation for this, but I am on my phone now. I would guess a sigmoid curve would simulate it.
I hope that gives you insight.
] |
[Question]
[
This is mostly asked out of simple curiosity since this is the backstory of a [LARP](https://en.wikipedia.org/wiki/Live_action_role-playing_game)er’s character within my story and thus has little expectation of scientific rigor. But basically, this character is one of the last survivors of a tribe who lived in a desert made of black sand. And I was wondering if making the desert sand a color completely on the opposite side of the heat absorption spectrum would do any crazy, unlivable things to the daily temperature there. Would it make the desert hotter? If so, how much? Would they even be able to survive there?
[Answer]
I can't find any spectrally-black sand deserts on Earth, but I can find [Reynisfjara, Iceland](http://www.theworldisabook.com/25006/walking-reynisfjara-black-sand-beach-in-iceland/), which has actual black sand beaches.
**There are more consequences than just heat**
I'm going to assume we have legitimate spectrally black soil form from normal planetary processes and not magic. In that case, soil is usually made up of oxygen, silicon, aluminum, iron, magnesium, calcium, carbon, sodium, potassium, hydrogen, and nitrogen.
>
> Eight chemical elements comprise the majority of the mineral matter in soils. Of these eight elements, oxygen, a negatively-charged ion (anion) in crystal structures, is the most prevalent on both a weight and volume basis. The next most common elements, all positively-charged ions (cations), in decreasing order are silicon, aluminum, iron, magnesium, calcium, sodium, and potassium. Ions of these elements combine in various ratios to form different minerals. More than eighty other elements also occur in soils and the earth's crust, but in much smaller quantities.
>
>
> The organic fraction of a soil, although usually representing much less than 10% of the soil mass by weight, has a great influence on soil chemical properties. Soil organic matter is composed chiefly of carbon, hydrogen, oxygen, nitrogen and smaller quantities of sulfur and other elements. The organic fraction serves as a reservoir for the plant essential nutrients, nitrogen, phosphorus, and sulfur, increases soil water holding and cation exchange capacities, and enhances soil aggregation and structure. ([Source](http://organiclifestyles.tamu.edu/soilbasics/soilchemical.html))
>
>
>
It's light colored when there's a lot of silicon, aluminum, and magnesium. It's brown when there's a lot of carbon and iron. Sand is yellow to white because it has an enormous percentage of silica.
Actual spectrally black soil is volcanic in nature and contains very, very high levels of iron and magnesium. The most obvious of these is obsidian. The point here is that truly black rock has more in common with metal than it does sand or soil.
* It's dense, meaning it's heavy, what life there may be in a desert will have a harder time moving the soil aside for roots or burrows.
* It will have finer, shaprer edges to the grains of soil, meaning you'll find "more dense" critters, armored against the rocks. This means thick chitin shells and dense, woody roots. Life will be, shall we say, angrier and more stubborn than you'd find in a traditional desert. Keep in mind that soils like this aren't particularly condusive to life, meaning you won't find that lovely green sheen over the soil you see at the beginning of *[Star Wars:Rogue One](https://youtu.be/JVnNdKdWBsY?t=20s)*.
* The soil will be much warmer than in a traditional desert, since it's absorbing a much wider spectrum of light. However, the thermal conductivity of volcanic soils is much lower than high-silica soils, meaning the black soil will lose its heat very quickly compared to sand after the sun sets. ([Source and a throwing-weight document](https://pubs.usgs.gov/of/1988/0441/report.pdf)) The sand would be very, very hot to walk on during the day, but cool to cold at night.
* On the other hand, because the soil is absorbing so much energy, the air will be colder during the day, have a rush of warmth as the sun sets, and yon about 2am will be very cold. Over all, a spectrally-black desert will be very cold.
[Answer]
Black sands will have more extreme temperature swings than lighter colors. Because of this, your black sand desert will get hotter during the day and colder at night than a regular desert. This is because all objects release and absorb some [Thermal Radiation](https://en.wikipedia.org/wiki/Thermal_radiation), with darker objects both radiating and absorbing more.
However, most of the exchange in thermal energy on earth comes from [conduction](https://en.wikipedia.org/wiki/Thermal_conduction) and [convection](https://en.wikipedia.org/wiki/Convective_heat_transfer), so the effects of it would not be very strong. Ultimately, it would not do any "crazy, unlivable things" to the temperature, and you could still have a livable desert.
[Answer]
I've been on volcanic beaches and in a part of the egyptian desert both called "black". For example, here's a picture of the beach close to where I was:
[](https://i.stack.imgur.com/3AX42.jpg)
There is not so terribly much difference to a white beach. After some time in the full sun, they are both hot and from what I remember, whatever difference there were was not very noticeable. The sand itself gets a little hotter, but since it absorbs more light, it reflects less heat, so when you are wearing proper footwear, it doesn't make much of a difference.
[Answer]
The Canary Islands are a group of islands that are Spanish territory off the coast of Africa 62 miles or 100km away at their closest point. They are also on the same line of latitude as the Sahara desert. They are considered to have a desert or semi desert climate.
They are also highly volcanic formed from an Oceanic hotspot in a manner similar to the Hawiian islands meaning that the volcanoes erupt what is known as Mid Oceanic Ridge Basalt or MORB.
This has lead to the creation of areas such as the Timanfaya National Park on Tenerife that would be described as having black sands and a desert environment. The temperature there is not wildly hotter than other deserts on similar latitudes. Although as others have said what defines a desert is amount of rainfall there are deserts in the South Pole that are at sub zero temperatures.
[Answer]
From what I know for sand to be black in such enormous quantities it's origin must be volcanic. Having magmatic activity around already makes a place pretty hot, although the sand may have originated elsewhere and traveled in various ways to the location of your desert, what would mean there's no high vulcanic activity in the area.
There are of course much more factors to take into account in order to give an exact answer: the average temperature of your world, how much of an impact does the greenhouse effect have, the axial tilt of the planet and the relative position of the desert to the ecuator...
But to give an approximate answer to your question: Yes, black sand would mean more light (thus heat) absorption from the soil, resulting in both a hotter overall climate in the area and much hotter soil.
The how much depends in a lot of things, varying from a simple no-go zone with little to no living beings, to molten glass lakes (the conditions for this may be a little too extreme for there to be life on the rest of the planet).
These types of deserts will always be hotter than normal ones. How unforgiving the area is depends on you and since you said the story has little expectation of scientific rigor there's always the possibility of heat-proof technologies paired with underground cities or just beings that stand extemely high temperatures.
[Answer]
From something I read a while back, the darker regions on the moon are actually volcanic rock which, when sunlit, stands out against the void of space, but would actually be black or nearly black if you looked at it on Earth.
The sunlit side of the moon can reach 100 to 120 degrees C (210-250 degrees F). Bear in mind it is exactly the same distance from the sun as we are, though it has no atmosphere.
[Answer]
A slightly different approach here.
The area is actually a desert BECAUSE it is black and normally that area would be a more temperate climate if it had normal soil and sand.
(This might go against some of the science that others are spouting but, if you aren't overly worried about the high science and just looking for something that sounds right(ish) then this could work for you)
[Answer]
You can get a first order approximation by visiting a large parking lot.
My usual experience when calculating what to wear outside is to say that clear sky makes it equivalent to 10C (20F) warmer out. And a 5-10 kph (3-6mph) wind makes it 5C (10F) cooler.
However there is thermal temperature and YOUR temperature. In a white environment you will be receiving sunlight from multiple angles. In winter you can easily double those numbers on a sunny day.
Secondary effect: In small black deserts (parking lot to, say 30 km (20 mi) across, the warm surface will set up convection. Sailplane pilots look for thermals from parking lots or ploughed fields. So for a small black desert the effect is self limiting. With larger deserts the air can't rush in fast enough. So you would end up with a warm low pressure area.
If you want to experience it here on Earth on a larger scale, visit "Craters of the Moon" national monument in Idaho. You may be able to reference weather station data, and compare. Not big enough to not be cooled from outside. Google satellite image:
<https://www.google.ca/maps/place/Craters+of+the+Moon+National+Monument+%26+Preserve/@43.1170294,-113.9920283,117932m/data=!3m1!1e3!4m5!3m4!1s0x54aa5f3acc0c2525:0x593b4ba65a2caf7b!8m2!3d43.2058067!4d-113.5001702>
You may want to check out icelands lava fields or the lava shields in Hawaii
] |
[Question]
[
## The Situation:
The year is 2014 and the city of Prague is under siege. Cut off from supply, the city prepares to defend itself with whatever is at hand. The Jewish community offers the services of as many Golems as they can make, but are concerned that they will be ineffective against modern weaponry. **How can the citizens of Prague enhance these Golems to combat modern era armor?**
All the synagogues work for several weeks manufacturing Golems, but the process is time consuming and they are only able to complete two dozen in time for them to be enhanced. This is the only magic known in the world, any enhancement must be a product of science.
## What we have to work with:
24 [Golems](http://en.wikipedia.org/wiki/Golem):
Descriptions of the mythical Golem are vague, but let us assume that the standard Golem is 9' tall and proportioned as above. Golems are made of clay, hardened by ancient magics to the same hardness as [Boron Carbide](http://en.wikipedia.org/wiki/Boron_carbide). They can walk, but not run, at the same rate as a jogging human. Golems require no maintenance, but must rest every Sabbath or they go rampant and kill people. Golems have hands and fingers, but they are thick and not dexterous. Golems are quite strong, able to bend steel girders given some time and effort.
## What we're fighting:
For simplicity's sake, we will need this Golem to compete with a specific military vehicle. The [BMP-3](http://en.wikipedia.org/wiki/BMP-3) (Competition is defined here as: "Able to engage and destroy at better than 25% casualties.")
[Answer]
There are a number of advantages the Golems have over both infantry and vehicles.
The first is that they can wait silent and immobile for a long time, they have no need to breathe or eat. They are also strong and tough, although not as strong or as tough individually as a tank. They would be essentially impervious to most small arms fire, heavier weaponry would be needed to shut them down.
You need to use these advantages rather than trying to engage head-on. Terrorize the enemy, make them dread every step.
*Statues*
This is quite simple, replace some statues with Golems and wait. On a suitable symbol the statues come to life and attack. This gives an instant fear and confusion factor, and with the Golem being in the middle of your troops using heavy weapons on them will cause a lot of collatoral damage.
*Underwater*
Streams and rivers allow the Golems to move around undetected and strike from unexpected angles.
*Underground*
Bury a golem into the ground on a street with a big stack of remote-controlled explosives.
It remains quiet and hidden until a vehicle passes over, at that point its arm comes out and attaches a pack of remote-controlled explosives to the vehicle. It then goes quiet again until the next vehicle passes and then repeats the process.
*Darkness*
Golem's don't seem to "see" in a conventional sense. They may well be able to operate at full effectiveness even in pitch black or smoke. They could be used for night attacks, or use smoke grenades to obscure vision.
*Gas*
Golem's don't breathe, equip the Golems with dangerous chemicals that produce poison gas, have them throw it and walk through it.
*Fire*
Golem's are fireproof, equip the Golems with flamethrowers and also wrap them in rags soaked in oil that ignites when they set off the flamethrowers.
*Underground and fire*
Bury golems under likely camping spots for the invasion forces. They would be completely still and silent so essentially undetectable if placed well. At a suitable time in the night they would rise up and find high value stores. They would set light to those stores then bury back underground under the burning supplies and hide themselves under the ashes.
**The course of the invasion**
It starts immediately as the army advances, strange figures striking in the night and then disappearing again. Soon the men are afraid to go near water as the enemy special forces are lurking in the streams and rivers waiting to attack.
You camp for the night and your supplies go up in flames, but there are no signs of any attackers. Suspicion turns on your own men and the guards on duty that night are shot for dereliction of duty, but the next night the same thing happens again.
As the convoy approaches the town there is no sign of resistance, no enemy fire, but suddenly the leading 6 APCs in the convoy explode from beneath. A thorough search finds no attackers in the area but there are remains of an explosive device found attached to the bottom of each vehicle. Again suspicion turns inwards and paranoia starts to spread. Guards are posted on the remaining vehicles overnight and supply depot guards are doubled.
The next day though despite all these precautions the remaining APCs also explode, again with devices attached underneath.
The remaining demoralized troops sweep into the town to find the area evacuated and no sign of resistance. As they move further into the town though strange hulking figures step out of the buildings around them. The ones in front shoot out vast tongues of flame, igniting into walking nine feet tall figures of flames. From the sides comes more of the figures, these ones throwing gas and smoke grenades. Then the statues in the center of the square come to life and charge towards the leaders of the army, brushing aside fully grown men like they weigh nothing and with bullet fire bouncing off them, barely chipping their surface.
The terrified men panic and turn to run but more of the hellish creatures are rising up out of the ground behind them. The panic turns into a mass stampede and they run for their lives, losing a huge number of men and all of the leaders in the process.
...and that's how 24 Golems defeat an army :)
] |
[Question]
[
Lo and behold! A zombie apocalypse broke out inside Roman territory. In the Iberia peninsula. Being smart as vitruvius is, he devised a plan on how to deal with the zombies. Use them as power sources!
Provided everything worked ok, what's the maximum power that can be extracted from this setup? Is there an alternative means to extract power from zombies? Would this provide enough power to move a war machine?
* Consider them to be human-like, with characteristic zombie gait, only differing in that they don't need to eat, they eat out of taste for human flesh, not out of nutrition. Do not consider normal metabolism. They can very well run continously, accumulating lactic acid without pain. There are no thermodynamic limits for them, besides that they can do whatever a normal human can do physically. They feel no pain and have an IQ between a cockroach and an anemone. In other words they are purely reactive. They seem to not have immune systems, so they rot under anything that consumes flesh. They only stop moving when they are out of muscle tissue. The difference in speed is due to activity in cerebellum, it's a matter of remembering how to run. The smart variety still remebers how to do trivial tasks, like opening doors. The dumb ones can only run towards a target. If they lack a leg they will be unable to stand up, walk or run.
[Answer]
**140 Watts**
We have the [data for humans on treadmills](https://conservancy.umn.edu/handle/11299/132115), so the assumption is that the maximum power for a zombie is the same. They were once humans, right?
You might shave off a few tens of watts due to the shuffling nature of their gait. But at least the power generation is more constant for a zombie, humans get tired too quickly.
You'd be much better off teaching one of them to ride a bike. Or maybe that's one of those things zombies never forget either? In any case, [the maximum for a bike](http://mapawatt.com/2009/07/19/bicycle-power-how-many-watts-can-you-produce) is closer to 400 Watts. Just don't let them escape after that, we don't need any zombies riding bikes around after people.
[Answer]
>
> Would this provide enough power to move a war machine ?
>
>
>
Do catapults and chariots count? They can pull from a catapult until it's set up in place. And if they can pull chariots at 30 km/h, even if that's not much, they can pull longer and farther than horses.
What about mobile fortresses?
[](https://i.stack.imgur.com/V07Li.jpg)
Pack your horde of zombies tight, add some helmets to protect their fragile heads and make them carry archers and supplies through the battle field.
[Answer]
A typical human can [produce](https://en.wikipedia.org/wiki/Human_power#Available_power) and sustain between 50 and 150 Watts walking, or as high as 400 Watts on a bicycle. However, that is for long-term, sustained output; since these zombies essentially never get tired, they actually can produce a lot more power. By setting the treadmill at an incline, stepping up the gears, and adding hand/footholds for the zombie to use as leverage, the zombies should be able to attain peak energy production of a human, [around 2000 Watts](https://en.wikipedia.org/wiki/Human-powered_transport#Available_muscle_power), or 2.68 HP. As a plus, higher gear ratios means that zombies won't run; this leverages strength, not speed.
Wear-and-tear will play a role over time, but as long as you have reserve zombies to replace those that fall apart, you should be able to power whatever you want. Romans already had several slave-powered devices, and zombies are much cheaper than slaves, not to mention easy to store: dump them in a sealed bucket of oil, and they'll last forever!
[Answer]
If you have enough of them it may be good enough to power the electric fence that you use to keep the zombies at bay.
Using said zombie power to store energy in some other form (like compressed air or recharging batteries) your energy need to power a war tank would only depend on whether you have the resources to build charging stations and charge holders and how many zombies you could obtain. IE a billion zombies could provide a lot of power but not if you don't have the charging stations. A billion zombies trundling a billion charging stations are wasted if you only have one battery to charge.
] |
[Question]
[
For sentient avians, knowing the location and behavior of currents in the air would be vitally important. Jet streams, thermals, downdrafts, and shear layers would all be important in their daily lives.
I imagine that bird people would want to map these currents. While they might change on a daily basis, common maps of persistent features in a landscape, as well as up-to-date maps of specific features in real time, would be incredibly useful for planning movement and navigation. Merchants and armies, in particular, would be highly reliant on these maps for planning logistics. The difficulty in doing so is that air currents are three-dimensional, and any map of these currents must be capable of informing its user as to the three-dimensional nature of these phenomena.
What would be the best way to create these maps? Obviously, how to display such maps will depend on the technology level of the avians, so for the purpose of this question, how would a race of avians with rennaisance-era technology map the atmosphere?
[Answer]
**Maps**
They would probably use something similar to our pilots. A [winds aloft](http://en.wikipedia.org/wiki/Winds_aloft) map. These maps describe the *prevailing* wind.
While wind from moment to moment can be going many different directions, that's mostly only true *very near the ground*. Away from the ground the winds are much more consistent and powerful (this is why wind turbines are built to be so tall).
These maps describe the winds at typical flying altitudes (for small planes flying <10k feet), and that works because realistically your avians probably won't occupy very much vertical space for normal flight. If your avians desire further precision in the vertical dimension, then stacking symbols of a different color to represent higher altitude winds would be a simple addition (which I've created below by merging two days of winds aloft maps). You would obviously want higher spatial resolution depending on the range of the avians, but the idea is the same, just imagine a tiny Alaska shaped island ;)
The symbols describe both wind direction and strength with these little symbols (called a wind barb).
**Measurement**
As for measuring these winds, without satellites, radios, or other electronics the avians would need to send out scouts to measure it by... wing. The avians could carry devices to measure the wind speed, either simple [anemometers](http://en.wikipedia.org/wiki/Anemometer) or even just a plain old [wind sock](http://en.wikipedia.org/wiki/Windsock). By hovering over a single spot they can take measurements and then repot them back to wherever the charts are being made. Their altitude during measurement will need to be estimated from experience or using the [old thumb (or talon) method](http://www.vendian.org/mncharity/dir3/bodyruler_angle/) against objects on the ground.
[Answer]
**Why would they need three-dimensional maps? Regular maps will be sufficient for what they need.**
Assuming the sentient avians descended from not-so-sentient avians, detecting local air currents should be very natural to them. Many of the things that might concern them, such as thermals and downdrafts, wouldn't be worth putting down on a map. You could mark on a map if there's a spot with particularly good updrafts or dangerous downdrafts, but there's no need to specify exactly how high they are - the specifics are likely to change enough to make detail on a map unhelpful. In general, local phenomena will change enough to make their instincts beat out what a map may say.
I doubt they'd need maps for [jetstreams](http://en.wikipedia.org/wiki/Jet_stream), either. On Earth, polar jetstreams are usually "7 to 12 kilometres (4.3 to 7.5 mi) above sea level", and subtropical jetstreams are usually "10 and 16 kilometres (6.2 and 9.9 mi) above sea level". [Some geese](http://news.nationalgeographic.com/news/2011/06/110610-highest-flying-birds-geese-himalaya-mountains-animals/) have been [reported to fly over Mount Everest](http://www.bbc.com/news/science-environment-30845250) (so about 9km), but even those geese try to stay closer to a 5.5km height. So it's unlikely that the jetstreams will be a major concern for your avians - even if they can get up there it'll be too high for them to stay in the jetstreams for more than a little while.
So what would their maps look like? Pretty much like our maps, except with more notes about the air currents. Like @Samuel mentioned, any notes would be about the prevailing wind conditions, but I think they would be much less detailed than the maps our pilots use - again, the avians would be relying heavily on their instincts. If there are places where the air currents are unintuitive to them, they'd make note of those, but otherwise the general shape of the land would be enough detail to allow them to know what flying conditions will be like.
Something you could take a look at would be maps of ocean currents. They'd probably have something like that to help show what the best paths for travel are. Additionally, they'd either have different colors/markings or multiple maps to account for seasonal variations.
[Answer]
**Maps**
I made a partial example map for the birds of a land called Tjerokya. It uses (crude) arrows to show the path of currents traveling across the land and sea. Indicating changes in three dimensions is harder, so I used colors to describe the changes. Redder colors mean rising currents, and bluer colors mean sinking currents (yellow and green are near the middle).
There are two additional features I didn't implement here:
* **Wind speed.** Longer arrows can be used to indicate faster winds.
* **Altitude.** Simply use thicker arrows to indicate higher elevations.
[Answer]
Like this (Very Rough Example - a picture is worth a thousand words). Explanation is after the picture.
---
---
This is a map drawn to represent a certain section of canyon. The two thickish curvy lines represent the cliff sides of the canyon. Circles with "X" inside represent other obstacles such as pillars in the canyon.
Each line that has arrows attached to the end represent the direction of a wind current. For example, in this current map, there are 4 lines that are "inside" the canyon, with 3 arrow pointers, and one line that is in the center with only 1 pointer.
The arrow pointers could be what the Avians use to determine wind strength - the more pointers, the higher the wind speed. Eg: each pointer is 25 kph (or any other value you choose). Following this map, the Avian reads: Oh, there are currents going in that direction that go at 75kph. There is also one that goes at 25kph.
But air is 3d. How do we know what level the wind is at? I draw attention to the numbers near each line. Of course, when the Avians do this they'll probably use a different color for the numbers, but the numbers represent a "depth" level. Perhaps 0 being ground level, and every increment of 1 is 50m.
Reading this map, you can see that the currents at the bottom of the canyon (approx 150m down (negative 3)) are at 75 kph, and the currents at 50m above the canyon are only at 25 kph. There is a current to the right of the canyon 200m up that goes at 25 kph.
But what about updrafts? Those are important for lift! Please see the sections on the map labled "UD L:X" where X is a number. It may be hard to see, but I did my best to draw a dotted line area around it. Those areas are "updraft" areas, vertical lift providing areas. UD stands for Updraft, and the Avians could use DD for downdraft (if that exists), etc etc. It's just to denote certain large areas of lift manipulating currents. L:X stands for the amount of lift they'll get. A higher number represents more lift, and lower is less. Note: the numbers I've picked for this map so far are arbitrary and you can use what you want - perhaps the maps can even include a legend and scale on the side that show windspeed/strength.
Of course, when the Avians do this they'll have colors to represent landmasses and ocean, etc, instead of doing it on crappy office lined paper...
[Answer]
You would need three dimensional models if we are talking Renaissance.
I imagine levels of maps here.
**Level 1:** Global
Create a wire frame globe and plot the prevailing winds with some sort of thread. The thread could be attached to a sliding mechanism attached to the wire frame to allow for adjustments. This map wouldn't need to change often. You could create something like this and put in in the center of each town to make it readily available for people 
**Level 2:** Consistent winds
This would be on a more local scale but cover the same types of winds as level 1. Mainly meaning winds that don't often change. Currents off the oceans or seasonal winds for example. The main difference here would be how localized the area is. A cube frame for the local regional air space would fit into this category.
**Level 3:** Local winds with local events. Thunderstorms or the gusts from forest fires would fall into this category...this would be tough to maintain and distribute. Predominantly I think this would be handled by instruments rather than maps...it just changes too quickly. In a computerized age you could probably pull it off but with renaissance tech you are probably going to need a lot of wind socks and wind speed gauges around town and along major travel paths.
[Answer]
While sentient avians would definitely make some note of winds aloft, there are other types of maps that are needed for safe flight as well. A map of ground features themselves, such as found on a sectional chart, is not only useful for figuring out where to park yourself overnight when a storm is coming in while, but for orienting yourself and navigating while in the air, especially over unfamiliar terrain (this is known as pilotage, and is taught to all airplane pilots as part of their fundamental flying courses). More sophisticated sentient avians who have developed or evolved blind-flying systems could have route maps and such that work with those waypoints, similar to today's en route instrument charts.
[Answer]
A map depicts a thing as it relates to another thing. Travelling in a car the other things are now exclusively visual landmarks on the ground. Humans used to use other things: the smell of the air, the temperature of the water. Sailors used the nature of the wind and appearance of the clouds.
Some avians are thought to have a magnetic sense and use that to migrate. Avians might also have an internal altimeter.
We think of a map as fixed: it shows what is. I like the idea of the "map" being variable depending on season, prevailing weather, the actions of other things in the environment. Possibly other things even less perceptible to humans like telluric currents which could be perceived by animals with magnetic senses. Reasonable beings would debate about which map was most appropriate for a given time. I am certain exactly these debates take place among sailors today.
/ they'd probably use something like memorized songs of flight paths between waypoints. Such descriptions of routes are what navigators used to use as well. Birds also follow paths from waypoint to waypoint IIRC. – Ville Niemi/
I like the idea very much of a map being a song. Different verses correspond to different situations, with the chorus marking the individual song. That would be fun to write too! The debate would be sung back and forth. 40,000 years ago I suspect most accumulated human wisdom was as songs. This is why even average humans are able to remember the tunes and lyrics from thousands of songs.
] |
[Question]
[
The size of a planet affects its gravity, its climate, and its likelihood of developing life.
Earth is large enough for an advanced civilization to develop. A smaller body such as Europa, while able support life as well, might not be large enough to birth an advanced civilization.
It is unreasonable for smaller bodies such as asteroids, to ever develop life? Also, what is the smallest a planet can be before it is no longer feasible for an advanced civilization to develop on it?
[Answer]
Whether a planet can sustain a civilization depends greatly on its size, because the planet has to be big enough to avoid these problems: Taken from [Planetary Habitability](http://en.wikipedia.org/wiki/Planetary_habitability#Mass).
>
> * lesser gravity makes atmosphere retention difficult...
> * smaller planets have smaller diameters and thus higher surface-to-volume ratios than their larger cousins. Such bodies tend
> to lose the energy left over from their formation quickly and end up
> geologically dead, lacking the volcanoes, earthquakes and tectonic
> activity which supply the surface with life-sustaining material and
> the atmosphere with temperature moderators like carbon dioxide....
> * Exceptional circumstances do offer exceptional cases: Jupiter's moon Io (which is smaller than any of the terrestrial planets) is
> volcanically dynamic because of the gravitational stresses induced by
> its orbit, and its neighbor Europa may have a liquid ocean or icy
> slush underneath a frozen shell also due to power generated from
> orbiting a gas giant.
>
>
>
So the answer would appear to be:
>
> Thus it would be fair to infer that the **lower mass limit for**
> **habitability lies somewhere between that of Mars and that of Earth** or
> Venus: 0.3 Earth masses has been offered as a rough dividing line for
> habitable planets. However, a 2008 study by the
> Harvard-Smithsonian Center for Astrophysics suggests that the dividing
> line may be higher.
>
>
>
<http://www.lpi.usra.edu/education/explore/our_place/hab_ref_table.pdf>
As for your question of can asteroids support life, the answer would be that it depends.
[This link](http://scienceline.ucsb.edu/getkey.php?key=3072) says basically the same as me.
I fail to find a specific number, but you can calculate a reasonable number from the sizes of Earth and Mars.
But after you get a planet of the right size the planet still has to have a lot of other criteria:
* Geochemistry
* Water
* Energy source (like our sun)
* A lot of other things, etc
[Answer]
I'm going to limit my answer to life forms based on carbon and water living on planets within what is commonly termed the [habitable zone](http://en.wikipedia.org/wiki/Circumstellar_habitable_zone). This ignores other possible life-form chemistries as well as special cases such as Europa.
Using our planetary system as a model, it is clear that Mars, may have had, at one time, the ingredients necessary for life to evolve, but that it was unable to retain them due to *insufficient gravity*. On the other hand, both Earth, and probably Venus did not have this problem.
Gravity is a function of total mass, and so density is an important factor. Part of the problem with [Mars](http://en.wikipedia.org/wiki/Mars) is that its density is only about 70% that of [Earth](http://en.wikipedia.org/wiki/Earth). Increasing the density of Mars to the Earth would raise the surface gravity to about 0.53 Earth gravities, which may, or may not be sufficient.
There are other complicating factors that may or may not be relevant, such as the role of Earth's moon, or of the Earth's magnetic field.
[Answer]
# It Depends
This is a complicated question, because it's hard to define "levels of civilization" in general. I'm going to make the (usually poor) assumption that the level of technology is the measurement of civilization, not things such as ethics or population size.
As you have noted, the body in question needs to have the correct conditions on which life can be supported. That means it must be neither too hot nor too cold; it must have an atmosphere, etc. etc.
If Europa may support life, it appears that anywhere from [.245 of earth's radius](http://en.wikipedia.org/wiki/Europa_(moon)) to bodies the size of "[super earths](http://en.wikipedia.org/wiki/Super-Earth)" can support life.
# Resources
It may not be a matter of size; it is simply a matter of resources. If you look at many civilizations in Earth's history, you'll notice that some advanced technologically while others did not. If you subscribe to the [Guns, Germs, and Steel](http://en.wikipedia.org/wiki/Guns,_Germs,_and_Steel) philosophy of civilization development, you need not just a body to support life, but the correct resources and opportunities for it.
[Answer]
The magnetic field was mentioned in a previous answer, and, in Earth's case at least, it's an important factor. The unusually large, molten iron core of Earth generates a significant magnetic field that [shields the atmosphere](https://en.wikipedia.org/wiki/Earth%27s_magnetic_field#Importance) from being stripped away by solar radiation (see Mars) and also [protects the planet surface](http://www.askamathematician.com/2014/07/q-how-does-earths-magnetic-field-protect-us/) from harmful radiation. Other things being equal, a smaller planet will tend to cool faster, losing its magnetic dynamo core earlier (like Mars).
[Answer]
Natural resources matter a lot more than planet size. You don't specify that you're talking about humans, which would need a planet with roughly the same gravity as Earth to thrive without modern levels of technology or higher. (In fact, a human culture with modern levels of technology would probably thrive, though not develop, in an asteroid, given the right resources.)
Availability of energy (most likely from a sun) is the biggest thing. Some would say that availability of metals is a big thing, too, but it could be possible to circumvent that with organic technologies.
[Answer]
There's no minimum size. Consider: Larry Niven: The Integral Trees/The Smoke Ring.
Both books take place within a gas torus pulled off a gas giant orbiting a neutron star. While both the neutron star and the gas giant are required to maintain the torus neither is inhabitable. The system could work although the gas giant is slowly eaten up.
The tricky part is evolving to the point of civilization before the gas giant gets totally sucked up and the whole thing disappears. (In the books the life is native, the civilization is stranded human starfarers.)
] |
[Question]
[
Before humanity develops actual bidirectional time-travel – assuming it’s possible at all – there will be years, probably decades or even centuries before that during which physics theories prove the general possibility of traveling through time. Philosophers will realize their duty to come up with the morale and ethics surrounding the topic (see section Sub-Questions below).
So, judging and extrapolating from the actual history and state of philosophy, **what would future Temporal Ethics probably look like?**
If you have read and understood [“Multiple History model”](http://qntm.org/models#sec5) or [lax type 4 (“Quantum‐Forking” or “Multi‐Divergent”)](http://www.xibalba.demon.co.uk/jbr/chrono.html#d) you *may* skip the Theory section coming up next, although it deviates in certain details and to help with that, keywords have been emphasized.
# Time-travel theory
Bidirectional time travel is not possible by our current understanding of physics. (Relativistic effects of *very* fast speeds are similar to a one-way trip to the future.) The **laws of thermodynamics** would probably be broken less, at least, if each travel worked by exchanging equal amounts of (random) mass-energy between origin and destination. Alas, we’re probably talking about *a lot* of energy.
Just to make it more interesting, I chose to use a **time-machine** that arbitrarily travels through time itself (like a Tardis or Delorean) and works autonomously. That means it’s neither a sending (and possibly retrieving) device located at the time of origin (as in Terminator) nor a pod-to-pod temporal teleporter (akin to a wormhole), although I think both are better justified than a time vessel. During time hops it can also [travel through space](https://worldbuilding.stackexchange.com/questions/12621/how-can-i-explain-that-a-time-travelling-apparatus-moves-itself-through-time-but) to [compensate for astronomic movements](https://worldbuilding.stackexchange.com/questions/1464/what-if-time-travel-had-to-take-into-account-spatial-distance).
I assume a finite but exponentially growing number of **time-lines** similar but not equal to those explained by Doc Brown in the movie [*Back to the Future II*](http://backtothefuture.wikia.com/wiki/Back_to_the_Future_timeline).
Time travel is almost instantaneous.
Each time travel branches off a new time-line *at the destination*.
My main difference to BTTF is, there are **no ripple effects** as time-lines exist absolutely.
As a (novel) corollary, there is always a new branch *at the origin*, too!
Branches at first only differ in the presence of the time machine with its passengers and cargo.
Their impact will make branches diverge more or less quickly. I also assume **butterfly effects** are a thing, i.e. little cause *can* have huge impact, but does not have to, i.e. any distinguishing relevance may just as well fade with time.
There is no direct hopping between **parallel time-lines**, which some may like to call **alternate universes**.
Unlike some varieties of quantum theory where each non-deterministic state change causes the creation of a new branch, I explicitly restrict that to time travel (even if that’s just for the sake of simplicity).
With time progressing forward there will be, by definition, more and more alternate universes.
Hops **to the past** are always along ones current time-line, up the tree.
Traveling **to the future** is along the time-line where the time travelers have been removed from existence upon departure. (Marty couldn’t meet his future self or son.)
If there are branch-offs between origin and future destination, i.e. there’s a local **time-(sub)tree**, travelers cannot choose to follow a certain path throughout, because they will reenter in *each* future branch of that tree at the same time, thereby bifurcating all of them!
## Implications
It is certainly possible to meet multiple **doppelgängers** of oneself: You first travel back and meet your younger self. Then you travel back again to a point between first arrival and first meeting. Now there is three of you. Any of them may die without affecting the other ones. There is **no grandfather paradox** and there are **no time loops**.
Time travelers can go back and **kill Hitler™** (or help the Nazis win WW2). That’s *not* changing their own history, however, only their *new future*. If they go back to the time they came from, they will hardly recognize it and nobody would recognize them for their *old history*.
There is a **trick** to travel to a future that has “yourself” in it and in all its history since your departure: First travel *back* an hour or a day. Convince your past self not to travel through time. Travel to *their* future. This will be very similar to what *your* future would have been. Even if you didn’t convince them and they go on to create a branch like you did by time-traveling, there would still be the other branch wherein the travel doesn’t happen and a “copy” of you will rematerialize in both.
One strange effect of this kind of branching is, you can never determine whether the time machine **actually works**.
Imagine this: you enter the chamber, set the destination coordinates, hit “start” and … space-time branches. Much like Schrödinger’s cat, you’re still here in one branch (wondering if the machine is broken) and you went away in the other branch with no way ever to return to the original branch or influence its past and future history.
You may of course live in a time-line that has had a time-traveler landing in who proved their story and thereby the possibility of time-travel, but that’s
only verifying the concept, not each individual travel attempt.
In this world, **egoist** time travelers can create a time-line for themselves where they’re [incredibly rich](https://worldbuilding.stackexchange.com/questions/20383/get-rich-quick-with-time-travel) and [powerful](https://worldbuilding.stackexchange.com/questions/18451/travel-back-in-time-and-rise-to-power), e.g. by importing future technology. People like that wouldn’t care about others, including alternate themselves in other time-lines. They wouldn’t care about the number of time-lines either.
**Altruist** time travelers, however, could try to create time-lines with as little human suffering as possible, although they know it won’t affect their original time-line in any way and they cannot go back to a familiar world. They gave up home. Likely, they would become restless travelers for good, like Doctor Who. Some may deliberately settle in a time-line they like and expect to remain likable, others will accidentally strand somewhen.
If time-travelers continuously try to improve their temporal tree, the percentage of **“better” worlds should increase** over time, and hence the probability of being in one.
## Conclusions
If we’re living in this scenario, there’re some conclusions to be made.
* Since there is only a single uninflicted time-line, but possibly myriads inflicted ones already, it is highly unlikely that **history as we know it** is without intervention.
* We have no actual **proof or evidence** of interventions and can therefore not confirm the possibility of time-travel.
* Certain historic events and people are very likely **prime targets** for alteration by *many* altruist time-travelers. Having the holocaust in our time-line, for instance, can mean one of several things:
+ There were actually worse things to fix which we will never know about.
+ Keeping it is considered to have more positive than negative longterm effects. (Time-travelers can test that empirically to some extent.)
+ We’re in a less likely branch where it didn’t get fixed or where an egoist time-traveller profits from it.
+ Humanity in our futures never develops time-travel (and aliens are not interested in Earth) and there are no active travelers in our past.
# Sub-questions
* Would **Temporal Ethics** develop in most time-lines with confirmed time-travel?
* Is there a **justification** or even an **imperative** to build a time machine and travel with it if the present cannot be changed?
* Would it become a moral imperative (*good*) to change the past for the better even though that won’t affect one’s own present?
* Would it be considered *bad* to actively or passively create time-lines that are worse for humanity overall than the uninflicted one?
* Would it be better justified to **improve the present** by importing knowledge from the future or by changing the past?
* Building and running a time-machine is unlikely to be easy and cheap, so only already powerful future entities (like governments) can start a **time-travel program**. Are their [motives](https://worldbuilding.stackexchange.com/questions/29316/why-would-government-want-to-fund-time-travel-program-to-witness-shameful-histor) more likely to be in line with the principles of Temporal Ethics than that of a random rogue individual?
# More related questions
* [Determining your universe's Time Travel Paradigm](https://worldbuilding.stackexchange.com/questions/20371/determining-your-universes-time-travel-paradigm)
* [Logically consistent time travel](https://worldbuilding.stackexchange.com/questions/12539/logically-consistent-time-travel)
* [Laws and usage of easily accessible time travel?](https://worldbuilding.stackexchange.com/questions/9052/laws-and-usage-of-easily-accessible-time-travel)
[Answer]
First off, I would suggest watching the anime "Stein's Gate" as it deals with a very similar type of time travel.
## Ethics I would expect...
**Time Travellers' society**
That said, most realities would likely only have a few time travellers as each time travel would reduce a universe's time travellers by one. (I suppose a time traveller's society could be "created" by travelling back to the big bang, not touching anything, and then travelling to the distant future, creating a future point that's largely unaffected by past events from a primordial past event. Group time-travel ethics could emerge from what would be this group. It would likely be proportionately small for whatever scope of people's they represent. (Only one per world in a galaxy would be a very large group indeed.) One thing that may happen is the group trying to maintain at least somewhat of a standard history (possibly automated?) so that they can still navigate time appropriately, which may give some semblance of more classical time-travel shinnannigans. But each time traveller would like have relative autonomy within their growing bactch of created-and-abandoned timelines.
At this point, I think a few ethics would emerge...
**Don't mess with other traveller's timeline areas unless asked, treat other travellers with respect.**
Basically, this is getting into MADD territory. Any time traveller would be able to easily screw up another traveller's timeline and get them forever lost and rather vengeful, at which point you'd be doing it to yourself as well since you can't actually remove them. They would only remove themselves by time-travelling away. Also means each timeline would constantly be depleting it's supply of time travelers asymptotically.
**Look out for the safety of the universe**
This may seem dumb (seriously, take care of the universe?) but it makes sense. When your "world" has changed from being so limited to so unlimited, you have a vested interest in ensuring it's as unlimited as possible. If the future ends, and you hop into it accidentally, you're dead. Most time travellers would also be effectively immortal (go to the future where anti-aging is perfectly researched, get it, return to travelling). There would be no limit to the time they could explore and travel to other than the duration of reality itself. So, for one, stopping the heat-death of the universe would likely be a priority.
**Universal Life-saving**
As per the previous mention, a time traveler could literally have all the time they want to live. If they're altruistic, why not save a copy of everyone and take them to an alternate future? Especially everyone you'd be sad about losing. Why not save everyone you want when you can? It kind of follows Hitchhiker's Wowbagger principle. If you're immortal and can travel through time, eventually you're going to get bored. People, in general, are the most interesting thing in the universe, so it seems that eventually one would desire to save them all just to watch how they would interact with each other. (How would Gandhi act if he had Hitler at his mercy? How would this changed Gandhi and the original Gandhi interact? How would your now-four types of Gandhis have a conversation with Martin Luther King Jr.? List goes on and on for "entertainment" value.)
## Is there a justification or even an imperative to build a time machine and travel with it if the present cannot be changed?
Yes. Present can't be changed, but that says nothing about changing the future or saving those from the past. Just because you can't change the present doesn't mean you can't save everyone in it, just that they won't be in that timeline anymore. For those who would argue, "But it's not really them," the line split. They're no more-or-less legitimate than their doomed counterparts. And to quote one individual, "There's mostly dead, and then there's completely dead." Otherwise, imperative would be personal comfort or desires.
## Would it become a moral imperative (good) to change the past for the better even though that won’t affect one’s own present?
Of course. After your first time travel, there would no longer be a "your own present," only your current present. So why not try to have the best one possible? A better present means likely a better future for you to experience. It'd be akin to upgrading your home. Except instead of a home, its your timeline.
## Would it be considered bad to actively or passively create time-lines that are worse for humanity overall than the uninflicted one?
Unless there was that time-maintaining system I mentioned earlier, I don't see how someone could be stopped from doing it, but it'd likely be self-defeating eventually if it got too bad.
## Would it be better justified to improve the present by importing knowledge from the future or by changing the past?
Mainly for one's own benefit or trying to save lives, I would expect.
## Building and running a time-machine is unlikely to be easy and cheap, so only already powerful future entities (like governments) can start a time-travel program. Are their motives more likely to be in line with the principles of Temporal Ethics than that of a random rogue individual?
Countries, governments, etc. are traditionally be self-centered. They'll probably try to bring tech from the future, but with the 50% reliability, you'd probably eventually run out of volunteers since "noone knows what happens to the failures." So they would probably use it just for tech and knowledge. Otherwise, you'd probably have a high likelyhood of those using it abandoning their post the moment they realize they're out of reach, dropping the return rate even further. Especially when they get a historian's look at their own government, which almost is never really that positive in retrospect.
[Answer]
The question is very broad (as most ethical considerations tend to be) but here's a quick try at general theory (akin to 'murder is bad, charities are good' in it's scope)
Temporal ethics would almost certainly evolve, and as with most incredibly powerful things that are hugely unpredictable and have the capacity to blow-back horrendously in the face of humanity, these ethics would be:
**LEAVE IT ALONE.**
**SERIOUSLY.**
*Unless its going to cure cancer/give us seemingly free energy/puppies for all..*
People would be dead set against anyone travelling to the past. At all. Going to the past is a Bad idea, as it might mean you accidentally destroy X thing or make a timeline where Y is the president, and that's unacceptable. No amount of tinkering in the past is likely to help, so leave our history alone!
Conversely: Travellers from the future are already here. They've probably already messed up their times as badly as possible, so we should exploit their knowledge and technology to make our own lives (and by extension, their futures) better.
As a result any temporal manipulation would be from timelines where it had all gone so horrendously wrong that backwards time travel seemed to be the only viable alternative, and those in power should never allow time travel unless such a situation were the case.
Any more detailed than that and I'm afraid you start getting into some major philethimorical hot water, and I haven't deigned to come back from the future with the Time Travel 101 handbook yet.
[Answer]
## Ethics are personal/irrelevant.
Due to the branching nature of the timelines, you only ever see a new branch.
Nothing you do can ever affect the timeline you come from, since ethics can never be enforced, you can only screw up "your own" life (and of course the lives of the people in the timeline branch you just created), but **you can never go home**. As soon as you've actually travelled in time, all you can do is spend the rest of your life trying to undo the damage you've done, but each time you travel in time you just create a new branch for your new changes. While from your point of view it may feel like you're making things better, **all you're doing is creating more and more divergent timelines**.
Other people from the prime timeline can't even learn from your mistakes, **there's no time travel in the prime timeline**. Every time you actually travel in time you're creating a branch, the prime timeline can never be affected by time travel.
## But I want to make the world a better place!
Well you can't. So there.
**Not only can you not make the world a better place, if you try then all the suffering is now your responsibility.** While there may have been similar people in your source branch who were suffering, you have just created new people, who didn't exist before, and made them suffer. This is your responsibility, all of it. You created them and it's your fault they're suffering. Not just on this planet, not just the ones you know about, but on every inhabited world across the entire universe in this timeline that you have in your selfish desires created. **It's all your fault.** All the unimaginable suffering across the entire universe, your fault.
*The only ethical thing to do with time travel is to destroy the machine along with any evidence it ever existed and any documentation relating to the required technologies.*
## But "horrible thing" happened to someone I love and I want to go back and fix it!
Again, you can't. You might be able to prevent it for a copy of your loved one but not for the actual person (now here's a good one for the hardcore philosophy). Once you push that button you can never see your loved ones again, only pale copies with different experiences, effectively different people. The people you knew have been left behind. To live out their lives (without you).
[Answer]
## Ethics?
One school of thought would certainly be LEAVE IT ALONE, as already mentioned, but we all know that won't happen. Humans are far too curious / greedy / rebellious / suspicious to follow that stricture. *Someone* will eventually build a prototype no matter how illegal the process becomes in any given society, and just knowing that fact will be enough to motivate *everyone* to try to do it first.
In fact, ethically speaking, it's probably an easier sell with this version of reality than many other sci fi implementations, since hey, not only are the ill effects not going to happen to US, but the miscreant who's doing the tampering won't be our problem anymore either! Hooray! Go right ahead folks, have a great time. Don't let this reality hit you in the ass on your way out.
This is the single biggest trick of this entire question. Ethics are, basically, a codified social contract. Right and wrong conduct is entirely relative to the society in which the conduct is executed. So the problem is that the time traveler *does not belong to the society he's influencing*. By definition he's an outsider, who has spun up his own personal version of reality in order to make his own utopia/dystopia/heaven/hell/playground/laboratory. Ethics, per se, don't even apply to this circumstance.
## It's worse than that.
But let's assume, for a second, that they do apply. That some society, preparing for time travel, has spent years and years wanging on about the rights and wrongs of time travel, the solemn responsibilities of travelers, and the dire effects of influencing uninflicted timelines. And let's assume, for the sake of argument, that these ethics are inflicted universally across the entire population of time travelers, just to make the point.
Per studies cited in this [New York Times](http://www.nytimes.com/2014/01/11/your-money/in-life-and-business-learning-to-be-ethical.html?_r=1) article, our ethical self is a wonderful, noble construct that we access consistently in hypothetical circumstances, but the percent of us who call up that same construct when thinking they're unobserved and actually *making* those decisions in the real world is very, very small. Ten percent was the stated percent for trivial decisions; weighty decisions are an undefined (and cannot reasonably be extrapolated), but assuming equivalency with trivial decisions, this implies that nine out of ten time travelers will screw ethics and do what they want.
In an uninflicted timeline, there is no proof of alteration, so not only can we not tell *whether* our timeline has been altered, we cannot tell *by whom* or *why*, and a time traveler *knows this*. The decisionmaker is *always* unobserved. So even if the traveler *does* identify himself as belonging to the society in question, his ethical self will only be tapped, on average, nine out of ten time(line)s.
## Amorality / Personal Aesthetics
So, in the end, we're left with personal motivation as ethic, and not much else. We can posit and posture as much as we like, but all the philosophical training and conditioning in the world will be unable to alter the basic truth that if nobody's watching, a human will flip a coin until it comes up heads. Once the tech is viable it's basically a done deal.
This doesn't, actually, answer your primary question in full, but that's kind of intentional. The problems of relying on the ethical self in unobserved circumstances are well-known even without the Times article's specific data. I strongly suspect a seasoned philosopher, or board of philosophers, charged with creating a system of ethics for time travel in this setup, would smile, shake their heads, and ask how much you were paying, because they'd know deep down it's all just blather when the rubber meets the road.
[Answer]
Agree with Joe Bloggs answer. But for fun let's investigate Temporal Ethics:
**Would Temporal Ethics develop in most time-lines with confirmed time-travel?**
***Almost certainly.*** It's certainly an easier topic than regular Ethics. for simplicities sake let's define a minimal ethics framework. You have a moral choice, a moral action, a goal state, and a moral function. A choice can be moral but the action could be unsuccessful in actuating the choice. Likewise if observed individually the morality of an action or choice could change (local, *"kill one"*, versus global, "*save many*", properties). You have a goal that you're optimizing for (most number of people with most happiness, etc.). You also have a guiding function that let's you determine morality (religion, common opinion, game theoretic, random, etc.) in relation to the goal. Much of ethics will deal with what is good and bad and try to precisely define the function. Regular ethics will likewise try to define the goal state as it provides a reference for building the metric that is the guiding function.
But there's good news! *Temporal* Ethics need only concern itself with the temporal aspects. That is, we don't need to define what is good, that's for regular ethics, we just need to define how our temporal aspects relate to the classical problem. The entirety of Temporal Ethics in actuality would be concerned with pinning down what time-travel is and how it effects the current time-line, as well as determining the dangers and weighing them in risk analysis, since regular ethics covers the other questions. As luck would have it we have WOG on the physics of the matter so we can bypass the quibbling part of Temporal Ethics and get down to what the "Final Conclusions" would be.
**Is there a justification or even an imperative to build a time machine and travel with it if the present cannot be changed?**
***No.*** Based on your premise, you cannot affect your own time-line whatsoever, if you could (destabilize the universe or whatever) then you could communicate and the main time-line would be self-reinforcing OR paradoxical. So, since we know there is no effects, there is no downside to time-travel. Each time-traveler basically makes his own universe when he travels. He populates a universe with initial conditions based off of however he acted to change the time-line and cause the split. He basically *sets the goal to optimize for*, he sets the goal. With two caveats: the moral functions that the people develop may not coincide with the "spawner's" goal. And there may be a "super-goal" either by being carried forward from the root of the tree or from an "extra-universal thing". If you keep traveling until you get to a universe that's altruistic/egotistic enough for you then you're really just tweaking your initial conditions until you get it right for what you want. Each attempt abandons the universes you were in prior.
**Would it become a moral imperative (good) to change the past for the better even though that won’t affect one’s own present?**
***No.*** There are two ways of looking at this: "Existential Probability" and "Existential Certainty". In the probability you want to increase the number of universes that are "good" so that the many copies of other folks might somehow live a "better" life, for some definition of "better" :). Now the problem is that you already have a main/prime time-line that is "good"/"bad". IF your initial jump does not cause perfect "good" you're screwed statistically. If you create a "bad" universe you'll have to jump again to try to do better. If you create one with the same level of "good" as the main universe you've achieved none of your goal. You have actually made it worse because each jump further increases the value of **N**, where **N** is the number of universes. Your goal as an altruistic time-traveler is to increase the average "good". Even a perfectly neutral jump diminishes the returns from future efforts. Likewise one "bad" jump could take a long time to repair. Since your first travel "determines" the average for a fairly significant amount of time you would NOT travel unless you were extremely certain of the results or desperate in your own time-line. Which brings us firmly into the risk-analysis territory of "Temporal Ethics". The other option to look at the morality is "Existential Certainty". Rather than discussing odds you discuss "empirical facts". YOU exist. You cannot effect another you. When you decide to travel, the new you is created on a separate time-line and the old one stays home unaffected. Since you are isolated you exists entirely within your current universe. Which may or may not have **one** time-traveler. You are *certain* of your existence. You are also *certain* that everything, including yourself, is existing in your universe and the probabilistic "good" matters not one lick, you have *certainty*, you can measure things and they will be unaffected by anything having to do with time-travel. You only can have zero time-travelers present if you're in the main universe. Otherwise there was *certainly* one time-traveler in your universe. Likewise you are *certain* that no time-travelers will *ever* enter your universe because the only one allowed always existed since the beginning. In fact, *you might owe your existence to said person*. The time-traveler leaving *could* cause an exiting effect on your universe (related to what is coming: We have no way of determining the effect of you leaving on the universe prior to your arrival in said universe). Since you could potentially independently time-travel you can be assured that your traveler leaving will not cause your universe to disappear. (Unless there's restrictions on time-travel outside of the main time-line which makes "Probabilistic Existence" increasingly more of a risky prospect). If you have all theses certainties then it *doesn't matter if you travel*. Everything in the new universe will have these same certainties and they will be permanent on entry. You can only create, never destroy. If *existence* is defined as "bad" in your new universe then they can easily destroy themselves, or in a pinch you can lend a hand. Otherwise they get what they have for "good" and "bad", they can change it themselves by either ordinary means or time-travel to a new universe with different "good"/"bad" ratios. Crucially, they cannot affect any other "good" or "bad" in any pre-existing universe. So as long as you existed before the created universe then "good" and "bad" mean nothing to you as far as time-traveling. And if you existed after then you just have to set about fixing whatever you find wrong. (Note that I don't consider that we should consider the feelings of the created universe. They don't matter. Simply because the probabilities are spread across the gamut of possibilities for "good" and "evil" and we have no objective way to deterministically quantify the amounts for all of time in the created universe or our own. So since you *can't* consider it: you shouldn't consider it. The best you could do is plot risk analysis for you unknown unknowns vs your known unknowns, which is ridiculous in this context since you can't even qualify your known knowns with a known amount of error.). Basically it boils down to "Don't do it unless you have a *really* good reason" vs "Do what you want". The only reason you need to consider the first one is if the laws of time-travel change off of the main time-line. Since WOG says they are a constant set of rules that really boils down to "Do what you want". In-universe though, the risk analysis will boil down to "Don't do it unless you have a *really* good reason" modified by our *certainty* in how the physics of time-travel works *across time-lines*.
**Would it be considered bad to actively or passively create time-lines that are worse for humanity overall than the uninflicted one?**
Depending on whether you look at it as probability or not we are once again divided on the pervasive thought. As far as actively creating them (versus "passively" as a result of going where you want...) you would probably only actively create time-lines if "existence" was valued highly by your moral function AND/OR the multi-verse was interpreted as "Probabilistic" as a whole. In the scenario where "existence" was was valued high enough by your moral function to lead to creation then the "quality of existence" would probably be inconsequential (although it could easily be factored in). If we're under a probabilistic scenario then it is definitely immoral. We of course know whether it is a probabilistic scenario or not, but in-universe they don't. So they will do as all risk analysis does and assume the worst. As such, creation of sub-par universes on purpose would definitely be seen as the height of immorality (you just slighted an entire universe!) accidental creation of sub-par would be unethical but could be fudge-factored via the "existence" part of the moral function into ethical.
**Would it be better justified to improve the present by importing knowledge from the future or by changing the past?**
**\*Only *justified* in a probabilistic context and only when risk vs benefit is carefully weighed.\***
As for a rough risk analysis: the only bad scenario is a "Probabilistic Existence" with a "bad" universe resulting from the travel. As long as the the probability of a "bad" universe is non-zero it is likely to happen at some point if you travel. You can't control universes outside your own. Sadly, **N** could be growing exponentially and your universe could have absolutely no say in it outside of the possibility of you making the initial choice not to time-travel. If you're not the main universe, you're likely screwed from influencing the relative "good" since you can realistically be expected to only *ever* be able to affect 100/**N** percent of the total "good"/"bad" ratio, where **N** is fixed at whatever it was when you decide to time-travel. This is because, since if you came into existence from time-travel it stands to reason that other time-travel events may have occurred and any time-travel choice you make may be duplicated for each branch in the tree.) If the chance of branches increasing is decently high then the "Probabilistic Existence" devolves into "Certain Existence" because, out of the likely-constantly-increasing choices going on among the branches, you will have almost no determining effect on the outcome. So just like "Certain Existence" this case assigns no moral value to time-travel, "Just do what you want".
**Building and running a time-machine is unlikely to be easy and cheap, so only already powerful future entities (like governments) can start a time-travel program. Are their motives more likely to be in line with the principles of Temporal Ethics than that of a random rogue individual?**
***Probably they will be ethical.*** Since it all boils down to risk analysis anyway, which they are certainly going to apply from an economic standpoint at the very least. We can be relieved as outsiders since we can know that their choice is inconsequential anyways. As in-universe people we can be relieved since we know they are going to be more sensible than a rogue mad doctor.
---
And that about covers Temporal Ethics. The entire discipline can be said to be composed of Temporal Physics, Ethics, and Risk Analysis. The main question can be said to be whether Temporal Physics changes between time-lines and if it's possible to influence the current time-line. A universe that has not answered these questions satisfactorily will argue philosophically about paradoxes, certainty vs probability, etc. and frame them as ethical questions affecting the lives of entire universes. If enough is known these questions will fade and all we'll have left are the unanswerables: Is existence intrinsically good, etc. Which could only hope to be answered by some complete description of everything. ***Temporal Ethics will thus consist mostly of pointless philosophical debates of both sides of the coin on the various issues. Mainly because the physics cannot be trusted unconditionally, and when it is trusted it raises questions that cannot be answered.*** (Like does it remain unethical for you to choose a "goal" that is unethical from your current-universe's frame of reference if it isn't in the new universe? Does an absolute frame of reference for morals exist (god, etc.)? And so on... basically the *really* big questions of standard ethics are the only ones that matter for temporal ethics.)
[Answer]
To make sure I've read this correctly, let me sum up:
* When travelling to the past, a traveler creates a brand new branch from his previous timeline upon arrival.
* When travelling to the future, the traveler immediately creates a branch, then slides along it until reaching the destination time.
In either case, the time traveler is powerless to affect his original timeline (where "original", in this case, means the timeline he left). However, the time traveler cannot ever return to the 'trunks'. There is no merging, which means there is never any repercussion to the time traveler. From the time traveler's perspective, when he goes to the past, makes a change, then returns to the present, he is in his own time. If he tells a friend "see you in 20 minutes", travels 20 minutes into the future, his friend will be waiting for him; the time traveler will not realize that he is in a different universe.
This has an interesting effect. The time traveler will always be the only time traveler in the universe; any other same-branch time travelers will leave the universe by starting a new branch, and any different-branch time travelers will never be able to rejoin that branch. This means that the traveler will only be able to see his own actions. It may be that he never learns that he is creating branching timelines at all.
The following experiment may reveal branching timelines: the traveler goes back 10 minutes in time. He finds himself about to use his time machine, and tells his double to instead return one day in the past. He sets his time machine to one day as well, and the two leave at approximately the same time. The traveler will arrive one day in the past on branch 1; the double, having left a split second later, will arrive in branch 2. The two will never meet.
That means that:
* A time traveler may well never realize that he is actually creating branching timelines at all. He will continue using his original ethical model, unaware.
* If the time traveler manages to discover that he is creating branching timelines, he will also realize that he can have no effect on previous branches; regardless of state, good or bad, those timelines are lost. That leaves him with two choices:
+ Continue in his current ethical model, making the timelines better (or worse) as he can, or
+ Stop time travelling altogether, knowing that any suffering he attempts to fix with time travel will double any previous suffering onto two branches.
It boils down to a time traveler either sticking to his original ethics, or ceasing time travel altogether.
[Answer]
One of the problems with describing ethics is that even the normal kind is still a very moving target for us. Last I learned, being ethical was being in a constant, sustainable intermediate state between excess and deficiency in all things (I think that's from Plato, but I don't know which dialogue). The problem is, this doesn't really help: how are we supposed to know what the intermediate state is for anything? If you're eating cookies, is one cookie intermediate, or is it deficient?
From this, I propose that the main obstacle between humans and a perfectly ethical society is a lack of knowledge of how to be ethical. So the best thing we can do is attain knowledge- note that if this is not true, attaining knowledge will help us discover that it is not true, which I think you can agree would be beneficial. So by proof by contradiction the best thing humans can do is attain more knowledge on the nature of ethics and how to be ethical.
Now, let's say there are two ways to attain knowledge: by experimenting yourself, or by learning the results of other people's experiments. The first approach is dangerous, as experimentation can cause negative results, but the result of learning is knowledge, which we've agreed is good. So for time travelers, the most ethical option is to travel to the place with the most to learn from, which I would think would be the future.
Once in the future, the travelers should attain as much knowledge as they can about the nature of ethics and how to be ethical. Since at the end of this process they should know more about ethics than me, I don't know what they would do next, but I presume they would then travel into the past in order to create a timeline of near-perfect ethics.
One thing I would also consider is the uses of branching timelines. If you travel back in time and create a perfectly ethical human history, all humanity in the multiverse will still be tainted by *this* un-ethical original timeline. However, if you were to create nearly infinite (or truly infinite) perfectly ethical timelines, the stains of this timeline would become mathematically nonexistent. So if you have the ability to branch your perfectly ethical society infinitely, you should probably do so.
But like I said above, I don't know what it is to be perfectly ethical, so the only thing I've proven here is that time travelers should use their power to get smarter. Once smarter, they should use their knowledge to be ethical.
[Answer]
Any study of morality will depend on how you value a time-tree. You suggest they want to make as many timelines as possible "good." However, you also state that they want to be in a "good" timeline, which is a very contrasting goal. In that case, you only need to make sure any downstream trees are good, and you can ignore any tree you didn't take. This is good, because an "evil" opponent could decimate your metric simply by engaging in billions of time travel activities just to split the timelines.
I think the issue you may be facing is that your phrasing for the ethics presumes a uniform distribution across all of the timelines, when that is not actually a reality that any time traveler faces.
In theory, the only altruistic possibility is one where you actively seek to prevent anyone else from acquiring time travel. once you're sure you're the only one, you learn what you can about how to make the world better, and jump. That prevents that particular branch from growing exponentially. Thus, if you make this world better than it, you've made a statistical improvement.
[Answer]
The question is too long to read, but I was inspired just by seeing the **title** and from the many time-travel stories I've seen.
A *branching* timeline is like a revision control repository (like *git* or *svn*) or "persistent" data structure in Closure. You can change things on a branch, experiment, do what you want, and it has no effect on the main dev branch. That's why we *have* branches. Changes are not destructive as the old state still exists and can be revisited: that means no "change" is real in some sense, and changing one way is not special as a diffwrent way can be done in another branch.
If branches are heavy-duty and there is a specific dev branch (like working in svn) then you might get something like Shadows in Amber, with ours being considered real and others have little or no concern for us no matter what happens there.
If people feel that every state has multiple successors but none is privileged, they might still get a feeling that nothing really matters because the states exist in a platonic realm and you don't *cause* bad things to happen but just *visit* such a state that already has a platonic realism.
If something *is* bad in their home timeline, what's the point in doing anything about it since it only affects one possible branch? If travelling back to kill Hitler you don't help anyone since that original still exists. If living without travel but knowing about this nature, what's the point of accomplishment if another branch can still be made or people can travel back and redo the history leading up to it?
] |
[Question]
[
I want two populations to coexist in a world with extensive tunnels carved into the rock. One population lives in the tunnels, coming out to trade and gather food. The other is aware of the tunnels but is wary of entering them.
I want the tunnels to go far enough that after a certain point there is insufficient air flow to maintain enough oxygen to breathe. The tunnel dwellers are well aware of this effect and know to only venture that far for short periods to avoid asphyxiation. To the surface dwellers they spread rumours that only the tunnel dwellers are capable of breathing the tunnel air, despite the fact that the regions where the tunnel dwellers live has perfectly breathable air for both populations (which are both human).
For tunnels that are mostly just over head height and arm span width, occasionally widening into rooms, after what distance into the tunnels would breathing no longer be sustainable? The tunnels are carved by humans, not by underground rivers, so they have no other end to create airflow from pressure differences.
---
Following [Monty Wild's answer](https://worldbuilding.stackexchange.com/a/459/109) here is some further detail. The tunnels are carved horizontally into sandstone. The humans carry candles and oil lamps with them when travelling further into the tunnels. There are over 50 separate entrance tunnels each leading to its own main chamber after about 40 metres, in which small wood fires are kept burning for heating and cooking. Further tunnels continue from the main chamber, branching and opening into chambers for storage. Some of these tunnels connect the main chambers to each other, but there is no interconnection between tunnels further in than the main chambers. Each of the main chambers is about twice human height and about 300 metres square in floor area (a circle roughly 20 metres in diameter).
I'm looking to estimate whether a group of humans could survive in the main chambers, and if so how much further into the tunnels beyond they could travel before breathing became impossible.
[Answer]
This is a problem of [mining air flow](http://en.wikipedia.org/wiki/Underground_mine_ventilation). When tunnels exist where there is no circular path allowing air flow, the air can become contaminated by outgassing from the walls of the mine and the activities of the inhabitants. The length of tunnels as described that would result in the air becoming unbreathable would depend on the nature of the material being mined, the processes that were taking place within the mine (i.e. human activity and/or combustion-powered machines), the frequency of that activity, and the distance from ventilated spaces, as well as the speed of airflow through those ventilated spaces (i.e. the potential for eddies to cause air exchange).
From soldiers' experiences in World War two escape tunnel mining, problems with air supply where humans are working in areas where there is only one exit can become significant over distances of a few tens of meters such that it was necessary to install ventilation apparatus to provide workers at the head of the tunnel with fresh air.
In a deep mine through material prone to outgassing, a lack of human activity and artificial ventilation could result in an area becoming uninhabitable within as little as a few days.
The sustainability of mining depends then upon the material being mined, the nature of the activities being performed in the mine, and the technological level of its creators. This is too broad a question to answer with a definitive distance given that these factors are neither stated in the question nor likely to be a constant over time.
**EDIT**
Given the edit to the question specifying the nature of the caves:
Since we are talking about sandstone that is presumably not prone to outgassing, we can discount that as part of the problem.
Since many of the main chambers described appear to be interconnected, each of these could be described as existing in a loop connected to outside air at at least two points. This would mean that outside wind is likely to cause a draught and air exchange, meaning that these main chambers would likely be habitable in the long-term by a small population without any particular ventilation apparatus. With a larger population, something as simple as sails to catch the wind and direct it into the tunnels would probably suffice.
Any main chambers which did not have a tunnel loop may suffer from air stagnation, as would the dead-end tunnels. This all depends on the size of the tunnels to the main chambers, as larger tunnels allows air eddies to penetrate more deeply. The smaller the tunnels, the lower the population the main chamber would support. However, the traversal of the tunnels by humans would to some degree provide impetus for ventilation, but it would not be as effective as wind ventilation.
The simple provision of a chimney in each main chamber would probably provide all the ventilation needed - the fire maintained in each chamber would cause the hot air at the top of the chamber to rise up the chimney and draw in fresh air from the tunnels.
My estimate would be that the main chambers that exist in a loop would be occupiable by perhaps 20-30 humans. However, dead-end tunnels more than ten metres or so long would be suitable only for occasional use without artificial ventilation. Main chambers that exist as a dead-end would be occupiable by far fewer humans, probably less than 10. Chimneys and fires would make all these main chambers occupiable by perhaps 30 humans.
It would probably be possible to make a dead-end tunnel several hundred metres long before lack of air exchange made breathing there impractical without artificial means of providing ventilation. The exact distance would depend on the activity to be performed in the tunnel. However, these tunnels could be made habitable simply by boring a small shaft to the surface.
[Answer]
Problem: If the tunnels are human-carved, how did the workers carve them absent oxygen? Especially if they're going to be using fire for light?
Forced airflow so that tunnels can be dug deeper than they can be supported normally (without artificial airflow) is a possible solution. But unless that tech is lost, whoever built the tunnels can get to the end of the tunnels whenever they want.
The builders would also have to have a reason to want to build/dig the structure. Digging is *hard* and removing the spoil is difficult, time-consuming, and expensive - especially as your tunnels get longer/deeper. What is/was worth that cost?
] |
[Question]
[
Imagine there is a country in which there are all important natural resources (oil, gas, metal ores, wood, etc.) in their natural form and which lies in a temperate climate region. There may be some portion of a sea. The country is completely isolated from the rest of the world - nothing (except for air, precipitation, etc.) can get in or out. *What is the minimum population and size of the country to sustain a developed industrial society?* (All the technology used there has to be produced somewhere in the country eventually.) The technology level is current. (Year 2014, realistic technologies that can be mass-produced with reasonable cost.)
By other words: What is the minimum amount of people and land to produce self-sustained agriculture and all relevant factories that are necessary for complete self sufficiency in industry from mining all ores to producing the final devices? Consider that people need to be educated and not all are geniuses that can be educated to the cutting-edge technology expert levels.
EDIT: You can assume the technology is initially present, it does not have to be invented, but next generation must be able to learn it and understand it. (For example people have a very good library, or computer database, as long as the computers are running.)
[Answer]
To maintain 2014 levels of technology, an order of magnitude estimate is **between 10 million and 100 million** people.
The key point here is specialization. The higher your level of technology, the more specialized individual workers must be to maintain it.
A good modern example is the island of Cuba. It has to be highly self-sufficient, because it is isolated from the outside world by the US embargo and other factors. It has a population of about 11.2 million and sustains a simplified industrial economy, but with technology at least a few decades behind the USA or Europe.
There is no barrier to Cuba obtaining the *knowledge* to build (for example) modern computers, but they lack the critical mass of population to support enough specialists to get the job done.
Now consider South Korea, with a population of about 50 million. Unlike Cuba, SK is a highly open trading nation; but SK is interesting because of its highly successful manufacturing industry. It seems plausible that SK is the smallest modern nation which could, by itself, build *anything* which is considered part of our current technology.
SK may still be a little small to sustain a fully diverse economy, including scientific research and development of new technology. To be really confident of maintaining modern technology, you might want to double the population (to about the size of Japan, with 127 million people).
By this argument, a comfortable population size would be about 100 million, and a minimum would be somewhere between 12 and 50 million (but probably closer to 50).
Just as an aside, you would probably need several hundred people to maintain even a "medieval" standard of living. Mining, smelting, and forging metals in particular requires a significant number of specialists. A single family couldn't do it. A fascinating example is the six members of the [Lykov family](http://www.smithsonianmag.com/history/for-40-years-this-russian-family-was-cut-off-from-all-human-contact-unaware-of-world-war-ii-7354256/?no-ist), who lived in total isolation in the Siberian wilderness for 40 years, and ended up with little more than stone age technology.
[Answer]
In Medieval times and before a single family, or few families at most, were capable of making almost everything they need to support they civilization ([subsistence economy](http://en.wikipedia.org/wiki/Subsistence_economy)). If you just need to smelt metal, [bloomery](http://en.wikipedia.org/wiki/Bloomery) in not that complex device, a single worker could build and operate (but would probably not have time for growing crops at the same time so others must feed him).
This, however, probably would not be "industrial" but may be a hint that minimal size is probably rather small, depending on the list of technologies you need to support. Not everything humans are currently doing and are capable of is necessary even for building a tractor, for instance, or steam locomotive.
[Answer]
(This probably is a comment but it's too big.)
Efficiency is going to be a big problem here--many things are far more efficiently done on a large scale. Small populations mean doing things less efficiently and thus dropping the standard of living. There are also things that simply can't be done on anything but a big scale. You either have a weather satellite up there or you don't (9 figures final cost.) You either have a GPS system or you don't (nearly 11 figures total cost.) Thus you have to decide what is actually included in your "technology is current" before you can decide the population needed to support it.
Also, you have to consider exactly what "current" means. Consider 3D printing--we are only scratching the surface of this but the limit isn't technological, but rather ramp-up time. 3D printers cost the same for 1 part or a million and thus the economics become more and more favorable when the number of items needed is lower. A small civilization where a large number of items are 3D printed isn't actually more technically advanced than ours even though it's not feasible at present. Likewise, CNC-based milling of parts would exist on a larger scale than present.
[Answer]
Population numbers are based upon current political, social, cultural and educational realities. How many less people would you need if you change these parameters?
For example: create a social and cultural change to the education of the next generation so the level of education off all children is the highest possible. Create governance and management of resources, both human and environmental, as efficient as possible, from economic and cultural incentives to the use of the most advanced technology currently available to set up infrastructure.
The real question then becomes, how much would it cost to set up a fully self-sufficient society and how many would be required to maintain it?
[Answer]
Considering the country is totally disconnected from the outside world, the country will have to do all the work for itself. Technological advance will need a lot of effort since there is no communication with the outside world, this country will have to do all the research on its own. Thus the country would need a huge population to support its needs.
[Answer]
exactly the current population of the world. considering our culture, our economy and every other aspect of social life we have achieved current level of technology with the current size of the population. if we implement a better culture which people could cooperate in a better way then we would need less people to maintain or achieve the same level of technology and comfort.
[Answer]
First to answer the question, yes it can be totally possible. Let us go to a real world example. China.
China while semi-isolated, had an advanced level of technology. The printing press were invented, fireworks, and even prototype machine gun-ish crossbows are found in historical data. We can say that resources were abundant in China, and the country, while not very big, could sustain itself. It might have been possible for China to have continued the same level of development.
Second, for the comments, why would they need advance. Quality of life, as noted by Irigi, has been a push for human society for years. Also a deity that encourages discovery can help. For example, a special heaven is promised. Another push for technology would have been civil wars. Wars evolve technology in all field, whether they be warfare or civilian ones.
I'll post some sources later.
] |
[Question]
[
Let's say that there's a "dumb" AI - it can only learn within preset limits, and cannot learn anything that is outside of those limits.
However, it's very good at imitating human speech, and the loudspeakers attached to its chassis are top-notch - so much so that, if you heard it directly but didn't see it, you would be unable to tell it apart from an actual human.
However, there's a way to figure out it's an artificial intelligence when it speaks into a telephone/speaker/etc. with it. Why? Does its voice reverberate differently than a human's over a phone? Do its attempts at inflection fall apart over the phone but not in person?
I recognize that it not just plugging into a device is inefficient, but, in this case, it has to use technology that's not attached to its chassis - it works for a baddie who carries it around to different phones in a city to call in bomb threats, but thinks that it can perfectly imitate a human.
Preferably, any answers will:
* not involve a conversation - just someone hearing the thing talk and realizing, somehow, that it's an AI.
* not change the baddie-with-a-bomb part
[Answer]
## Compression.
Phone line companies want to save money by having each call use up as little bandwidth as possible. This is true both for communication over wire and by cellphones - the more calls you can fit in the same space, the better. Their engineers have been hard at work optimizing how much and which ways human speech can be simplified as much as possible and still be understood. The process takes into account both what sounds are used in speech and how human hearing works - a bunch of the sounds are actually missing in the receiving end, but when we listen we can reconstruct it.
Of course, this process has its downsides. One of them is that because it's so optimized for human speech it's bad at most other things. Music, for example - that's one reason why hold line music always sounds so terrible.
The AI doesn't just replay a human speaking voice, it generates its own. It learned to talk to people by speaking in person, and so it arrived at a way of speaking where it sounds just like a human, but looked at in a spectrum analyzer the overtones and frequency distribution is usually quite different. This leads to the phoneline compression algorithm completely ruining it - important frequencies will be cut off and it will sound very strange and choppy. The exact sound may vary a bit, but the end result will be to human speech what hold line music is to a proper studio recording - it'll just sound terrible to listen to in an inexplicable manner.
[Answer]
**The breath of life and plosives.**
In real life, unless the person's mouth is right by your ear, you'll not be able to tell the difference between high-quality reproduction and the real thing.
On a mobile (a modern one at least) the microphone is facing away from the mouth on the end of the phone, people in call centers have mike-guards - but in a phone booth, more primitive tech dominates.
The microphone picks-up the breath sounds and the pop from [plosive speech sounds](https://en.wikipedia.org/wiki/Plosive). These aren't there from the speaker, it might take a few seconds and a bit of thought to figure it out depending on how bright/distracted the police are, but it'll be conclusive and unmistakably that there's not a mouth involved.
The clever tech who set this up would need to simulate breathing (fairly easy considering AI), and an actual burst of air perfectly timed to hit the mike, doable but quite a bit of hassle as mechanical parts necessary are more in the animatronic vein than the programming one.
[Answer]
## The AI has learned to pick up contextual clues from speech that humans would typically pick up from visual clues
That is, where when we meet face-to-face we pick up clues from, for example, if the person is smiling, or how they hold their head, the AI has learned to pick up clues for the same things, but from speech instead of visual data.
When talking to the AI in person, this is completely irrelevant - they respond taking into account all the clues available.
However, the AI doesn't differentiate between talking in person and talking over the phone. When talking to somebody, the AI might comment on the fact that they're smiling, or how they're looking around, because it's picked up clues from the person's speech that it has learned is associated with certain movements, giving the impression that it can see the person it's talking to event though it's a phone conversation; it doesn't know that a human wouldn't comment on these things when it can't see the other person.
[Answer]
### Ad Block
* In 2024, the first consumer-grade perfect voice-synthesising software libraries hit the market. By *perfect,* I mean that humans cannot recognise them as such.
* As a result, the telephone marketing and scamming industry bloomed. Together with some speech recognition, it was now possible to sieve out gullible people without requiring any human work.
* In 2025, a crafty employee of a telephone company found a way to quickly train neural networks to detect the output all relevant voice-synthesising libraries by hallmarks that are not recognisable by humans and not easily removable. The authors of the libraries never “fixed” those hallmarks because they were inaudible to humans and thus there was little incentive. (Also see [Matthew’s answer](https://worldbuilding.stackexchange.com/a/211346/308).)
* The phone company quickly implemented this algorithm as a selling point. Any voice detected to be synthesised would be distorted on the fly in a way that clearly marked it as such. Customers could also opt in to have such calls be terminated immediately, or they could opt out of this feature for privacy, but few ever did.
* Other phone companies quickly followed.
* In 2026, the telephone marketing industry died a quick but silent dead. Nobody mourned it and people went on to harass “customers” on the Internet.
* Twenty years later, almost everybody has forgotten about all these events, but the algorithms are still in place, because they cost next to nothing and the reason why they exist is still there.
Now, your AI has no reason (or capability) to reïnvent the wheel when it comes to speech synthesis. Instead it uses the existing, “perfect” libraries and hits the forgotten ad block.
[Answer]
# Feature was out of scope
An AI is a software, and software development has its own quirks.
The team that developed the AI did good on the whole face to face conversation requirement, but conversations on phone were out of scope for version one so that never went through Quality Assurance.
In a face to face conversation, the AI reads facial clues from the people present. Without seeing a face, the AI cannot process speech patterns correctly and sounds like a year 2010 GPS device.
[Answer]
**The AI causes interference**
If we assume that the baddie is using payphones, and perhaps that all such phones are a certain model... perhaps the AI, unknown to the baddie, also emits a very distinctive and high-pitched sound when it talks (or just all the time) which is normally inaudible to humans (in person), but for some reason affects these phones.
Did the baddie steal this AI? Does he not know very much about it? One way this could be more believable is if the effect is a deliberate safeguard built into the AI by its creators, sort of like the [special markings](https://en.wikipedia.org/wiki/EURion_constellation) on paper currency and such that prevent them being printed on ordinary printers. Software on the phones detects this inaudible "watermark" and does something that makes it *blatantly* obvious to the listener that they're hearing the AI. (Such as overlaying a voice softly repeating "artificial intelligence" over and over.) However, it might be a stretch to explain how your baddie doesn't know about this.
[Answer]
The AI's speech algorithm is deterministic. Not in an obvious way - they don't speak in a constant rhythm where every syllable is the same length - but ultimately there's an algorithm choosing how to intone each word, how long each syllable should last, and so on. Whoever wrote the algorithm didn't think to randomise it, so if the input is the same, then the output is the same. When the AI says the same phrase and expresses it the same way (e.g. "good afternoon" at the start of a conversation), the audio produced is exactly identical.
A human listener would not be able to pick up on it, but with a computer available to analyse the audio, there would be no doubt that the voice is not a human's. You would be able to take two instances of the AI saying "good afternoon" at the start of a conversation, overlay them on top of each other, and it would just sound like one person saying "good afternoon" twice as loud instead of two recordings played at the same time. But of course you can only do this when a recording is being made, so you can detect it's an AI over the phone but not if you're hearing it in person.
This does also mean that they only realise it's an AI when they catch it repeating some words it's already said before with the same intonation/expression. So maybe on the first call or the first few calls, they don't know it's an AI yet.
[Answer]
**In person, you are distracted.**
[](https://i.stack.imgur.com/vGyUc.jpg)
<https://www.pinkvilla.com/entertainment/news/deepika-padukone-her-wax-statue-voice-inside-me-said-i-would-it-be-statue-purpose-443200>
She is a master of body language. Her moves are perfect. She is dancing when she is breathing. She is astoundingly, preternaturally attractive. And she smells so good. Yes a little bit of an accent, and some funny turns of phrase, and sometimes she doesn't get it. But those eyes! Does she like me? The way she tosses her hair and laughs at my lame joke! Oh my gosh did I remember to tweeze my nose hairs?
[Answer]
Different psychoacoustic model. Researchers who created the AI used speech samples in [MP3](https://en.wikipedia.org/wiki/MP3) to train its speech (because that was what their spoken corpus provided, or the intern tasked with preparing speech samples in common format had no clue{been there, seen that...} or anything). The result is that AI speaks in high quality MP3 psychoacoustic model and sounds perfect in person, but the phone line (mobile, because who uses landlines anymore?) uses [GSM-AMR](https://en.wikipedia.org/wiki/Adaptive_Multi-Rate_audio_codec) codec that is rather averse to re-encoding MP3s. (replace the codecs with whatever is being used at the time of the story)
Side note and an alternative: there are low-bitrate codecs that work well for non-tonal languages, but make tonal languages quite unintelligible. The AI speaks perfect [Pǔtōnghuà](https://en.wikipedia.org/wiki/Standard_Chinese), and it knows about the codec used on the (low quality phone connection) being bad for Mandarin tones and it compensates for the effect. The very first Chinese language phone interview gives it away by the sound quality being unnaturally good.
[Answer]
### Pronunciation of names
In English, pronunciation of names is *highly* non-standard, since names have origins in multiple different languages. Who would think the word "Michael" should be pronounced the way it actually is, for instance? My name is also tricky for text-to-speech engines (and for just about every non-English speaker too!). And then there's surnames which diverge even more radically.
And that's before we get onto place names. Some place names are not pronounced the way it appears they should be, especially in the UK. Many of them are fairly well-known - "Happisburgh" for instance is pronounced "Hays-burra". The US has a separate problem though where place names taken from elsewhere in the world are not pronounced as they would be there. "Orleans" in France and "New Orleans" are pronounced differently; and Bill Bryson has an example of a place called "Cairo" which locals pronounce "Kay-ro". Saying "New Orleans" with a French pronunciation will clearly be wrong.
And the final giveaway is the confidence in their tone when faced with a name which is even slightly non-standard, or which is longer than usual. A human being will tend to stumble over an unfamiliar name, or at least sound hesitant, and maybe check they're saying it correctly. For a long name, like some Spanish surnames, a human often won't be able to hold it all in their head at once and will have to read it off the page, causing short pauses as they look down to read. An AI doesn't have any idea of what's "familiar" or what's "long" - it'll simply sound out the phonics the same, every time.
[Answer]
**The AIs can mimic human speech just fine - it's the other way around.** They can talk all day, but they won't know what to talk about because they can't understand your questions.
Think of automated transcripts that exist today - of crystal clear voice captured by professional audio equipment in a noise-proofed room, the AI has plenty of time to ponder over it, and still makes grave mistakes. And any slight degradation of quality makes it just give up. Or transcribe a minute of speech as just `[Applause]`.
Have you ever noticed people sound a bit different over the phone? If you have, you've probably moved it to the subconscious level pretty soon and not even consider giving it a second thought. Human brains are very flexible. They'll tune to any signal as long as it's there. They'll just filter out unreasonable amount of noise ... or insert data that isn't there just because there's only one way to do it that produces sensible results. And the more you restrict the output domain, the more error it's willing to ignore.
For an AI, noise that would be no-sold by a human brain will be amplified, looked for useful data in, and overwhelm the circuits that should be looking elsewhere than they are... such as tiny errors that are the result of data compression. Tiny, but in places that the AI speech recognition module is most reliant on. In one word - a disaster. Of course there's still noise in person, but having a realtime video feed of the human's speech organs helps the decoding process immensely. Plus directional mikes, of course.
AI brains are kinda similar to human brains ... scratch that. The design of AI brains takes major inspiration in biological brains, but there are huge chunks left behind. Specifically, the inspiration it did take is that you can compute any function by summing, multiplying and clamping often enough. What it does miss out on is that the human brain is made out of feedback loops of feedback loops of feedback loops. Not that the AIs don't know that - but they simply don't have nearly enough computing power to actually run that kind of stuff. They tweak a few virtual knobs until their output matches the transcript. Then they pick up the phone - and the data is completely different. They can try to turn a few knobs but not nearly fast enough. They don't know which knobs to turn, there are thousands of them, and they need a bigger sample than a few milliseconds to determine if the way they turned the knobs was good or bad.
They could take a recording, and then play with it for a while - six to eight hours let's say - then they could decode it... maybe. But by that time it's too late. And even if they do find out what knobs to turn, it's no good. The Internet is slightly less clogged up the next time they make a call, the phones choose a different codec that produces different type of noise (chosen such that it wouldn't be very noticeable to a human) - or maybe slightly less of it, and the AI has to start all over again.
[Answer]
Because they rely heavily on body language (postures, facial expressions) for understanding what humans say, and are at loss when they miss these clues, are unable to detect sarcasm, humor, etc...
[Answer]
## Multiple Loudspeakers don't sound good up close
You mentioned the AI has top-notch loudspeakers. If you have multiple loudspeakers they can sound like a single voice from a few feet away but right next to a phone mic it would sound like parts of the voice are at different distances (you can adjust this to make the effect more or less subtle). Depending on how the loudspeakers work and how the AI simulates speech, on the phone it can sound like multiple muddled voices, or perhaps it can sound like the voice's absolute volume implied distance and tone don't match. like if the AI "yells" at the top of its "lungs" but somehow it's quieter than its normal speaking voice. Overall, creating a voice that sounds like an actual in-person human being from a distance probably wouldn't hold up from only an inch or two away like on the phone.
[Answer]
### Repetitions
Say something, talk about something else for a while, then say again the first thing. Do it again. The second or the third time a human would ask why you keep asking the same thing or at least would answer with a questioning tone to signal that they are confused, an AI with prepared responses to specific sentences and taking into account a short context would just repeat the same answer with the same tone.
[Answer]
Two options
## It's too fast
Phone conversations are a little bit awkward. There is missing nonverbal communication that humans rely on to figure out context and meaning. However, the bot's designers were not really smart enough to handle that nonverbal stuff, so when the robot communicates, it relies strictly on voice recognition. The visual systems are not connected to the communication system in any way. Basically, it is a text chatbot that has text to speech and speech to text converters. It also has a limited ability to pick up on verbal cues, like speed and hesitation.
To compensate for this inability, it's got very fast processors. In person, it seems like it's picking up on your body language and facial expressions, but it's actually just thinking really hard about what you said, faster than any human could.\*
As a result, all of this information is still available over the phone, and the robot communicates over the phone just as smoothly as it does in person. When two humans have a phone call, it's clumsy: they talk over each other, they have some trouble with the lag, and they slow down because they can't see each other's faces. So when the robot is on the phone, and it sounds the same as it would in person, it's a red flag.
\*This does imply that you could detect a robot by showing paradoxical behaviour. If you sound totally friendly, but give the bot a death stare the whole time, it wouldn't pick up on the hostility and would just interpret your words based on how they sound.
## It isn't confident about who it's talking to
The bot makes bayesian inferences about who it's talking to at all times, and it's never 100% certain. When it can't see the person it's talking to, it's less confident about who it is. It (probably) won't use the wrong name or anything, but it might shift to a slightly more generic, "public speaking" voice to cover its bases in case it has you wrong. It also might tell you things that it should know you already know, because it isn't 100% sure who you are, e.g. calling the Serson city police chief and saying
>
> I've planted a bomb at the Serson City Hall, it's going to blow up in 30 minutes unless you clear all of your Serson City police officers off of the bridge across the harbour.
>
>
>
A human would call in this threat differently. They wouldn't say "Serson city hall" because the police chief would know which city hall you meant. They would also say "your officers" instead of "your Serson City police officers", and "the bridge" instead of "the bridge across the harbour", because a human would be 100% confident that it's talking to the chief of police. This AI never reaches 100% confidence, and so it hedges its bets.
[Answer]
Moire effect from the sampling frequencies of the systems involved. Moire effects only show up when you have two separate sources of lines that are close to the same size or a multiple thereof.
Digital audio has a sampling frequency--normally well outside human hearing so it's irrelevant but it's there. You have the AI emitting a digital signal, you have the phone picking up and transmitting a digital signal. Normally the speakers and microphones wouldn't function at those frequencies but for some reason they do in this case. (Easy enough to explain for the AI, not so easy for the phones.)
[Answer]
## They're faster.
Their AI nature means they can control the phone lines. Like the police, they can hear you and talk to you as soon as you start ringing, even before it seems to connect.
As such, when you hear them speak on the phone they seem faster than a normal human being. They speak earlier, and know what you said near the phone.
[Answer]
It's too good at picking up information from the person on the other side of the line. AI asks a question and their conversation partner nodded into the phone- don't we all do at times? The AI heard the movement of the air or maybe the other person's neck cracking so very slightly and they know the person nodded although there is no way a human could know. If you'd be in the presence of the AI you won't notice its overpowered since you assume that whoever you're meeting just saw you.
[Answer]
**The AI doesn't have a "phone voice"**
Humans speak differently on the phone (source: personal experience, but in case you never noticed it, just Google "do people speak differently on the phone?").
Over time, people develop their "phone voice" by learning through trial and error, how to be understood over the phone.
The AI lacks a phone voice and as a result, it's inexplicably hard to understand, while easy to describe and recognize, by the humans at the other end of the line.
Scene 1.
Operator: "911, what kind of emergency is this?"
AI: "I'd like to call in a bomb threat"
Operator: "Sorry hun, I can't understand you. Is this a police, fire, or medical emergency?"
AI: "You're going to need all three"
Operator: "I'm sorry, could you please slow down and speak up a bit?" (whispers to supervisor: I think it's THAT GUY "the mumbler" we were briefed about this morning!)
**Bonus: the AI voice breaks Call Transcription & Sentiment Analysis**
Most large call centers IRL today have Automated Transcription with Sentiment Analysis where the Associate gets a running transcript of the call on their computer screen in real-time, along with an indicator of the caller's mood after each utterance.
Because calls from "the mumbler" will have a tone unlike any conversation the Call Center Software AI has ever been trained on, the Call Transcription & Sentiment Analysis will behave in some peculiar way that is clearly distinct from human calls.
[Answer]
AI needs context. You could simply mix in things from well known fiction or popular culture as if they were fact, so long as they were kept in context an AI would take them at face value. A human would notice if you were referencing a TV show as if it were real life. An AI wouldn't realize that the Fry and Leala that you were talking about meeting up with were characters from futurama. Or that you probably weren't going to that Brad and Angelas wedding at the weekend. A human would at least notice the similarity of the names.
[Answer]
AIs are actually really bad at speech synthesis, but humans don't notice because of the [McGurk effect](https://en.wikipedia.org/wiki/McGurk_effect). With audio-only input, the human brain no longer is automatically correcting for mispronunciations, so the voice sounds wrong.
[Answer]
**Too good to be a human**
You plug your AI directly to the phone line (or even some central phone station, avoiding the bad "last mile" of a phone line), and as a result the sound is way too clear and free from any noises that always occur when a person is calling via a real phone.
[Answer]
**Trick the AI into doing stuff humans wouldn't be able to**
Trying to find shortcomings in the AI is a fruitless endeavor. Either the AI is competent at imitating humans or it'd be too easy to warrant a question here. So we're dealing with a good AI. Good, but dumb. If you turn your conversation a bit to the inquisitive side, the AI may be tricked into questions which answers a human wouldn't know (like advanced physics, complicated calculations where a human would just tell us to get our own calculator or so. For the AI trivial stuff so it may not think of deflecting the answer),
OR, going off of other answers here, produce sounds that a human mouth wouldn't be able to (whether these difference would be directly noticeably by a human or only detectable via spectral analysis can be made up depending on the needs of the story).
[Answer]
**Body language**
Body language is a large part of human communication. The AI takes that to the extreme, being almost solely reliant on non-verbal communication. It uses microexpressions to read emotions, understand sarcasm, and overall helping it figure out the context in which something is said.
When trying to interact over a phone, the AI cannot read body language; kind of like what online chatting in plain text is like for humans. The AI will try to filter the meaning out from the tone of one's voice, but even then, it is very poorly optimized for that. It will think something is sarcastic when it isn't, try to calm people who raise their voice for other reasons, and all-around give answers that aren't really expected in the situation.
This problem is made far worse because of the compression. Even if they did pick up emotions from the tone of voice, those are too distorted by phone.
**Not made for conversations**
The AI is not only very well made to blend in with humans, but it is also designed to stay in the attention background. Being dressed in something inconspicuous would prevent too many interactions that could be failed. The AI could apply body language when walking around too, making itself look busy or irritated. People will expect that the AI is late, and short 'irritated' answers before moving away wouldn't be strange in the situation.
[Answer]
**Audio packet frequency**
The phone lines sample and deliver sounds at some low frequency to save bandwidth, giving them that characteristic machine-sound when you talk to someone on the other end. Robot voices are digitally sampled tones at a higher frequency with a coincidentally large least common multiple/divisor. As a result, when a robot speaks over the phone, there's a characteristic phaser sound, as the robot's voice samples sometimes do and sometimes don't line up perfectly with the phone's sampling frequency.
Human voices, on the other hand, are pure analog signals, and so they are always on-sample when recorded by the phone. A trained ear can pick up the difference.
[Answer]
>
> not involve a conversation - just someone hearing the thing talk and realizing, somehow, that it's an AI.
>
>
>
The above imposition makes very difficult to answer your question.
To detect the voice in the phone line is artificially made and based upon this claim it is an AI voice is a problem! You see, artificial voices have existed for decades now. Why ,today, some one detects a artificially made speech and tell: Hey, it is AI talking there!
The artificially made voice could be generated by some kind of "Scrambler" whose utility is only to keep the bad guy identity (genre, age, accent) a secret.
<https://en.wikipedia.org/wiki/Voice_inversion>
<https://en.wikipedia.org/wiki/Scrambler>
Several good answers explain how to detect a artificially voice made. But your problem is to detect an AI!
>
> not involve a conversation
>
>
>
Pitifully is impossible to detect a REAL AI without conversation. In deed the tool necessary to detect an AI was created before the very first computer able to simulate some primitive AI be created.
<https://en.wikipedia.org/wiki/Turing_test>
If you need a example of a Turing test in use I strongly recommend one of the best SF movies ever made:
<https://en.wikipedia.org/wiki/Blade_Runner>
The argumentation scene in the start of the movie is an enhanced Turing test.
But not everything is lost; may exist a way to detect if a voice over a phone line is an AI. Of course it is technical Mambo Jambo :).
Your "dumb" AI is not that dumb. In deed it is pretty good and even over the phone line it is confused like a real human voice. So, the good guys take it like a real menace and have it recorded.
What is very usual in movies and TV shows is ask a polygraph expert to listen and to analyze the record.
<https://en.wikipedia.org/wiki/Polygraph>
A seasoned polygraph expert will check the speech looking for special clues that indicate that the bad guy's intentions are real. The key is people lying are able to speak "normally" but if you check the graph in the computer/polygraph screen you see the effort he/she did to sound normal. They can fake the voice, but they can not fake the emotions. This way an expert polygraph operator can identify a liar.
Well, an AI does not have emotion, so an expert seasoned polygraph operator looking to the record's graphical could infer that speech was not being generated by a person. The key clues in the graphics are illogical.
If you afford to stretch the rope to the maximum: the polygraph operator is so good that he/she is able to distinguish the illogical clues by only listening the record :()!
[Answer]
(This is rather constrained; you want the hearer to be able to pick something that speaks perfectly, as anomalous, given speech as the only medium.)
You specify that the AI is limited, but I can not see how to leverage that without a conversation (which is excluded)… except as below.
I like the idea of some anomaly in the speech (especially the breathing aspect), but other answers have that pretty much covered.
One possibility is to have an electrical or mechanical sound made by the machine. One obvious one is interference between the AI’s speakers and the telephone electricals. [I think I read that in another answer, but I did not find it in a quick search.]
The mechanical alternative is, for instance, that the AI “holds” the telephone handset in some way, and there is a mechanical noise such as a cooling fan hum, or a fast clicking caused by vibration, or some noise caused by the AI holding the phone way too tightly, or the hum of hydraulic pressure being maintained… that is conveyed far better through contact that through the air.
In another vein… I am assuming that the bomber is using the AI purely to avoid using their own voice. The other possibility is to build on this aspect, and have a bomber who actually has some defect themself. Perhaps they are from a different sub-culture, and have chosen an AI that, for instance, says “Hello!” in a way that immediately puts anyone from *this* city on edge, but sounds fine to the bomber.
Perhaps the bomber has tuned the AI‘s speech to sound good to the bomber, but [also] such that it sounds artificial to others.
Perhaps the bomber has poor eyesight, or is not familiar with the phones in some way… such that they position the AI holding the phone such that it blocks the microphone with a “body part” that has peculiar auditory characteristics, such that the person at the other end will notice.
Perhaps a tangential idea is acceptable, such as that the AI produces speech with two simultaneous “carrier” pitches (pitch of voice, in a human)… but the poor bomber is tone-deaf to the higher pitch.
Perhaps the bomber is slightly deaf, and has turned up the volume too high on the AI’s speech — noting that a human being speaking loudly sounds different from that.
I like the idea that the AI is a standard one that (for instance) was used in a huge telemarketing campaign recently, and everyone will recognise its voice instantly… but somehow the bomber missed out on this.
I like “John Dvorak”s answer here; the bomber might be listening along to the AI, but not hearing the other end, and the AI might be completely screwing up the conversation, while delivering perfectly, lines that are inappropriate.
] |
[Question]
[
If you have miles of steel pipes 10m thick, could you pump water from the sea to the centre of Antarctica, then pump it into the air like a geyser so that it falls around the pipe. As the fallen seawater freezes and makes a cone, extensions are added to the pipe to raise the height and more water is pumped through. Every kilometre, a pumping station is added, until the pipes and the frozen cone grows higher. Can such a mountain be made tall enough to allow a train running on a train track going up the cone to escape earth's orbit?
[Answer]
The maximum height a mountain can have on Earth is a tad more than what Mount Everest is high. This is due to the fact that when you increase the height of the structure, you are also increasing the load. After a certain point you will be adding too much weight for what the material can sustain, and the entire structure will crumble on itself. The potential energy you will be storing in the structure will be higher than the energy needed to melt it, et voilá.
Incidentally, this is also the reason why planets are spherically shaped.
Now, ice is even less resistant than stone, so it doesn't take long to answer no to your question. Moreover, as all the glaciers around the world show, when loaded, ice exhibits a plastic behavior and flows. Another reason for making what you ask impossible.
[Answer]
You've already accepted an answer, but aside from the structural issues (and the sheer mindboggling amount of energy it would take to pump all that water up that high), there's another misunderstanding:
>
> allow a train running on a train track going up the cone to escape earth's orbit?
>
>
>
Getting into orbit isn't simply a matter of getting up really high. The altitude at which you orbit is strongly related to the speed you orbit at (and vice versa); so the most important thing is to be moving *really fast*. A mountain just high enough to poke into the Low Earth Orbit region needs to be about 160 km high, and at that altitude you need to be going over 7.8 km/s for a circular orbit or you'll just fall back down to earth. The fastest trains in the world are around 267 mph (or ~165 m/s), so they're clearly never going to be able to enter orbit.
If you want to just "step off" your hill into orbit, you'll need to be all the way up at geosynchronous altitude... *35786 km*. That's over 5 times the radius of the earth, so you'll have a problem finding enough water in the solar system to build an ice mountain that high. (*edit: also, as people have pointed out, the mountain would need to be at the equator so earth's own rotation would provide orbital speed at the top of the mountain, so your polar arrangement would always require a substantial speed boost of the order of several km/s, give or take an km/s or two*)
If you allow *any* sort of train, then you can build an electromagnetic launch system, like a [Star Tram](https://en.wikipedia.org/wiki/StarTram). The biggest star tram design, the gen2, needs at least a 1000 km of magnetic track, inside a vacuum tube, with the business end 22 km up in the air. The design has the advantage that it doesn't even need a huge hill to support the top end, and so is *easy* to assemble compared to trying to build a mountain into space.
And this is without going into the details of circularisation burns for orbital insertion... getting into orbit isn't a trivial exercise!
[Answer]
L.Dutch has already explained why it won't work, I want to add that if you try to do this in any reasonably short amount of time, you will create a huge turmoil.
* The amount of energy needed to pump thousands of thousands of cubic kilometers of water 3 km uphill (and that's just in the beginning) is ~~staggering~~ mindboggling.
* A good part of this energy (+ the heat of crystallisation of the water(!)) lands in the center of antarctica, making a huge low pressure weather system, in other words: a cyclone.
* this draws in more water from the air around Antarctica, which precipitates on your mountain (so far so good!)
* the increasing pressure speeds up the glaciers, Antarctica grows
* the inflowing air from the north is relativeley warmer, much more turbulent weather
* you move mass closer to earth's axis, and the conservation of angular momentum dictates that earth's speed of rotation increases
* if you don't do the same on the north pole, things might get a bit wobbly
* before your mountain has reached ten kilometers in height, the sea level will have sunk by twenty meters or so.
* then, Antarctica gets so heavy that it starts to sink (like the continents did in the ice ages, only faster), and the oceans swallow up large parts of it.
* and what all that will do to earth's tectonics, I don't want to imagine.
All in all, I'll say this is a bad idea. ;-)
[Answer]
Starfish Prime's answer touches on this, but all the answers so far seem to be missing the most significant problem with this question.
The question assumes that it is possible to "**escape Earth's gravity**". This is a very common misconception, based on the observation that people in the space station float around as if there is no gravity. The "as if" is the important thing. The British TV series "[Rocket Man](https://en.wikipedia.org/wiki/Rocket_Man_(TV_series))", was based on this false concept, so the questioner is in good company.
In fact the Earth's gravity is still very much in effect in the space station, the force being 85% of what it is at the surface of the Earth. The astronauts and the space station itself are all affected by this gravity and are continuously falling and accelerating downward toward the Earth. They *appear* to have no gravity because they are in free-fall, as are the observers.
What we think of as gravity is actually not gravity itself, but the effect of resisting gravity. Gravity pulls us down, but the floor prevents us from moving. This pressure we feel on our feet is the force that resists gravity, not gravity itself. If we stepped off a high cliff, that feeling would go away. We would *feel* weightless, *as if* there were no gravity, yet we would be very much affected by gravity in that situation.
What happens is that as the astronauts fall down toward the Earth, they are also traveling parallel to the Earth at 27,600 km/h (17,100 mph). So as they fall, they also move sideways to a part of the Earth that, due to its curvature, is farther away. The sideways motion, the gravity, and the curvature of the Earth all balance out and the station ends up traveling in a circle, orbiting the Earth.
Anything at that height traveling sideways at a faster speed will move away from the Earth. Anything traveling at a slower speed will move toward the Earth. But when the orbital speed and height are perfectly matched, the station stays at the same distance from the Earth's surface.
Imagine being fired out of a cannon aimed horizontally. You would travel in a path that slowly, and then more quickly, curves down to the ground. Now use a more powerful cannon and you will still follow a curve, but you will travel farther before you hit land. Keep increasing the power, and eventually your path will curve down at the same rate that the Earth's surface curves down. You'll go so far that you'll actually go all the way around the world and crash into the back of your cannon. This process is how the space station stays in orbit. (The cannon scenario ignores air resistance and the Coriolis effect, but where the space station is there is no air, so that's not a problem.)
Really, the concept that "**there is no gravity in space**" is totally wrong.
So the basic premise of this question is false. The stated purpose is impossible. It's also an excellent example of "[The X Y Problem](https://meta.stackexchange.com/questions/66377/what-is-the-xy-problem)".
This would be a much more realistic question (actually two) if it were asked as:
* How high could an ice mountain be built on Antarctica?
* If we could build a 100 km (60 mile) high platform, could we use it to put satellites into orbit by firing them from a cannon or using an electric sled to accelerate them sideways to 28,000 km/h (17,500 mph)?
[Answer]
There are potential projects that aim the same thing. Getting to the orbit without rockets by using today's technology. Obviously none of them are using a giant ice mountain. This may provide some insight to these methods: <https://en.wikipedia.org/wiki/Non-rocket_spacelaunch>
] |
[Question]
[
Modern cities are built from concrete with steel rebar because it is abundantly available and provides enough tensile strength. Concrete requires cement. Cement is made from limestone. Limestone is made from coral and skeletal remains. On lifeless planets there are no organic materials such as limestone because there was never any life. There's basically just a lot of basalt and other igneous rocks.
If you were going to build a city on another planet, what kind of materials would you use to provide the kind of tensile strength that you need?
[Answer]
I would actually use... cement, because your premise is wrong:
>
> On lifeless planets there is no organic materials such as limestone because there was never any life.
>
>
>
Limestone is **not** an organic material (I guess the right word would be an ["organic compound"](https://en.wikipedia.org/wiki/Organic_compound)). Limestone is just calcium carbonate. And there's no reason why there couldn't be sedimentary deposits of calcium carbonate without biological elements.
If calcium (and carbon, and oxygen, and hydrogen) present in the planet's crust, you will be able to synthesize cement out of it, albeit at a much higher cost than using calcium-carbonate-rich limestone.
You mention:
>
> There's basically just allot of basalt and other igneous rocks.
>
>
>
[Feldspar](https://en.wikipedia.org/wiki/Feldspar) is an igneous rock containing calcium. Melt it down to separate the silica and aluminium, and you'll be able to synthesize cement.
Granted, the cost would be very expensive. So to answer this question one would need to know the geological composition of the planet's crusts, to see which useful compounds are readily available. Methane-rich planet? Synthesize plastics. Aluminium-silica rich? That means clay, which means ceramics. The best material to build *cities* with will depend on the availability of local compounds (which varies *wildly* from planet to planet), and the industrial tools that the colonists can drop on the planet (e.g. nuclear furnaces).
---
Edit: User @Luaan pointed out that limestone is a [biogenic substance](https://en.wikipedia.org/wiki/Biogenic_substance), one produced by alive organisms, and that made me remember about [oil-eating bacteria](http://news.nationalgeographic.com/news/2011/04/110405-nsf-oil-somasundaran-video/).
So if the lack of biogenic materials is a problem, but the planet's crust has the chemical elements needed for those materials, a solution would be to use engineered bacteria (or other microorganisms) to produce those materials (e.g. turn feldspar into limestone). This would fall into the umbrella of terraforming.
[Answer]
During the roman empire they didn't know modern cement, but they built "small thingy" like the [Pantheon](https://en.wikipedia.org/wiki/Pantheon,_Rome) by using [pozzolan](https://en.wikipedia.org/wiki/Pozzolan), which is basically volcanic ash.
That would be a good material to use.
[Answer]
# Carving.
Take the ancient Jordanian city of Petra, for example. They put giant steps into a mountain so that they could test the quality of the rock.
The benefit to building steps was so that nobody would have to hang by ropes or dangle off the mountain - during the build process.
It was this technique that enabled the constructors to stand on secure ledges while they literally carved around the mountain rock.
That being said, I'll assume your builders don't have hundreds of years to commit with a hammer and chisel. So you might want to pack some impressive technology.
[Answer]
**Use any kind of mortar that isn't Portland cement.**
The substance that, today, we usually just call "cement" is more properly called Portland cement, and it was only invented in 1794, by a chap named Joseph Aspdin. There were cities in the world long before 1794, so it's clear that cement is not required for cities. The stuff that's between the bricks in a wall is *mortar* and, while cement is the most common form of mortar today, many other mortars have been and still are used.
There is plenty of [information about mortar](https://en.wikipedia.org/wiki/Mortar_(masonry)). Mortar can be made from all kinds of substances, including gypsum, lime, clay, asphalt and good old mud. Of these, only asphalt requires life, though lime is made from limestone and the largest deposits of that on earth are life-related.
[Answer]
High precision cut stone.
When stones match together, you do not need mortar to seal them together. Given a high enough precision, you could cut hexagonal blocks and use them to build your walls. These blocks would give more stability than the standard rectangular "brick" when subjected to earthquakes and other vertical and side to side horizontal motion. Front to back horizontal motion could possibly "jenga" a block to slide out of place. Actually a slightly concave surface on the upper 3 sides and a slightly convex surface on the lower 3 sides will sync is all up and make the walls immovable.
The stone constructions in the Andes used massive custom cut stones with no overall pattern. These have proved remarkably resistant to strong earthquakes that sometimes happen in the area. There are stories of the stones "dancing" during a strong earthquake, only to settle back into place when the earthquake ended.
[Answer]
Pyramids. Big blocks of stone (basalt / granite / sandstone) and good masons.
Obtain carbon from carbonaceous chondrite meteorites. Find source of calcium (Gypsum minerals in fossil seabeds). Make cement. Also if carbon / hydrogen available then plastics.
Use clays and fire interlocking blocks and or create glasses.
If the technology available refine iron/steel, aluminium, magnesium.
Cities could also be below ground.
Also note that on a planet without life you will also probably be dealing with a reducing atmosphere.
[Answer]
Steel frames, glass or ceramic cladding and a prefabricated composite sandwich for the floors replacing the current prefab concrete.
Not a vast difference from how most city towers are built currently, but quite heavy on industrial base, so not for initial colonisation but rather for a mature colony. Tower foundations are currently built with poured concrete, but if you stick to low rise until suitable levels of biological matter have built up, guano for example, then deep foundations are less of a critical factor. You won't need high rise until you've built up a large population anyway.
Initial colonisation will probably be done with corrugated iron huts and other prefab facilities.
[Answer]
There's a whole history of NASA planning buildings on the moon, but if you want something semi-conventional:
**Steel and glass**
Very future-present. Entirely inorganic. Requires only iron (very common planetary mineral) and silica, which need to be purified. This is usually done by reacting with carbon, but if carbon is scarce other reducing agents exist and can be recycled.
**Plastic**
If you can get carbon from somewhere, like the atmosphere, then you can chain it together to produce light modular structures made from polymers.
**Other Ceramics**
Clay is inorganic, although produced by running-water ancient processes. There's a whole range of other materials that can be made through "firing" processes, and tend to be very hard.
**Carved Basalt**
Inca-style. Especially with modern cutting technology. It's not as easy to work with as concrete and tends to produce low, massive buildings, but they don't have to be that way with modern techniques and the use of some structural steel.
[Answer]
One of the oldest builing materials is [Loam](https://en.wikipedia.org/wiki/Loam). It has good strength and can be used for walls and even bigger builings by using it in combination with some pillars. (You must protect it from water aswell)
It even helps with good room humidity :)
[Answer]
If you build with arches (or vaulting which is sort of the 3-d equivalent if you consider a wall as 2-d) there's no tensile strength needed... all the load is compressive. You can use precision-cut blocks or just about any material that will stick together to fill the gaps between blocks that are not precision cut. So you can build using whatever rocks are available... and anything that is vaguely cement-like for gap-filling. The building material doesn't have to need any tensile strength and nor does the filling material, it just needs enough strength to hold itself in place. You could even use something like lead hammered in.
Look at all the mediaeval cathedrals in Europe, Roman aqueducts, castles... all of them are just about 'heaps' of stone in compressive loading with nothing tensile at all. You only need reinforced concrete or steel or timber to make lintels and flat spans... without it, you're limited to arches and somewhat more massive floors - you built a barrel-vault 'ceiling' and then you probably fill the top of the barrel vault up with loose fill to get a 'level' surface for the next floor up. Okay, no wood for the roof, you just make it vaulted and waterproof... and fit drains.
No skyscrapers, but you can build several floors up before the walls at the bottom get so massive they use all of the room space. But it's a lifeless planet... so you can build wide and low, there are no neighbours to complain.
[Answer]
Even if cement isn't available you really just need something to hold your aggregate together. Two ideas that spring to mind are:
* Bags
With bags you just fill them up with any old sand, dirt, rocks or whatever you happen to have lying around. You then just stack them up. You can even design them to reinforcing bars through them and/or tie them together with straps.
* Glue
With glue well you just, well glue stuff together. The glue could be almost any kind of plastic or resin you desire. Mixed with the right aggregate it could be as strong as steal.
* Bags + Glue
Just put the two ideas together, aggregate, mixed with a resin and maybe some kevlar or carbon nano-tube fibers, poured into kevlar or tyvex bags that are already the correct shape and size. Stack and tie them together.
[Answer]
Look at the work being done to use Lunar Regolith as a building material.
The three ways that I've seen are to use heat to fuse it into a glass, use heat to sinter it together or import a polymer to use as the fixing agent. The third method is not too expensive and the volume of polymer to the volume of fixed material is relatively small.
See [this article](https://en.wikipedia.org/wiki/Lunarcrete).
[Answer]
Cities don't necessarily need to be *tall*. They can be *wide*. While concrete reinforced steel is *commonly* used in skyscrapers, its worth remembering that there's other materials strong in *compression*
Assuming its a lifeless rock, you have *lots* of space to build. Quarry whatever ignesious rocks you have and build *out* rather than *build up*..
The incans had a city that was built entirely out of precision cut, [interlocking stones](https://en.wikipedia.org/wiki/Pumapunku). With reasonably high tech cutting tools you could do similar work on harder materials. While I'm not a civil engineer, I do also wonder if you could get a similar effect to rebar (the tensile strength of steel adding compressive force to the stone here) by drilling through and threading/clamping steel rods or wire .
[Answer]
You can build it out of anything depending on conditions. In very dry places house of mud work. If no rain or bugs, consider sugar. If cold you can make them from Ice. You can make them from trees, salt, metals, foam, plastics.... get the picture. BTW on the moon, melting the sand will create a form of glass cement that be used for construction.
[Answer]
Cities solve a problem for its residents. Could be safety, community, commerce, weather protection etc... There really is no one reason to live in a city. So the design of a city has a lot to do with the problems of people that live in it. In a environment with perfect weather, no hostile neighbors or crime then a society could flourish in tents and simple structures.
[Answer]
Robert Zubrin, who has thought about colonizing Mars extensively, suggests that the best building material for that planet may be brick. It can be made easily out of the clay abundant in the Martian regolith, and although water (which is scarce) is required for the manufacturing process, nearly all of it can be recycled. He also suggests that most structures would be built underground, both to protect their inhabitants from radiation (which Mars' atmosphere, lacking an ozone layer, does not block, but which a few feet of soil would protect against), and to compensate for the fact that the air pressure in man-made structures would be much higher than the Martian atmosphere.
[Answer]
You say that concrete is necessary for construction, that concrete requires cement, and cement is made from limestone that contains organic materials. Hence no limestone or concrete for building materials when building cities on a lifeless planet.
Any simple chemical compound can be chemically synthesized from elements or from simpler compounds.
Limestone may be formed from organic remains, but
>
> Its major materials are the minerals calcite and aragonite, which are different crystal forms of calcium carbonate (CaCO3)
>
>
>
<https://en.wikipedia.org/wiki/Limestone>[1](https://en.wikipedia.org/wiki/Limestone)
Calcium carbonate contains calcium, carbon, and oxygen.
Portland cement is made by heating limestone (calcium carbonate) with other materials.
On a lifeless planet with no limestone calcium carbonate and the other materials can be obtained by heating up rocks to melting or vaporizing temperatures and centrifuging the liquid or vapor to separate the elements and storing the elements separately until they are needed.
Compounds may be synthesized by machines like 3-D printers that form chemical compounds element by element, perhaps. They would take elements from their storage bins as needed.
Melting or vaporizing mountains of rock to reduce to elements would take immense amounts of energy. But the space colony will probably have fusion reactors to supply almost unlimited energy, and/or gigantic flimsy space mirrors to focus vast amounts of sunlight on small areas to generate energy.
Thus if a lot of concrete for construction is needed on a lifeless planet the cement will be chemically synthesized.
[Answer]
You can also carved rock, the same way the guys have been doing it before the (re)invention of modern-day cement. The cities of Petra would be a good example.
You can also resort to adobe houses, made from mud bricks. Just make sure to kiln-fire them.
For the decorative purposes, look for marble in the planet you've landed on.
You can also synthesize calcium carbonate for use in cement.
[Answer]
Any structure built on Mars would either be underground or be buried over. Now here is a novel idea. Build it out of Pycrete. Mars is so cold at night that the few hours of daylights it would stay frozen. It would provide a great barrier to radiation, and would actually help keep structure warmer at night. It is also easy to work with. Water in Pycrete could also serve as the reserve for the colony. Building would be made by using inflatable bags which are filled with water and dirt to make the structure.
] |
[Question]
[
Like our good SciFi prophet [Isaac Arthur](https://www.youtube.com/channel/UCZFipeZtQM5CKUjx6grh54g) postulates, for a civilization with a decent space presence planets are overrated and rubbish.
1. They're down there in the deep gravity well.
2. There is no resources on them that can't be reached far easier on
asteroids or tiny planetary bodies, or be made up in space via
factories or 3d printers (and nano-assemblers if need be) from raw
materials mined in asteroids.
3. There is no environments there that can't be simulated to convincing
enough degree on a large O'Neil station habitat with bonuses of
being predictable and completely controllable (Gravity, light cycle,
geomagnetic fields, climate, atmosphere, and so on).
4. A cloud of space station habitats could easily provide living space
several million times larger than the surface area of a planet,
while using just a very tiny fraction of its mass for the
construction.
5. And even appeal to "we like it better that way" would work only for
that generation who were born on planets to begin with - for those
born on space station or space ship and who lived all their life
there, it would be unnatural and weird to live under an open sky.
Not to mention that in a realistic scenario only *one* planet is truly habitable for humans, and even those other planets that have biospheres of their own would require decades or centuries of terraforming efforts to make them comfortable for our species. For planets that don't, those terraforming projects would last millennia instead.
Yet, there is a huge human presence in space across many solar systems with habitable or not so much planets in them (setting with a decent but not dirt-cheap or ultra-fast FTL), and these humans decided to not convert these solar systems into swarms of rotating habitat modules with population of trillions, and appear to have at least 40% of their population be living down the gravity wells, for reasons that aren't just "we like planets". **What those reasons could be?**
n.b.: technically there's not only humans but all sorts of aliens as well, but I'd guess that any reason valid for humans I could apply to the aliens more or less effortlessly as well.
[Answer]
## Stability
Nothing beats the radiation shielding of 1,000 kilometers of magnetic field + 100 kilometers of air + (at night) 6,000 kilometers of water and rock.
For heat, nothing beats 22 billion cubic kilometers of atmosphere to dissipate, by whatever means necessary, heat concentrations. You can have 1 terajoule nuclear blasts, or multi-terajoule meteor airbursts, and life goes on with barely a blip (unless you are immediately at the location being affected).
You have [24.5 million billion kilograms](https://www.climategen.org/blog/how-much-ice-is-on-antarctica/) (pentillion) of glacial heat reservoirs that can sink 24.5 hexillion joules of excess heat, and keep the mean temperature pleasant.
Your oxygen and water is recycled automatically by the biosphere. The oxygen quality, with very few exceptions, is stable. Same for the water.
## Infrastructure
With a lot of your life support taken care of you, nothing beats how many people you can cram into a cubic kilometer of earth. You can stack people horizontally, on the roof, or beneath the surface. You can do this with materials as flimsy as particle board. No need for structures that can hold atmospheric pressure, fire + leak detectors, or maintenance kits. In the [2,600 square feet](https://www.quora.com/What-is-total-square-footage-of-space-on-the-ISS-How-many-people-can-be-accommodated-on-the-ISS-at-one-time?share=1) (240 m²) of the International Space Station (hosts 6 people), planetside you could easily fit 50.
Likewise, you have to travel a few tenths of an astronomical unit to pick up a body of water. Planetside, it falls from the sky, or you can pump it up from a well -- it is where you are.
Need minerals? They are often laying on the ground, just begging to be picked up and put to use.
Need biologically engineered construction materials? "Wood"™ just grows right next to you. It might drop bits of bio-engineered hardware on your roof, or you can collect in bulk with a saw.
[Answer]
Unless I'm living underwater, if a large hole appears in the side of my home due to some incident, my immediate emergency response is put on warm clothing. My second is to cover the hole with anything that might be handy: piece of wood, a piece of plastic, just enough to keep the heat in and weather out. It might be uncomfortable until more permanent repairs are made, but I'm not going to die of minor things like rapid depressurization, asphyxiation, falling into an endless void until the life support runs out...
Heck, in many place or parts of the year, I might not even have to be in any rush to fix the hole and decide to take care of it in the morning.
Or if there's a fire, well, I can run outside buck naked and survive until help comes. In certain places, this might only be a few minutes because of cold, but in others, you might survive for quite some time until assistance arrives.
People *vastly* underestimate how much life support and safety they take for granted by living on an earthlike planet.
[Answer]
**Planets are fail-safe.**
A space colony has to be operated and maintained by competent and responsible people. Most people aren't and this is not entirely bad (we need the other kind of people to make innovations here and there or to run the administration). Well, a planet can be screwed up as well, but it takes a lot of effort. A space colony can be destroyed in a hearthbeat.
And where do you evacuate a failing space colony? All of them are expensive as hell so they are at capacity. Building a spare one is long and expensive as well, keeping a separate one "just in case" for an insurance-like model is a logistical nightmare.
**Planets are sustainable.**
You don't leak atmosphere on a planet. Everything you waste is waiting for a technology or economy to improve and becomes a resource. A planet has an ecosystem and a water cycle that recycle most of the stuff by itself.
**Planets are big**
Bilions of people can live on one of them, benefitting from network effects, urbanisation, social, cultural, political and genetic diversity. A large economy can power research, education, military and other kinds of development. This makes planets competitive - just like a large city or a country is competitive against the small ones.
Most people are OK with the gravity well and they can contribute to the economy and other things just as well from down under.
Making a space colony for even a milion people is an engineering and safety nightmare.
**Planets are cheap**
You can develop a space-hungry, workforce-hungry and mineral resource-hungry industry that is impossible in space. Think Taiwan Semiconductor Manufacturing Company (TSMC).
**Mineral resources**
SOME things may be easier to mine on asteroids as on Earth they may be concentrated deep underground (heavy metals), but you'll need a complex and expensive enrichment/separation industry. On Earth, the water cycle and the biosphere concentrates (or did so in the past) a lot of things. Here, we have copper mines with ~0.5% copper. I doubt we can find an asteroid with a deposit that rich (or, for that matter, 1/10 of that). And good luck digging down to the core (easier than on Earth, but still quite hard).
[Answer]
Beavers that have never seen running water in their entire lives will start gathering twigs on hearing it. We aren't that programmed, but we may not prove to be absolutely blank slates. Living in space may prove to be subtly (or egregiously) badly suited to human beings, even those born on space station or space ship. Perhaps we need genuine gravity, and the subtle discrepancies produced by rotation-simulated gravity prey on our bodies and minds.
[Answer]
## Cthulhu dislikes Dyson Swarms
Any argument about planets being safer of more stable assumes that your automation and general engineering capabilities are rubbish (on the current day level instead of on one one might reasonably expect form an interstellar civilization in other words). The environment might kill you isn't a good reason not to settle a place, it hasn't even kept prehistoric humans form adapting via technology (clothing for the northern hemisphere, boats for Polynesia). It won't keep an advanced civilization from mastering new technologies and building space habitats. The only way I see to get the classical "planetary" Scifi-Setting is that something that humans can't solves keeps them planet-bound.
**I propose that your setting has some kind of K3-civilisation level "gods".**
Maybe they are sleeping, or waiting or have a political system that is so gridlocked that they haven't done anything for a billion years. No one really knows. Asking stupid questions results in vaporization. The only thing that is certain is that they handed you, and any other civilization a list of ten(-thousand) commandments. Something like this.
*Don't make pizza with pineapples, that's just disgusting.*
*Don't research zero-point energy, you morons might cause a false vacuum collapse.*
*Don't develop a solar system beyond K1.2 (obviously relative to a K-type star!!!), this means no Dyson Swarms, you simpletons.*
*...*
*If you disagree with or break any of these rules, we will collect your entire civilization, crush you into a black hole and let you orbit the galactic core along the the [23463] others.*
*- sincerely, the K3 civilization in whose backyard you are playing*
Something like this would allow you to have any number of otherwise illogical rules or limitations in your setting. From weapons restrictions, over a prime directive to a strong preference for inhabiting planets.
[Answer]
**Supply**
Logistics of mining in space is a lot more complex as mines will be small and distanced. Some mines will not be worthy of a big mining ship with a strong long term life support system. Those ships, workers will need shipments from other places. It will consume a lot of time and workpower.
**Comfort and Freedom**
Everything in a space station is a utility service provided by the station. So, you need to pay for the air you breathe. Water might get rationed from time to time.
If you are born in space you will hear stories of planet living where the land is vast air is free, water falls from the sky. You will hear about cheap excess amounts of animal products and magnificent animals themselves. Large trees you can climb. You are free to light a fire on a planet!
On a space station, as you stated, EVERYTHING is controlled and needs to be controlled in order to stay alive. Planets, thanks to their size and complexity, are much more forgiving in the sense of resources.
**Competition between species**
Also since planets are excellent environments to reproduce with enough space to supply the population your people will gain advantage over other alien species. High population can be a burden but it is needed to survive againts other technologically equal alien species.
[Answer]
Space habitats cost an enormous amount of money. Who's gonna pay for that? The people imagining O'Neil cylinders have been dreaming about bustling Moon cities and rotating habitats in Earth orbit by 1980 since the 50's. We don't have any of those simply because nobody is willing to finance them.
Those up-front investments would only start to pay off after probably hundrets of years, and no corporation is thinking that long-term.
In contrast, a colony requires quite little up-front cost, depending on how basic you are willing to get and how friendly the planet is. You basically can just drop a few hundred settlers with seeds and saws on the planet and let them do their thing wild west style. They'll even pay for it themselves, they won't need their earth money anymore anyway.
[Answer]
**Homesteading and Independence**
On earth, we see this phenomenon currently. Some people are attracted to the idea of settling on a plot of land and doing as much as possible themselves. Some are able to live "off-grid" independently from the rest of society, in various community sizes and various levels of import/export of goods and services with others. Some humans would rather work harder doing manual labour on their homestead and live in comparatively lower luxury just so that they don't owe anything to anyone. No mortgage, loans or debt of other kinds.
This is near-impossible to do in a space colony, because a small pod for one person (or family) just doesn't work. The systems that keep it stable are so advanced you need multiple specialists to keep it in working order. A larger station is a better solution and getting it working is an effort by the entire society to keep its members alive. There is no way to control everything yourself, you have to depend on others. The "Do It Yourself" days are gone.
[Answer]
**A space colony is like a hive. If you're part of it, you must work for it.**
There was this story I read, settled in a post-apocalyptic world. Some of the world's most socially powerful people, made use of their influence to build a safe haven.
However, if you wanted to be part of it, there was a condition. By working for them, in return, they allowed you to stay. So basically they maintained social hierarchy, even if there was no money anymore.
A space colony is one gigantic beast to maintain. Even if a lot of things are automated, it might not be truly become fully autonomous. So you require people to maintain it. Beside that, any person living on it, is one more mouth to feed.
In that kind of situation, I can see at least 3 group of people that would live on the planet:
1. If you are unlucky and a colony deemed that you were not necessary to them (in making them thrive), then you have no choice but to try your luck elsewhere. Either knock on another colony, or live on a planet.
2. Related to the first group are those who would want to join them. Whether because they're family members, or because they believe it was unfair.
3. And last, you also have lone wolves who would rather live on their own. But that can hardly be done on a space station. No matter where you go, you will always be part of the colony. So the only way out is on a rock.
[Answer]
Isn't this kind of like asking why fish prefer to live in the ocean?
Humans evolved on Earth, so we evolved quite specifically to live in Earth-like conditions.
In general, the more Earth-like an environment is, the more humans will find living there to be comfortable/healthy/enjoyable. Sure, you might be able to approach Earth-like conditions in a sufficiently high-tech space habitat, but it's likely you will never be able to 100% replicate "the real thing", and any deviations away from Earth-normal will result in some level of discomfort/dissatisfaction amongst many of the people who live there, which will in turn drive a certain amount of demand for on-Earthlike-planet real estate.
[Answer]
Because in the final analysis Earth like worlds and space stations/ships are all just habitats i.e. places that are capable of sustaining human existence. The only difference between them (apart perhaps from scale)? Habitats have their environment on the 'inside' while Earth like worlds have theirs on the 'outside'. So location is simply a matter of need and opportunity - choice.
(Edit; and part in fun) So its simply a case of choosing the right type of real estate for your current lifestyle and moving in. (Footloose and single) a small apartment on Centauri Station close to bars and the entertainment district. (Married with kids) perhaps something with a big yard and a pool down on Deneb 4
[Answer]
In [aquarium hobbyist culture there's a rule of thumb that larger fish tanks are less maintenance and more resilient to change](https://www.fishkeepingworld.com/what-size-fish-tank-should-i-get/). This is because they're just so big that the environment is self-correcting and is a lot more tolerant to local fluctuations. Nano tanks, on the other hand, are a huge amount of maintenance and often have problem with oxygen depletion, ammonia buildup, and other fun problems. This applies to all self-contained environments and is why, for example, humans can pollute the oceans, kill off the megafauna, cause global warming, and burn the Amazon but still have time to reverse their environmental destruction rather than the environment turning into an outright hellscape. By contrast, compare this how often "we need to fix this because otherwise life support will go down and we have no margin for error" issues come up in human space travel either as theoreticals or actual issues like with Apollo 11.
O'Neill cylinders and other space stations are basically microtanks designed for the human species. They have little margin for error, are super vulnerable to radiation and micrometeoroids, and would require your population to spend a significant amount of time performing maintenance that they could spend on leisure, research, or cultural pursuits. They also have the issue that precious water, atmosphere, and oxygen can be very easily lost through breaches or venting, and in many cases it may not be possible to move your space station to absorb an asteroid to get some back. By contrast, because of gravity and magnetic fields those resources tend to stay attached to a planet. You could build a really, really large space station that bypasses these problems by having a larger environment but by that point you're just building an artificial planetoid like the Death Star.
[Answer]
# Simplicity
If you live on Earth, your address may be something like:
>
> 2020 Somewhere st
>
> Some City, ST, 00000
>
> Country
>
>
>
And you only need to care about North, East, South and West. For example if you wish to visit the bakery, you go south for two blocks and then turn right.
Now if you live in space, your address needs to contain the following data, from the point of view of a base planet in the system:
* Eccentricity
* Semi-major axis
* Inclination
* Longitude of the ascending node
* Argument of periapsis
* Mean anomaly
([I am assuming that a small space station in orbit around a star would be catalogued the same way that asteroids in a belt are](https://en.wikipedia.org/wiki/Orbital_elements#Alternative_parametrizations)).
Might look like this:
>
> e 0.22997227±0.00000003
>
> a 2.773841434±0.000000004 AU
>
> i 34.832932°±0.000003°
>
> Ω 173.024741°±0.000006°
>
> ω 310.202392°±0.000009°
>
> M0 144.97567802176°
>
>
>
This is the address for 2 Pallas in our own solar system, by the way.
Your "cardinal directions" are [prograde, retrograde, radial in, radial out, normal and anti-normal](https://wiki.kerbalspaceprogram.com/wiki/Maneuver_node#Directions).
To visit aunt Bertha, you need to wait for the perfect launch window so that you can do a rendezvous. Might take months and you'll need an immoral amount of fuel.
Since I'm not a fan of astrogating just to buy toilet issue, I'll choose living in a good old planet any day.
[Answer]
**Beyond whether or not it's practical, it can be something as simple as one's principles or beliefs**
There could be a group of people. They may be a few handy, or they may be a vast majority of those who still live on a planet. They have in common that, they believe walking on earth is the right thing to do from their perspective.
Maybe it's because they must remain connected to their roots, maybe because they do not want to anger their gods, as they're afraid going so far away into outer space would be like challenging them.
Or, if you are also interested in fantasy stuff, maybe they are shaman, and being on earthly grounds allow them to better connect with the elements.
[Answer]
# Violence and Economics
O'Neil cylinders, Dyson spheres, Ringworlds and other space colony megastructures indeed have many benefits, as you indicate. They have vast population densities and don't have annoying gravity wells to contend with. But they have some drawbacks: They take forever to build and they are relatively fragile. If you can either amplify these drawbacks by presenting hostile circumstances, or negate these benefits with the right technology, then space mega-colonies will be the exception rather than the norm.
---
## War
One reason your civilisation does not build many space mega-colonies is because they are in a constant state of war, or at least suffer major wars on a regular basis. Wars present numerous pressures against space colonies.
### Weakness
Firstly, space colonies are fragile. Consider an O'Neil cylinder or a Ringworld. If you can make a large enough hole in the hull in just one point, the entire thing can tear itself apart. A [Ringworld](https://physics.stackexchange.com/questions/41254/why-is-larry-nivens-ringworld-unstable) or a [Dyson sphere](https://physics.stackexchange.com/q/40739/208235) can be pushed off axis and crash into their star (as long as you can push harder than any restoring forces). These space colonies all present large areas of exposed hull which can be targeted by weapons, and the amount of shielding is limited.
Compare with Earth-like planets. While planets are still easy to shoot at, planets automatically come with protective atmospheres, and the cautious can put a further few hundred metres of rock between them and the sky at little additional cost. Planets are also far harder to destroy, being bound together by gravity and having vast amounts of matter to distribute shocks through. Space colonies have no such gravity or spare matter.
While shields and point defences can reduce some of the risks, such defences can apply equally well to planets and space colonies, or even better to planets if such defences require vast heat sinks.
This assumes you do not invent some easily-mass-produced indestructible building material. If you can cheaply convert matter into unobtanium hulls, then space mega-colonies become better protected than planets. But even with unobtanium, there are other reasons not to build mega-colonies.
### There's no time
Secondly, space mega-colonies take forever to build and use up the engineering capacity of your solar system. In war, you don't have time or production capacity to waste.
You could disassemble a planet and build an O'Neil cylinder, or you could build your colonies on a planet in a fraction of the time and cost. Then the population of your solar system will be able to direct their energy towards the war effort. If you have time to build a mega-structure, the Empire could do with a few more Death Stars, not frivolous housing.
### There's no need
While planets have lower potential population densities than mega-colonies, this is not a concern for your war-torn civilisation. They are constantly acquiring new solar systems to inhabit, or losing solar systems (and reasonable chunks of their population) to their enemies. As such, the principle benefit of these mega-colonies is never needed.
Additionally, if territory changes hands on a regular basis, then there is no sense spending vast resources to create a mega-colony when there is a good chance it will fall into the hands of your enemies in the near future. You might build these mega-colonies in your core territory, but territory with even a remote chance of becoming contested will use the cheaper planetary colonies.
---
## Space Elevators and Expansionism
Another reason your civilisation might not build many space mega-colonies (independently of war) is that the technologies and space available to your civilisation make mega-colonies redundant.
The first benefit of living in space is not having to climb a gravity well to travel. However, if your civilisation has a cheap way to ascend (or descend) gravity wells, then expensive space mega-colonies lose this advantage. This method might be space elevators, or a reactionless drive, or a (cheap) torchship, or teleportation, or antigravity, or anything else you can imagine.
The second benefit of space mega-colonies is efficient use of mass in terms of livable surface area. However, it may be cheaper to find another planet to live on than to disassemble your current planet and turn it into a mega-colony. If you have decent FTL travel and communication, and the galaxy is not yet fully occupied, then finding a new world and maintaining a connection with the rest of the civilisation is easy.
In the core worlds you may get some of these space mega-colonies, unless galaxy-wide travel is cheap and instantaneous. These mega-colonies would be the Kardeshev-Type-2.5 equivalent of our skyscrapers, used to produce a high population density close to central infrastructure. But you would still have a substantial amount of the population living in the space equivalents of suburbia and rural regions, which use cheap and readily available planets for their colonies.
[Answer]
To address a small portion of your question, terraforming a planet, assuming that is a thing, need require essentially no time at all to accomplish.
Send out a terraforming suite ahead of the colony ship. Have the colony ship travel at extremely near the speed of light on a trajectory which puts the colony ship at the new planet in whatever number of centuries is required for the terraforming suite to accomplish its task. Relativistic time dilation will ensure that that very little time will have passed for the colonists (basically acceleration and deceleration), despite the passage of centuries (as needed) for the terraforming suite and the new planet.
This removes the barrier of "Un-inhabital Planets" from the list. The answers others have given become that much more feasible. A universe could have thousands of planets in the process of terraforming with colonists in transit, even if FTL is involved.
[Answer]
Under the Principle of Non-exceptionalism, the reason populations do not expand much beyond the planets has to be something which applies to all systems, and all sophont species.
A single culture with an inclination for expansion will do so quite well with FTL ... unless it cannot.
Perhaps the Peak Phosphorous limit is quite low in this setting? Or some other phlebotinum limit caps the population in each system.
[Answer]
Your civilization has a large presence in space, out of planets, but those stations are inhabited by only robots and a temporary or semi-permanent maintenance crew. These space stations would be like modern oil rigs or ships. They would have a relatively comfortable environment for the engineers to live, with indoor tennis courts, living quarters, cafeterias, greenhouses. Employees could live and work there for months or even years if such habitats have artificial gravity, but (most of them) wouldn't want to spend their entire life there.
People would want to live a normal healthy live on an actual planet with an atmosphere, with nature. While it is possible to live in an artificial environment for extended periods of time, it is not healthy in general. It is not the best solution.
And the more automation and robotics you have, the less reasons you need people to be there. You could eventually reach a point where most of the space facilities are automated, and have automated repairs and maintenance as well and you have only a small group of engineers overseeing the systems.
[Answer]
There will be a large presence is space, but with mastery of space, the energy requirements to drop into/climb out of a planetary gravity well will be small.
Earth will be a tourist destination, a repository for original ecologies, and general gene bank. Moderate numbers of people will choose to live on Earth, but most will prefer the higher wages, and controlled lifestyle without hot weather, blizzards, mosquitoes, and general unpredictable environment.
[Answer]
All right, lets make an artificial planetoid or space station suitable for human habitation. First off, we're going to need an atmosphere to allow people to breathe. You could enclose everything inside a metal and plastic shell, but that's very vulnerable to puncture by micrometeorites. An alternative way to do that is build something with a lot of mass so that gravity will keep the atmosphere attached and...oh.
However, we don't want our atmosphere to be stripped off by solar winds or our population to be bombarded by cosmic radiation. Space stations tend to have very thin walls (compared to a planet) so what we can do is generate a magnetic field to...wait a minute.
Additionally, our population is going to need a lot of resources, as well as extensive environmental controls in order to maintain the environment at a stable level. So to do that, we'll have extensive ecoscapes spread across the surface to provide wood, food, and oxygen just...like...forests...yeah.
We also need to be at the correct distance from the sun to grow our food and power our solar panels, which means we need to place our space station within the habitable zone and...why aren't we just colonizing the planets in the Goldilocks Zone again?
[Answer]
Planets might not be very efficient for space-faring, but they sure are good for people. Let's examine your reasons.
1. They're down there in the deep gravity well.
I've never woken up one day and decided that I hate that fact.
2. There is no resources on them that can't be reached far easier on asteroids or tiny planetary bodies, or be made up in space via factories or 3d printers (and nano-assemblers if need be) from raw materials mined in asteroids.
Trees are nice.
3. There is no environments there that can't be simulated to convincing enough degree on a large O'Neil station habitat with bonuses of being predictable and completely controllable (Gravity, light cycle, geomagnetic fields, climate, atmosphere, and so on).
I like to simulate the outdoors. Why would I ever do that when I can just walk outside?
4. A cloud of space station habitats could easily provide living space several million times larger than the surface area of a planet, while using just a very tiny fraction of its mass for the construction.
Irrelevant to people. Having more humans doesn't make me feel any better.
] |
[Question]
[
I have time traveled to the past on an oriental country in southeast Asia. I want to hide my island from European colonists using some technology available in both the future and the past.
Would building giant mirrors solve my problem? Thanks!
[Answer]
Publish the highest-quality maps for your area (Google maps.)
As more people see that your maps are the best, they will come to rely on them.
Obviously, leave your island out. Mark safe waterways far away. Leave some white, "unexplored" spots far away and hint that there might be valuable resources.
If you feel like it, mark your area as containing dangerous phenomena, like the Bermuda triangle.
Obviously, you'll have to sink the occasional ship that dares venture near your island. Do sink it. That will only heighten the perception of a "dangerous" area. (Well, it really is..)
[Answer]
Just loudly advertise that this island is the St Teresa's Benevolent Hospice for Sufferers of Leprosy and Syphilis. NO visitors allowed, but donations of food, clothing and money will be accepted.
You will enjoy your solitude in peace.
[Answer]
Shortly — don’t leave witnesses who have dared to approach your island.
There are 3 possibilities to make an island inaccessible, with 17th century tech:
1. in the 17th century they used compasses to navigate seas. If you place electric coils on your island, it might tamper with the north direction that compasses show. And it can allow ships to be misguided into dangers like rocks and so on.
But it cannot prevent navigators using the sun and stars for plotting a path. 17th century navigators would probably be aware of a strange island that stops compasses working.
2. you can use 20-21th century surveillance drones and anti-naval artillery systems to simply sink approaching ships. No witnesses. People will know there is strange island where ships disappear, but nobody will dare to approach it.
3. you can use anti-ship mines, but it’s worth notice that 20th century mines used during WW2 were triggered by metal ship hulls, and 17th century ships were made of wood.
[Answer]
## Sargasso.
Everybody *thinks* that it is an old myth that European sailors lived in dread of becoming mired for years in the vast shoals of [sargasso](https://en.wikipedia.org/wiki/Sargasso) that blocked the dead center of the sea. Little do they know the truth. Who would have thought that lunatics from the future were farming sargasso by the ton and weaving it together with tough plastic ties in a barrier completely surrounding their island?
[Answer]
**Building giant mirrors won't help**
There seem to be promising ways for optical trickery to help. See the following:
<https://www.findlight.net/blog/2018/06/25/optical-cloaking/>
It was just a quick search that shows optical cloaking. Seems promising right? Build gigantic mirrors all around the island that use this trick and *presto!* it's gone.
Unfortunately it's not as simple. In the article they are talking around the subject with "*if you look head on to to wall*" and "*taking advantage of the focal lengths of a set of lenses*". Each of these is directional and specific. You can't just place the mirrors or lenses all around the island and hope it works. Each is directional and making curved glass will make it much, much more difficult. If you manage it somehow you'll still be able to see some oddities, as whatever is behind it will be shown from the mirrors. If you'll be at an angle or at different distances, it often looks weird.
That is even under perfect conditions. What will happen at a beautiful sundown? Thanks to the large uniform rays you'll easily identify that the light was mirrored or bent at the island, making it stick out more. What about maintenance? The mirrors might deteriorate, or simply get wet or dirty. This will make it stand out again and make it a point of interest.
Mirroring or lensing anything will have a huge set of problems. You're better off killing/taking prisoner of the ships that land there and sent the empty ships back to sea/sink them along the coast. Stories, warnings and mystery will do the rest. Or just have it far away from the land, so most boats won't even try to cross that part of the ocean as their vessels aren't good enough to reach too far out onto sea. The chances of being discovered then are small.
You could even just put speakers all around the island with some lights in the trees. If colonists come close, activate some sinister music (they even had mass hysteria at one big musical piece in a concert hall one time as they weren't used to it!), some dangerous sounding/unknown sounds and a light show. Yes it might be known to the colonists, but no one will dare to get on the island.
[Answer]
South East Asia -Coastal Island? Or one of Indonesia or Philippines or that area?
You would also have to keep hidden from the Asians. News would spread.
Go inland. Some places deep in Papua New Guinea didn't have contact till WW2 (cargo cult) With current tech, easy to set up a base deep in the jungle of the one of the mountainous islands and fly in and out where you please.
Some of the large islands like Java or Borneo or ones of the Philippines could have thousands of people hidden for hundreds of years.
[Answer]
**Post Some Signs**
A few leper colony signs would encourage ships to sail off elsewhere. A quick shamble along the beach wearing some rags for added. Some artistically posed skeletons in the jungle.
Any sort of disease threat would frighten off sailors. They will mark it on their maps and avoid the hell out of the place.
[Answer]
With 20th century technology, it is very simple:
* Keep some submarines patrolling your island and nearby waters.
* Use some radars or sonars to detect any approaching ship.
* Launch a torpedo against any ship that comes closer than, say, 300 km from your island.
[Answer]
Reefs. Far enough out they will stop any ship from sailing past and seeing your island. You will have to move a lot of mass, but you won't have to kill anyone, in case that helps.
[Answer]
You could create a **constant hurricane around the island** strong enough to keep 1600's ships at bay.
You would need to account for the fact that some ships may want to get in and out but as the scientific documentary *Wonder Woman* has shown, this is maybe not even needed.
[Answer]
Rename it to Iceland, Frozen wastes, or Here-Be-the-Kracken, something terrible sounding, so that people ignore it and won't want to go there.
[Answer]
**Harpoons**
Or, more specifically, a surface-launched [Harpoon Block II+ ER Anti-Ship Missile](https://en.wikipedia.org/wiki/Harpoon_(missile))
You can hide your island pretty well if you turn any wooden ships and their sailors into a pink mist when they get too close. You'll be able to sink them well before they get into visual range of your island, rumours of a cursed section of sea will spread when ships don't return, and there won't be anyone to tell the tale of why.
[Answer]
There are some good answers here:
[What natural phenomena could make an island unreachable?](https://worldbuilding.stackexchange.com/questions/83317/what-natural-phenomena-could-make-an-island-unreachable)
Given this is the age of sail, why not go for putting the island deep in the "doldrums".
[Answer]
## **Maybe you could spread fear by poisoning people with radiation, poisonous gas or powders if they get too close to the island.**
Combine this with maps marking the area as dangerous or cursed and magnets which make compasses go haywire for full effect.
You could make them feel sick, get burn-leisions on the skin, vomit, hallucinate and even pass out. On leaving the area (depending on how long they stayed) they could fully recover and confirm to others the area is a no-go.
I suppose there's nothing stopping you from mining radioactive materials like [Polonium](https://www.thoughtco.com/the-most-radioactive-element-608920) and a poisonous gas like natural gas or some chemical reaction bi product gas in the 17th century. Certainly [Arsenic concoctions](https://dirtysexyhistory.com/2017/05/04/a-field-guide-to-historical-poisons/) were easily obtainable in the 17th century.
(Just something related I found **on [Wikipedia](https://en.wikipedia.org/wiki/History_of_chemical_warfare)**...)
>
> Leonardo da Vinci proposed the use of a powder of sulfide, arsenic and
> verdigris in the 15th century:
>
>
>
> >
> > throw poison in the form of powder upon galleys. Chalk, fine sulfide of arsenic, and powdered verdegris may be thrown among enemy
> > ships by means of small mangonels, and all those who, as they breathe,
> > inhale the powder into their lungs will become asphyxiated.
> >
> >
> >
>
>
> It is unknown whether this powder was ever actually used.
>
>
>
[Answer]
## Nuclear weaponry
I am quite sure that people in 1600s (maybe even until late 1800s) will NOT attempt another voyage or exploration to an island that retaliates with tactical nuclear missiles within some range.
Imagine an entire fleet of ships wiped out violently in a giant magic fireball, followed with a ripple of tsunami-like waves afterwards. A giant mushroom-shaped hot smoke that rise hundreds of meters high. Such things will frighten nearby observers that happen to be within line of sight. Survivors of such explosion (if any exists) or people near enough will develop weird diseases due to radiation. "What is this sorcery? What is this curse? Is this the work of that fireball?"
Scared of such cursed area in the ocean, explorers will perhaps not try to get too close. Haunted and terrified? Yes. Curious? Maybe. Willing to risk certain and utter destruction? Definitely not.
Missiles that are launched high to the air and strike back down is a majestically terrifying thing for the explorers to behold, while underwater torpedo is a stealthily mysterious one. Either option is okay.
tldr: Bermuda triangle, but nuclear weapons.
## Cartography
I take the main inspiration from [this answer](https://worldbuilding.stackexchange.com/a/200058/79717). Publish best maps for your surrounding realm using data that is available in 21st century. People will eventually rely on your high quality, detailed, and very accurate maps. You can then work from there to hide, exclude, spread rumors, etc etc to minimize explorations. There are few tips, some from linked answer/comments, that you can use to remove your island from the map:
* Plainly just exclude your island. Replace it with just the blue oceans.
* Hide your island under/near the compass rose, i.e. the sign that says "NORTH THIS WAY".
* Hide your island under/near markers with very large fonts, e.g. "Indian Ocean" or "South China Sea". Put your island underneath, or if you feel creative, inside the letters "e" or "a" or "O".
* Hide your island under an inset map. It is usually assumed that inset maps are drawn over an area with nothing of interest, so no one thinks it's something worth to see/get to. Additionally, make the inset map a red herring, detailing other islands! (As an interesting side note, Northwest Angle becomes practically a US exclave in Canada because early border treaty draws inset map over its location, while not knowing what actual geographical landscape lies underneath.)
* Plainly mark seas surrounding your islands as "cursed" or "not for exploration" - or whatever language works best with the European explorers, complete with a tale about "people in the past" that came close and wiped out in giant magic fireball with radiation diseases. Bonus: if the island is luckily close enough to a civilization for it to witness, even only one curious voyage's tragedy will be enough to make rumors naturally develop among the peoples and confirm the "cursed" and "not for exploration" tag on the maps.
tldr Make really good maps and mislead people using them.
---
In hindsight, I just realized this answer has a prior assumption that you are trying to hide a comparably small island, not a Southeast Asian island with the size of Java or Mindanao.
[Answer]
just make a rumor about your island that people die here be ready if someone comes there did not walk back alive. So the rumor will become true. And also use todays technology to tackle any stealth invasions. Also what you can do never ever make anyone mark your island Just make it a sea. or water like Bermuda triangle . It would be a long term strategy and work.
[Answer]
**Tunnels**
Low tech but effective. Build whatever infrastructure you want underground on an island without any interesting resources or supplies.
If anybody approaches, spot them with your advanced surveillance technology and retreat to the base until they sail off. If they prove persistent or are unable to get away (castaways) then break out the chloroform while they are sleeping.
[Answer]
## **What's yours is mine, and mine what's yours**
Surround your island at a distance in a network of [naval mines](https://en.wikipedia.org/wiki/Naval_mine). Primitive sea mines were documented in China as far back as the 14th century, and the English used naval mines in the [siege of La Rochelle](https://en.wikipedia.org/wiki/Siege_of_La_Rochelle) in 1627. Sailors of that time would have at least heard about mines and the massive damage that they can do.
Your island will appear on maps, but the area around it will be marked as an active minefield. History books will tell stories of a conquered Chinese warlord who was banished to a inhospitable wilderness island, and kept imprisoned there by an impenetrable wall of the same sea mines that he used to torment his enemies. Minesweepers won't be developed for a very long time, so any remotely sane sailor would stay far away from the minefield.
Historical records of the island all say that it has no real value or resources of interest, *especially* not worth getting blown up over. Nobody has been dumb brave enough to verify those records, so you should be able to stay isolated in peace for quite a while. The notations on maps are accurate, so they won't draw any suspicion.
[Answer]
**A film projector to scare them**
(not an idea of mine, [the Beagle Boys already had it](https://www.comics.org/issue/14629/)).
Everybody knows that sailors are very superstitious, so you could use a film projector to cast some footage of monsters or ghosts on the cliffs or on some well-placed big blankets.
This should be enough to frighten the sailors and keep them at distance.
In orderd to keep the ships far, you could also use the same idea with some of your ships. You make them sail in the night and when you notice any foreign ships moving too close to the island, you project some scary footage on their sails. Ilarity ensues
To add to this, you can
* pay some people to tell frightening stories about the island in the taverns of the ports nearby
* fly a swarm of drones in the night. They should have some faint light and stay at a fixed positions around the island: the sailors would see some never seen before stars, which would confuse and scare them.
[Answer]
If you don't mind being distant from south east Asia, but within easy reach you could consider:
* [Norfolk Island](https://en.wikipedia.org/wiki/Norfolk_Island), off the east coast of Australia. Uninhabited
when the British rediscovered it in 1770 (Captain Cook). It was
occupied in March 1788 & turned into a penal settlement.
* [Lord Howe Island](https://en.wikipedia.org/wiki/Lord_Howe_Island), off the east coast of Australia. Uninhabited
when the British discovered it in 1788 while en-route to Norfolk
Island.
* [Montebello Islands](https://en.wikipedia.org/wiki/Montebello_Islands), of the coast of Western Australia. It is
close to Jakarta, or as it was in the 1600s, Batavia in the Dutch
East Indies. Similarly for nearby [Barrow Island](https://en.wikipedia.org/wiki/Barrow_Island_(Western_Australia)). Any islands north of [Geraldton](https://en.wikipedia.org/wiki/Geraldton) (latitude 28° 46 'S), in Western Australia, the Dutch would most likely have known about.
* [Rottnest Island](https://en.wikipedia.org/wiki/Rottnest_Island) might be a possibility. It was too far south for
the Dutch to be interest in. It was uninhabited when Europeans
rediscovered it in the 1600s. Nearby there are also [Carnac](https://en.wikipedia.org/wiki/Carnac_Island) & [Garden Island](https://en.wikipedia.org/wiki/Garden_Island_(Western_Australia))s.
] |
[Question]
[
In the school of fine magic, all magic teachers must undergo a course on forbidden dark magic such as witchcraft and voodoo curses and achieve a satisfactory result in the exam before they are qualified as a teacher. It is forbidden so they can only do theory but they must also swear never to teach their students anything on dark magic. Why bother getting into dark magic when you can neither use it nor talk about it?
[Answer]
This is quite simple... Teachers of magic are taught about the forbidden dark magics so that they will recognise when a student asks about or practises dark magic.
Every teacher needs to be able to recognise when a student is starting to head into forbidden territory, or worse, *has* strayed into the forbidden. How else would they be able to know when to discipline the students or deflect their questions that threaten to stray into forbidden territory?
[Answer]
**To counter a danger you must first know its nature i.e. what it is, what it does and how to recognize it. Only then, knowing that, can you fight it.**
So all mages are taught to at least detect and recognize black magic, including what traces it leaves when cast (both on the person and the place) and what counter spells are effective (or at least what basic counter spells are anyway).
This in turn means any mages deemed experienced and reliable enough to become teachers *have* to be exposed to dark magic, because otherwise they cannot teach others the basics of detecting black magic and protecting yourself and others from it. That said this 'exposure' is only done under strictly controlled circumstances by the most experienced/senior mages using dark tomes that have been seized over the years and then carefully secured out of harms way.
So the course covers the following;
* History of dark magic, its theory, symbology and tools (no dark tome required)
* Exposure to dark magic and its traces, (what it feels like). Tome required.
* Spell Types (Examples explained and demonstrated). Tome required.
* Detection of DM and counters to DM. This includes not only white magic spells but also common dark magic spells that DM practitioners might use to detect, attack or counter white magic practitioners. So basically both types of magic at the more common level. Plus importantly spells black mages can use to try and avoid detection (and how to counter those). Tome required.
Passing the course does not grant access to a dark tome. Only the most elite agents of the Guild or whatever tasked with policing dark magic get advanced training in all aspects of dark magic and full access to dark spells. And even then only under supervision and as required for specific missions.
[Answer]
## So-called "dark" magic is really just the fundamentals.
When you're learning how magic works, you need to learn how to shape and channel flows of woo. Woo flows through everything, so to learn how to affect anything you need to learn the rules for how it flows and how to affect it.
From there, there are some easy and obvious shortcuts, like killing things to use all their woo. The problem isn't that the "dark" arts are inherently dark knowledge, it's that direct application of any of that knowledge is evil. Most of the remaining curriculum is about how to avoid manipulating woo. That also lets you have white magic as the super-advanced learning that lets you manipulate woo in helpful, healing ways (like the difference between a gladiator and a surgeon: both know enough anatomy to put a blade in the right place, but the outcomes are fairly different. )
[Answer]
### Because you need to be ready to counter people who do use it and don't have your scruples or common sense
This isn't specifically for teachers, it's just higher-level magic. Consider it degree level, or black-belt level. Most people with degrees or black belts don't teach - but getting that degree or black belt is naturally a prerequisite for teaching.
I used to do a little jiu jitsu. Part of jiu jitsu is learning how to apply chokes, and as a student you also learn to tap out when you're in a choke and can't escape. But the brown and black belts occasionally practised fully choking each other out, because at that level you're working on skills beyond just what happens in the dojo, and your average pissed-up Friday night brawler isn't going to tap out nicely or let you tap out. The person applying the choke learns how to actually make it effective, how long you have to hold it on for, how to tell the person is out, and the first aid required to keep them safe when they're out. Meantime the person being choked learns how to process this mentally so that they don't panic and can respond when someone grabs them from behind in a pub car park.
The same applies here too, especially if your worldbuilding allows for combat magic. (And really, who's going to create a fantasy world with magic and *not* have magic duels?) The first steps in teaching anything dangerous are always very carefully judged so that the trainee doesn't seriously endanger themselves or other people, whether that's in woodworking, tree surgery, hang gliding, scuba diving, weapons skills, or anything else. Until the student can show they're working safely in a sandbox environment, they aren't ready to be let out.
And once they get to that level, they're ready to deal with the rest of what the real world can throw at them. Their basics are solid, but more than that, they've been drilled with a respect for how they can hurt themselves or other people if they screw up.
It doesn't mean people won't still dick around - drivers speed all the time in spite of being taught the dangers, for example. It's illegal, and you know you might be caught and fined, but it's mostly harmless and a good driver knows when it's safe. Mild witchcraft is likely to be the same - if you've got a problem with weeds in your garden, why not hex the plant so it dies, for instance. But if you accidentally hex the farmer's field next door, prepare for a big fine. So your magic users also need to be ready for clean-up operations when people don't use common sense and dick around without adequate skills. Hanlon's Razor still applies: Never attribute to malice that which is adequately explained by stupidity. Or more to the point, whatever someone could do intentionally, a suitably incompetent person could also do just by being a bit crap.
As with other crimes, there's a difference between minor accidents happening and major injuries or deaths. We already have many ways people can deliberately or accidentally kill themselves and other people. Magic merely adds another way to that long list.
[Answer]
How can you test bullet proof armor without also creating guns and bullets?
To use Harry Potter as an example, there is the Dark Arts as a subject. Defence against the Dark Arts.
One of the teachers demonstrates the 3 unforgivable curses in class. One of which is, basically, mind control. The Defense against it is having a strong will. How can you know how to defend against it without knowing about it and, possibly, practicing against it?
There are weapons we have that we'd never realistically use against each other. We have schools and scientists creating defenses against those weapons "just in case". How can you create defenses without learning about, researching and even creating mock - or real - weapons to defend against? How can you create a vaccine against a bug that doesn't exist? Bullet proof armor without having bullets?
So TL;DR: You have to know and use within controlled and safe circumstances the tools and weapons against which you have to protect against.
[Answer]
Magic is analogous to a computer system, and each spell is a program. Beginners know only how to use spells made by others, and beginner-level spells have a myriad of safeguards built in. More trusted spellcasters are taught spells without as many safeguards, and masters can write new spells. What the general public describes as "forbidden dark magic" are merely spells with no safeguards built in. Any master can make these "forbidden dark" spells, simply by leaving out the safeguards altogether.
Consider your basic "Cut Bread" spell. It functions by destroying all matter within a thin flat region, but has safeguards to ensure that it is only being used on bread. Those safeguards verify that the target region only contains bread, and shrinks the target region as necessary to avoid harming anybody.
The combat spell "Blade" operates on the same principle as "Cut Bread", but without those safeguards. It continually destroys solid matter within a narrow region, which may includes somebody else's body. It's a more dangerous spell, but is also much more efficient as it doesn't need to check the safeguards.
Master spellcasters can take this even further. Even "Blade" has some safeguards, to restrict the region of destruction and to avoid harming the operator. A master spellcaster could create a generic "Destruction" spell, with no safeguards whatsoever, which is limited only by the energy provided to the spell. These are the forbidden dark spells, which every master knows how to make, and every master knows not to.
[Answer]
# Dark magic requires you to tap dangerous forces and contract with deadly beings.
It's not just a matter of casting an evil spell. Curses tend to involve binding an evil being to a person to hurt them, and that requires negotiation with very dangerous and hostile magical forces that can hurt society.
Knowing the theory helps but it's not a very small first step. Actual dark magic requires contacting these beings and negotiating a price. This contact means a lot of higher level spell crafting with kinder and better entities is now impossible.
# If you start casting dark magic, you won't be able to cast the super epic light magic that requires negotiation with good entities.
As such, more powerful people have less incentive to go evil. They'd lose their most powerful powers, and it would require months or decades of negotiation to gain the same level of faction relationships with the dark side.
Do you want to be able to cast a boils on the penis of your enemy dark spell, or a spell that will resurrect a friend light spell? A spell to make your enemies have mildly bad luck, or a spell that lets you burn a village down with holy fire?
A student can go dark, and they'll lose nothing, except their lives when they turn evil. Teachers lose more. Teaching teachers the theory helps them keep student on the light side.
[Answer]
## Dark magic is the exploitation of mistakes - teachers must learn about it to teach students which mistakes are particularly dangerous
A dark magic user isn't actually much of a threat to people who use no magic- instead their power lies in the ability to corrupt the spells of others to do them harm.
Essentially, magic is hard: everyone makes small mistakes from time to time, and these mistakes cause your spell to do something that you didn't want, where the exact outcome initally seems random. For example, a student messes up when transforming a teacup into a cat, and the cat comes out with pink ears!
However, the unwanted outcomes aren't actually random: they depend on the exact magical circumstances where the spell is miscast, and these circumstances can be subtly manipulated.
Dark magic users learn to exploit these mistakes to make your spell do their bidding- instead of the cat just coming out with pink ears, this allows everything from stealing your thoughts to stealing your powers!
As a result, it is crucial even for a beginner to learn the kinds of mistakes that are exploitable by dark magic users, so that they can be much more careful about them. In particular, if a student makes a charm they intend to wear in public, it is wise to first show it to a trusted teacher who can check it for mistakes that would make the student vulnerable to any dark mage they come across.
(All of the above is true in our world if you replace magic with programming and dark magic with hacking. Real world computer science curricula have to make difficult choices about how to teach computer security while convincing students not to go practice their new skills against public websites)
[Answer]
**Dark Side is Built in**
Understanding **Magic as a system** requires a good knowledge of both white and dark magic. Studying dark magic is more than a purely defensive act, instead, understanding both sides, including the darkness is vital. As you complete your education, and go on to your professional calling as a sorcerer, watch out.
At the *elementary level*, it is known that a spell controls both a negative and a positive force like magnetism or electricity. At an *intermediate level* of magic casting, you may learn attack spells which require negative emotions, and it may take concentration not to let the take over. Human fight or flight mechanisms may be required for an attack spell, but also can push a spell out of control. Depressed or bitter intermediate magic users are dangerous. It gets worse. At an *advanced level* of magic, the power that is accumulated increases the temptation of going to the dark side and become a world eating super villain. "Absolute power corrupts absolutely."
The teachers have responsibility to keep the students safe, and also come up with good lesson plans that show the risks in each branch of magic.
The fine print:
Divination: Divination requires understanding of future problems so it has a dark side. Wanting to know the future on a low level may not have a big dark side, *will there be good food in the meal hall tonight? beans.* but consulting the fates on future problems can lead to visions of extreme darkness. \**What is the worse thing that will happen next year? demons will attack the school and possess the head teacher and you will die in the battle.*
Abjuration: Although it is defensive, magical barriers can pose dark problems, such as locking beings in magical prisons, or depriving people of their magic powers just when they really need them.
Enchantment: Tempting to give an artifact too much power.
Necromancy: Reviving the dead party members might be useful in certain situations but creating Liches and Undead armies can pose problems. Enough said.
Illusion: Sounds harmless, but illusions can blur the difference between reality and perception, such as creating a dense carpet of spiders or snakes - a gateway to madness.
Conjuration: When some giant demon arrives with a proposal to lose your soul it is probably a result of a conjuration.
Evocation: Evoking guardian angels sounds OK. If evoking Tidal waves, Infernos, Rolling thunder, or Whirlwinds, there are lots of possibilities for things going wrong.
Transmutation: Altering somebody into a goat or a frog for an hour sounds OK, but for longer it might be a problem.
[Answer]
# Forbidden Dark Magic Drills
First, let's hopefully try to lighten the mood a bit, because this is about to get dark.
Forbidden Dark Magic often requires specific materials in their rituals, or if cast as a spell, you need to use a wand - can't cast a forbidden spell just by speaking its name - you need wand movements and an actual wand. So when practicing the basics as a teacher to get familiar with what to spot, you simply don't use those materials needed, or make sure your wand is safely stored away; worst cast, you end up avada kedavra'ing your desk drawer.
So if you use scented candles (Or if those work as well, glowsticks) during a summoning ritual, it doesn't work, or if you use a lead bar as your casting implement, it doesn't actually cast magic out the far end. Teachers can learn what doesn't work, and practice a bit both to be able to spot others trying to practice the forbidden arts, but for additional, potentially darker reason.
## So, what happens if Forbidden Dark Magic is more commonplace than preferable?
A lobbying group in the magic community for the manufacturers of the materials needed for the forbidden rituals, and wandmakers, doubles down on the belief that their materials are not at fault. "Candles are a perfectly fine light source as long you're handling them safely" and "The only thing that stops a bad guy with a wand is a good guy with a wand" become known phrases among political groups in the Ministry of Magic in charge of writing the regulations on said materials.
Fire Drills aren't just regular drills in the Magic world - teachers are tasked with creating fake summoning ritual areas with scented candles or glowsticks out of sight, and if no student comes across them and repots them - or takes them down, they end up starting a controlled burn throughout the school, as kids learn to single file and exit the building, or cast fire extinguishing spells on reflex.
The main reason for the practical approach? Sometimes, actually Forbidden Dark Magic is performed at school by kids as a prank or by accident, and having to handle actual outbreaks of ritual summoning turns out to be a known source of danger.
As would Forbidden Dark Magic spells...sometimes there are actual Forbidden Dark Magic users on school grounds causing a whole lot of danger. So teachers are required to practice the timing of forbidden magic and incantations with lead rods instead of their spell casting implements so that they can simulate fake users, to teach their kids to learn the Unforbidden Lighter Magic spells that provide protection against these spells, or how to dodge said spells based on the reflexed of a teacher who's practiced and has reflexes prepared such that, if you can dodge the line of sight for a teacher using a Dark Forbidden Magic spell in your direction, you can dodge it in real life - or learn to take down the caster in a non-Dark Forbidden Magic way, to stop them from being able to cast the spell.
To that end, teachers need to know where the limitations are, specifically to prevent themselves from actually putting kids at harm - as well as potentially having practiced against lead bar targets so that they can evaluate if students would have actually gotten out of the way of someone casting Dark Forbidden Magic in their direction.
[Answer]
**Maybe the only (or best) way to teach Magic is by controlling a student’s mind, guiding them through the use of Magic.**
Similar to a driving school car or training aircraft with two sets of controls where the teacher can always take over if things get dangerous. Except in this case the teacher sits in your head instead of the co-pilot seat.
] |
[Question]
[
I am aware of [this question](https://worldbuilding.stackexchange.com/questions/55804/developing-a-government-that-can-hide-an-immortal-ruler-and-their-secret-to-imm), but I think my situation is somewhat different. In the low-fantasy setting I'm working on, the king is a vampire in a world in which vampirism is punished by death. But it is still appealing because vampires do not age. Vampires have a strong desire to drink human blood, and once they start, they usually cannot stop without killing their victim. It's not a biological necessity, but they suffer ever-increasing withdrawal symptoms if they cannot drink enough blood often enough. Like a reverse hang-over; it gets worse if they don't drink. The only supernatural advantage vampires have is their immortality. There are no exceptional abilities inherent in vampirism, though immortality allows one a lot of time to become extremely skilled and knowledgeable in many fields. There is no illusion magic he could learn to hide his appearance or immortality.
So it seems the king has two main risks to worry about. First is getting a steady, safe supply of blood. Second is avoiding suspicion; people are going to find it odd after a few decades when they notice their king doesn't age. The commoners are easy to fool, they never meet the king anyways. But the highest magistrates are another story. He can't simply avoid them, it's a feudal society and he has to delegate authority or he'd simply be overwhelmed. There just isn't enough time in the day for one person, even an immortal, to do everything. These magistrates are mortal nobles from the most powerful families, dukes and counts mostly.
So how does he maintain his secret with these risks in mind?
[Answer]
The idea of the king is immortal, the appearance of the king is unchanging. Because that's the mythos of the king.
### Replace the crown with a mask
The mask is the king and the king is the mask. The king is forbidden to publicly remove the mask.
If the king seems elderly or infirm, it is the solemn duty of a senior member of the court to challenge the king. The challenger is given a set of robes identical to the king and the challenger's mask. This is a Thunderdome grade challenge, two enter, one leaves. The body is disposed of within the Thunderdome. The one who leaves is wearing the mask of the king and is henceforth the king. It is forbidden to acknowledge which of the people who entered is the one who leaves. If the king takes too long to emerge from the Thunderdome, another may enter to check on them, however only one may leave and that one is the king.
The king is continuous, the king is immortal.
Such a system is begging for an actual immortal of some sort to subvert it, especially a vampire as it has a steady blood supply from the challenge.
[Answer]
## Every Decade or So He Poses As His "Son"
Every twenty to thirty years an old man "retires" from the public life, passing power to his heard-of, but rarely seen "son". The king does a good enough job at acting and dressing the part, and keeps his court at a sufficient distance that the amazing resemblance is dismissed as "strong Romanian genes".
There really is an old "king" and "queen" who retire. The actors playing the role of retired king and queen accept the sumptuous lifestyle the role provides, with the conditions that they don't give up the game. Portraits of the king in his "later" years are discouraged (or maybe family portraits are circulated with each "new" monarch). An actor betraying his role will be dismissed as having developed dementia.
There is a problem with the staff. Nobility, even in the present, have an ever present house staff : they dress the noble, bathe him (in some cultures), transcribe his conversations, read and dictate his mail, read books to him, prepare and serve his food, cook, clean, manage the financial affairs of the house, and manage the affairs of the extended holdings. In fact, the schedule of the staff - to a small degree - bind what the noble can and can't do.
A staff this intimate will pick out an impostor in an instant, and it would raise questions (and be difficult) to get on with no staff at all.
Instead, the "new" king brings in his own staff : all new hires. The former sovereign's home has it's own staff, who welcome the unfamiliar retiring king now moving into their care. It could be said that this is tradition to give the "new" king a clean slate to work with (and counters arguments of preserving tradition, with arguments of preserving this tradition). The retired staff will be provided an ample pension to live out the remainder of their lives, provided they continue to behave with decorum and confidentiality.
There are many children really raised in the household. They may actually be one of the queen's children, or a quietly adopted orphan. As is tradition, the plethora of children are in the care of individual nannies and tutors, and even close siblings barely see one another until adulthood. The children always attend a representative selection of the world's finest private schools.
The "heir" is, purportedly, one of these children. Maybe he was the little kid who looked so much like papa. Because even close family barely knew the non-existent heir, it's easy to explain a lack of recollection, because there is no troublesome heir to have to handle. Tutors are paid well to recall the boy - if anyone should ask. These arrangements having been made for in advance.
## Prisons are Nearby, Have Private Cells
In many aristocracies, there is a national prison either on the estate grounds of the king (Emperor Justinian), or very close by - within a few minutes walk. It is also not uncommon for tunnels to exist connecting buildings : such as the royal home and the prison. It would not be hard to imagine such tunnels (maybe several) exist in this kingdom allowing private entrance and exit from the prison.
What makes this prison unusual is how many 1-room/1-prisoner individual cells there are. The cells have thick solid doors, no windows, and are generally separated from each other by an unusual amount of distance. Line of sight is broken up by few narrow hallways, instead a bunch of poorly laid out, curving, labyrinth of halls with thick sound-soaking walls filling the gap.
It's certainly not uncommon for someone in antiquity to get a scratch and die from infection only a few days later. The inventor of sterile practices, Ignaz Semmelweis, suffered exactly such a thing in as modern a time as the 1850s. And mortality rates as high as 20% due to infection were also standard.
If a solitary vampire were prowling the deepest floors of this prison every night, and a single prisoner died every night, it would not raise suspicion. In fact, the guards and staff might think the lower floors harbor some kind of infection and intentionally start sending the worst of the worst into the "pit" to meet their end.
[Answer]
A few options I can think of:
## He uses a dynasty of puppets
If the vampire king is ruling publicly, he'll be caught after a few decades when it becomes obvious that he isn't aging. He needs some figurehead to rule for him. He offers another noble family a bargain: they get to become the royals and live lives of idle luxury, so long as they
1. Only give edicts and pass laws that he approves, and
2. Never reveal the secret of who truly wields power.
If you need a way for him to effectively bring about this state of affairs, the noble family could be his own descendants (if he can have children as a vampire) or he could adopt a child to claim as his own heir.
**edit**
As @Frauke points out, this situation is unstable as soon as any members of the royal family decide they want to *actually* rule. This is difficult to overcome, but not impossible. The trick the vampire king has to pull off is to make himself indispensable to their position. He could approach this in a number of ways, and might combine some of the below:
* Place himself at the head of a masked priestly class whose purpose is to uphold the divine right of the royal family, and without whose support the royals should be considered illegitimate and overthrown.
* Get them addicted to a drug he controls the supply of and for which withdrawal is fatal. He could also prevent them from knowing what the drug is, making it more difficult to find a way to subvert him.
* Force them to sign private contracts acknowledging that he is a vampire and that they support his power to control them, and placing these with some highly paid and trusted servant with instructions to reveal them if he dies. This would make it difficult to retain power in the event of his death (the king collaborated with a *vampire* to gain power??). Of course, it also introduces another person who might discover the plot.
## He changes his face
If your setting has magic that allows for it, he could also change his appearance periodically. This would still require that he has a dynasty as justification, but instead of ever permitting them to know his secret or actually take the throne, he fakes his own death, kills the next person in line, and then assumes the throne as his own heir.
**edit ii**
You've updated your question with
>
> There is no illusion magic he could learn to hide his appearance or immortality.
>
>
>
In this case, the only way he could do the above is if he can control the appearance of his descendants in some way. He might select a child to adopt on the basis of their resemblance to him (@James McLellan's excellent answer expands on non-magical versions of this) or, as @Mahab suggests, use masks to hide his true appearance.
## He changes the law
If he's an absolute monarch, he could simply change the law to permit himself to publicly be a vampire and rule forever. If he's not, he can still change the law, but needs to be more careful in how he goes about it; if he rushes things, the Parliament or other body might realize what he's up to and put a stop to it before he can complete his plans. In either case, he should probably start by breaking down cultural institutions and norms that paint vampirism as evil, gradually normalizing it before revealing himself to be a vampire. This could either be by aggressive control of religious/political/media leaders, or by providing ethical alternatives to forcible blood drinking such as blood banks (if you've got a higher-tech world) or voluntary blood donation. Perhaps make sacrificing yourself to preserve the life of the king a noble act? (The people don't need to know that blood-drinking is unnecessary).
Luckily, he's got time for this. As people become less and less suspicious of vampires, they'll also become less suspicious of a king who doesn't seem to age. If he can achieve this cultural transformation within about 50 years, he'll probably be okay.
[Answer]
First "people gonna find out". What people? Commoners don't even know the name of the current king (they are too busy being opressed by their immediate owner and trying not to get killed by influenza before they hit 25y old).
The nobles are nobles. You give them offer of wealth and not being turn into literall Bloody Mary and they will be more than happy to oblige.
If you don't want to disclose the fact at all just roll with regular, typical, native to almost all nobles - genetic impairment due to marying your cousins. The child is born, doctor say it's better to send the kid to better climate and for schooling, they come back only after the current king is "dying". And suprise, he have his father eyes.
Proof? The belowed, beatifull lineage of Habsburgs. They were so nicely vampiric and immortal that people didn't even think "wait, maybe it's just one guy?" but instead rolled with "ohhh, that must be the feature of all of them". And called it "Habsburg Jaw" instead "people don't die". Because you know you can't live forever so it must be something else. Oh well, they were of course accused of witchrafting but they were the kings. You just execute accusers.
Immortal one guy or many different people? You decide
[](https://i.stack.imgur.com/B9HcZ.gif)
[Answer]
**Your vampire king is a beneficent supporter of healthcare with an elected council.**
Basically, your ruler has two problems;
1) Access to Blood
2) A ruling class that expects to be around him long term
Dealing with the blood issue first, your king takes a keen interest in the health of his subjects, meaning that he is patron of several of the hospitals in the capital. He gets regular tours, but also expects the run of the place so he can see the unedited truth of the state of health care in his kingdom. He wants to promote medical research, etc. and ensure that his subjects are going to get access to the best care possible, no matter how forlorn their chances are.
This means that he has a de facto warehouse of terminally ill people and others who are expected to die of natural causes on whom he can prey with little suspicion. So once every couple of weeks another old person or person with cancer dies - it's all part of the circle of life, etc. And in reality, the net benefit of his patronage is going to be high so if he wants to preside over last rites or something with some of the patients, all that really means is that he cares, right?
Right?
As for the magistrates et al, your king has a treat for his subjects - democracy!
Well, not real democracy as that would kind of defeat the purpose, but I'm thinking that he introduces a form of parliament that acts as his court and provides him with advisors, magistrates, administrators and the like, but instead of coming from the nobility, they are term-limited elected officials. The rationale behind this is that he needs renewal of ideas and a limit to the amount of corruption among the adminstrators of his government, and that it breaks the classist structures of society so that the individual on the street feels represented in his interests to the king and has a real say in the influence that is brought to bear on the king. The king is not obliged to follow any of that advice of course, but at least the common voices are heard.
The term limits would come in the form of epochs - say 10 years. After each block of 10 years, all positions are spilled and incumbents or former incumbents cannot stand again. Once every couple of epochs, the king is 'replaced' by his son, who has been mentioned in dispatches and no-one is any the wiser.
To that end, your king can rule for hundreds of years if he's careful, gradually building up the persona of the next generation and allowing for the steady abdication of himself to that new persona at regular intervals. The subjects get superior healthcare with a mortality rate from hospital treatment that never quite drops to zero, and the people are given an opportunity to participate in the machinery of government in a manner that is not determined by their ancestry. This would encourage good educational standards, and eventually you may well even get a society sufficiently enlightened that they repeal the death sentence on vampires.
That might not help your king of course as not being killed and being allowed to hold high office are two VERY different things, but ultimately a well educated, well cared for populace is ALSO your best defence should your status as an ex-human ever be revealed.
[Answer]
Frame challenge from *"in a world in which vampirism is punished by death"*:
### Why should a feudal monarch care about that? Who can punish the king?
A feudal king is not just above the law, but he *is* the law. Henry VIII is a great example of this. When he wanted to do something which was explicitly illegal and immoral at the time (namely divorce), the only people who had any kind of power to oppose him were religious - so he changed the law for himself, and created laws which broke his opponents' power. If anyone spoke out, they became victims of judicial murder. The fate of [Thomas Cromwell](https://en.wikipedia.org/wiki/Thomas_Cromwell) demonstrates how anyone in society could be executed without trial at the king's command, simply because the king chose to do so at that point in time.
The only realistic internal check on a feudal monarch is mass revolution. As usual, lords need to be kept sweet, and the peasants need to be not excessively oppressed. A monarch who can manage that has basically no internal enemies, and hence no real opposition. If the king is incompetent, of course he deserves to be deposed anyway. But a competent king (and a long-lived vampire should have longer to learn the lessons of statecraft) can avoid that happening.
Of course there may be external threats, from other countries who discover the king is a vampire. Henry VIII and Elizabeth both faced real existential threats to their country from the combined Catholic states of Europe. Again though, a competent king ensures his country is adequately defended. With no time pressure to "make his mark on history", a vampire will not feel the need to embark on expensive military campaigns abroad, which will make his country generally more prosperous and improve his popularity, and the money saved can be spent on defences instead.
### And why only the king...?
If vampires are well enough established to have laws against them, there must be more of them around. A cluster of vampires could run things more efficiently. With a selection of natural abilities and aptitudes, they would appreciate that each brings something to the table, and that they are stronger together than separately.
One vampire becomes the nominal "king" for some period of time, and the others pose as his lords. Every so often, the king "dies" and is succeeded by one of the lords. The new king then appoints another lord - who looks surprisingly similar to the old "king". This would likely be enough to avert suspicion from opponents, or at least give enough plausible deniability that they could not act on any suspicions.
[Answer]
Could your king hide behind some kind of mask whenever he is out in public?
This could easily be spun as some kind of cultural custom where the common people are not 'worthy' to gaze on the king. So they see him through a mask or veil. Perhaps there is a veil in front of the throne room? This would lead to a certain mysterious aura about him sure but most people would put it down to megalomania and not that hes a vampire.
A mask would mean he could still go around publicly without fear of being caught out, though he might have to use a stick - walk a bit slower, and hunch a little as he got older to keep the illusion going.
I dont see how he could keep it from absolutely everyone though, as there would be times when he would need to take it off and may need help with this. But surely a select few people he trusts could be a party to this information... and some who he has leverage over?
As for the blood issue, what is the religion of his kingdom? Could there be a weekly/monthly sacrifice to appease the gods... the sacrifice is carried out by the head of the church (our vampire king) behind closed doors, as a sacred duty.
[Answer]
**The king has genetically identical sons and daughters.**
Each time the king has a child with one of his daughters, the DNA of the kings original wife from long ago is diluted. The result: his current children have almost the same DNA as the king. The king of this country often dies in battle, publicly and bloodily and is buried. Often the king is (apparently) too old to be fighting but it is a tradition in this country that their kings die in battle. Being a vampire, he is of course not dead. One of his sons becomes kings and shortly thereafter the king leaves his grave and takes the place of his son, with fresh styles and new hair, and continues on.
As regards drinking blood, the king sidesteps the loss of control by having blood brought to him. Certain medical patients with an excess of humors benefit from scarification and bleeding. To prevent vampires or witches from getting this blood, it is brought to the castle and safely disposed of in a central location. As it turns out this is the king.
[Answer]
If vampires exist, then it's possible that religion does too.
The king could say that as king, he is head of the church, and as proof of that he has been granted especially long life by the gods (or possibly even claim to be a demi-god himself, which also has examples in history).
He would need to build up a sort of cult of personality like the Kim family in North Korea, in order to keep his immediate subordinates in line, while at the same time, keeping them happy (i.e. we're going to be well off as long as he's king, so why question it?)
[Answer]
Blood supply is simple: Sometimes, irrefutably guilty criminals - convicted of the most heinous crimes, and condemned to lifetime imprisonment - die while in prison. That is, after all, why it is called *lifetime* imprisonment. Some of these prisoners just happen to be granted a private royal audience first.
How frequent this is would depend on how long the withdrawal symptoms take to build up - if feeding is only required quarterly, or annually, then I suspect the King would weave some narrative of ritual or tradition around it for the benefit of those courtiers "in the know" - arrange it for an equinox or solstice, and imply that it is necessary to "maintain the strength of the kingdom" or something.
Disguising himself will vary based on how old he appears - simplest would be if he has the appearance of a young man, mid-twenties to early thirties. He makes sure to always wear a mask for official duties - the ceremonial garb is what people think of as "the King", identity is shown through a signet ring used to seal documents - just like the royals of old, or the Pope.
Next, the King is not married, he is "raised from the people" - adopt a young orphan boy (or several, to have spares in case of illness or accidents) who are raised (separately!) as the "future ~~Batman~~ king", and *occasionally* seen out-and-about at court. They are raised by servants, well educated, et cetera. As they get older, they are seen out in public less frequently - or, at least, only when wearing masks themselves.
When these "Princes" are of an age that the King can pass for one of them, the King "dies". The body given the funeral is actually one of the "Princes" - the same one who is declared the "new" King, and publicly takes up the mantle and garb. The other Princes are either elevated to nobility, or married into existing nobility - minus, of course, any who have course to suspect the scheme and instead "die of heartbreak, at the passing of their beloved Father"
[Answer]
**Blood Supply:** This is relatively simple. The vampire king must have some accomplices. These people can be criminals or whatnot and their job is to make people disappear. I'm also guessing that the king has access to a (secret) dungeon to satisfy his needs and dispose of the bodies.
**Longevity:** Although I like all the answers so far I cannot help but notice that they are ephemeral. The king can extend his rule for decades (maybe a few centuries) but ultimately he cannot rule forever. The longer he plays this game the greater the chances of being discovered. So, if I were him I would try to come up with an ultimate, long-term plan. Maybe he's exporting money to a nearby kingdom so that he can fake his death and move there a new and rich citizen. Maybe his plan is to change the people's views on vampirism (amazing things can happen in 100 years), etc. However, he cannot "realistically" stay king ***forever***.
[Answer]
So there are a number of individual issues that have to be addressed, each one with its own set of plausible solutions.
**1. Long-Term Goals**
There is the question of ruling forever, but will this king want to? When you are basically ageless, the perspective of time most likely changes. So in say 300 or 400 years, will the king still want to rule? Can the feudal monarchies in your world survive that long and will he want to be a part of the political revolution that follows or at point will retiring filthy rich to an island be the goal of the day? That or sneaking out to avoid the revolution
It may not be part of the question directly, but the length of time he plans to rule combined with his personality will influence what kind of plans and preparation he will be willing to undertake to maintain his rule.
Is taking a few decades off and letting another house rule in order to travel to pursue knowledge part of his plans or will he want to be on that throne for as long as he is able to be?
**2. Laws against Vampirism**
>
> In the low-fantasy setting I'm working on, the king is a vampire in a world in which vampirism is punished by death.
>
>
>
Who has made this law? The global religious order, the king (or a previous one), or a coalition of monarchs?
Depending on the monarchy style, then the king will have the power to arbitrarily change the laws to suit his needs. Of course there are the lower nobles that administrate his lands and might object to such a radical change of laws through revolution, or accusations of vampirism because of such a sudden and drastic change in laws. So slowly changing the laws are still the safer order of the day regardless of his effective power. Should the king's laws have to go through a parliment that has actual power, then it is trickier, but again the slower approach has a higher chance of success.
The end goal would be legalization of vampirism outright, but even arranging a change of laws so that vampirism is not outright illegal while a vampire provably killing somebody is punishable by death is a lot of breathing room because at that point, the law can't kill your for existing. At least not directly.
**3. Blood Supply**
>
> Vampires have a strong desire to drink human blood, and once they start, they usually cannot stop without killing their victim. It's not a biological necessity, but they suffer ever-increasing withdrawal symptoms if they cannot drink enough blood often enough.
>
>
>
The key word here is "usually" -- it implies that with enough self-control, a vampire can end up not killing their victims. If the king understands his condition enough to know how often the desire needs to be fed, and how much blood can appease it, then he could theoretically keep it fed to a point where a few most trusted servants are fed upon nonlethally in their sleep. However, that would lead to people questioning things which could be a Bad Thing if he is caught or a retainer objects.
Another possiblity not previously mentioned is that the king moonlights as an executioner or acts as one under special circumstances. Death by exsangunation for feeding purposes followed by a swift beheading to hide the evidence deals with both condemned criminals as well as the king's hunger. The beheading also conveniently prevents the now dead body from rising and if chopped in the corrct place can hide the fact that there are/were fang marks on the body.
Naturally, the king's executions are done in private. The official reason is to keep certain criminals from gaining fame and popularity at the headsman's block as a martyr. An alternative reason is that the condemned do not deserve a public death. The real reason is of course to hide the blood feeding before the actual execution.
An interesting thought might be that the king is the last point of appeal with a lethal twist: The loser of the appeal has a date with the king's fangs in private for wasting his time. This will only be for people making the appeals -- it would have no bearing on items brought to the monarch directly.
As stated, a more modern king will have access to a blood bank for a rare (and heriditary) medical condition. While it not fresh from the vein, it is still human blood, and so long as he is not demanding the best of the best, there should be no problem using the most common blood or something equally plausible.
**4. Avoiding Suspicion**
>
> [P]eople are going to find it odd after a few decades when they notice their king doesn't age. The commoners are easy to fool, they never meet the king anyways. But the highest magistrates are another story.
>
>
>
This is the larger problem and has been covered better by other people so I won't really touch this concern too deeply.
One thing I will observe is with enough time, your king will more likely want to be known as a sagacious ruler as opposed to a battlefield conquerer. He will have had the potentially extra decades to accumulate knowledge and wisdom. This is not to say that he will shy from war when needed, just that it will not be his primary method of consolidating power. Also, a war might even be a good time to plot faking his own death and being his own successor.
Makeup and hair dye will be the kings best friend in appearing older than he is. That and acting skills. As there are no special benefits to his immorality aside from the agelessness, then that should be sufficient.
If he has perfect recovery, as in he is immune (or highly resistant) to infections and other non-violent means of sickness or death, then extoling that as a divine blessing or gift could be the way to go.
[Answer]
He is immortal because he is blessed by (the) God(s).
Why looking for a new solution when there's already one existing ? ;)
For his hunger he will declare that all the judgments in the country have to be done by him because he is the direct envoy of God. Then have the prisonners be locked in individual cells for interrogation and it's done.
[Answer]
## Incorporate it into the religion
You're not just a king; you're a priest-king. Your dictates, at least those made in ceremonial court, are not just human law, but they are also divine law. Your unusual longevity is not against the law, because it is a gift from the diety, obeying a higher law, just as the orphans you consume are not innocent victims but exalted devotees, who will be richly rewarded in the afterlife.
[Answer]
I would argue that he doesn't need to hide his immortality, in fact, that would make people more readily willing to follow him, especially into battle. ("Wow! Our king just took twenty arrows to the chest and shrugged it off! Those guys are so screwed!") He could certainly argue that his Divine Right to Rule is self evident by the fact that God (or some other entity) has not yet saw fit to kill him.
As for concealing Vampirism, a permanent war would provide him with the opportunity to lead his troops into conquests, drinking the blood of his foes during daring night raids.
Also, which rules of Vampirism are we following? If this guy is like Dracula (from the book), then he can absolutely appear during the day (which most people would take to mean he is not a vampire), provided that he is back in his "box of dirt" from either dawn to noon or noon to dusk. Bram Stoker doesn't ever consider what would/does happen should a vampire fail to do this, (as Dracula tended to despise the day anyway) but you could. Even if anyone did discover he was a vampire, he could easily make them submit to his total control, like Renfield.
If this guy follows the Nosferatu (silent film) rules of vampirism, he still gets the Renfield-esque abilities to control people and certain animals. He just can't appear during the day. Perhaps he could explain it via his sleep schedule, (all the night raids tire the king out) or he busy dealing with "appointments."
I recommend looking up the vampire Barnabus Collins, from the soap (not the movie) Dark Shadows. He is able to successfully conceal his vampirism for many seasons, although he is found out by a witch.
] |
[Question]
[
The Illuminati, Men In Black, NWO, Lizard people and various other secret organisations exist in my world, and for some reason (probably related to plot) they all favour having ‘hidden’ floors in tower blocks. The basic idea is that you walk into an elevator with X floors, punch the right buttons and end up on the X+1th floor (where the secret headquarters are).
Of course, it would miss the point of being in a high rise building if the headquarters didn’t have windows, but it would also miss the point of being secret if a third party could spot the fact there was a secret floor by simply counting the exterior windows.
What architectural tricks can be used to hide the fact that a whole extra floor exists from the outside of the building?
**Restrictions**
1: There must be one more floor than is recorded (architectural plans can be altered after construction), so no disguising the Secret Headquarters as another company.
2: All floors must have natural lighting and a view out over the city. Bonus points if you can achieve natural ventilation as well.
3: The number of floors visible from street level/adjacent buildings must match the number of floors recorded. More sophisticated methods of surveillance (thermal imaging, satellites etc) are not considered here.
4: No skyscrapers/all glass construction. Secret societies have a certain brooding monolith aesthetic that needs to be upheld.
The best answer is the simplest, most plausible way to hide the extra floor. As always real world examples/tricks that are already in use are encouraged.
[Answer]
The easiest places to hide an extra level are **the bottom and the top**. You can have all the subbasements you like, though they come with neither a view nor natural light. Either of these can get written off as maintenance levels.
You've excluded full glass towers, but **dark glass towers** hide their floor count better than clear glass, also having a dark tower looming over your area does carry that brooding monolith aesthetic that you're after. (They clad my local one in something more friendly recently).
The US is famous for not having **floor 13** in many buildings, so that's vacant for your uses. People will see 80 on the lift, they'll count 80 and be happy.
Speaking of counting 80, the **off-by-one error** is your friend here. US buildings count from 1, Britain counts from Ground (0), if you put the building on enough of a slope you can have LG, G and UG before you start numbering them and the count on each side differs anyway.
Buildings of irregular shape have issues with window cleaning. Images of the Shard in London show robot arms sticking out at various levels for the window cleaners. You could close entire floors off as maintenance levels for heating/aircon/window cleaning without the day to day occupants blinking. Even easier is rather than having entire secret floors, you close off half a level.
**Double height auditoriums** also give you an excuse to close off the rest of the upper level of a pair. They'll know there's one on a lower floor and accept a level being missing above it.
*You have so many secret organisations going that it's probably easiest to put apparent high ceilings on the outside, lower ceilings on the inside and have a secret floor on every second storey.*
[Answer]
**The rooftop**
What everyone knows that on the roof of every modern building there are a couple other boxes of stuff and an assortment of pipes connected to them. The AC, the elevator motor, the brains of a solar cell array...
What everyone knows is that those are typically not visible from the floor level.
What everyone knows that those boxes don't count as floors even though they can are big enough to house humans, and have a means of being entered by humans. Sometimes it's a locked door on the top floor with a rickety staircase that leads there. Sometimes the elevator goes all the way up to the engine room. Most likely both.
What people don't realize just how much stuff you can hide in one of these cubbies. An elevator engine takes up a lot of space. Sometimes the engine room is in the basement, rather than on the roof. That doesn't mean it can't have a rooftop engine room anyways - devoid of the actual engine assembly, of course. Instead, there's a spacious conference hall, open windows (opaque from above, thanks to special lensed glass, and hidden by the roof lip from below), walls of TV screens, perhaps a "service" door (or a retractable wall, be it for extra secrecy or just fanciness) in case the leader wants to take a rooftop walk, what have you.
[Answer]
Does the floor really need to be 'hidden'? I used to work in an office tower where the entire fourth (I think) floor was dedicated to machinery. I don't know what kind of machinery they needed an entire floor for. I think it housed the climate control stuff, and perhaps server space. This floor didn't have windows, but there's no reason why such a floor couldn't have windows for architectural reasons. I didn't find that floor strange, and I never heard anyone else about it.
[](https://i.stack.imgur.com/nQV43.jpg)
It's the second floor of the tower section, with the big grills for (presumably) the HVAC clearly visible.
Although now I'm thinking about it, it might have been just this hidden society floor, of course. This was a bank, so that would be the secret meetings of the elite to control society. Wait, that isn't actually secret...
Thinking some more, do you actually need a hidden floor? Any self resprecting big company has some top floors for the directors only, where the underlings are not allowed to come. Nobody questions that. Any self respecting secret organization will have one or more front companies readily available.
**edit**: I should've just [wikipedia'd](https://en.wikipedia.org/wiki/Mechanical_floor) it of course. That page offers many ways to hide secret floors in plain sight:
* "As a rule of thumb, skyscrapers require a mechanical floor for every 10 tenant floors (10%) although this percentage can vary widely", so just vary that percentage, and use some extra "mechanical floors" for secret meetings.
* Some types of buildings require outrigger trusses connecting the building core to the external shell at regular intervals for structural stability. If those are more than what's actually needed for mechanical floor space, there's your secret society floor.
* Sometimes the mechanical floors are clustered together. If you pair the mechanical floors and give them a lower ceiling height, you can add a third floor, while making it look on the outside as if the mechanical floors have an extra high ceiling height. Apparently that's just normal.
[Answer]
# Windows spanning floors
If you pay $$$, you can have single panes of glass spanning floors. These do not have to all be the same height. Let’s say a side of building is 5 windows wide. On first floor, have windows that are 8’, 10’, 11’, 7’ and 9’. As you go up the building, shuffle the window sizes around randomly, just picking sizes so they add up to the same amount in each column when you reach the top. Anyone outside the building cannot count floors just by looking at glass. Inside the building, it gets hard to be sure whether a given floor outside has the right place inside.
The weakness will always be someone measuring the height of your building and dividing by X, where X is standard floor height, but you can cover that by cribbing a few inches from each floor over the height of a tall enough building.
[Answer]
### A pyramid of penthouses and tilted windows.
Have a big building as tall as you need, and then put penthouses in a pyramid at the top:
```
+-------+
/ \
+-+ +-+
/ \
+-+ +-+
/ \
+-+ +-+
| |
| |
```
You cant see them from the ground. You can put "penthouse" in the elevator buttons and rent one of them out, all the other floors can be secret.
By tilting the windows upwards it can reflect the sky. That's a good way to make the interior of the penthouse very difficult to see and examine from anyone up high. It also makes it difficult count windows from close up.
A high atrium in the public penthouse could explain the additional height to the casual observer.
[Answer]
This may not be as hard as you think.
Most large buildings are divided into offices. With a little bit of cleverness, you should be able to arrange that some chunk of a floor is simply (but not obviously) inaccessible via normal means. Put such an area above and/or below a double-high floor. Make sure it's *obvious* that the double-high floor exists so no one questions why there isn't an elevator stop for it. Then tuck a small stairway or ladder right next to the elevator on the floor that "doesn't exist". This gives access to the otherwise inaccessible area of the floor you carved into bits.
Of course, in modern buildings, do you even need to bother to hide it? Just set up your building security so that only employees of an office can go to the floors of that office.
[Answer]
I'm reminded of an old puzzle: Robinson Crusoe found a regularly-perforated hatch cover, and by some clever sawing made it into a solid table.
I think that in practical terms, if every "floor" in a building actually comprised several areas of slightly different elevation with ramps or a few steps between them, and if the external windows were similarly irregular, it would be possible even using fairly old techniques to make the appearance of the building so confusing that nobody could work out what was in it.
Or there's always the Trump way...https://nymag.com/news/articles/shortlist/trump/index.htm
[Answer]
Build plenty of utility floors. In reality part of each utility floor is your secret headquarters. When you make your plans the space that will become the secret space is occupied by stuff that's going to be easy enough to remove after construction is complete.
The inspectors will not see anything wrong during construction and since it's a utility floor people aren't going to be wandering around.
I don't believe it will work, though--they'll be located by traffic analysis.
[Answer]
Another answer. Does the architectural codes require the windows to be organized in a regular pattern? If the building is in a style with lots of windows randomly spread over its outside walls there's no way to deduce the number of floors from the outside. In fact any regular pattern would also do as long as it is not bound to the floors.
The thumbnail image of this video might be an inspiration:
<https://www.youtube.com/watch?v=bkzhsnjZKAQ>
[Answer]
Just use British level numbering when building and for the plans and door numbering and elevator controls, and American level numbering *only* for floor number as displayed in the elevators and on the ground level. It will take *DECADES* before people notice the discrepancy, and locate your Evil Empire one floor up from the ground.
British Building:
fifth floor
fourth floor
third floor
second floor
first floor
ground floor
American building numbering, ***for THE SAME BUILDING***
fifth floor
fourth floor
third floor
second floor
**YOUR SECRET BASE HERE**
First floor == ground level floor
[Answer]
This doesn't meet all of your requirements, but I would ask you to reconsider the need for people to be fooled about the number of floors. Rather, we can hide in plain sight by fooling people about the layout and contents of those floors:
1. For example, a huge luxury hotel with amazing luxury suites on the top three floors. Several different reclusive billionaires end up renting all of the suites on the top floor on a pretty-much permanent basis. You need to use a guest card to take the elevator to the top floors. HQ goes there. The recluses of course need their minions, who show up every day...
2. You could also do this with penthouses in a very exclusive condo building. In both cases, the floor isn't hidden, it's broken up into units in such a way that people don't think about it as a large office area.
3. If you insist that the floors be "hidden", I'd think you could still take the top N floors and build a conference center, theme park, or some kind of area that would have a large auditorium in it. There would be "fake windows" to keep the look of the outside even though the Auditorium is a black box with no windows. "Looking at the top floors, you can't even tell that there's a huge no-windows auditorium up there. The architects cleverly placed fake windows in the same pattern as windows below." A "four-story-tall" black box auditorium will be extremely hard to see in perspective. It could easily be three stories tall with fake catwalks, ducting, etc, and since it's all dark up there -- painted black actually -- with lights shining down to blind you, who would know there's an entire office floor up there?
4. Or have the top two floors be HVAC and surrounded with huge LED video displays that play ads, etc. What looks like a solid panel of LEDs from the street would actually just look like a grid from inside, and the brightness of the LEDs would keep people from having a clear view behind the lights. Have a super-efficient HVAC system that only occupies the core of those floors -- which you would immediately see if you managed to get to that floor on the elevators -- and the periphery, with it's nice view, would be yours.
In the last two cases, people would know that the floors are there in some sense, but you'd fool them as to the contents and from the inside it would be very difficult to tell any different. In addition, it would provide the excuse for a variety of different people showing up.
And ultimately, what better place to hide a super-secret HQ than in the brightest and most visible spot in the city? Hide in plain sight.
[Answer]
Here's what I would do: instead of having extra floors, just have the elevator open in both directions, then on one floor, using some magic key or whatever, it opens in the other direction where there's a hidden compartment or room. The nice thing is that that is much less conspicuous as it just looks like the elevator shaft is a little larger on one floor. In fact, hidden rooms aside, this would make a great "maintenance area" in any high rise, since it's easily reachable, yet out of sight as well as it has a nice security door by default.
[Answer]
Take some lessons from the Bar Convent in York. They wanted to have a church (and a convent) in a time and place where they suffered persecution.
From the outside, it just looks like a regular flat-topped building:
[](https://i.stack.imgur.com/C8v2W.png)
At the top, on the inside, there is a domed chapel:
[](https://i.stack.imgur.com/DNlkL.png)
Observe the natural light from the large windows, and the natural ventilation. The key here is that the uppermost section is not adjacent to the street. A person looking upwards from the sidewalk can't see the centre of the roof, and by measuring the angles exactly the builders were able to make sure that no-one could actually see the dome.
For your secret society, then, the key may be to make the top level of the building a dome or pyramid so that it slopes away from the street and can't be seen by passersby.
[Answer]
* Remove that floor from the lift/elevator control panel, so the lift goes from
20 to 22 but floor 22 is labelled as 21. May need to finangle the car speed to make it go faster across that gap too. And will have to have trusted elevator technicians.
Bonus points if you hide the floor between floors 9 and 10, and call it 9&3/4.
* Disassociate the external cladding pattern from the floors. You could have windows that span 2+ floors, but this might be noticed, so have windows that are only ~13% of a floor height, but 7~8 of them per floor. Would have a "wood-like texture" to the outside.
If you want to forgo hard science:
* add a "magic portal" in the back of the lift-car that can be accessed by a secret button, or by dialling a special number on the button panel.
* Use a TARDIS as your lift car, so the entire secret area is inside the "penthouse" liftcar.
[Answer]
Everyone can judge the size and volume of rectangular boxes; few people can judge the size and volume of curved shapes.
E.g. Saint Paul's Cathedral in London has an inner and an outer dome; the space in-between contains the actual load-bearing structure, the shape of which architect Christopher Wren thought was much less attractive than a spherical dome. When you visit the building, you can't really tell from looking at it that the interior and exterior dome aren't one and the same.
[](https://i.stack.imgur.com/9GkVV.jpg)
When you visit St. Paul's Cathedral, you can go up into the space between the domes. I'd recommend it to anyone visiting London.
[Answer]
# Televisions on the real floors
During daylight hours, it is very hard (bordering on impossible in recent years) to tell the difference between a modern TV screen with smaller-than-human-perception pixels showing an outdoor scene and an actual window. Floor X+1 can have real windows while floor X has screens. Cameras outside the building provide the feeds.
You’ll have to make sure the real floor empties out before sunset — true black pixels are nearly impossible to get right, and your subterfuge will be uncovered.
If you have control over the design of the real floors, arranging furniture to keep people from pushing up against the glass can make the illusion even easier to maintain.
[Answer]
Build the building on a sea cliff, and hide the extra floor at the bottom of the building. You can still get plenty of light in. Have dark glass extend beyond the bottom of your extra floor, and it will be difficult to tell where the floors end and where it becomes your 'architectural feature' glass at the bottom. Add in that the sea stops people getting too close to see in, and it should keep your society hidden.
For extra confusion, number it from the first non-secret level as 'ground' with the main entrance on the nth floor, whatever the top of the cliff comes out as.
[Answer]
I think you could make good use of the 'maintenance floor' idea. For example, there is a state-owned office building in Richmond VA, the Monroe Building. From its Wikipedia entry: "137 meters (449 ft) and 29 floors. Only 25 of the floors, however, are actually occupyable as the top and middle two are maintenance floors." It looks just like a perfectly ordinary skyscraper (by Richmond standards), and it has what appears to be a band of some type wrapping around the middle couple of floors, the maintenance floors. Nothing suspicious or odd-looking about it, and no reason for anyone to enter them. You could use something like this to hide in plain sight.
[Answer]
Consider turning the space vertical.
What if one corner *of each floor* of the building was sectioned off from the rest of the floor on each level, to put space for a stairwell and office. People could enter through some fire stair door. Each floor wouldn't have much space, but it could be as tall as fit person could climb.
If the rest of the floor was divided diagonally into two different office spaces for two (or more) different tenants, each tenant might reasonably conclude the other had the corner space that they didn't.
---
With many of these proposals, I don't think it is the general public on the street or the other tenants in the building that are going to be the problem. It's the trades-people. The plumbers trying to trace the source of a leak. The fire inspectors staring at the plans, wondering why they haven't had access to some areas. The electrician wondering if they can run cables through the cavities. The junior at the architecture firm blagging to their friends about what they designed.
[Answer]
Have several buildings connected to each other but they are all at slightly different heights. This causes things like floor 2 of one building to be at the same level as halfway between floors 3 and 4 of another. Your "hidden" floor is explained as you skipped a floor number in one building to keep the numbering more consistent between the different buildings. You can even say the floor does exist but its just structural, again to try and keep the floors in the different buildings more in sync.
[Answer]
Instead of using clever architectural tricks like fake windows, you can instead hide the windows on the floor by large advertisements on the outside wall of the building. Any person who will try to count the number of floors will just see the advertisement, making it very difficult.
[](https://i.stack.imgur.com/m1yNY.png)
[](https://i.pinimg.com/originals/75/8f/74/758f748650406e121d5406cd8287efea.jpg)
] |
[Question]
[
In a world where people have advanced robotics and A.I. to the point that most people can just have a machine do things for them, is there any reason for slaves to be used also?
Obviously nobody needs slaves, you can operate farms and factories with paid labor or robots. Not to mention just doing things yourself. But aside from the robots, those options have existed since the invention of money. But slaves were kept anyway.
The only benefits I can currently imagine it gives is that you can capture your own slaves rather than pay for expensive robotic solutions. Or an owner may just want to dominate people and their slaves can't object.
In this scenario slave ownership is illegal. But that doesn't ever stop it in the real world. Here in the U.S. slavery has been illegal since 1865 but that isn't stopping people today.
Is there some other possible reason that an individual or corporation might seek and own many slaves when they could get the job done with legal means?
Alternatively, is there a job slaves could do that wouldn't be possible with robots or legal workers?
[Answer]
One of the ultimate signs of wealth is being able to command services from other humans at your whim. The ultra wealthy have maids, pilots, cooks, drivers, guards, etc. and even if these jobs could be automated, there's still a feeling of power that one can derive from commanding others who are like you, and it's a sign of power to others.
So, some hypothetical reasons for having slaves despite it not being fiscally wise:
* **It's fashionable.** In high society, owning slaves is expensive and training them well is a sign of status, despite machines being able to do the same jobs better
* **It's traditional.** Certain traditions really don't want to die. Maybe, your empire was built upon the idea of conquering other peoples, and slavery is just a holdout.
* **It's fun.** Some people enjoy ordering other people around. Slavery is just the ultimate level for a control-freak, and for the twisted, it might be a way to indulge reprehensible fantasies
* **It's punishment.** Denying the free will of another sapient being is arguably the ultimate form of punishment, potentially even worse than death. Slaves are held as punishment for crimes (although what constitutes these crimes can be very flexible)
---
*Note: I shouldn't need to say this, but this answer in no way endorses slavery. Duh.*
[Answer]
**SEX TRADE:**
*(and assorted criminal activities)*
I hate to point out the obvious (ok, that's a lie; I LOVE to point it out) but most of the slavery in the US not linked to sweatshops is in the sex trade. Even with AI and fancy machines, there's something about a real person you can't quite get right, and the harder they try, the weirder it seems.
The same rule generally applies all over the world. People and their base instincts don't care what is or isn't illegal - they don't even seem to care what others DO or DON'T want. They just want it. It's so prevalent, they have a separate term for it - white slavery.
While this applies mostly to the sex trade, any criminal operation will be likely to employ involuntary labor - either through actual imprisonment, complete control of dependent people (like often happens to illegal immigrants) or substance abuse (like working for your dealer to get drugs). A computer and a robot are nice, clean, efficient ways to get work done, but evil or criminal work doesn't want to be seen. The more efficient machines get, the more sophisticated the monitoring and tracking.
I read a story once where an alien crash-landed on Earth, and was put to work making amphetamines in a country lab. If you are breaking the law by doing (X), why not break the law and use slave labor to do it?
[Answer]
John Milton wrote a poem called *Paradise Lost*. There is a passage where Lucifer says:
>
> Better to reign in Hell than serve in Heaven.
>
>
>
I come from a place where people are willing to have a lower salary if it means others will receive even less. The most important thing is to have a greater salary in comparison to others. Take it to the extreme: people would be willing to be slave drivers if that meant they could be better off than other people who would be the slaves.
In a society where everyone is equal, that other person who is smarter than you might one-up you at something. Many people get anxious thinking that could happen, so the way to keep that from happening is crushing other people's spirits.
Any similarity with the real world is not a coincidence. We have not achieved the state mentioned in the question yet. But the fact that people have to fight for equality, and the fact that there are people fighting against equality kinda shows where we are.
[Answer]
A lot depends on how far robots, AI, and androids have replaced humans. The more they replace us, the more reasons you can find to own a slave.
1. **Show of power**: few things make you look more powerful than owning someone else. Slaves being illegal only means it's harder and more expensive to get one, and with robots becoming more common and accessible, slaves really becomes luxury items.
2. **Sex**: sex-slaves are probably the most common kind of slaves today, and I can easily imagine it becoming even more common in a world where almost every other task is replaced by robots.
3. **Illegal activities**: you haven't specified how advanced your robots are, and what limits their AI has. In a world where consumer robots' AI has been coded in such a way that prevents them from doing some illegal activities, human slaves are the only source of labor for such jobs. From processing drugs to murder, you might be unable to get a robot to do it (or it might be less safe, considering a robot can probably be easily tracked and/or hacked by a rival).
4. **AI phobia**: the rich and wealthy are often the ones with the weirdest "phobias". I can easily see someone insisting they don't want robots inside their house, and would rather have humans doing chores. But in a world where robots have become cheap, it's unlikely you can find someone willing to clean your bathroom and iron your clothes... Unless you buy them! Same goes for nannies, caregivers, and so on.
5. **Flesh and blood**: you can't always replace the human experience with a robotic one. From simple illegal fighting matches, to the weirdest torture or experiments you can imagine, people will be interested in getting slaves for it.
6. **Other Entertainment**: most people do their jobs because they need money, and that goes for the entertainment industry too. So if you want someone to play at your party or to entertain yourself privately, you might have to go through some illegal dealings with some shady company "employing" slaves.
These are just some of the reasons to own one. The more advanced AI becomes, the more some people will desire to go back to having humans to serve them.
[Answer]
**It is Seen as an act of Public Service.**
In the future complex and **expensive** body modifications are the norm. In fact it's very hard to even buy things at the grocery store without the augments that link your genetic code to your *bank account*.
Of course when this took off, a large proportion of the population was *left behind*. They were unable to function in the newly integrated world.
So what to do with these dispossessed baseline people? It is seen as a kindness for a large company to collect 1000 of them and build a non-integrated compound where they can live out their lives. This is expensive but less expensive than giving them all augments. It is also a one-time cost.
Eventually the overlords realize the people are not happy to just sit around in the compounds. Making *paradise compounds* is too expensive and doesn't really fit human behaviour either, since a certain level of strife is required to stop people going insane with boredom.
To introduce that strife and regain some of the money, they companies give all the people jobs in their factory. The argument is their lives are similar to the 21st century before modifications came into fashion.
**The big different being, of course, they are not allowed to leave.**
[Answer]
## Any Effort Requiring More Capability Than One Human Being (or Robot) Possesses
We do projects with teams of people because we need the versatile expertise. Teams build houses because sometimes you need many hands to get the job done. Teams sell fries because many hands get things done quickly.
## Moving Bar of Want
Machines replacing people has a great deal of historical example. Calculators used to meant floors of mathematicians painfully working on problems with paper and pencil. Word processors were divisions of a company that took scribbled notes, typed, and edited them.
Each time we simplify a large task, it opens up opportunities for us to reach farther. Now we use all that spare calculating capacity for algorithms to best figure out which movie you want to watch next. People are still required to hit this moving bar of want, roughly in the same quantities as before.
## Waste of Resources
When you see someone pushing a lawn mower, think for a second: that's a $\approx 1 \times 10^{18}$ ${operations} \over {second}$ supercomputer. And it's being put to pushing a sled around in a square pattern.
## Or Is It?
We're good for most things because we're very smart. You can take a group of people and just drop them into the situation with no prep and trust that they will "sink or swim", or otherwise figure out the problem that you (the employer) can't even really articulate, certainly can't document, and definitely are not yet prepared to automate.
## So, Why Free?
We all have projects we want. Let's say it's movie making. You want your cast of hundreds of extras, a few good primary actors, some talented writers, a steady (and maybe visionary) director, artists for set design, marketers, lawyers, practical and CGI effects talent, lighting, sound, camera operators, carpenters for set-building, electricians, and so on.
Let's say robots can replace 75% of that. That still leaves you with some percentage of jobs that have some element (creativity, training, personality, star power) that has not yet been codified into software, and only exists in people.
If you don't have a bunch of resources, you want that lingering 25% to fit in your budget.
## What If You Really Could Do It All for Free?
Let's say you could produce an entire film on A.I. or robotic resources. Is it the film you want? Or, are the pioneers the guys who are doing bleeding edge stuff over there? The stuff that can't be mass produced; isn't that what most folks want to do?
## Business Models Built on Free Labor
*Robinson Crusoe*, strangely enough gives us a classical model of how this happens. Before the title character's unfortunate stranding on the island, and after a career as a sailor, he has semi-retired to a job of plantation owner in South or Central America (I'd have to look it up). He works the plantation at first by himself, but sees an opportunity to expand. He can't work all that extra land himself. He doesn't have the deep pockets to pay laborers on an expansion that ultimately might not work. So he looks to buy slaves to make the expansion.
[Answer]
You need slaves to moderate social media.
Why not robots?
This job requires an intimate familiarity with human morals, politics, thought and culture. Any worker who is not an active, self-aware participant in human culture will get it wrong. If a machine is an active, self-aware participant in human culture, it's not a robot, it's a mechanical person (and forcing it to work without compensation would be slavery under the Mechanical Rights Act of 2177).
Why not free persons?
This job exposes the worker to the worst parts of humanity. It's difficult, it's degrading, it's traumatic. It makes you cry, it makes you hate your own species. The workers are regularly exposed to every kind of illegal or abusive content that you cannot legally compel a free person to see: gory violent imagery; racism, sexism, speciesism, mechanophobia and other forms of hate speech; illegal pornography and memetic hazards; unthink and enemy propaganda.
The profit motive
SpaceBook, Spaceblr, Space Exchange and so on would simply not be profitable if every moderator was paid a wage commensurate with the hazards of the job.
[Answer]
**Because ending the slave trade is too dangerous**
Imagine the setting, the blue-crested lizardmen enslaved the green-crested ones twenty-thousand years ago and made them build pyramids and harvest the grain-like stuff.
Now everyone lives in space, robots can do all the labour. Slaves are not *needed*, but what to do with them? Many of them might harbour deep resentment and hate towards the blue-crested maser lizards. Even if they mostly don't the blue-crested boss lizards might think they do. If they were given freedom they might go seeking revenge, blowing stuff up or killing.
Its safer to just keep them chained up, its stable. You have thousands of years of history showing that that is safe and it works. If they need to be locked up and kept prisoner anyway then work keeps them busy and distracted.
So you could pay 100 currency to have a robot build a home for you. It costs 300 to have it slave-made, but the government is desperate to keep the slaves in chains to contain civil unrest, so they will subsidise a slave-built home by 210, so you only need to pay 90 if you go for slave labour. As far as this society's distorted goals are concerned you are going a social good - like sponsoring a prison.
But why not genocide? you might ask. Any number of reasons. Maybe that is seen as immoral. Maybe they are worried that if they tried that they might initiate the very inter-race violence they are trying to suppress.
Final point: maybe the slaves are a useful source of organs for donation or blood for transfusion. Perhaps vat-grown lungs are not yet up to snuff so your robots can't yet fill that niche.
[Answer]
One thing people seem to gloss over is that such a level of full automation where you dont need humans would mean that there is no more work or wage or an economic system.
Imagine this: you are a CEO that can swap its workforce that has a day/night cycle, requires breaks, sick leave, vacations, need to earn experience and will not always work as hard has they can for some robots that can do the same job 24/7 without needing enough pay for houses, food, water and commodities. You'll switch to robots! Many assembly lines have already done this, with the remaining staff there to observe and maintain the robots.
If all big companies do this you get a problem: they build things to sell, but most of the people are unemployed and cant buy it anymore. You have to restructure the entire society to a post-scarcity socialist/communist like society or you have to watch most of the population die out or form sub-economies while shunning large amounts of the robotic society produce and services.
The most important things in a society where no one has to work would be things like creating art, social status, feats of strength, culture, religion.
Now consider that moment where society has to restructure itself or watch large groups of the population lose their jobs and the economy falling to ruin. Imagine that during this transition process people who were rich and owning the robots figured that owning people was more enjoyable than watching them die, so it became acceptable to own slaves. Perhaps as "social support" at first, but as people were wholly dependent on these handouts they were made more and more into slaves. It became signs of status, power, social standing, the things that have just started to matter more in a this society.
[Answer]
## Some people are just sadists
They enjoy dominating other human beings by bending them to their will and have them perform menial tasks. Doing the same with a robot just isn't the same. You *know* its a machine and it doesn't *actually* feel bad when you kick its face into the dirt.
So some of the powerful but less moral people of society might keep illegal slaves just because it pleases them to feel power over other people.
[Answer]
**Some Types of Labor are Better Done by Humans than Robots**
Having slaves doing these kinds of work earns money for the masters. In Roman times, the most valuable slaves were literate, or had an exceptional skill. Slaves in your world might still be skilled technicians, researchers, singers, novelists or whatever else. The master 'invests' in educating their slaves and reaps their profits. What kind of work can robots still not do in your world?
Sex slavery is another thing a human can do better than a robot.
Slavery can also exist to keep a lower class down. The upper class would never allow their slaves to become equal, even if robots could do the same jobs better.
**Paradigm Shift: Debt as Slavery**
Debt, for example, via credit cards, is similar to slavery. The masters may not even need to take care of the slaves, just have a perpetual interest payments going back to them with a clause to rollover debts to children when the parent dies.
[Answer]
It would be due to two major factors:
1. The very fact that people's direct labor is so very valuable.
2. The fact that property can be mortgaged or leased out.
Bear in mind that for thousands of years not much was more sought as a prize of war than slaves. (Why wouldn't you do the Nazi thing and just kill them, then move your own people into the empty, ready lands? You won, and it's so much more secure. But dead people don't produce wealth for you...) No matter what some economists have said about slavery being a dead loss to society, things ran very nicely for folks who took slaves in the greatest quantities they could bear. Besides, mortgaged slaves (as part of property available to plantation owners for mortgaging) were the economic millstone, not in and of themselves and the fact of their slavery, but due to the greater debt burden the plantation gradually took upon itself in order to stave off bankruptcy... that was the unworkable economic system. Farther back in time, or away in distance but the same time, slavery was very workable and lacked that one element: financial source entities that had no use for whatever physical property they took as collateral. Other times and places had entities providing loans which would be happy to take the collateral of slaves and use "it", lease it, and gradually sell it off their hands when it exceeded their own needs.
But that was to a large extent, and mostly, as the centuries drug on, the average worker type slave, a fieldhand, a ditch digger, a human mule. To be sure, even goldsmiths could be slaves (again, not as recently in the West, but reasonably recently elsewhere) but it wasn't usually (or almost ever) the situation of Negro slaves in the New World. In Sumeria for example, the Code of Hammurabi specified that such a slave owed only 20% of his earnings to his owner. "Toby" didn't likely even get better food.
So low level (low value, but needed and therefore useful, labor) slaves were still prized and sought.
Today though, the hallmark of our economy is all the ways in which we amplify the value of a single worker. Not only in production line teamwork but in having a single worker operating one or more machines that can be programmed to produce far, far more than he ever could and usually better. Those workers are worth more whether they get paid more or not. The company I work for produces eight times what it did 20 years ago with the same number of workers. If the low level slave was of important value even 100 years ago in China, India, the USA (a sharecropper by any other name...), and so on, just think of how valuable a modern worker can be. Even jobs that actually take far more knowledge than one thinks (Subway worker) need workers. They pay "poorly" because so many more people can do those jobs than can do "doctor." Not because they lack value.
All those robots and all that equipment, both of which are only getting better, amplify the value of a slave. At least until AI follows chess playing engines and outperforms humans.
So to sum up, the very existence of value-amplifying machinery makes the slave of greater and greater value, not lesser value. It has always been the value a HUMAN provides vs. what the old style machinery (oxen, horses...) provided and the way a human amplifies the value of the machinery in return by being able to supervise it, feed it, and correct it when it begins to go off-track that makes humans so valuable and therefore, so worthwhile as slaves. Add to that the way people with piles of money have some pretty poor choices for how to make money earn more money (providing mortgage money for \$80,000 houses even in recessions is just risky and a poor investment, but it represents "all there is" for they guy sitting on a huge pile of money without a business he has the genius to run without getting any more involved in it than he does with that lending), and it is only natural (just kidding, it's a sickness: you have \$30 billion and you want more?) they should want a huge new idea for collateral capital. It's like buying Yahoo on Day One was. What other ideas are out there for huge new sources of mortgage-ready capital? Temp agencies would move right into that owning and leasing of slaves market. Sadly... the world seems pretty ready for it. Even today there are millions of slaves. That nice Saudi fellow who sells you super-priced gasoline? He owns a couple-three Fillipinas. And a wide, mature market means they're all "fungible": no sweating that one got cancer and you're gonna lose everything with him dying or for healthcare to keep him performing. Easy-peasey to sell him off to a mine that is used to wearing them to death in six months anyway. The small, personal benefits of what those two larger points above enable...
So definitely, an ultra-advanced society could easily still make very happy (for the owners) use of slaves.
They'd just have to avoid that millstone the plantation owners had and honestly, given that Wells Fargo just doesn't have a use for slaves, really, not by the millions, so they'd dump them like stolen homes depressing the value of slaves and thereby hammering the whole slave owning elements of an economy causing them to default on their loans as they had to pay back (tomorrow) at least what their collateral no longer covered causing further sell-offs and lowered values... none of which would be grief to the lenders... well, a "run" on slaves like that could easily be the driving force or blow that leads to whatever societal upheaval is the backdrop for a story. Very akin to bank runs after the 1929 stock market crash.
[Answer]
## Human money farms
As automation progresses, the question becomes is everyone better at something than a robot? and the answer to that is likely a resounding no. Capitalism stops working when robots become better at all of the jobs that a person with no extraordinary talents would be able to do. People often talk about how important things like art, entertainment, research, and IT work would be in such a world, but you can't employ a full population off of such specialized labor. Not because there are not enough jobs, but because not everyone can specialize enough to beat a robot at anything at all. When society reaches this point, the only way to prevent a runaway economic collapse is to stop making jobs a necessary thing.
If only 10% of your people are smart/talented enough to be gainfully employed, then there are only a few possible ways this could play out.
1. Your lower 90% either starves to death or revolts and has to be exterminated. This drop in population will cause a new wave of unemployment followed by more revolutions and more exterminations until someone someone steps in and forms a socialism that will support the unemployed masses.
2. Your lower 90% successfully revolts and forms a socialism that will support the unemployed masses.
3. Enough leaders see the problem before it boils over so they form a socialism that will supports the unemployed masses before then.
No matter how it plays out, you will inevitably end up with a "lazy socialism": a system where you are given a ration to live off of regardless of whether you are gainfully employed or not.
With this backdrop in mind, picture a world where you have a chip in your arm, and as long as it detects your biometrics, it functions as your government issued ration card. You use it to buy food, furniture, clothes, services, etc. Everything you need to live and be happy thanks to the hard work of robots.
The thing about this system though is that as long as you are alive, you can claim your ration meaning you don't actually need to make a slave do work for you to make money off of them. Just keep a bunch of people chained up in your basement, and swipe thier chips to buy whatever you want. Sure you have to feed them, but the government is not so cruel as to make the lower class have to survive at a true sustenance level baseline, so you use thier chips to pay for the absolute minimum it takes to keep them alive and you pocket the rest for yourself.
**So instead of slave labor looking like this:**
[](https://i.stack.imgur.com/aiJxp.png)
**It would look like this:**
[](https://i.stack.imgur.com/VS0yA.png)
[Answer]
# Slavery is not economical. It is very costly
At some point in the past, production of any kind was very labor intensive. The ideal of any male was to have a wife that would "produce" a lot of kids so they could be put to work. And become wealthy by keeping a good percent of their production while they grow up. Slavery, defined as owning a person, has very high costs. And the only jobs that can be done by slaves are the most labor intensive, and least intellectual. For the fundamental reason that people do not like being "owned" by someone else. There needs to be armed men ensuring slaves don't insurrect or escape. Some will act against their owners and will need to be punished. Others need to be warned of consequences of their escape. Ect... For the little value of the possible jobs slaves could do. It does not make economic sense.
# Civilization gap may change the economics of ownership
If there was two groups of people where one of them had access to near endless resources Lets call it rich. While the other is at our level of access to resources, that would be the poor group. It could be that the rich could pose such a threat to the existence of the poor group, that the poor group would have no recourse but to resign itself to slavery. Over the years the enslaved group would become more and more submissive. The degree to which technology could enable the rich group is critical. It could be that the rich group does not even have to worry about the politics of "educating" the poor group about their new circumstance. Robots and AI could do it for them. Robots could do all the dirty job of threatening, punishing and policing. While at the same time supplying the rich group of slaves only when they have been truly enslaved. At that point the question becomes to what end? Clearly we humans have proven ourselves capable of the most insane activities. And this action could be perpetrated by just a portion of the advanced civilization. It does not have to be sanctioned by the whole.
# Long term risks
The biggest problem is the long term risk associated with psychological harm. Clearly the distinctive quality that could create the inhumane wish of enslaving another human being. Is our actual human condition, and that as humans we engage each other at a cognitive level. This cognitive interaction is precisely where the risk lies. Because in an advanced civilization where individuals have access to immense resources, the possibility of a few antisocial individuals causing extraordinary harm is very real. The psychological harm required could be creating the people who would eventually destroy civilization. We humans are just too random, It's impossible to predict what interactions those potential slaves will have in 100, 1000 or 10000 years from now.
# Humanity may not even be capable of being highly civilized
All this brings us to the last point. Which is, will humans ever be highly civilized. The risk posed by people who could potentially be enslaved, already exists now. There may be enough crazy people in this world. That at some point a small group or even an individual could do huge harm to our civilization. What will the smarter people decide to do? Will there be two civilizations? One of poor people who are learning to be a part of the advanced group. And a rich group who's biggest preoccupation is the safety of the rich group from itself and the poor group?
[Answer]
**Avoiding government surveillance**
Advanced robots require very high technology level. Governments can oversee their production and enforce mandatory surveillance features.
Legal workers demand pay, and may leave to other work opportunities. They can also be disloyal and share your secrets.
Volunteers / cult followers are loyal and don't need to be paid, but they need to share your goal. If you want to keep your goal completely secret or if few other people would agree with it, you would have to trick them with a fake goal. Depending on the work you need the workers to do, this might be difficult.
Thus, if you want to do something that requires a lot of work and that both majority of the population and the government would disagree with, slaves would be the most economical and easiest to control workforce.
[Answer]
Because they are afraid of AI uprisings (perhaps from experience in the past), and so they don't allow AI robots. Therefore for jobs that require intelligence, they need sentient **organic** beings.
The jobs that would require a high level of intelligence would be those that pull together multiple disciplines and require seeing the world through multiple lenses, self-modification/adaption, creativity, and intelligent communication.
* Research and development, engineering, scientists, etc
* Personal servants (they have to be intelligent enough to understand any command you give them and perform a wide array of complex tasks)
* Creative endeavors - writers, film-makers, musical artists, actors
Of course, you would need to invent some reason why the advanced civilization values having some other race perform some of these jobs. Maybe they value cultural diversity, or having people that look at things from different angles, or it's about novelty, or they all got really lazy, or some combination of these. Maybe all forms of work (outside of management/government) are delegated to other races because the aliens think they're the ultimate life-form in the galaxy and they shouldn't have to do anything.
[Answer]
**Cultural**
There may be a number of different reasons why this is so.
* **"Because it's always been done this way."** People own and use slaves because, in whatever culture you define, "it's always been done this way." In a situation, such as this, people (both slaves and masters) may be so acculturated to the concept that they don't even think about it.
* **It emphasizes the stratification between socioeconomic classes.**
+ Other answers allude to this, but it may simply be to show, "look at everything I have the wealth to afford."
+ In a society such as you describe, it is likely that there will be a high level of automation and, possibly, corresponding unemployment. The basic socioeconomic classes might well be the aristocracy, a microscopic middle class, and the people on the dole. In such a society, servitude may even be seen as a step **up** from being on the dole. Slaves may have a better lifestyle than those who are merely subsisting on government assistance. I.e., better food, clothing, and medical care, as the owner is likely to want to protect his investment and have their appearance reflect his wealth.
[Answer]
I'll start with describing "an advanced society". Imagine a society in which the cost to build and maintain a robot is less than the cost to grow and feed a human.
Growing and feeding a human requires food, and food requires energy. Land growing crops has a cost; if that same land (or same crops) converted into energy is sufficient to makes and maintains a robot that is more capable than a human at a given task, that human isn't efficient at that task (in the medium term; in the short term, you could have excess humans).
In a sufficiently advanced society, robots and AI are more efficient than humans at every task. This would include everything from mining to developing new technology.
Such robots/AI do not have to be sentient. It might just turn out that describing a problem domain from natural language isn't "AI hard", and solving that problem domain through experimentation isn't that hard either. So you literally say "I want a better hand computer", and the non-sentient AI looks at human behavior, works out what you mean, and solves that problem.
In this society, a given human has no natural economic need for another human; there is nothing the other human can sell them that they couldn't get cheaper from an AI.
As you transition to such a society, wealth is going to be held by various humans. They are quickly going to pass on the management of their wealth to AIs (as, again, AIs do a better job), harvesting a small amount of it to enjoy themselves (if they harvest too much, their wealth will erode).
Those without wealth will find themselves without economic purpose. Initially governments will support said economically worthless people with stuff like basic income. Almost all services, from police to military to legislation, ends up being taken over by AI and robots; areas where this doesn't happen will experience a constant drain on their relative competitiveness compared to areas that do. Vanity jobs, like "President" or "Sherriff" can exist, but they (economically) are little different than providing humans with toys to amuse themselves. Sometimes the toys can shoot out someone's eye, but they aren't *important*.
It has been said that power flows from the barrel of a gun; but really, it flows from economic usefulness. The greatest power the populace has ever had is the power to die and deprive the ruling class of their productive surplus. In modern times, the non-ruling class's productivity in first world nations is immense, and huge amounts of wealth are harvested by providing the non-ruling class with economic and political distractions, like democracy, human rights, salaries and home ownership.
With the collapse of the economic usefulness of humanity, and a ruling class still existing, the non-ruling class becomes useless to the ruling class. Democracy and the like will be dismantled over time, and things like universal basic income and human rights will fade.
As this happens, enslaving otherwise useless humans could become something a "soft-hearted" rulership caste could do. Rather than let those purposeless drones starve, they are given economically useless "jobs" that amuse the ruling caste member.
So long as this all falls within the "harvested excess" play money of the ruling caste member, where the vast majority of their wealth goes towards shoring up their power, this is economically feasible.
Now, over time, the rulership caste themselves is worthless. A self-perpetuating non-self aware AI+robot engine that seeks to maximize its own power would be more efficient than one with a parasite ruler attached to it, simply due to the drain of resources and possible executive power errors of said ruler. So this phase, where a cruel sociopathic rulership caste enslaves the remnants of humanity for amusement, would only be a passing one.
[Answer]
When people demand a higher degree of freedom, they are actually demanding a very specific right or set of rights, because its absence became noticeably to them (physical or psychological pain). On wealth nobody asks questions.
**Scenario 1:** Unnoticed slavery. And I mean nobody, not the slave, not the master (that in turn may be slaves too). I recommend British movie "Moon" from 2009.
Also, when you say slave in what are you thinking exactly? Unpaid labor? Because, I myself, ultimately am an slave of my biology. I will die someday, for example, and nobody asked me if I agree to that design.
Slavery as legally considering some people as property of other people is the more classical and direct meaning.
**Scenario 2:** direct slavery, with laws supporting it and everything.
**Good this is not required**, because this scenario sounds unbelievable. Our own world requires people to do certain things, it was never a matter of if you are in mood at the time. There are ways to motivate people to cumply. We are just becoming better at it. You learn to properly use your tools to avoid damaging them before the job is done, right? With people is the same.
Slave longevity is as cheap as is longevity of the life form being enslaved. But the slave system is expensive and inefficient if the enslaved life form is self conscious. Cows doesn't asks questions (as far as we are aware), while humans don't like the word "slave", or anything that may imply that they cannot do X or go to Y, while other humans can. In the end, humans will challenge any system and see by themselves what they can or cannot do.
Slavery failed historically because it became evident that it is not viable. Maybe some people prefer to remember it as "good group of people killed bad group of people". With cultural evolution is never as simple as that. In the end slave system isn't maintainable. If it were maintainable, it would have lasted to today.
**Why an "evil" company, people or single person may choose to have slaves?**
You can play with the possibilities here. Maybe a space colony was cut out of technological solutions. Due to natural disaster or whatever. People not used to hardships refuse to do their jobs and specially to take the ones traditionally done by machines. Then, in desperation, the managers of the colony decide to implement a system that lets them force people to cumply.
Make that believable is the challenge.
**The endless loop of rediscovering or reborn of slavery at certain places.**
This is a different problem. Our civilization has a certain level. But for varying reasons, some people may loss access to certain things. If the situation remains through the generations, you have a disconnected community.
This is also a symptom of going backward in cultural evolution.
While I don't believe this can happen at planetary scale, it sure happens in specific places or even to specific individuals. I cannot speak of the possible reasons for that, but a trick to make it sound believable is to restrict the phenomenon to specific districts, cities, companies or even individuals.
One thing I never bought from science fiction, is when you have space ships but everything else resembles middle ages or roman empire. It's lazy.
[Answer]
I think that slavery is useful. Immoral, but useful. Somebody has to do the hard work, right? I think sometimes it can be about power, because it's generally fun to dominate someone and even use them for your own personal devise. With that said, I think slavery existed because people wanted to make profit off of them.
Is it not a big boy business move to make people pick your cotton, or work in your factories? I mean slavery isn't much different than paying people 40 cents an hour. It'd probably cost you more to feed your slaves today than 0.40 cents an hour, let alone house them and them not die.
The biggest thing wrong with slavery in the 1800s was the fact that they legitimately beat them to death if they didn't work. The slave owners actually enjoyed this, often times believing they deserved it because they were slaves and eventually turned that into being black. I believe it's a great example of what happens when we view people as identities instead of individuals.
But yeah, slaves = no work + profit, and I'm not against the concept....I'm just against doing it to people, especially targeting a people by identity. If we could get to a part in society where machines did all of the work and required little maintenance we would either eliminate some of the unenjoyable things to do in life and create other jobs doing other, more important jobs or the economy capsizes due to unemployment -> lack of spending.
Though, that's been a fear for a while. Technology is not an enemy, it's the people who weaponize it.
] |
[Question]
[
In my universe, humans are pretty good with AI and have some experience in space combat, as nations fought for resources.
Regarding the world, humanity remains in the solar system and is in space mostly for science and resources - humans in space stations, scientific colonies on mars/venus, small colony on the moon. Anything away from colonies and space stations is automated.
In terms of combat-relevant technology, it's close to current technology but with significantly better drives and power generation. Lasers are big and heavy in order to be effective at cutting through or overheating enemy spacecraft, other weaponry is mostly conventional and guided (either missiles or AI-controlled drones that close in until non-guided weaponry is effective). No shields, blasters and the likes, distances in combat tend to be on the high end.
There are crewed control ships close to the fights to give broad orders with only a few seconds of delay, but they'd mostly stay out of combat. However, for storytelling reasons I'd also like frigate-style missile artillery ships to be crewed. What viable reason could there be for them to require a human crew on board?
[Answer]
# Frigates are "Jack-of-all-trades" ships:
For an all-out war, legions of robotized attack ships are great. They can exterminate everything with the best of them. But history shows that navies spend most of their time NOT at war. That's a lot of potential just gathering dust and rapidly becoming obsolete.
Furthermore, space is big. On Earth, naval officers can be controlled by instant communications. But more traditional naval officers lived in a world where they were days or weeks (possibly months) from getting orders from command. They were trained to deal with situations on their own - sometimes ones with no direct military application.
There are plenty of situations where you just need the navy to be present. ANY military vessel will outclass a pirate, or intimidate a space station. Life is messy, and everywhere you go, you need to arrest deserters, capture fugitives, provide emergency relief to disabled ships, or even possibly ferry replacement parts into bad areas where unarmed freighters fear to go. A naval vessel might be the ONLY representation from a government that is astronomically (literally) far away. Then there is dealing with frenemies, neutrals, belligerent multinationals, and the like.
All these tasks require a human presence and human judgement that can't wait the 3 hours for a human to answer an AI about what to do. In truth, the humble frigate is the premier vessel for any junior officer to be assigned to. If you get assigned to a laser battlecruiser, you only gain experience in administrative functions. Frigates see real action and real choices.
* Traditionally, frigates were quite small ships. To emphasize the multifunction role they play, the ships might be modular, so a weapon system can be detached and a shipping container-style cargo attachment or med-bay added. This makes your ships very adaptable for story purposes.
It is also a test bed for these same officers. Great ones (the Picards) get promoted to admirals. Incompetent ones screw up something and are assigned to duty on ships where AI make all the real decisions. A few are gifted at the job but don't have the temperament to do anything else. These officers become legends.
[](https://i.stack.imgur.com/57VTG.jpg)
(Okay, the [Rocinante](https://expanse.fandom.com/wiki/Rocinante_(TV)) is a corvette-class frigate, but the principle is the same)
[Answer]
A dead man tells no tales.
Humans can be easily and quickly terminated, should the necessity arise: an electric discharge or a poisoned needle directly from the helmet, for example, and the subject is dead.
An AI instead is more deathproof when it comes to recover information post mortem, and nobody wants to hand over vital information to the enemy.
[Answer]
## The AI Insisted
To the extent that some handful of your AI are nearly as self-aware and emotionally sophisticated as people are... The AI don't like risking themselves any more than you'd expect people to.
Turns out that humans expect ships carrying humans to be saved from destruction if at all possible. The more sophisticated AI figure that having a human on board gives them a better chance to only be sent on survivable missions as well.
If the AI are capable of some degree of deception, they may suggest that one of the other answers given here contributes to human-on-board being "optimal". (And maybe they're not even wrong, exactly. And maybe a really good AI is as fragile as those meat-bags, and you're not even sacrificing much maneuverability to bring one along...)
[Answer]
**Humans are creative, AI is fast.**
Humans can conceptualise a situation far better than any AI, especially simpler AI. Perhaps the larger bright AIs may approach human level but not the type fitted in smaller ships or limited structures. AI's tends to be narrow minded. An AI programed to cook can bake a cake, slice vegetables or boil and egg like no one's business but if asked to make a fire may struggle in the absence of a stove. Extrapolating to the complex environment, the infinite possibilities and unknowns in a theater of battle AIs are not ideal. HOWEVER, that said. Combining humans with AI, is quite deadly. Humans perceive the environment, using the AI's to keep track of targets and battle space elements, relate this in a way to easily digestible to humans. Allow the human to give general orders or maneuvers to the AI for the AI to execute, again, in a seamless manor, Maximises the abilities of both.
**Humans distrust advanced AI**
This is a typical, though quite logical trope in SciFi. Fearing the machine overlords is quite reasonable. For Humans to design AI with limited capability. Hardwiring them to narrow and specific actions quite a viable prediction.
EDIT: looking back I don't think I related exactly what I was thinking.
The human in a combat situation can conceive of strategy, deception and deducing countermeasures against the same. These strategies' can consist of maneuvers and multi target actions that could never be thought of by an AI or executed by a human. But well within possibility of an AI to execute. AIs could be given general orders to execute evasive maneuvers on detection of incoming ordinance. With reaction times measured in NS they would be far more effective. As well as precision high speed maneuvers against targets in tight situations.
[Answer]
## War is *political*
Sure, you can delegate the decision making about targetting, evasive manoeuvrers, repair priorities, etc. to your AIs but do you want your AI choosing whether to prioritise rescuing escape pods from an allied vessel or chasing down the fleeing cruiser with a key enemy general on-board? Do you want your AI deciding to fire first and potentially start a sector-spanning conflict, or wait and risk the squadron getting crushed in a first strike attack by the enemy? When do you accept surrender? How do you negotiate a peaceful end to the conflict? Is that suspicious looking civilian vessel really a refugee transport or is it being used as a ruse to hide military intent?
AI can act, and inform, but political decisions are left to humans. Therefore you need humans involved in the decision making. On a larger vessel you need more humans to be involved in more decisions. And you need them to be on-board because the turn around times on stellar scale communications rapidly become too slow.
[Answer]
**Evasive Manoeuvres, Mr Paris!**
Having a meatbag at the helm makes the ship's manoeuvring system impossible to hack.
[](https://i.stack.imgur.com/Qorgw.png)
Space is big. Weapons take a long time to reach the target. Missiles take minutes or hours. Lasers hit almost instantly, but you have to hold the laser on the target for a while to do damage.
The ships defend themselves by constantly moving back and forth. When your missile gets here I will be thousands of kilometers away in some random direction.
You cannot predict what direction I'll dodge because I haven't chosen it yet. I only chose AFTER you fired the missile.
An AI could in principle do the manoeuvres for you. But the AI is vulnerable to being hacked by the enemy vessel, which can then predict where I will be in ten minutes and launch the missiles to detonate there. Hacking happens at the speed of light.
Tom Paris can be a pain in the ass sometimes. But he cannot be remotely hacked, and we have to give him that. You have to give him that.
[Answer]
**There are no dedicated military vessels.**
<https://en.wikipedia.org/wiki/Standing_army#United_States>
>
> At the 1787 Constitutional Convention, Elbridge Gerry argued against a
> large standing army, comparing it, mischievously, to a standing penis:
> "An excellent assurance of domestic tranquility, but a dangerous
> temptation to foreign adventure.
>
>
>
Your spacefaring peoples are suspicious of dedicated military forces, because owning and maintaining such means the owners will be tempted to use them. Or the forces themselves make take matters into their own hands. So it has been on earth and so it is in space.
Your spaceships and space warriors are in effect a militia, being summoned away from their regular space jobs to make war. They are a "well ordered militia" and their ships carry armaments in case they are needed. Hopefully these armaments have been maintained and there are storytelling opportunities in that respect. Maybe not all the ships sent to war are actually as ready as their reports suggest. If there are sophisticated artificial intelligences aboard these too are largely concerned with civilian matters - running models, doing math, calculating positions and so on.
[Answer]
## Because people need a hero.
I watched the movie *Don't Look Up* last summer (and hated it, but that doesn't matter). It seems to bear no relation to your question, what does a comet hitting Earth have to do with military spaceships, but this quote popped into my head as soon as I read your question:
```
Randall: "Shouldn't this mission be accomplished using remote technology?"
Teddy: "Washington's always gotta have a hero."
```
Simply put, it's not for practical reason that they send people up there. With advanced enough AI we could fully replace human brainpower and possibly do better. But people like seeing people do stuff, which will probably never change. It's the exact same reason that videos on YouTube have facecam, because we like being able to associate something to a person, someone that they can look up to, and not just some random strings of code running inside a computer. It's human nature, and it will certainly stay that way for a good long time.
[Answer]
**For Human Factor**
1. You did not mention any robot or android capable of doing advanced fixes and maintenance, sure there are some fixes that can be done autonomously but any major "on the go" fix would require a technic crew.
2. Even with command ships giving orders within seconds, there is a fine line between life and death (maybe more like a win or lose at this point) decided in mere milliseconds. Maybe you have given a shoot order but the target vessel is just a scientific vessel that is better be taken and interrogated. You may even end up having the cutting-edge technology your enemy was going to use on you.
3. On the battlefield nothing goes as expected, your frigate now is a field hospital with an extraction crew, sure the crew may not be prepared for this exact situation but what do you prefer, no crew or inadequate crew with a chance to help you?
Even with the most advanced AI's a battleship without humanoids (either it is sentient robots, androids, or even your basic humans) is as better as a scout ship. You will always need hands on the deck.
[Answer]
# AI Have Weaknesses
[Are these muffins or dogs?](https://www.google.com/search?q=muffin%20or%20dog%20ai&client=ms-android-motorola-rev2&prmd=ivn&sxsrf=ALiCzsaZ6LL3PRprTGp8mguJEFAKEiwymA:1654703001469&source=lnms&tbm=isch&sa=X&ved=2ahUKEwidvPGEmZ74AhVnA50JHZTgBekQ_AUoAXoECAIQAQ&biw=412&bih=771&dpr=1.75) Would an AI successfully understand new things? Does it suffer from the "I have a hammer, so everything is a nail" style of thinking? Is AI capable of going rogue?
Nevermind things like [adversarial AI](https://en.wikipedia.org/wiki/Adversarial_machine_learning) which may be very good at confusing or outright fooling the frigate's AI using very simple methods. These methods or weaknesses can be bizarre, like a misplaced pixel or a missile being painted blue. It's something that a human can clearly see as an error but the AI does not.
# Humans and AI Support Each Other
Having humans around as a check to AI is needed! They can work together to protect each others' blind spots.
[Answer]
Your AI is not quite good enough for the jobs asked of "frigate-style missile artillery ships".
Even today we automate what we can, and put humans in positions that require humans. In your world the thing humans have is intelligence. You have artificial intelligence that is good enough for the types of craft you want to be fully automated but not good enough for the types of craft you want to have humans. It sounds quite viable, the missile launch decisions are somewhat complicated (what is the most valuable target, what is likely to be decoys) and require timing faster than the round trip time to your control ships.
[Answer]
Because the crafts contain a human pilot who utilizes AI systems such as resource management or advanced weapons targeting. Giving you a "best of both worlds" approach. One system can back up or augment the other.
For example, if the ship's power system is disrupted a human pilot can manually repair it.
[Answer]
AI is great at handling situations that they've been trained to handle. When they encounter something radically different than anything they've ever seen before, not so much. Humans do significantly better when confronted with novel situations/problems. They may not always make the *optimal* decision, but they tend to at least avoid the options with the worst consequences. Say your military fleet encounters a new civilization whose cargo haulers have a profile that looks startlingly similar to the light military cruisers used by your archenemy. Making the wrong decision here could incite an all-out war. That's way too risky to trust to an algorithm. A human crew would be far more capable of using context and nuance to ascertain the truth of the situation. They might notice that the lettering printed on the tailfin is in a completely different language, spurring them to investigate before acting. The AI wouldn't have even paid attention to that; there hasn't ever been a situation where that was relevant, so the AI was never taught to consider it.
Similarly, you undoubtedly have complex treaties and formal agreements with neighboring civilizations. [Situations](https://en.wikipedia.org/wiki/Kobayashi_Maru) frequently arise where these legal requirements conflict with basic mission objectives and standing orders. Law is complex, and you need more than hard machine logic to navigate such situations. A human crew can better predict not just what actions to take, but the consequences of those actions, how others will interpret their actions, etc.
In other words, look at the Spock vs. Kirk conflicts in any classic Star Trek episode. Spock represents your AI, making decisions based on logic. When situations go *really* pear-shaped, it's usually Kirk's borderline insane strategy (implemented over Spock's objections) that saves the day. AI doesn't come up with those sorts of ideas, you need that little bit of lunacy that only an organic mind has.
The other big benefit is that a human crew is extremely adaptable. You can retrain them fairly easily when needs and circumstances change. Moving some of your security officers into repair roles during an emergency can save your ship. If this was an AI vessel, you wouldn't have that flexibility. Your automatons wouldn't have the right parts to flexibly adapt to new roles and even if they did, reprogramming them would require extensive engineering and testing work that has to be done in advance. You can teach a human the basics of welding, first aid, or search and rescue in a couple of hours. Make changes to your rules of engagement, or sign a peace treaty with someone? A quick memo to your human crews is all it takes to implement these rule changes. No need for extensive software development, testing, and deployment. And best of all, updating a human crew's standing orders doesn't risk accidentally bricking the crew and disabling your navy.
[Answer]
# Laws and safety
I'm pretty sure there is a law in the real world that prevents fully autonomous killing machines. There must be a human able to monitor the situation and decide to attack, or not. This has multiple reasons. Basic human rights for one. A machine could mow down a thousand children as they were marked as enemies. They could do inhuman harm to enemies, letting them needlessly suffer.
But another big one is responsibility. A human can of course do those things. They *have* done those things. With killer robots like drones it is now even easier to fire a rocket at a school bus full of children. The operator is far away and often has lottle emotional involvement. This is intentional to make them more effective at killing.
But at least you have someone to blame. You can take a guy who pressed the button to court. You can punish them. They can serve as examples for others. If you dismantle an AI it will probably not feel like justice. The AI is unlikely to feel chastised and might not care to be dismantled. The AI can learn by tweaking the rules, but that can happen with human intervention as well. Targets can be chosen better next time. But with punishing AI there is no *justice*.
That, and it makes people a whole less afraid if either side doesn't have fully autonomous death machines that kill indiscriminately, without mercy or remorse. Nothing more scary than a host of murder machines where no one can say 'stop' the moment a decision is made to kill.
[Answer]
Are the AI capable of performing boarding actions? Questioning civilians? Bringing in high profile targets for questioning? It may well be that once the missiles start flying the human crew are a liability, but the rest of the time they're needed to carry out all the other things the ship does.
If you want to address that liability in a shooting war type situation, maybe in extreme circumstances the AI takes over, the crew board escape shuttles or go into drug induced comas so as to let the AI do it's thing.
[Answer]
### The chains of command
The modern chain of command for an effective military relies on officers being able to break their orders down and distribute them down the line. Indeed, sending generals down the field to micromanage troops is very ineffective, and is a good way to get your best officers killed.
It requires some level of creative thinking to break down a complex problem such as "let's capture this region" into thousands of "go there" and "shoot that" orders. Humans are capable to think beyond their programming, which can be a good and a bad thing in general, but a great advantage when facing a new situation. Humans have a greater capacity to evaluate their own actions, which is also helpful in new situations. They also have human emotions, they can evaluate their own actions, they can tell when an order is illegal or unreasonable.
You might read the above as a bunch of flaws for humans, but that also means you don't need to hold their hands. Humans will take care of themselves.
While a current technology AI would be perfectly able to execute orders, it's not at all clear it would be capable of thinking up these orders, or that it would be able to tell what winning a war looks like. In short, **even if your ships are largely automated, a human crew is still required to give it any purpose**, in real time.
But that's not all.
### The laws and customs of war
A human pressing the trigger can be held responsible. The human who ordered them to press the trigger can be held responsible. And the human who ordered them on the front, and so forth. With humans, we have a clear chain of responsibility.
A machine isn't accountable. You can't try an AI for war crimes. You can't court-marial an AI for disobeying orders. So what happens when something messes up? Who is going to take the blame? The programmer, the operator, the maintainer, the commander, all of the above, someone else? Who is responsible for autonomous systems failing is a question that is still unanswered, and it's unclear that it ever will be.
But one possible answer is that **if responsibility can't be clearly assigned, then AI shouldn't make decisions**. The laws and customs of war were not designed with automated systems in mind because the idea of war has always been man versus man. You can't incentivise a machine to follow these rules because the machine doesn't have a family, it doesn't have self-consciousness, it isn't afraid of dying, of capture, of reprisal.
The laws and customs of war exist to protect everybody from the extremes of war. But, simply put, a machine can't be held in line. It has nothing to win, and nothing to lose. It has no reason not to follow its programming to any logical extreme, and you often can't predict what that extreme could be.
### Single point of failure
One last point here.
An AI is one system. Your frigate, most likely, would be controlled by one system. This system would have a bunch of subsystems, but all the control system will the solely in charge, and will not be challenged if it decides to turn against you, to commit genocide as a shortcut to victory, or to do anything you don't want.
A human crew operates much differently. It takes more than one human to mutiny. Humans act as safeguards against each other. If one fails, others will pick up the slack or will prevent it from failing further.
You can't tell what a human is thinking more than you can tell what an AI is thinking. But when it comes down to it, when a commanding officer, it can be stopped or replaced. **When the command AI fails, nothing will stop it**.
[Answer]
This is a question that comes up a lot in fiction like Star Trek and Iain Banks's Culture series. Between their slow reaction time and their inability to handle even fifteen gravities of acceleration, humans are a liability. Why would you even want one on a warship?
The key to this is "war" ship. Not battleship. When it comes down to it, war is something that humans do with other humans. We could have machines do the actual fighting, but there has to be a human at the top of the command structure somewhere.
## Nobody wants machines in charge
The answer that most fiction comes up with is that nobody wants machines in charge, and nobody would let a machine decide who needs to die, for fear it would decide that they, themselves might need to die.
This isn't the only answer, but it's a good one. You could come up with some schema where there's a maximum amount of firepower that a person is allowed to be in charge of. AI's could take care of targeting and maneuvering, but a human is required to decide which objects are targets.
## Machines have no sense of purpose
Machines are highly capable, but they don't actually have objectives. You could certainly GIVE a purpose to machines, but they have a hard time taking into account the considerations that humans have when pursuing those objectives.
Take, for example, exploration. You want to go to X system and just see what's there. You could tell a machine to do this, and it would take pictures and measure pressures and analyze materials, but it wouldn't stop and wonder why the plant life was blue in the southern hemisphere and green in the northern hemisphere. It wouldn't find the concentric hurricanes on the poles of a gas giant particularly fascinating.
## Exception handling
When you tell a machine to go kill something, it goes and kills something. Maybe you can provide it with an exception where the target has his hands up, or is too injured to fight, or is under age. You probably won't think to tell it to watch for people who look like you, but with a scar on their face.
You can tell a machine to go fix something, but it probably won't take into account the newborn kittens that have taken up residence in the fusion tube while it was down. It'll just clean them out and restart the process.
You can tell the machine to go get something, but the machine probably won't be able to improvise if what you ask for isn't there.
## Negotiation and strategic initiatives
When it comes right down to it, wars are about trying to make the enemy give up. Deciding who to kill, when and where, is only part of the equation. A human could decide to invoke a terror campaign, threatening the enemy's cultural icons. A human can decide that you need to take a surgical approach, targeting engines and weapons, or a resource restriction approach, targeting life support, food stores, and supply chains. Even if you only have one human per fleet, these decisions have to be made on a very small scale.
Plus, a human would be necessary to tell the machines when to stop killing. If a human is onboard to make these decisions, you reduce collateral damage.
## Everything else
In the US Army, it's said that front-line warriors are only 1 person in 7. Admittedly, machines would improve the logistics and repair formulas a lot, but you will always need someone who decides upon priorities.
[Answer]
## Humans are needed for making repairs.
Assuming the AI isn't massively more advanced than what we have today—a while back, someone asked [why we can't send a robot to repair the JWST](https://space.stackexchange.com/a/57374), and one of the answers basically came down to that robots are too inflexible. 'Wiggle two parts until they fit together' is a difficult task for a robot, but one of the easiest things for a human to do. Repairs might look like a robot with a screen with directions while a human actually manipulates the parts.
An AI might also lack the creativity to kludge a solution to limp back to port if critical systems are offline but parts can be cannibalized from elsewhere.
[Answer]
## Mutually Assured Destruction
Long ago, mankind figured out that it can't completely wipe itself out if it doesn't use AI. An AI on AI war, in contrast, can and probably does.
AI's are allowed to assist in all manner of combat except weapon firing; if AI is used for weapons, the victim will activate thousands of antimatter bomb drones and it's Multi-World War 4.
[Answer]
# Rethink the Definition of Human
## From Human to Cyborg
To a caveman we are practically a hivemind. We can talk to someone accross the globe almost in real time, we have information of millions of people at our fingertips. What makes it so? Well... smartphones. Just a prosthetic leg becomes "your" leg, a hearing aid becomes "your" ear and a smartphone becomes "your" telepathy organ. Which is why a lot of people already feel weird not having it/giving it away.
Now let us extrapolate a bit: Next thing will be glasses. Google is going to try again, Apple too. The question is just when we can make technology small enough (either make batteries lighter or chips so much more efficient, that they need far less energy). Then you have an even tighter connection. The next step will be a direct connection to your optic nerve/hearing/smell etc. Looking from 2022 into this future would cause many people to call these people cyborgs/hivemind - they will still call themselves human.
## From Machine to Cyborg
While humans incorporate aspects of digital processors, machines/digital processors incorporate aspects of neuronal nets. Not only are "artificial neuronal nets" trying to emulate the way human brains work, we have by now also tried to grow brain tissue to incorporate into a computer: <https://www.biorxiv.org/content/10.1101/2021.12.02.471005v2>. In this experiment real brain tissue (real neurons) learned a task in 5-10 minutes, what takes artificial neuronal nets a couple of hours at the moment. In general there is a push in artificial intelligence/AI to create application specific integrated circuits (ASICs) for AI tasks (e.g. Apple's M1 has a neural engine core, similarly Google's tensor chips). Why? Because simulating neuronal networks artificially with general purpose computers is much more expensive than building circuits which are *just* neuronal networks.
(These neuronal networks tend to be bad at calculations btw., something that classical computers are really good at)
## Two paradigms of computing
It starts to look like there are essentially two ways to do computing:
1. Rule based (classical computing)
2. Example based (machine learning/ai/humans)
The advantage of rule based computers is:
* no mistakes
* can be understood/explained
* can be made extremely fast
The disadvantages of them are
* not adaptable to new situations (new rules need to be implemented)
* difficult/impossible to find the "correct rules" for complex tasks (e.g. image recognition -> mapping a bunch of pixel values to "cat" or "dog")
* can be understood also means: mind can be read/hacked
The opposite is the case for example based learning. We do not understand how a neuronal network works, and the only way to hack/trick one is by feeding it bad data (i.e. fake news for humans).
So if you extrapolate from here: humans are a intelligence which works purely example based. A human with a calculator is a hybrid already. A machine which uses a neuronal network for image recognition and then uses deterministic logic on the labels is also a hybrid. Both humans and machines converge to some form of hybrid - a cyborg. Interfaces are already being developed.
## Theseus Ship/Continuity Wins
Now humans might become cyborgs (from our perspectives) but they will always call themselves humans. Even though the humans in your story might be intelligence-wise indistinguishable from computers. The only difference between AI and humans is the physical platform then. And the remarkable thing about a humans physical form are: hands. Humans would be on board of a spaceship because they are an intelligence, with multipurpose tools called hands which can repair things very well. That being said, legs might not be so useful in zero gravity anymore. So they might very well have 4 hands like apes climbing in trees.
[Answer]
## Ship's AI can aim at the target and plot courses, but humans do everything else.
If your verse could afford it technology-wise, I propose you the use of particle weapons. As described [here](https://www.reddit.com/r/scifi/comments/43wtl7/particle_beams_the_ultimate_hard_scifi_weapon/), particle weapons fire particle streams that upon impact with the target ship blossom into all kinds of radiation, which seriously messes with delicate electronics, such as AI's mainframe server. So if you want your ships to be reliable, you need to opt for simpler electronics that facilitate the necessity for human control.
Even without particle guns, humans can still do lots of things AI is simply unable to. Like, for example, fixing that wire back into place after it was torn out due to the stress of the fight.
and then even further, your setting might just simply have technophobic international (interplanetary?) laws that deny AI rights to autonomy and mandate that they should be accompanied by humans at all times?
[Answer]
Due to the natural (and probably justified) fear of an AI uprising, international law requires that every AI be hardcoded so that it is unable to kill humans, even by accident. They can do everything else in a battle, including aiming the weapons, but you need a human onboard to actually press the button that will end another human’s life.
Once you have all that goes into keeping one human button-pusher alive in space for long periods, you might as well add a few more for social needs (to keep the button-pusher from going insane) and whatever else makes sense for your story.
[Answer]
If your AI are not sapient, a human would be needed to make quick judgement calls. Say two nations currently have heightened tensions, and one begins making military exercises near the border. A human would look at that and think, "OK, they're just beating their chests and posturing," and would do nothing. An AI might look at that, and with no human to stop it in time, might consider it a prelude to an invasion, and make a pre-emptive strike, kicking off a war.
[Answer]
# Stalinism
Joseph Stalin was particularly worried about treachery among his subordinates. So he figured out that having lots of watchdogs watching over each other kept everyone too busy to try a coup.
He even had two distinct police forces at supranational level keeping tabs on each other.
So, your spaceships. They have people and AI. If the people becomy mutinous the AI will snitch and deal with the problem. Likewise if the computer tries to play a HAL 9000, Dave will put it to sleep. Until either side attemps betrayal they can cooperate on missions.
[Answer]
Because **Economics**.
Advanced AI is very expensive, while human-based [cannon fodder](https://www.merriam-webster.com/dictionary/cannon%20fodder) is cheap.
You do not want to risk losing limited number of expensive AIs on the front lines, as their power is far more important for strategic parts of the war.
Basically the same why you usually don't put a firearm in some Admiral hands and send them to the front lines. It would be a senseless waste, given that they are much harder / more expensive to replace than regular rookies.
[Answer]
* Redundancy:
Systems get damaged. Human crew may not be damaged at the same time. If they aren't, they can fill in the functions of that damaged system long enough for repairs to be made.
* Decision-making:
If your combat AI is not a true [synthetic intelligence](https://en.wikipedia.org/wiki/Synthetic_intelligence), then there will almost certainly be edge cases where it makes a bad decision, where the human crew would make a better one. Therefore it makes sense to allow the humans to override the AI in this case.
Of course, it can also lead to scenarios where the AI comes to a conclusion that seems completely ridiculous and impossible, but is actually the correct one. Then the crew overrides that and bad things happen.
] |
[Question]
[
Imagine if we would hit a point in time where we would accept that living in a virtual world is better for being happy and would make us near immortal.
And then we would build something like the matrix and upload our minds into a virtual world.
I don't imagine it like in the movie “Matrix” but more like our brains would be uploaded like a program.
And even if our body dies we would still live as digital form in some computer/program, if we had some large supercomputers and big storage where we would be saved.
We still could die, for example somebody could destroy the server or a natural disaster destroys the server and we would be lost.
The server should live long enought that the human mind would evolve in some form or another that they won't need the server anymore.
So we need a way to make a supercomputer/server near indestructible.
Making it 100% indestructible would be the goal but I can't think of something really indestructible.
How do I make the server/virtual world indestructible?
## Things to keep in mind:
* The goal is 10.000 years
* Natural disasters could happen all the time, so the server should
survive these
* Where would we put the server?
* What protection will it get? (Just buried under the earth?)
* What components would be used to make it near indestructible?
* This world is set in a semi-far future, and we could place it
anywhere in our solar system, so not just the earth
[Answer]
**Redundancy**
You do not need to make a thing indestructible. You need to make the data undeletable. Imagine I wanted to destroy the word of God as written in the Bible. It would essentially be impossible. I could get rid of every bible in town but there are more in other towns. There are millions and millions of them. Even an apocalypse would miss the one in the forgotten nuclear bunker in North Dakota.
Have your database multiply redundant. Infinitely redundant sounds impossible but for a science fiction you could make it so - data coded in protonic spin, or the positions of gluons or something like that.
If you are super duper redundant then losing your data is less of a possibility. Corrupting your data becomes a bigger threat. Consider the data in our own DNA: multiply redundant with a copy in every cell. But when a copy goes bad and is not caught by repair mechanisms: cancer.
Has this circled back to Agent Smith?
ADDENDUM
I was thinking about the ramifications of virtual life with infinite databases. Maybe all the databases are backup and only one is being used. A cool thing, though (to be revealed halfway through the story) is that they are actually all being used. There are infinite parallel virtual worlds with versions of us in each. This becomes like the parallel dimensions as seen in many shows (and my [favorite episode](https://en.wikipedia.org/wiki/Parallels_(Star_Trek:_The_Next_Generation)) of Trek:Next Generation) but you do not need scary spacetime rifts - it is extremely easy to hop from one reality to the next.
[Answer]
# You don't make it indestructible.
You make it decentralized. You make it redundant. You make it run in something like the futuristic version of Google's server farms, where your search or your email or your doc hits some random server out of a pool of available servers. If one of those guys crashes, literally no one notices except some poor, overworked, engineer who has to swap the hardware and build a new server node in the farm. Then you have farms in multiple sites on multiple continents / planets / solar systems (scale out as needed for your specific Sci Fi vision).
Put it like this. **Netflix has a "[Chaos Monkey](https://medium.com/netflix-techblog/5-lessons-weve-learned-using-aws-1f2a28588e4c)" that intentionally crashes their systems.** (their name, not mine.) This is a utility that randomly kills things on their production servers. They do this because it *forces* their engineers to design systems that can withstand interruptions or crashes.
This way, even if a natural disaster DOES disrupt your entire building / city / continent / planet / solar system, *no one dies.*
You will still need network engineers -- even if they are AI-driven robots -- to go around, replacing dead parts. Maybe even software engineers replacing bad code.
But it's significantly cheaper to build commodity-grade hardware that can survive for a few years to a decade than to build an everything-proof hardened data center that's indestructible.
With sufficient scales of redundancy, you don't even need to really plan for major disasters. You just wait and when a center goes offline, you auto-fail to the backup site while recovery people/robots rebuild or repair the old site. Or if your disaster took the site off the map, you build a new offline center somewhere else and keep going.
# You have two measures that matter.
In the plans for this, you basically have [two measures](https://www.brentozar.com/archive/2011/12/letters-that-get-dbas-fired/) that matter...
### Recovery Point Objective (RPO)
>
> RPO measures how much data you’d lose if your server went down and you brought up the secondary server. It’s measured in time, not megabytes. The less time you have, the more frequently you have to get the data to a secondary location.
>
>
>
### Recovery Time Objective (RTO)
>
> RTO is how much time you’ve got to get your server’s act together. Some companies measure it from the time you learn about the problem, some measure when the service is first unavailable. The clock’s starting point matters a lot.
>
>
>
**In your scenario, both of these measures are basically zero.** So you've got some work to do. And there's no way to build a single "box" strong enough to make these measures zero. So you have to have more than one box.
You still need an infrastructure and the industry to support that. So maybe there's a robot army out mining asteroids for raw materials to build new servers. Maybe that is controlled by your people or by a good AI that can do the work for your people.
[Answer]
**10 000 years doesn't need to take 10 000 years**
I'm not sure I fully understand this requirement:
>
> The server should live long enought that the human mind would evolve in some form or another that they won't need the server anymore.
>
>
>
But if what you need is to spend 10 000 years on the server, just run the server really quickly. If you're running the simulation 1 000 000 times faster than reality (i.e. it can simulate 11 days of virtual time every second), you only need to keep it running for 4 days. And if something bad happens and the server fails, the meat-brained human is still alive so you can just run the thing again, no harm no foul.
[Answer]
I have one word for you: *maintenance*.
For something to be indestructible for that long it has to have a system of maintenance. And those have to have back up systems, as well as back ups of those back ups.
Just the BUILDING your server is in is going to need maintenance.
Stuff needs replacing, even in the future. Foundations crack.
So you will need nanites, and you will need robots or androids, or else it won't be pretty.
Robots will also need to be repaired and maintained.
Your server will be indestructible in that it will be maintained and protected. The idea of just leaving it be without that..you need to watch Life After People.
Your scale is 10,000. Even with advanced materials which do not yet exist on earth, destruction happens, unless you maintain.
So, what you will need is a series of failsafes in place. And you don't want to think single server here--over 10,000 years, that way lies death. Everyone knows you always have a back up...
1) General blue print for the whole system is present in all maintenance droids.
2) Droids should be in locations other than just one.
3) There's a planetary defense system for objects from space.
4) Multiple memory caches rather than just one. If one fails, you have back ups. There could be a relay system with old copies of the system. Scary bit is that people could lose time and not know it, because everyone has lost time--because the server in one location is destroyed or isolated, for one reason or another.
5) There will be mining for raw materials and a supply chain, because it will be needed. Earth will be easiest, even if they are bots, because we have a variety of materials, and conditions easily allow for construction and things like blow torches. Another planet's not out of the question, but Earth has too many advantages to ignore. (Although there are liabilities such as flooding that might not happen on a planet without water--but it will be a planet without water. And you'd be surprised how useful water will be in maintenance.)
**The goal is 10.000 years** a very long time.
**Natural disasters could happen all the time, so the server should survive these** You would need a complicated predictive modeling system in order to prepare for those via maintenance bots.
**Where would we put the server?** Underground is best. But one location is not a good idea.
**What protection will it get? (Just buried under the earth?)** Active defenders in the bots.
**What components would be used to make it near indestructible?** There's lots of bleeding edge tech in this area, carbon nanofiber, self-healing concrete are place to start, but microscopic maintenance might be a bigger help than the creation of materials.
**This world is set in a semi-far future, and we could place it anywhere in our solar system, so not just the earth** Earth will make things more and less difficult in ways I have outlined above. We are used to working in our own gravity and atmosphere, so it would certainly be easier to build an efficient system on our own planet for something this advanced.
[Answer]
You're going to want to work your way up to a [Matrioshka Brain](https://curiosity.com/topics/a-matrioshka-brain-is-a-computer-the-size-of-a-solar-system-curiosity/) at some point. Since that's our goal anyway, let's go the whole hog.
Your server is going to be part of an [interstellar spaceship](https://www.universetoday.com/15403/how-long-would-it-take-to-travel-to-the-nearest-star/). I'll assume that if you're able to upload brains, you have at least fusion power. Your ship's outer layers will be fuel tanks to hold hydrogen; below that will be a nice chunk of hull to keep everything inside where it belongs. Next layer will be raw materials, silicon, iron, oxygen, that sort of thing. Next layer, maintenance robots that keep everything running during the cruise. Finally, at the centre of the onion, you'll put your servers, safely held behind several miles of structure. Liquid hydrogen will cycle through the servers to keep them cool, then cycle back out to the outer hull to radiate that heat away into space.
Your ship will head for the nearest red dwarf star, Proxima Centauri, under fusion power. It'll take a couple of years to accelerate up to around ten percent the speed of light, then the engines will shut down and only a small onboard fusion reactor will keep running to maintain power to the servers.
During the flight, the robots will maintain the servers, make sure everything's running nicely. Out in interstellar space, everything is cold and quiet; no disasters to cause us any hassle.
The ship will cruise for fifty years or so, then decelerate towards Proxima Centauri.
The great thing about red dwarfs is that they're so very stable. They'll burn quietly for trillions of years without throwing a hissy fit the way our sun is likely to.
Once the ship reaches Proxima Centauri, two things will happen.
Robots will be sent out, with or without human minds to accompany them - your choice - and start to mine the system for materials.
Other robots will remain with the ship and start dismantling it, converting it into one or more static structures with solar collectors on one side, servers on the other. These platforms will be a home of humanity for the rest of time.
The materials-gathering robots will begin assembling two new starships, and more platforms. The starships will be loaded with new copies of humanity, and head out for more stars. The platforms will continue to multiply until all the material in the system has been used up, or the star is completely enclosed inside orbiting platforms - a Matrioshka Brain.
[Answer]
Several possibilites. Here are some ideas how to get there, but please be aware that you can only get very close to 100%. I do not want to talk about materials because this sounds like a dead end to me.
a) Do not localize your server. Spread out your storage. Check out "the internet"
b) Have someone or something repair the broken parts.
c) Put it into space or on a very boring planet/moon where there won't be many natural disasters. Take Pluto for example.
d) Make your advanced civilization advanced enough to be able to calculate for example i) the trajectory of every object in space that could destroy the "server" or network if you put it into space or ii) all natural disasters that will happen wherever you put it. iii) Anything else.
I could do that all day and at the end we might reach a number close to 100%.
[Answer]
Redundancy and replication
Redundancy has been covered by others, there's nothing i have to add here.
But let's face it: nothing will last for 10'000 years and still function if it is more complicated than a brick.
So you need to replace things from time to time. This in turn means you need replacement parts. And unless you want to stockpile everything you might possibly need, and at least five times as much as you are going to need to account for failing infrastructure in the storage and whatnot, you should be able to create everything you need to replace every bit of your system.
This is where i actually have good news for you.
We are corrently well on the way of automatizing more or lesss everything, at an increasing pace.
So as soon as you have autonomous robots that are not only able to provide maintenance to themselves and to automatic factories for (pretty much everything) but also able to re-create everything that they typically maintain, including themselves, you should be set. Now all you need is a multi-redundant system that will notice failing elements and be able to replace them, and your self-replicating maintenance robots that keep everything working smoothly.
The only thing your robots cannot produce themselves is energy. But conveniently, there is a very large fusion reactor nearby that won't stop providing "free" energy any time soon. So let's consider that settled, too. Because, really, humanity having advanced enough to be able to set up that system, it should be safe to assume they learned to stop digging up dead dnosaurs to make light...
Where do we put that beastie?
Right here, on earth, spread around the globe.
First of all, this thing will have to be built. And some people will want to supervise the building. And being able to breathe while one does so is generally considered convenient.
But this planet has more to offer: A magnetosphere to protect against radiation, and an atmosphere that burns up small objects moving at very high velocities. Both are commodities not to be sneezed at, so let's make use of them. The fact that you can make use of existing infrastructure also is a bonus.
[Answer]
Since there isn't any requirement for the server to be on Earth my thought is to send it out of the solar system into interstellar space. You could hand wave some type of 10,000 year power source powered by the radioactive decay of such and such material with an absurdly powerful and energy efficient super computer which should be coming soon if Moore's law holds for that much longer. Instead of interstellar space you could also just put it in far orbit with the sun in the Oort belt which allows you to use solar panels although then you are subject to things such as solar wind and the like. At that distance collisions are still astronomically unlikely in a 10,000 year time frame especially since scientists can accurately map and predict the trajectory of orbital objects on that timescale. In interstellar space there are 100 atoms per cubic meter which is essentially nothing for it to collide into. For comparison a single grain of sand contains 3 x 10^22 atoms.
Better yet create some redundancy and send off millions of these ships. Even if 99% of them fail due to some technical error a few thousand still exist and can achieve the next stage of human evolution.
[Answer]
Make it into a humongous mecha with weapons, and tools, and the ability to clone itself. In this way, if it foresees a catastrophe, it will be going to put a good use of the server's capacity and ask the humans "What to do?"
In this way, the server will have an active, and not just a passive defense, Planetary Annihilation sessions also tend to took so long, because the main unit, the commander can flee and rebuild the base elsewhere.
As far as components go: Graphene and other carbon allotropes, as it's strong, light (perfect for mechas), inert, a good conductor, and you can easily make it into a 3d material by making it into a gyroid shape at the molecular level:
[](https://www.youtube.com/watch?v=VIcZdc42F0g)
[Answer]
Your question sounds very similar to one of the central plot lines of [Greg Egan's *Diaspora*](https://en.wikipedia.org/wiki/Diaspora_(novel)#The_Polises): it spends a lot of time discussing life in a *polis* (the hardware hosting a simulated reality for digital intelligences called *citizens*). Polises are located in isolated locations (e.g. deep under the Siberian tundra), and have multiple redundant copies (with merging protocols to allow citizens to combine the experience of their separated instances).
[Answer]
Others have already mentioned redundancy, replication, and maintenance, which I would combine to say: start with X redundant (and hardened) systems, and any time one is damaged or even threatened, build two more.
[Answer]
There is only one type of system known which can last this long, and that is a biological one which self-repairs. You could encode the data in some kind of ecological system, or something mimicking one. This could be a big soup of bacteria, or a swarm of nanobots or something like this. If computation speeds are an issue with this system, people could live out their lives at much slower than real time without them (i.e. 10 years for the stored people could be 100 years of 'real' time).
Watch out though, evolution always finds a way ...
[Answer]
Re visiting the idea of nanites. Lets say you had giant swarms of them that passively float along the ground or maybe swarm in the air when not needed. They break/die, but the other ones assemble new raw materials from the ground. The gen 2 will obvious upgrade themselves, and each generation will get better and better.
At this point, in the best case scenario they can actually convert atoms to other atoms.
Also plenty of redundancy in multiple locations.
So everything is humming along fine.
BOOM
Earthquake a server farm falls in and is destroyed.
The swarm comes in, and to as much degree as possible breaks the building into tiny specs, and move it a safe distance away. In the case all is lost, the swarm takes the elements from the ground, and makes a brand new server center atom by atom. There will be billions and billions of nanities so speed shouldn't be too big of an issue.
The server plants may either have nanities that complete build new parts and rescue materials from the old and/or have 3D printers.
Eventually replicators aka Star Trek will be invented.
Click boom, new server materializes from energy. Click and the old server is recycled back to energy. As long as the nanities can repair the replicators everything is good.
The key here is that robots and machinery are too prone to failure, where as nanities would self repair and regenerate.
Obviously each server farm would have to be self sufficient with solar,wind, water,diesel, gas, or whatever you got generators and backups.
It is best to give up on hard drives and go total SSD, solid state, storage. Solid state storage has too many advantages to ignore.
---
If you can't change atoms into other atoms, large wasteful production plants will have to be built. The nanities will then have to fly the raw materials that they mine all over the planet to product planets. Other will have to move those new items to where they are needed.
IF everything works properly server farms will randomly fall into lava pools, the oceans, and cracks in the planet, and they will simply be rebuilt a new elsewhere. Maybe you can make some air tight, and actually intentionally place them underwater.
---
The other option is of course space ships with the same general idea in mind. Nanities floating around everywhere doing maintenance. Some kind of space scoop to keep a steady supply of raw materials flowing. Even just in earth's orbit or near earth's orbit would probably get you 10,000 years easy. Moving again when our sun become unstable in whatever time that takes.
[Answer]
If virtual worlds exist, then they may be nested. Logic shows that the *vast majority* of worlds are simulations, in this case. So, the world containing the server is probably a simulation too.
Discover how to access and exploit that. Either move your own simulation “up” a level (gaining orders of magnitude performance boost!) or set an *indestructible* attribute on the server in the universe’s own simulation.
[Answer]
Simple. I don't know if you've read any Isaac Asimov but from a book in his Robot series, Robot Dreams, there is a computer that slowly evolved to be moved by humans into hyperspace, the upper dimension. Indestructable, it eventually became God to another species. It is assumed that the same thing would happen again, but I'm getting off-topic. My suggestion is to put it in hyperspace.
[Answer]
The coming paragraph doesn't answer your question per se so feel free to skip it:
The concept of people living in a computer system is unachievable with our 1s & 0s.
That being said, quantum computing could- in theory- be possible. Unfortunately it's in opinion that you could only transfer thoughts and memories; Desires and emotions wouldn't make the transfer, but hey, you would live "forever" and perhaps it could be simulated. The main controversy is people wonder if it is "you" that's in the system when you're transferred.
The system you're thinking of dissent nearly exist and as others have already said you need a redundant system. So far machines cannot run on their own there still need an "acolyte" of some sort either human- or other bio electrical being that heals technician the first one is more plausible. People that only purpose is to serve the system.
Even with all redundancies if the "server's" (or servers') environment in the real life world is destroyed Ott becomes in hospitable for it then the system could fail. To help counter act this a probe could be set to launch into doable if earth becomes inhospitable- even if it's a space station it would have to leave at a moment's notice. Then theirs a question if it will or not survive the transit to another planet even it assuming it's not looking for a habitable one. So in that case there should be more than one capsule splitting the load to limit collateral damage.when got think about it space would be the best option. You then have the problem of deleting memories of persons of a system loses data so the "persons" that do survive so that they don't feel lost or if the system resides to delete a few to save memory or power.
If your system doesn't use an "upload" of consciousness like the brain of the the persons' in a type of stasis would help remedy the allocation of memory space and ram it would also allow the system to tap on the physical brains as processing power for both the environment and problem solving. This would also help remedy the lack of emotions especially if the brains are properly maintained as well as fed the proper chemicals and hormones to achieve emotions in those acolytes I mentioned could be a brain placed into a bioelectrical android temporarily outside the "environment" l to perform the requires maintenance everyone would have to pitch in our be "expelled" permanently from the system.
] |
[Question]
[
I am looking for ways to tell time when the sky is completely blacked out all the time.
I am aware of nails and other metal objects inserted into candles. Due to vegetation dying due to this calamity, sources of candle making materials could be in short supply. Such as: bees, animal fat,uhh human fat.
Magic is rare, but available, to alleviate some problems.
Godly given magic is also a rare commodity as worshiping souls are becoming more and more rare.
**EDIT for clarification**
Cause of blacked out sky: Super-volcano event causing an ash-cloud that will last years, maybe decades. After which an ice-age will begin.
Crops, animals die or are eaten. Villages without walls or militias are preyed apon by creatures and other villages.
Travel is risky due to ash-storms (tornadoes of abrasive ash) and creatures/brigands that prey on the traveling caravans. Caravans now use
a herd mentality. "They can not get us all.."
Using torches/fires also ill-advised as that is a beacon to said creatures/brigands.
People reactions to:
* Mages: Untrusted but needed as they bring firepower. Scapegoated by others as cause.
* Priests: varies from saviors as they can still provide some meals, to zealots as godly magic is becoming more and more scarce as worshipers die off. Some have demanded only those who worship the local deity be allowed services. Think salem-witch trials stuff
[Answer]
It seems that what you are after is a [water clock](https://en.wikipedia.org/wiki/Water_clock). There's many designs, but the simplest is a water-filled jug in which floats a shallow bowl with a hole drilled into the bottom. Water trickles into the shallow bowl, until eventually it sinks. This provides a consistent and repeatable measure of time.
[Answer]
**Tide chart.**
The moon is concealed. But it is still there. The moon pulls on the sea and causes tides. The times of the tides are known.
<http://www.mvtimes.com/community/useful-information/tide-charts/>
[](https://i.stack.imgur.com/4OC51.jpg)
Tide charts predict high and low tides for a given place well into the future. If you ran out of days, you could start with a tide chart for current days and extrapolate into the future.
It turns the tide chart on its head. You can pay attention and mark high and low tide. Usually you know the time and so look up the tide. Here you know the tide and use it to look up the time.
[Answer]
You can also use an hourglass, filled either with sand or water.
It tells you the passing of time, and if you have enough of them, with different sizes, you can also tell multiples of a base unit of time.
[Answer]
Medieval time measuring is a topic in itself - a very dense one. First of all: forget what you know about time now. In medieval times one did not measure in minutes or seconds, at best in hours, if at all, and then usually to indicate when to meet or because of religious reasons (the "horen" or hour prayers for example). If one needed shorter time measurements, it was usually to make a speed pickup, like aboard (to calculate distance traveled), or for some tournament, training or tactical reasons.
Let's for the sake of the argument, assume that our people are cave dwellers or in an otherwise dark but not freezing environment. No sky to speak of, no animals that generate lots of fat. However, in the dark, mushrooms grow. Not all bioluminescent funghi do glow evenly at all times - some could be used to judge a general "before noon" "afternoon" and "night".
Then there are bioluminiscent insects with a known pulse span, but that is only good for short terms. Like "10 pulses" for measuring the time it took McGuffin to get from the door entry to the couch.
That's it for "living" clocks, but let's see if we can get other ones...
The famous water clock could work: a basin is filled and then water flows out at a known rate, and the basin is refilled. we know that the upper hours have a little more volume in regards to the water contained (more water = higher pressure = higher flow rate), but that can be adressed for by checking that against an hourglass in the making. Which is another method.
But we can modify our waterclock to use a thin tube and a well refined, thick fluid like oil instead and then fill the lower basin back up to the reservoir at specific times. That would be an oil clock.
But as we have oil, maybe crude oil or naphta, we could also put a whick into the oil tube with a swimmer, and then ignite it. The oil will burn at a slow rate, and lower the level slowly - if measured out correctly, this could give good measurements over long periods of times, maybe even several days to a week within a somewhat ok space.
But let's go mechanical! Our cave people might have a source of flowing water (that is, unless the dark sky is eternal winter, then... forget time measuring at all, you don't need time in the wolf-winter before Ragnaröck), which should be steady enough. If water flows, it can move a waterwheel, like from a watermill. Using this power source and a few gears, one might make a simple clock that turns the hour indicator once or twice a day, maybe even some other dials that indicate it is working (minutes), before or after 'noon', day of the week, phase of the moon etc.
[Answer]
There's no real reason a normal clock wouldn't work. The oldest clocks are over 1000 years old, and they can be built with simple tools if they are large. <https://en.wikipedia.org/wiki/Clock#Early_mechanical>
[Answer]
A large pendulum could do the trick such as [Foucault’s Pendulum.](https://www.fi.edu/exhibit/foucault%E2%80%99s-pendulum) In addition, various mechanical timepieces using pendulums from the old-style grandfather clock to a cuckoo clock, to spring driven devices.
[Candles](https://historyplex.com/candle-clock-history-facts-limitations) could also be used with hours marked off as they burn.
[Incense clocks](http://www.japanese-incense.com/time.htm) would be another way as well.
[Answer]
We're making a whole new world here, right?
## The Land Speaks!
Each day is split into four phases.
"Dawn": During the time that the sun would have risen, a priest feels a sudden surge of excited energy. It causes a hastening of his actions breaks him from slumber. This speeding up is something they call the Fastbreak. He receives new energy from the deity and can produce food. This energy diminishes through the day.
Midday: The animals become suddenly enraged and attack. They all seem to let out a sudden collective howl as something inside of them causes them to lose control of their senses. Nobody wants to be out during this time, especially alone. They call this time NoOne Time.
Evening: The mages feel a sudden surge of energy replenishing what they have used through the day. Suddenly the air crackles like lightning, followed by a humming noise that you can't get away from. It's hard to talk over the din because even plugging your ears doesn't diminish it much. This time is called DinEar.
Nighttime: The land feels a sudden surge of energy. The volcanoes become much more active and will emit a sudden BOOM signalling this time. New ash, smoke, and a black glowing mineral cover the area. The mineral is of very uniform grain size, making it perfect for hourglasses. They call this mineral Black Ash Minite.
Priests and Mages know to pace themselves on the use of their energy. They can FEEL it leaving them. Since NoOneTime is the most dangerous time of the day, mages have to be especially careful not to deplete energy overnight on frivolous magic lighting or heat. It makes for a nice tension point for nighttime magic use.
[Answer]
You'd need one of the rare and extremely valuable [sunstones](https://en.wikipedia.org/wiki/Sunstone_(medieval))! Even through cloudcover and smoke, with holding a sunstone towards the sky will tell you at what azimuth the sun is, making it possible to track both time and date! Important happenings such as solstice or mid winter "blot" can be ascertained by knowledge and a sunstone.
The priests naturally hoard them, as it lets them keep track of the important religious dates, the mages covet them for they need precise timing for their occult rituals. Ensue chaos and war ;)
[Answer]
There its a plethora of ways to do such thing, from water clocks to sand clocks, gravity clocks (they sound fancy but they are just falling stuff over time) in general have existed since always, time its relatively easy to keep track, but if you are looking for some magical/medieval cool kind of clock you could do a buffed solar stone, vikings used to have huge quartz stones as a magnifying glass to see the sun under the thickest fog then they used it to cast a shadow into solar clocks to tell time and to orientate themselves, so if there's magic you could do some kind of buffed solar stone that helps you to find the sun even through the ashes to do the same, to orientate yourself and to tell the time.
Ps. also eruptions usually throw lots of quartz to the air, specially powerful eruptions
[Answer]
A **Fire clock** within a building / opaque lamp will set you up - fire needs tending to or it goes off, you know.
In a world without the sun to provide natural light and heat, someone has to be in charge of maintaining the community's artificial light+heat source - let it be a big firepit in the village's main hall (Viking setting, anyone?). Inside of a building, you're not exposing your village to Night Shades/brigands of the Dark.
Since a bunch of people rotate to be in charge of this socially important task, and they need to keep track of when to place extra wood into the fire (wood is also scarce because, umm, no sun for trees to grow properly), the **Great-pit**, where everyone gathers to warm up and cook and eat (also, in a medieval setting it's easier to get your fire from an already lit one) is a good place to get your time reference.
When venturing out, use an opaque lamp and measure time by the amount of fuel remaining/size of flame (that's affected by the amount of available fuel)
[Answer]
Possibly some people have the condition chronometria, an innate ability to detect the passing of time much more accurately than most people. The condition is somewhat rare, and before the disaster occurred, those who had the condition often found employment on ships or in mines. Some chronometriacs found a religious calling, and provided accurate timekeeping services to monastic orders.
After the disaster, the unusual condition becomes more valued, possibly even leading to an order or guild of timekeepers.
The exact mechanism by which chronometria works is perhaps unknown, but theories could include an unconscious awareness of one's own heartbeat, sensitivity to influences from the heavens, divine inspiration, and witchcraft.
[Answer]
Personal biological signs could be used. Breaking the day into a number of small meals with society agreeing to try to all eat together. The day might be split into 5 parts, around 4 meals.
[Answer]
Ynneadwraith's answer got a lot of support as a most obvoius one (I upvoted it too), yet it's not accepted... What are you waiting for? Some "magical stuff"?
Here you go:
* Some "predcestors'" left artifacts. This can vary from monoliths to lost watches. Artifacts don't even need to tell the exact time, just to change their state with constant periodicity. "Oh, Sarah, haven't seen you for eleven thetas".
* Sense of time of commoners. A racial feature - they just perfectly know, how much socks they could've knitten (the second/minute/hour is just a human invention) since their last meeting with their buddy. "Oh, Sarah, haven't seen you for an entire two thousands socks"
* Some other regular event (like regular earth tremors or smth.)
The main question to you is "Why would they want to measure the time in such an unpredictable world?"
] |
[Question]
[
In [Plague-inc](http://www.ndemiccreations.com/en/22-plague-inc) the most typical strategy is trying to infect everyone, while staying hidden by not harming infected people (when a virus, bacteria, fungus is found, people start working on the cure). Once everyone in infected the epidemic starts to kill.
However, because it is a game, it has some "advantages":
1. A human player:
He knows that he has a strategy to execute. The strategy may be quite strange, like infect everyone without causing them any harm so 'they' cannot find him. Once everyone is infected he evolves lethal symptoms to kill. The effect of this strategy is to maximize his goal: infect, kill. Stay hidden while infecting 'them' would give him a head start, as 'they' are not working on the cure until he gets into the 'kill' phase.
2. Full environment data is exposed.
The player knows how many of 'them' are left. He knows if anybody or a region is not infected yet.
3. A specific goal: to kill all people, not to survive (as a virus). Kill all hosts also means a virus (or anything else) would not survive, because they are parasite.
In reality, those advantage may not be fully available.
Thus, I would like to ask if there are any realistic explanations for the case of a disease (virus, bacteria, fungus) executing the strategy "infect all before you start killing them". In this case there are no human (or alien sentient) monitors directly.
[Answer]
An infection suddenly becoming lethal after infecting a majority of the population is pure fiction.
The closest real world analogue are diseases that have an asymptomatic infectious phase before they start harming people. Unlike in Plague inc. where every infected person suddenly gets ill, real diseases don't coordinate between people.
[Answer]
The most egregious break from reality in Plague-Inc is that every pathogen around the globe suddenly mutates from harmless to lethal at the same time. This is not how real-world diseases work. When there is a mutation, that's actually a *new* disease which evolves locally in one place and then spreads from there. Anyone infected with the old strain won't experience any of the symptoms of the new strain until they also get infected with that one.
If you want a humanity-exterminating killer disease, create a disease which is:
1. highly contagious
2. has a very long incubation period without any symptoms
3. is deadly when it actually breaks out
think: airborne HIV.
[Answer]
## [Quorum sensing.](https://en.wikipedia.org/wiki/Quorum_sensing)
This concept pretty much is defined by the question. An organism behaves in one way at low population densities, but then switches to an alternative mechanism once they reach higher densities. This is usually done using a chemical trigger upon reaching high population densities.
While this system only works on relatively short ranges in known biological systems, there is no reason that this mechanism cannot be expanded to larger systems.
For example, an infected host can constantly send out large amounts of spores, which do a double job of infecting new hosts and indicating that it is now infected. When infected hosts detect a critical threshold of spores, they start expressing the lethal set of genes, which results in them killing the host.
## Reality check
However, it must be noted that this system is extremely unlikely to evolve naturally, and would likely have to be engineered. No monitors are required after the initial engineering phase, however.
This is because killing the host is evolutionarily detrimental to the pathogen's fitness, and there is a huge selection pressure for mutants that violate the quorum sensing and do not kill the host. An engineered pathogen will have to include elements that inhibit the selection pressure.
[Answer]
Consider a parasite with two reproductive strategies. Success is fitness: the number of progeny produced. The parasite does not know the big picture worldwide.
A: A parasite which runs its host into the ground is a dead end after that. But in the short term a lot of progeny will be produced by the dying host which equals a lot of genetic fitness.
B: A parasite which limits reproduction and keeps the host healthy will maximize opportunities for transmission. But in the short term it does not have the fitness of one which maximizes reproduction in a single host.
In a circumstance where transmission is easy (for example a crowded refugee camp or a dorm) you could use mode A without much fitness disadvantage - the ease of transmission means the short window before your host is moribund means you can transmit and run your host into the ground both.
In a circumstance where transmission is more difficult (spread out population) you want to maximize the period when your host is mobile and well, to facilitate transmission.
If there is a point at mode B (stealth) where additional transmission is unlikely because all local hosts are infected, then I can imagine an individual parasite which switches modes and runs the host into the ground with rampant replication. When Mode B is unlikely to provide additional benefit so an individual parasite (or a single in-host population) that switches to mode A gets the most fitness. The possibility for making this switch might be built into the genome of the parasite. There would be a balance of selective pressures: for an individual to switch early and give its own progeny the runaway advantage vs staying low level and giving your progeny the contagion advantage.
HIV does not plan ahead but this switch is more or less how it turned out. A large asymptomatic population facilitated transmission (B type) with persons dying (A type) only later in the course of the illness. Many other viruses use this approach - maintaining a B-type stealthy population reservoir in a well population that can then serve as the nidus for an A-type epidemic when circumstances are right. This is how the viral diseases that ravaged New World populations got to the New World. No-one would put a person dying of virus on a ship for a long ocean voyage - these people were virus carriers.
As re every single person in the population suddenly becoming ill (as apparently is the case in Plague Inc) consider again HIV. The number one cause of death in persons with advanced HIV is pneumonia. The [death rate for flu among persons with HIV](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2775097/) (pre-HAARt) is between 100 and 1000x that of the general population. If you posit two hits - a set and spike type deal - one could have all the infected population fall ill and die because of a second factor which comes through.
[Answer]
I'm thinking yeast infection.
What if the disease was a type of fungus. It's perfectly viable in the normal environment, including the air and most surfaces, and generally lives comfortably on the skin or inside an animal host. It's ubiquitous and nobody looks twice at it - except maybe when that sandwich you left in the fridge starts getting fuzzy. If it's part of the natural body symbiont flora in the digestive system, mucus membranes or skin your body won't have a strong immune response. It's impossible to get rid of due to its prevalence in the environment.
We've got ubiquity and stealth, what sets off the mass extinction? A drop in a critical nutrient or energy source makes the humans (and other animals) the best option as a seed bed to keep the fungus alive. It doesn't particularly care about the life of the host, it's just food. Killing the host quickly would eliminate the immune response and make the food even easier to get at.
I'm thinking necrosis of the skin and exponential growth in the mucus membranes are the primary symptoms. Yeast infection and thrush at a grand scale.
There are some fun fringe scenarios too.
* The fungus likes mucus membranes in the mouth and nose. Rapid growth
plugs the airways, suffocating the host. Growth in the lungs would
work as well.
* Gut flora go wild, starving the host as they use all the nutrients.
* Byproducts are toxic to the host. If it is in the lungs, a fermentation process would release carbon dioxide, suffocating the host. Maybe it produces something like cyanide?
Even if somebody does survive, the whole ecology is going to be devastated. Most animals will be dead from the same infection, and it might cause enough growth and mutation to start going after plants.
I have no idea how realistic this would be, but it fits the model.
**Addendum**
An alternative to the resource shortage surge in growth, you could try the strategy of the [periodical cicada](https://en.wikipedia.org/wiki/Periodical_cicadas) . They hibernate for a large period, usually a prime number of years. They then burst from the ground en mass and breed like mad. Any predator is rapidly overwhelmed trying to keep up with the sheer volume of prey. Make the fungus experience a rapid growth cycle periodically. If the period is long (say 97 years), people would remember the last time time as a rather annoying bit where food spoiled faster, and a lot of ponds got really scummy. But this time, something in the modern environment provides way more energy than the previous cycle and you get the huge problematic attack on people.
[Answer]
As others have pointed out, it won't work like in Plague Inc: If a relatively harmless virus spreads through the population, and somehow evolves in one place to become lethal, then the lethal version has to spread *again*, the harmless viruses will not suddenly all change to become lethal.
However, it is possible to have a virus that first infects everyone and then, later, kills many people. It probably won't infect 100% of the population nor kill 100% of those it infects. But it could affect a large enough part of the population to end society.
The evolution of such a virus without a human designer is very unlikely, but not impossible. Here are some options for how it could work:
## Long Term Effects
The initial infection with the virus is harmless and only causes whatever symptoms are needed to spread the virus. But in the long term, either the infection damages the body so thoroughly that it becomes difficult to survive, or it causes some secondary effect (through toxins, destroying tissue, overstimulating the immune system...) that kills the host.
It could take many years between the initial infection and the secondary damage, so that people won't discover the connection and won't take drastic measures to avoid the virus's spread before it's too late.
A real-world example is HIV. The reason it didn't infect everyone is because infection can only be spread by intimate contact or medical procedures. So humanity as a whole had time to find medication that can render the infection relatively harmless. If the infection was spread easily by casual contact, things would be quite different.
In this scenario, it would almost *have* to be a virus, because bacteria or fungi are generally easy to kill and therefore are unlikely to remain active in the body for very long. Bacterial infections generally aren't as contagious as viral infections, either. However, they could in principle kick off some other process in the body, that ends up killing the host when the bacteria are long gone. For example, they could produce harmful prions somewhere in the body, that cause nerve degeneration years later. In this situation, the connection between the infection and the deadly effect would be especially hard to establish.
## A Secondary Trigger
Again, the virus infection itself is harmless, but the virus stays active in the host's body for some time (months or years) and ends up killing the host once some secondary stimulus is introduced. This would have to be something that happens to everyone, but not often. It also needs to be something that can't easily be avoided: If people start dropping dead after swimming in a pool or getting anaesthesia, those things just won't be done any more.
Maybe the virus has a deadly interaction with the common cold. Or it makes the body unable to tolerate heat, cold, summer sunlight. Or it causes a deadly allergy to some common pollen: All these things won't show up for a few months if you time it right. Various science-fiction triggers can also fill this role.
For this scenario, your infectious agent could be anything. Virus, bacteria, even some environmental chemical (though you'd have to explain how it spreads to *everyone*). And since the trigger can be something that everyone is exposed to at roughly the same time, you could have the sudden effect that you want. However, the death rate will probably be lower than in the first scenario, because there will always be groups of people who manage to avoid either the infection or the secondary trigger.
---
There's one other thing that makes reality different from Plague Inc: Just because people notice that a virus exists and may be connected to some deaths, that doesn't necessarily mean they'll find a cure in any specific timeframe. So your virus doesn't have to be undetectable to have the intended effect, it just needs to be able to spread in a hard-to-avoid manner.
[Answer]
In order to become lethal universally in short order, there needs to be some sort of universal stimulus. The mutation for lethality must also be somehow beneficial to the virus in the short term by allowing it to find new hosts, or overcome a new obstacle. Consider the following scenarios:
1. A rapidly adapting, highly communicable disease that is naturally parasitic of humans is normally not deadly to them (think common cold). If someone were to develop a medicine that suppresses the virus and distribute it worldwide, the virus will adapt to overcome this. **If the simplest mutation to overcome the new, global medicine also happens to be lethal, the virus could essentially spontaneously mutate in every region of the world and kill all of its hosts before it had time to scale back.**
2. A new alien pest (not necessarily other-worldly, but maybe previously isolated) like a rodent rapidly spreads around the world. The virus, which normally infects humans, has a simple mutation that will allow it to infect these new pests, but will start killing humans. **The upgraded virus can spread from pest or humans, to pest or humans, so it takes off and replaces the old virus, and probably very similar versions of it emerge in many places because the changes are so advantageous.** Essentially the virus changes preferred host from humans to pest.
Any way you look at this, there needs to be some sort of trigger.
[Answer]
The problem, as other answers have allready pointed out, is that you need every instance of your virus to change in a very short timeframe.
Normal mutation obviously doesn't allow for this, so you need another factor that will cause the change. A global factor.
Introducing "Killer Cold Bacterium A (KCBA)":
Under normal circumstances it acts like a mild cold. Some light headaches, mucus, and joint aches. Like a wart-infection it turns dormant, but never really vanishes. It also happens to be resistant to broadband antibiotics.
Considering it's minor effects on the populace, Health Care Officials are reluctant to use more targeted Antibiotics treatments, because they fear the spread of further antibiotic immunity.
However, what we didn't notice was that KCBA also leads to increased absorption of nitrogen from the air. Under normal circumstances this doesn't cause harm, but after a melting glacier releases a significant amount of formerly bound nitrogen in the air, it causes mass-suffocation of anyone that is infected.
[Answer]
You could have a virus which has evolved to kill large numbers of social animals by only becoming dangerous when exposed to another chemical. So it infects a tribe and then they get killed off once they start sweating or coughing up something which makes the infections dangerous then a whole tribe can go down.
This could have evolved if the bacteria has a symbiotic relationship with a predator, something which might struggle to take down a pack of prey. The bacteria can then reinfect the Predator once it has come to eat the dead prey. The bacteria would have no negative effect on the predator though.
I don't know the biology behind that but as long as there is a benefit to it in an evolutionary sense it could evolve.
## My take for your story
This happened years ago but the bacteria mutated to have a period of ninety years or so. It infected all of humanity but as a harmless bacteria. Now lifetimes are longer though, long enough for the bacteria to start producing the dangerous effects and no one suspects the elderly are the cause until too late.
[Answer]
Given the OP's question seems to imply this is a deliberate attack by a mad scientist or evil organization, then there should be a two stage process in play:
1. Spread the infection. A genetically engineered virus or bacteria is released in such a fashion that it can reach and infect large numbers of people (for example, released at a major air hub or large metropolitan region). The organism infers the hosts, but there is no outward sign or anything amiss at this point.
2. An artificial stimulus is released which triggers the infectious organize to change into its lethal form, causing mass die offs in a very short time-span, making it almost impossible for the authorities to develop any form of countermeasure.
The trigger would have to be something which can be quickly released and absorbed by the hosts in a short time frame, either a second organism, a chemical trigger or (very speculative) using some form of electromagnetic radiation as a signal to change.
The big problem wold be to find something which is both fast acting but not so ubiquitous that it might be stumbled upon by accident, alerting the authorities that something is amiss (mass die offs in an urban setting due to a relatively insignificant chemical accident might be a possible tip off). This sort of binary biological warfare agent seems unlikely in the extreme, but some sort of clever genetic engineering may make this avenue of approach possible.
[Answer]
# Path 1.: Bioaccumulation or long lasting damage
What you're looking for is a disease that doesn't directly cause death. Think of something like [Hepatitis B](https://en.wikipedia.org/wiki/Hepatitis_B) (not exactly what you want but close), or other diseases which can be carried unknowingly for the whole lifespan in some hosts.
Your disease would be harmless to all hosts but would come with long term damage.
## Example: liver damage
All you really need for that is a harmful waste product that bio-accumulates in liver over months or years. I'll continue with liver example, but remember there are other parts of body that can get slowly damaged and it takes a while before you notice [and then you die](https://xkcd.com/1839/) - brain, heart, CNS, kidneys, digestive tract...
Still, you - as a disease - would probably get found. There are people with liver issues who have their liver inspected, there are people getting liver operations etc. Doctors would notice something amiss. If goverments acted quickly on their advice and checked the healthy population livers, humanity might survive.
However the casualties would be pretty impressive still. Just imagine, 90% population with failing livers. Yellow skin and eyes, people vomiting and shitting themselves. Quite interesting from storytelling perspective.
## Other examples:
### CNS damage
You can make acetate or other organic solvent disease's waste product. These solvents slowly damage CNS. But people would probably notice the smelly breath and the dizziness.
### Serotonin imbalance
Make it slowly disrupt serotonin levels (eg. again, by producing serotonin as a waste product). While serotonin imbalance doesn't kill you, it can make you kill yourself or someone else - what you'll be looking at are serious switches in mood, severe anxiety and sleeping disorders. Those people will look like zombies, but will be even more dangerous. If you want horror, this is a great path you can take with your story.
Great thing about this is that it's really hard for average person to admit to themselves that they have these switches in mood. You can expect mass craziness.
# Path 2.: Competing diseases
Imagine another disease disperses along with the other one and, once they reach certain maximum levels in every host, they start competing in a harmful way. Imagine it being nuclear war between two diseases in your body. Not so realistic, but cool.
Bonus points for different symptoms in different strains.
[Answer]
As others have pointed out, you can't spontaneously apply a new mutation to every virus (or whatever) at once. If one population of the virus evolves into a lethal strain, the new strain needs to start infecting the human population from scratch. But suppose that the original strain, while otherwise harmless, weakens the immune system in a specific way that prevents it from being recognized as a hostile body. This is beneficial in of itself, since it allows the virus to remain in a host indefinitely, and not harmful to the host as long as no other illness exists that takes advantage of the weakness.
But suppose that after this original strain has infected the entire population, a new strain mutates in such a way that it becomes lethal after some incubation period. The lethal strain still needs to spread normally, but because everyone is already infected with the original strain, their immune systems have already been modified to ignore the new strain. If it's airborn, it'll spread extraordinarily quickly, even once it turns lethal and quarantine measures are put into effect. Presumably, there would be [a few places](https://en.wikipedia.org/wiki/Madagascar) that are isolated enough to keep the disease out, but most of the world would be helpless to stop it from infecting the majority of the population.
[Answer]
It's rarely ideal for a parasite to try to kill its host. Dead host means no more resources for the parasite, and that's no good. Therefore, most diseases limit the damage they do to their hosts. Most of the well-known exceptions are diseases that recently jumped between species, and they're not very successful -- Ebola, for example, doesn't usually spread very far before dying out, because it kills its hosts too quickly and too effectively.
BUT! That evolutionary calculation changes when *another* parasite is present. If there are *two* parasites present, competing for the same host resources, it turns out that it can easily become beneficial for each parasite to try to burn through those resources as quickly as possible, basically trying to take away those resources from the other parasite. "Burning through resources as quickly as possible" is generally not very good for the host. So, some parasites are harmless *until* their host gets another infection, at which point they switch over to a much more dangerous mode.
You could imagine an infectious disease doing something similar if it erroneously detected other copies of *itself* as a competing parasite. So if you get an infection once, you're fine, but if you get another one (say, a slightly mutated strain from a second source), it goes nuts and kills you. That way, the disease would be relatively harmless until it built up in the population, at which point you'd start getting double infections and deaths.
[Answer]
Realistic? And biological... Basically impossible, unless somehow a collection of viruses can exhibit intelligence...
Perhaps program your virus's evolution, somehow ensuring that certain traits would evolve at certain times, being able to customize what traits are evolved in.
Possibly some signalling could happen, somehow making your virus radio-sensitive or chemically or something, so you can broadcast a signal from your location, or the virus customizes humans to broadcast heartbeat signals towards other infected, giving data like, "some number infected, some number to go", etc.
Maybe this virus can infect anything, turning plants, and moulds and stuff into servers to direct the viruses that are inside humans.
[Answer]
The only ever scenario where something like this could be advantageous is in sparsely populated world of nomad humans, which have scientifically advanced medicine but don't ever communicate between them. Either because there are strong magnetic fields confusing radio waves, or just because they hate each other, for instance because of continuous splitting into religious sects which think everyone but them is straight-out working for the forces of evil.
Then the virus could choose to go undetected until it has infected the whole tribe, then kill off everyone to lay a massive amount of spores, which will infect the tribes taking the land or passing there.
This because the tribe could find a cure if it could see the illness in action, so the best strategy for the pathogen is to leave no witnesses. This works if tribes never communicate: every tribe coming in contact with the virus will be a dead tribe soon, so no knowledge accumulates towards a cure. Which is a pretty valid advantage for the virus.
[Answer]
As many others have pointed out there is no means of communication, and thus a Plague, Inc type switch is impossible.
However, lets consider a very skilled bad guy who wants to do this anyway. Can we come close?
Yes.
Our pathogen must be a bacterium, of course it's made resistant to all antibiotics. Said bacterium likes to colonize the upper respiratory tract but causes no symptoms while doing so--but if the patient gets a cough for any other reason the disease goes along for the ride.
While the existence of the bacterium might be noted it will be ignored because it doesn't cause any symptoms. However, in time it is discovered that this "harmless" bacterium isn't so harmless after all, it just has a very slow incubation period.
Now, the bad guy is ready for this, he didn't think it was as harmless as everyone else and made a vaccine. The vaccine is legitimate and works, providing basically complete protection to anyone or anything it's administered to. (Said bug must infect something with a fairly short lifespan that is used for the testing. Perhaps a chicken.) However, if the vaccine is administered to someone already infected for a substantial period of time it's quite another story--the bacterium reacts by releasing a viral payload it has been carrying. This has an incubation period of weeks while it produces nothing but a mild cough, then it turns very lethal when the viral load gets high enough.
Thus the medical community provides the trigger, by means of something that to almost every test is safe and effective.
[Answer]
The key is to have the plague harmless and virulent. Preferably the body's immune system doesn't even recognize it.
Now the trick is to make it fatal once you get to a certain point.
If it was me, I'd use bacteria and have the bacteria pick up and store toxins that the body would normally handle in small amounts. The bacteria would release said toxin upon it's death.
Now if the bacteria used telomeres like human cells do, they would lose some every time the cell divided. Once the telomeres run out, the bacteria would die releasing the toxin.
Basically the bacteria would spread and spread but suddenly all around the same time, they would all die taking the host with them leaving mankind with no time to develop a cure
[Telomeres](https://www.tasciences.com/what-is-a-telomere/)
[Answer]
If you're looking for something that'll kill 100% of the population, I think you're out of luck without resorting to fiction.
The other answers rightfully point out that the organisms behind infectious diseases don't coordinate. **But humans do**. And infections can alter the effects of normal human behavior.
Make a virus that infects everyone with no symptoms but causes some major harm a while after a major human event happens.
Example: a virus that massively accelerates lung cancer in the presence of smog. This is definitely possible and similar situations exist in real life (for example, asbestos exposure dramatically raises the risk of cancer when exposed to other risks like smoking. It's not hard to imagine a virus that does the same thing).
Or maybe a strain of HSV-1 (which has infected the vast majority of the population) that drastically accelerates aging after a certain duration of infection (so that if you've been infected for a long time you just drop dead). Perhaps by shortening telomeres? This isn't really what you're looking for, but it is a human trigger in that now we live long enough to make this a problem.
It's also worth noting that most oncoviruses (cancer-causing viruses) probably wouldn't matter if life expectancy were shorter.
Edit: better example: a virus that has a powerful symbiotic effect on another infection. Pandemics are a relatively new phenomenon; pre-modern era, people were too separated for everyone to be infected. Now with globalization everyone can be exposed to relatively harmless infections. So give it a latency period that kicks into high gear later. Like a virus that waits 10 years and then kills you the next time you get the flu.
[Answer]
There are diseases where the initial infection is not lethal, at least with proper treatment. The HI virus comes to mind: the host is quite survivable, the virus can always spread by transferring bodily fluids\*, and it's almost impossible to cure.
Another example would be the measles which can bring about some nasty complications years after the infection.
Herpes is a third example of a very persistent virus, though it's not nearly as deadly as required by Plague-inc.
\* Is there any medication to make people less infectious?
[Answer]
Let's start simulating with a small and dense community, such as a single isolated town of 1000 people, to keep it simple. Every host frequently has contact to many others and the bacteria in infected hosts can form a network and stay in touch with all others. Now, after we have infected everyone with our harmless disease, we need to modify it to become lethal. I will consider multiple options:
## [Horizontal Gene Transfer](https://en.wikipedia.org/wiki/Horizontal_gene_transfer)
Bacteria have various methods to share DNA with another bacterium, most notably [bacterial conjugation](https://en.wikipedia.org/wiki/Bacterial_conjugation). This is for example used by some bacteria species to spread resistance genes. You start the trigger by implanting the gene in a small group of bacteria and let them share the genes with others. To modify the diseae in another infected host, only one modified bacterium would have to reach that host to start giving it the already present bacteria. This is a lot faster than letting the bacterium replicate from scratch. You could also include genes that somehow help to increase the chance and speed of the gene transfer.
## Chemical Signals
Alternatively, the genes to produce the lethal toxin were present all the time, but the toxin wasn't produced because a trigger was missing. Most (bio)chemical reactions need a certain environment (eg temperature, pH value, presence of catalysators) to happen at a reasonable speed.
You activate the trigger by exposing some of the bacteria to substance A, which acts as a catalysator to produce toxin B as well as more A. The catalysator travels from bacterium to bacterium, signalling to start producing the toxin. You could also have A and B being the same substance.
## Pulling the Trigger
*Disclaimer: What I describe in this section is a stretch for reality-check and would require significant new inventions in the biochemical principles of nature.*
Maybe we can use the complex nature of biochemical reactions to make our bacteria smart enough to "pull the trigger" themselves. Each bacteria could carry with it some signature information of every host it (or its predecessors or other bacteria it met) has ever had contact with. I'm not sure how to distinguish multiple hosts. Maybe we take a sample of the DNA (which should be slightly different in any host), maybe just a rough analysis of the chemical mix in the blood or whatever. It doesn't have to be exact, for we can never reach 100% accuracy.
These signature tokens should be shared amongst our entire network (but a bacterium will accept each token only once), so that at least some bacteria will have the entire set of the infected hosts available. All bacteria repeatedly "count" the tokens by putting a certain substance in the pool for each token. Once the concentration of that substance is high enough, i.e. the number of infected hosts roughly meets a certain predefined value, the bacterium starts the trigger.
Of course there is always the problem of mutations that let a bacterium start the trigger early, or getting the trigger from another source by accident. There can never be full certainty in biology. (And likewise I believe that it's absolutely impossible to kill off 100% of the world-wide human population with biohazards)
[Answer]
Could we lead the immune system of the body to help spread an even more sinister infection?
Consider it a two stage process with two different infections, assuming you have either a good distribution system or a well centralised patient zero:
1. An infection that is highly contagious but does very little to the body, such that the host's immune system creates antibodies for it.
2. Secondry virus would be very similar to the first so that immune systems uses those previous antibodies to fight it. But it is altered to use this unprepardness in a way to kill the host.
This is the way that I would try to develop it anyway. The first will pass by with very little fanfare maybe even being called a seasonal flu. But the second would kill, optimally I would like it to shut down the immune system so that even common infections will lead to deaths (evil laugh).
[Answer]
**Attack mode - Spread by spore communication**
I envision some type of flesh eating germ that normally aids in the breakdown of a dead body. The germ itself resides everywhere (like staph), but simply does not hurt people unless they are already dead. It remains fairly docile until the host's body dies, at which point it signals (through spores) to the other germs that they are in danger.
At this point, the spore signals cause other germs of the same type to move into rapid consumption and reproduction mode. Perhaps these spores would not be naturally airborn, but rather be transported by other means around the decaying body (signaling the germs to begin the decay process). Perhaps, this is due some type of stickiness of the spores that prevents them from leaving the body surface.
But the twist would be that there is either a mutation that causes the spores to be airborn, or some chemical introduced into the atmosphere which allows the spores to become airborn (maybe chemical warfare by a bad actor). This causes all these germs to enter the attack phase and release their spores. Suddenly every human dies within a short time period.
[Answer]
What you want is a "binary" disease. Each part is relatively harmless but when mixed together, they become dangerous and usually lethal.
The first part should be some sort of bacterium or virus that can be easily spread, such as an influenza virus or a new version of the hundreds of viruses that cause the common cold. Since there are always new strains of influenza viruses developing, this will not cause much concern. Nobody worries about being exposed to a new strain of the common cold or the flu. They just buy the local remedies to alleviate the symptoms until it goes away. Perhaps it is even included in a version of the flu vaccine. In this case, the virus would only be dormant.
When you have ascertained that enough people have been infected (perhaps by reading various CDC publications such as Morbidity and Mortality Weekly), you introduce the second portion, which need not be a virus or bacteria. This chemical needs to be easily absorbed through the skin and which can be easily added to something people use every day. If this chemical, which is harmless on its own, was some sort of additive that allowed a printer to use less ink, then your government would probably buy it and use it for enormous runs of something it prints and distributes to everyone, like tax forms or money.
When the chemical is absorbed through the skin, it triggers a mutation in the original virus. The mutation is lethal but has a dormancy period that allows the spread of the deadly mutated virus far and wide. Your mutation could be similar to some virus that does not have a cure, such as Ebola.
When people start dying, the deaths will be widespread and rapid. Even if they discover that your additive was the culprit, you would not be suspected of planning anything like this. It would be one of those mysterious anomalies.
] |
[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/116376/edit).
Closed 5 years ago.
[Improve this question](/posts/116376/edit)
Mana is the life energy present in all humans. It allows the body to sustain itself and perform its necessary functions to keep us alive. It also gives us the ability to use magical spells and rituals.
Mana content increases as we get older, and determines the strength of our magical abilities. This leads to the strange fact that the demographic with the highest amount of mana are the old and decrepit.
Despite having more life energy than others, their bodies become weaker and frail with age. This is a contradiction because the more life energy you have, the stronger and more youthful your body should be. How can it be the case?
[Answer]
**Mana *is* your life force.**
People in this world don't age naturally (or, at least, that's not the principle process). What actually happens is that as time goes by, their youth/vitality/health gets leeched away by their spirit-self, bolstering their mana.
*Mana is a symbiotic spiritual parasite that slowly drains you of life while bolstering your magical ability.*
If you want, you can complete the circle with a full lifecycle for mana. Upon the death of a powerful mage there's an explosion of mana (doesn't have to be an actual explosion, could look like a burst of light or invisible spiritual energy, or even a conscious entity) which then goes on to infect others around them. That opens up a whole boatload of neat narrative hooks. Perhaps you have some people who want to be mages so wind up hunting mages down to steal their power. Perhaps another set of people are so fearful of an accelerated death that they treat it like a disease. Perhaps you could even wind up with conflict within a mage itself between their physical and spiritual selves vying for control (either consciously or sub-consciously). Perhaps up to a certain level of power your body can heal as fast as its vitality is drained so you're faced with a choice: live long in mediocrity or go out in a blaze of magical glory.
So much potential!
**Additional thoughts/consequences from the comments:**
* Engineering short-lived uber-mages as a last-ditch defence by getting a number of living mages to sacrifice themselves in the presence of one other person.
* Death curses: funnelling all your remaining life-force into a curse at the moment of your death.
* Are mages who intentionally purge themselves of mana immortal? Could be a neat ideological difference between groups
* Human sacrifice to power colossal magical works
* What happens if a mage manages to bind their spirit-self to an object/suit of armour on their death? Do they become immortal/undead, but with no way to replenish mana other than killing for it?
* What happens to mages during warfare/seiges? Does the death of your mages risk gifting mages to the enemy? If you kill a mage in a confined area (seige), could that create a dozen lesser mages who then start building power as their life leeches away?
[Answer]
## **A Glutton's Game**
As it turns out, the similarity between the words 'manna' and 'mana' is no coincidence. The amount of mana a person's body can produce is directly related to the amount of food said person has consumed in their lifetime. Those who haven't lived as long simply have had fewer opportunities to stuff their mouths full of whatever. If you're a biblical literalist or a killjoy you could have the mages all be gorging on a specific magical ambrosia or literal manna; or just the sugary plant syrup we use to symbolically represent it in real life. If not, they could cram fried chicken or pies, or whatever food pleases them down their throat
In short, no manna no mana.
PS: For a darker bent, you could have the process of building up mana function like a form of bioaccumulation, much like mercury in fish. So more you eat, the more mana you take in, and the more poisoned you become, which also explains their poor health later on.
[Answer]
They gather mana for longer time. Just switch mana with radon. The longer you are radiated by it the more Radioactive contaminated you become.
Same thing with mana, everything in the world emits it. The longer you live the more you gather and your body became used to store it. So even is you spend it on some spell you can easily recharge to previous level and your body can withstand such surge.
Young bodies react to extra doses just like you react to shot of vodka when you're 10. You throw up and get sick for a week.
[Answer]
Older practitioners have learned skills to collect it more efficiently and use it more sparingly. A practiced expert can get the job done with maybe 20% the mana used by a less experienced user. A gradual transition from showy, spectacular effects to subtle or subliminal approaches also helps.
[Answer]
**The body is like a shelf of books.**
<https://www.youtube.com/watch?v=sPScqP3mFKQ>
[](https://i.stack.imgur.com/tGoGo.jpg)
Depicted: Professor Martyn Poliakoff of the excellent Periodic Videos series. Note his book shelves. They have accumulated a lot of stuff. Some of those shelves look kind of tenuous. They are overflowing. The Professor is asking a lot of them.
So too the body. It accumulates mana. Mana is good stuff but it is not always easy to hold. Just as the Professor's shelves are full of good stuff but straining to do it, mana strains and wears the body even as it brings beneficial energy.
There is balance: the wear and strain with beneficial life force, humility with wisdom, impetuosity with youth and strength, the yin with the yang.
[Answer]
## The so called Mana is a bacterium
In real life, we've got lot of bacteria inside us, essential for life. Your world is not so different, except one bactery give the ability to use magical spells.
As it's a slow-growing bacterium, old people tend to have more mana than young people.
This bacterium has however some cons, and reacts poorly with other bacteria, so too much mana is not that good for health.
Making mana a bacterium can also produce an interesting disease: lack of mana. In the case of real-world bacteria, some diseases can change our intestinal flora, changing the balance of bacteria. Therefore, sometimes powerful wizards may become mana-ill, and will be unable to perform any spells for a certain period of time.
[Answer]
## Casting Spells ages you
It's not commonly known, but using mana is actually what ages you. However it is so inherent in everyone that many low levels spells are cast by your body autonomously (much like we breathe without needing to think about it). Some few monks have achieved near immortality by training themselves to not use magic, but few if any have managed to keep from doing so in their sleep.
[Answer]
**The mana organ never stops growing.**
Mana comes from a mana-gland. It secretes the mana as needed. Like the human ears for instance the organ never stops growing. Old people have big ears and a big mana glands. Fortunately it's in a part of the body that can deal with it. Or is it?
[Answer]
# They have saved for the future
[Mana is actually a currency](https://worldbuilding.stackexchange.com/a/112321/21222) you can use to pay the universe for magical effects, besides trading with other people. Wizards are more savvy into the economics of it and have been investing and [saving](https://youtu.be/nqhLn76kCv0) for a real long time.
This also explains how they can pay for their richly embroided nightgowns robes, their towers, magic labs with all those expensive glasses and scroll paper, gems and chemicals of all kinds etc. It does take a lodestone to cast disintegrate and those don't come cheap, you know.
[Answer]
It's not that old people have more capacity to hold mana. Humans have much the same mana capacity all through their adult lives, but the mana is kept away by a field of life force - a bit like magnetic fields repelling particles of the same polarity. (Recent research results indicate this field of life force is generated by [Telomeres](https://en.wikipedia.org/wiki/Telomere))
[Answer]
The body can either produce body energy (in the youth) or mana (in the elderly), not both. Add to this that mana production requires an adult body (more or less like growing a beard or breast feeding).
The main concern of the body is therefore first to grow, develop and reproduce. Once this has been taken care of (or at least we can suppose it is), the body can devote itself to mana production.
[Answer]
**Mana is your soul.**
As you live, your soul grows. When you die, it breaks free, to the next world. We live to make a soul.
[Answer]
>
> Despite having more life energy than others, their bodies become more weak and frail with age. This is a contradiction because the more life enregy you have, the stronger and youthful your body should be.
>
>
>
This is a common misconception among outsiders.
As you spend more time around our people, you'll notice we're generally quite lively to begin with, and our elders are considerably more mobile and independent than non-magical elders. This is because of the levels of mana we cultivate during our lives.
Unfortunately, we're not immortal, and while the body is the instrument of our will, it has limits and age does prevent our elders from enjoying the full physical use of the vigor which naturally accompanies the higher levels of mana they've achieved.
Because of this, they often turn those prodigious energies to scholarship, philosophy, and the deep magics.
Oh, that guy? Yes, he is quite frail. The deluded fellow thought he could extend his life by hoarding his mana. Our elders have as much mana as they do because the years spent using and cultivating their mana has grown their capacity. He didn't do that and his mana atrophied, leaving him in that pitiful state.
Hmm? I think he's around 50. Quite the tragedy, self-inflicted of course, but he had so much potential!
What!? No, the rumors that our bodies have become dependent on mana for basic survival are a pernicious heresy.
[Answer]
Hope I am not just repeating other people, I don't think I am.
mana is linked to your metabolism, as you get old your metabolism slows meaning you use less energy just by living, instead of this energy turning to fat (middle aged spread) it turns to mana.
This does mean that certain people would be very powerful their entire life as they were born with slow metabolisms.
And like health you have the choice of power or long life, or to be one of the lucky people able to have both.
[Answer]
## Usable Mana is wasted life force
Your body is filled with life-force pathways that allow your essence to circulate and keep your body functioning. When you are young, these paths are stable and efficient, keeping the majority of the energy contained and sustaining you. As you grow older, the barriers along the streams weaken, and more life-force leaks out and pools in the surrounding flesh. This leakage is what they call mana. The more that is leaking out, the more is available to you to use but the less is making it to your body to sustain it.
## Possible Ramifications
* **Accelerated Leaking:** Its possible that drawing on mana often or heavily could add strain to the body and increase the rate of leaking. Thus, intense magic usage will bolster your mana reserves more quickly, but also cause faster aging.
* **Pooled Mana:** On the flip side, if mana remains pooled in the body for too long it may cause issues. It could self-react at high concentrations, or stagnate and become useless, or even rot and turn "evil" or corrupt.
* **Relation to health:** This allows for differing baseline levels of health/mana. Healthier people will have more life energy, and so may in fact have more mana *and* be in better shape compared to somebody else the same age.
[Answer]
Mana usage with age is similar (in outline) to Type 2 diabetes. The production rate of mana remains constant over a lifetime, but aging interferes with the body's ability to use that mana. So the levels of unused mana, available for use in practicing magic, increases with age.
Just because mana is available doesn't mean that your body can use it.
[Answer]
## Ghosts
Ghosts are the next stage in a persons life cycle, and as they age more and more of the mana they've accumulated sequesters into their ethereal body, and less into their physical one. Eventually the imbalance is too great, their physical body can no longer anchor their ethereal body at which point the person dies, and moves on to their "afterlife" as a ghost. However this process is fraught with risk, and most people don't successfully make the transition (which is why there are so few ghosts). Of course you can change the risk to best fit your story depending on how likely you want ghosts to be.
[Answer]
**Mana is proportional to a body experience**
Mana is a life energy that increases when you learn new things, both physical like learning new sport disciples/martial arts/etc and intellectual like learning sciences/languages/etc.
So older people posses more mana because they simply learned more things through their lives.
**Dependency on age is not linear**
As I suppose, your main goal is to deal with the contradiction that old, weak and fragile people can have more mana. To solve it, lets assume that mentioned dependency is not linear: it grows slowly since childhood through adulthood and drops rapidly after very old age.
[](https://i.stack.imgur.com/fLCDZ.png)
[Answer]
# Mana is toxic
Mana is like radiation, it progressively accumulates in our body and we aren't able to get rid of its damages. I mean, you can spend mana on a spell, but the damages that it has provoked in your body aren't healable.
And if you try to use mana on spells it won't reduce your damages, it'll do the opposite. Think about bleach, I have read one time that if you accidentally drank bleach you have not to vomit it because it will damage twice your esophagus and throat (damage when in, and damage when out). If you spent mana, it'll burn inside you twice.
# Mana is a subproduct of life
Each second we live, we breathe or move, a particle of life force is burned from our soul in order to produce that "energy" we need to breathe, move o even think. But like the second law of thermodynamics say, any process can have a 100% of efficiency, even flames produces heat **and light**.
That is your mana. Your life is coal, when you burn coal it produces the light of your everyday life (which you spent to move, talk, play, work, etc) but also it produces heat an ashes which actually they are your mana.
Basically, that heat represents your mana energy used to cast a spell (when more you burn warmer you are), while your ashes may (if you want) represent the accumulated damage of your old body.
[Answer]
## Mana is the force of the next realm bleeding into our own
The creator, in an attempt to shield us from the horrors of the 4th dimension/afterlife/truth, chained us to reality with when writing us into creation. (DNA, [Telomeres](https://en.wikipedia.org/wiki/Telomere#Shortening) specifically, if the civilization is advanced enough).
*or*
Alternatively, evolution has favored resistance to this unbridled power, which naturally selected those who don't spontaneously combust.
---
As we age, those chains degrade and it's influence grows. The grip of the next world becomes a constant burden. Modern medical science is capable of preventing this shortening and increasing longevity, but this decreases your access to the primal source and, realistically, just delays it's inevitable embrace.
Using the power also strains those chains, increasing their degradation. When they break, you are pulled into the next world, becoming a mana ghost. This means when you're at your strongest in mana, you're also closest to passing/death.
Cancer can then be described as a partial "breach", allowing in the influence that is so harmful to our existence on this plane.
[Answer]
Mana is accrued at a rate dependent on physical health and maturity. Perhaps mana isn't exactly accrued, but rather is drawn on from every prior living moment, but for practical purposes it is accrued over time. The maximum mana accrual rate is in the mid 20s. If not used, it is a mathematical integral of the person's health over the previous part of their lifespan, plus additional mana gathered from other living things via consumption.
When something dies, the mana rapidly drains away. People who have been resuscitated after being clinically dead have permanently depleted mana and make lousy magicians.
Small quantities of mana can be gained from eating living or recently living things. This is why magicians are often part time farmers or have a more or less symbiotic relationship with the farm - so that they can get their food as fresh as possible (missing reference :P). Some magicians have given up on this and prefer their food live, eg mealworms, locusts, small octopus, etc... In any case, an old magician would rather live off their fearsome reputation than do real magic.
[Answer]
As you say, Mana is Life Force. It is stored in every cell in your body.
In a newborn baby, that Mana is locked up tight, and almost impossible to access. As you age, your cells become more porous to Mana, making it easier to access. (This is why, contrary to popular belief, sacrificing children generates almost *no* power for your ritual)
So, even if an elderly mage and a young mage had the same amount of Mana stored up, the elderly mage could unleash that force in a shorter period of time - and Power is Force delivered divided by Time taken.
On the other hand, this means that when a mage gets *too* old, they have trouble "holding on" to their mana - it tries to leak out. As a result, their bodies take longer to heal, and they start to take on a more wizened appearance.
To the uninitiated, the resulting nimbus of magic seems an awe-inspiring example of thaumic power - but to other mages it shows that the person in question is approaching the end of their life. Of course, the ability to instantly throw their entire Life Force into one very **Final** spell just makes them all the more dangerous to oppose...
[Answer]
Mana and body energy are related. Your body can produce a certain amount of the two added together, but young people produce a higher amount of body energy, & less mana. The production of the resource they are made from is close to constant, but the ratio is not. A teenager can carry a heavy burthen a long ways, but can barely cast basic spells, and an old person can't carry but a little weight a little ways, but can cast the most difficult spells with ease because of the difference in the mana:body energy ratio. The resource they are made from might increase production under duress or in response to trauma/adrenaline, which could be why you suddenly have a burst of energy in response to those things.
[Answer]
## Mana is a spiritual alternative to physical health
Quite simply, old, fragile bodies would quickly disintegrate if it wasn't for all the spiritual energy and pure will holding them together, and maintaining the individual's firm grip on life.
This explains why the elderly quickly pass away if they feel they are of no use to the community.
Mana is directly proportional to wisdom and spiritual awakening, thus, individuals with a lot of mana are seldom interested in physical attractiveness or physical strength. They generally prefer to deepen their spiritual knowledge and orchestrate complex movements in society or reality itself. Perhaps exceptions exist; certain individuals who expend a lot of energy on prolonging their youth because it gives them more tools for seduction, deception, anonymity or "going among the people".
[Answer]
first, everything is relative. you might be old and decrepit, but if not for your mana levels, you would already be dead. relatively non-magical folk live less than 100 years, while the most powerful (and decrepit) wizards are thousands of years old.
secondly, your body is a conduit for channeling mana into the world. when you are young, most of your mana is used up just living and growing, but as you stop growing, the excess mana starts to damage your body. in the short term, casting powerful spells can cause injury or death. in the long term, minor damage from hundreds of smaller spells adds up to what we call "aging". people who exercise their magical talents regularly with 30 minutes of light sorcery daily live the longest and healthiest lives. on the other hand, people who never perform any magic frequently end up injuring themselves by emitting sudden uncontrolled flares of mana when they are ill or upset. getting more powerful as we age simply compounds the problem since it is harder to burn off all that mana without hurting ourselves.
lastly, nothing can escape the force of evolution. it's in your genes' best interest that you die after reproducing so as not to compete with your offspring for resources. somehow your genes will find a way to kill you off, magic or no magic. it's true that every few thousand years, someone creates a spell to stop aging, and they become biologically immortal. for a few generations no one dies of old age, and so everyone becomes very cautious not to die from an accident, illness or injury. people become isolated to avoid illness. they stop travelling by sea to avoid drowning. they stop having children to avoid death in childbirth. innovation and exploration grinds to a halt, and the birth rate plummets to almost zero. typically however, there are a few people for whom the immortality spell doesn't work. those unlucky folks and their decedents don't have time to play it safe, so they take more risks in the hopes of striking it rich or finding true love before the reaper comes for them. they also tend to have children as a sort of vicarious immortality. after a few hundred years, the mortals will multiply exponentially, while the immortals slowly die off from accidents, injury, disease and famine. eventually a plague sweeps over the land killing the last few immortals (and 90% of the mortals). and so the cycle repeats....
[Answer]
**Oxytocin**
Oxytocin is a circulating hormone that is necessary for muscle maintenance and regeneration, and is also prevalent in the human Brain, however as the body ages the amount of Oxytocin that is produced decreases, this leads to the aged appearance and longer recovery times after injury, if you linked Mana inversely with a chemical such as Oxytocin, that would mean the higher amount of Oxytocin in the body the weaker the Mana, making the natural aging effect still make sense as well as older members being more capable of using that mana.
**Dopamine**
in a much similar way as oxytocin, Dopamine levels decrease with age. so could be used in the same way, the amount of Mana ability would be being inversely proportional to the amount of your chosen naturally occurring chemical.
This could be done simple by either of these chemicals hampering a persons ability to use it or diminishing its effectiveness
Edit: another thought... Chronic stress or depression is also linked to lower neurotransmitter levels such as sertonin and dopamine, so that could be a link to when someone is really angry/depressed they could be more powerful.
[Answer]
You dont get more mana, you just become more efficiënt with using it in spells.
Also, the state of the body does not have to correlate to your mana capacity directly. Say you are a healthy man who breaks his leg in a fall and starts bleeding heavily. His mana capacity can be anything depending on how much he used and stored before the injury, but now that he's bleeding he suddenly needs more mana to stay alive. And if he stops the bleeding and heals it doesnt matter to hos maximum capacity if he heals up completely or is lame for the rest of his life.
Now an older body could contain more mana than any young body, but also require more upkeep as the body has changed. As the body ages at some point you start using more than you can recuperate and you'll die. Also means that older people need more care when using spells as they get it back slower and need to refill a larger capacity. But you could have tools that can counter that partially allowing a regeneration within a day or something.
[Answer]
Your life force may be strong, but the human body still ages. Ever know an old man with pep in his step? Strong life force, weak body. Or collagen still wears out and we wrinkle, or bones still age. But your life force (or maybe connection to it) doesn't necessarily follow suit.
[Answer]
**The amount doesn't increase**
You could make it function in such a way that instead of them accumulating vast amounts of mana that they simply become much more proficient in using it sparingly from years and years of practice. A young man might use 100 Arbitrary Unit of Mana to cast a Firebolt while a wizened man who has cast millions of spells could cast the same level Firebolt for only 35 Arbitrary Units of Mana. This could make it seem like they have a much more vast pool of it.
[Answer]
As humans get older, their immune system weakens, allowing microscopic Mana-chlorians to proliferate inside the body, like any other germ. Since Mana-chlorians generate mana, older people have more mana.
] |
[Question]
[
Would a chainsaw be a practical weapon in the medieval ages where swords and bows were the their main armaments? How well would it do against swords and shields?
Disregarding the problem with fuel of course. Just go with one of those chainsaws that always show up with a suspicious hockey masked man.
If the chainsaws are not all that practical then what can be done to improve them?
[Answer]
To quote Miguel Valdespino on Quora about using them in combat...
>
> Chainsaws make poor weapons. While they cause a lot of damage to the
> enemy, they suffer many problems as weapons.
>
>
> * They are poorly balanced for fighting and very heavy.
> * They require fuel or power to operate.
> * They are noisy.
> * A mistake can severely damage the wielder.
> * Parrying with it can cause chain failure.
> * Chain failure can injure the wielder.
> * Most failures make the chainsaw ineffective as a weapon.
> * They are only effective in melee fighting.
>
>
>
I'd like to especially highlight the points of failure. A sword's or pike's point of failure are breaking (somewhat unlikely) or (eventually) growing dull. A chainsaw has drastically more points of failure, and most of them far more likely to happen than the sword's or pike's points of failure.
So the first time the chainsaw jams on a sword or has the chain knocked/bent off the track you're going to have the world's most awkward club, and little more.
And even if indestructible, a wall of pikes (8' - 12') will keep attackers at bay far better than chainsaws, as the pikes are easier to manage, easier to use in formation, and have far better range.
**Okay, But How Do We Make Them Better?**
You'd need to find a way to *increase* the torque, *increase* the fuel efficiency, and reduce the weight.
You'll have to make the chains thicker, and provide a strong guard to keep them on-track despite the chaos of being used in combat.
You'll have to reduce the likelihood that they'll jam, or some *very* fast way to unjam them. Perhaps a switch to quickly reverse the direction of the chain would help.
You'll want to tip the blade in a material strong enough to cut through metal. There's not a great way of doing this, as typically this is done as a grinding wheel (which would be less effective against wood and flesh; construction cutting devices typically are built for-purpose because of this), but tool steel with cobalt is sometimes used.
Ideally one would increase the range while not increasing the weight. I'm not sure how you'd do this, though.
You'll want to include safeties so that if the chain *does* break it contains it as much as possible. Hopefully also a dead switch so if it's forced out of the soldier's hand back on him it won't injure him.
Even with all the above listed fixes (to degrees that I imagine would be reasonable if engineers took to the task for a few years), somebody trained with a sword seems like he'd be more effective in a 1-to-1 fight, and in formation I can't see any real use for them, being strictly realistic.
[Answer]
>
> **Would a chainsaw be a practical weapon in the medieval ages?**
>
>
>
Hahahaha ... oh, wait. You're serious.
No, they would not be at all practical or effective. I mean .. they might scare some people, but have you ever used one? They would not be anyone's weapon of choice.
>
> **How well would it do against swords and shields?**
>
>
>
Terribly. Block with the shield, stab with the sword. I am now the proud owner of a slightly used chainsaw.
>
> **If the chainsaws are not all that practical, then what can be done to improve them?**
>
>
>
Nothing much. A chainsaw is a tool meant to simplify modern life, and optimize a process. That process is cutting down poor, defenseless, stationary, unarmored trees.
Mankind has had a lot of practice at optimizing killing tools, and the result was the semiautomatic carbine, not the chainsaw.
Believe it or not, swords, shields, and armor were very well thought out armaments, and the soldiers of the time would be experts in their use. A chainsaw would not cut through plate armor, would get stuck in chainmail, have a difficult time going through a gambeson (while the owner is stabbing you in the face), be cumbersome to wield, and generally is quite a finicky machine which requires spare parts, maintenance, and fuel. By comparison a sword is easy to use, light, and a damned bit more dangerous.
[Answer]
Nex Terren I believe is right, it's not feasible.
But if you were forced to use a chainsaw in a medieval battle I would recommend taking the chain and the arm off. Those break very easily in my experience. Now you have a heavy noisy metal box with two nice handles. If you got close enough you could bludgeon someone with it. To improve upon it add a long handle to it and use it as a mace or hammer.
[Answer]
Have you ever used a chainsaw? Unless you position it JUST right it jams or the chain comes off. Don't let that spoil your fun in a fantasy story though! Chainsaws are iconic. Enjoy them.
[Answer]
For everyone here saying a chainsaw isn't effective, they thought it wouldn't be for that episode of mythbusters either. And yet, it was far, far, far more effective than an axe, and [actually takes less time to wield](http://nerdist.com/mythbusters-tests-axe-vs-gun-vs-chainsaw-in-zombie-apocalypse/).
>
> 57 zombies killed for semiautomatic pistol, 67 for the axe and…wait for it… 190 for the chainsaw. Savage, with the chainsaw, was able to “kill” all 190 of the attacking zombies in just 4 minutes.
>
>
>
Is heavy? Yes. Train for it.
don't wear armor so that you're faster than anyone who is, and then aim for any exposed flesh, like the face or neck. Really depends on how much armor and if they are wearing chain mail. Chain is the most difficult problem you'll face. But not everyone had chain that covered EVERYTHING.
Would it need to be adjusted for armor? Absolutely. I suggest industrial diamond tipped teeth.
Would another blade stop it? Pretty likely, but you can build guards for that.
You want chainsaws, baby, you got 'em, even if most people find them laughable. They might breakdown, but for fear and awe in the first few minutes of battle, nothing beats the chain saw.
Now, there are chainsaws that snag less and you don't have to worry about positioning as much--that's what you want to start with, and then make your mods. These chainsaws cost a mint. The standard ones of late often have safety features built in, FYI, so as to not cut flesh much.
EDIT: Wanted to add something about armor. This really depends on WHEN in Medieval times you want to do this and WHERE. Early armies were peasant conscripts of a lord with very little training. Chain mail and a full suit of armor is expensive, and depending on where and when, not as common as you might think. Leather armor was far more common. It's the fully trained knights on horseback you'd have to watch out for. Hopefully the horses are armored. I like horses.
[Answer]
The best melee weapons were always
Spears>swords>maces, and there were reasons for that.
Spears have an incredible range, they were the safest weapons in a battle.
Other than being incredibly easy to use and being one of the few weapons at the age that could penetrate armors for a fast kill.
Swords had little to impact, even broad swords, and didn't have much slashing efficiency... not even the most romanticized swords like katanas had the power and cutting efficiency you see in movies, plus they were incredibly hard to use and master. Every Hollywood actor is just a kid agitating a stick compared to the least trained swordsman.
What made them one of the most effective weapons was their manoeuvrability, a warrior could do anything with a sword due to their incredibly light weight, plus any single part of the sword could be a weapon.
Usually a good sword man could perfectly keep an incredible pressure on the enemy without ever putting down his guard, even with a single sword and no shield.
Maces are the third best for simply being smaller but heavier swords with an actual capacity to destroy armors and easily stun the enemy. Even with the best armors that couldn't be penetrated by virtually anything the hit of a mace in the chest would not break the armor but directly destroy internal organs and bones. What makes it even better is a mace could break any blade or spear with a good hit or even someone dumb enough to directly hit a mace with a sword using great force will destroy his own sword and some fingers. But being heavier made the mace inferior to swords, even the most mighty warrior would damage and eventually break his tendons for stopping a mace swing in mid air to change manoeuvre while a sword user could do it faster and with no side damages.
A chainsaw has none of these utilities and every possible side effect, is heavier than the mediocre giant zweihander swords, heavier than maces and axes.
They give no manoeuvrability, it can only do a few predicable offensive actions and can't defend, while most weapons could both parry a hit and 0,05 seconds after counter attack from any direction.
Other than that the other medieval weapons could disarm a chainsaw carrier in literally just the blink of an eye.
Then there's also the fact that with a chainsaw one has little to no mobility, soldiers, warriors, gladiators and duelists all use 100% of their body to fight not only the weapon.
In a technical way even throwing stones would be more effective than fighting with a chainsaw...
Just try to imagine a soldier running around with a chainsaw, rolling, dodging, and blocking hits... well, no you can't cause not even giant axes and hammers which were way lighter than a chainsaw could not offer many of these possibilities. That's why usually those carrying giant and heavy weapons were defended by 10 or more soldiers and even then the giant axe/hammer carrier could only hit distracted enemies or damage it's own allies, and they usually didn't survive much either.
[Answer]
You may be aware of the Warhammer 40K weapon, the [Chainsword](http://wh40k.lexicanum.com/wiki/Chainsword).
[](https://i.stack.imgur.com/uC1v3.jpg)
It isn't medieval, but might suggest the sort of changes which you could make to a chainsaw to turn it into an effective melee weapon.
[Answer]
Don’t use it as a person-to-person melee weapon.
Use it as a tool behind the lines, or by a saboteur. Want to get rid of that pesky trebuchet? A few cuts through some critical (wooden) members will put it out of commission.
[Answer]
Chainsaw would stuck in mail and can't cut through armor plate. The problem of the chainsaw are :
* It's heavy. You are less mobile, the strike will be very slow.
* It take time to cut. It's not lightsaber like effective you have to push through the target.
It would be very effective against a shield and unarmored enemies but in the time the chainsaw go through the shield, you are open to any attack and the guy who see his shield cut to his arm will not stand waiting you remove his arm. He will strike you in your exposed armpit and ... you're dead.
However chainsaw would be a game changer as a siege weapon. No need for a giant tree and 20 people to operate a battering ram. Just a guy with a chainsaw can cut a hole in a very thick door.
If you make it a magic weapon you can say that it is light as a sword and it cut through steel then you have a good weapon. But the way it exist in our world it cannot be used in close combat.
[Answer]
If there are only a few chainsaws then they would probably be more effective as a weapon of fear than an actual battlefield device. The sound, smell, and visceral impact of such a tool would impress quite a few folks.
If they are very common tools, a weaponized chainsaw makes little sense outside of usual chainsaw uses (like cutting into wooden walls, doors, or siege engines). The spinning blade of a chainsaw is relatively fragile and if it breaks the chainsaw is useless. So you are unlikely to get more than a few swings in battle before your big clunky weapon is damaged. Many shields are rimmed with metal (or would at least be spiked with nails) which would defeat a chainsaw if they were a common weapon in battle. Chainsaws are not great for thrusting. Most importantly, they are VERY hard to control, so a line of guys with chainsaws are very likely to loose control and hit their own guys (or themselves).
This type of weapon is unlikely to see use outside of elite honor guards designed to LOOK fierce but not be all that effective in battle. Maybe gladiatorial type combat?
[Answer]
There are many aspects of every aspect of human existence, war and combat not being the exception.
If you want chainsaw be a weapon for a duelling, the way most of the movies depict medieval battles, you need to make it not to be chainsaw.
Replace the unwieldy engine with the magic\nanomachine one, that fits under the chain, where only guide bar usually located. Voila, you have chainsword, now you need a powerarmor, strong user or a peculiar combat style to ensure that most of the chain movement energy is spent on tearing the enemy flesh, and not onto propelling the weapon in the direction opposite to the chain movement.
Replace the lumbering chain with parts from slaughterhouse equipment and you obtain a perfect weapon for peasantry oppression.
That said I've never heard about cutting metal with any equivalent of a chain.
---
However, combat is not always like in Lord of the Rings, people also tend to need to kill things in conditions of limited manoeuvrability. In organized battles as opposed to random skirmishes infantry fights for example used to be a mishmash of desperate stabbing of two tightly packed conglomerations of humans. That is: a murderous blob of humans protecting itself with shield wall at front while wildly flailing spears and halberds tries to create a breach in the shields of opponent blob. When a breach is found, the attacking blob can inject its angry front-liners into the enemy wreaking havoc to its structure, killing and maiming its constituents unprepared to meet enemy at this side of the shields.
This is literally 'shoulder to shoulder' to allies and 'face to face' with enemies, in such conditions swinging a longsword is highly problematic hence a variety of weapons with smaller swing has appeared.
Making a strong blow in such situation is difficult, much less pushing the weapon between the shields and swinging it to hit someone. Thus a weapon, that 'swings on its own', would be a treassure here. You just need to push the chain in the opening and shift it slightly till it catches onto comething and watch out for blood spray. Or just push it against enemy shield and rely on those beside you to keep you shielded till foe's arm comes off.
Thus, assuming all possible technical tweaks like putting teeth on every link instead of [normal way](http://www.madsens1.com/GRAPHICS/chain/seq.jpg), reinforcing the bar, adjusting the housing to not to jam on minor flesh patches, the chainsaw might make the weapon, the wrumming of which would whiten the face of hardened warband soldiers. Or warm the heart of the dwarf fending off the insurrection of tentacled demons from deepest tunnels.
---
That being said, I believe circular saw, if available, would supplant the chainsaw from the manslaughter niche. And if mechanisms of bloodshed are considered and only limitation on gunpowder is imposed, I believe, a civilization with access to combustion or electric engines, needed for the above discussed tools, would quickly abolish the weaponized tools in favour of Da'Vinci's mechanised mowers.
[Answer]
I have no experience of such things, but I imagine a chainsaw makes quite a mess of someone, and the completely alien noise a Chainsaw makes (in the eyes of the medieval militiaman) would make it a very effective psychological weapon.
I completely agree with all of @Nex Terren's points, with all that we know, a chainsaw is an extremely impractical weapon. But if you play to it's strengths and use it for showboating and demoralising the enemy, which history has taught us is often more important then experience or equipment, it could be a very effective weapon of war. Just not an effective personal armament, swap to a sword and shield before you charge a band of pikemen!
[Answer]
Actually there was an accident involving chainsaw and massacre attempt. It failed miserably: chainsaw jammed after second hit.
In case of battlefield it would be even less effective due to armor and so on.
Sorry for necro post, just wanted to add real example.
[Here is news link, it is in russian language](http://m.nn.by/ru/articles/185659/)
[Answer]
As someone who's worked as a lumberjack, I'm quite surprised at the answers here: I think everyone is imagining one-on-one duels between people dressed in plate armor, for which, admittedly, they might be poor because of their weight, one-handed balance, inability to parry well and inability to slice through metal.
But given to your front line, against a force who lacked them, it would be *devastating*.
Chainsaws are deadly. They are the most deadly tool you can use without a license.
They wound about *thirty thousand* people a year in the US alone. The wounds take an *average* of a hundred and ten stitches. That's when *not* trying to cut people up with it. About two hundred and fifty people a year die from them.
Consider two spear-and-pole-wielding lines meeting, but one is equipped with spears, the other pole-saws.
The spears get mostly deflected by the shields. The pole-saws *slice right through* all the leather armor and felt padding and wooden shields and other nonsense. They meet a surface they can't penetrate, the pole saws actively grab onto it, pull it to one side, and crawl around it.
Yes, you'd need a secondary weapon. But the majority of the foe's front line now needs an average of 110 stitches. You've struck terror into their hearts and nobody wants to step up to the meatgrinding machine that is your front line.
Chainsaws are an excellent tool, then, for massacres of lightly armored foes by a heavily organized force.
But they come with a downside: they are the most deadly tool you can use without a license, because they mostly maim *the user*. The whole "moving of their own accord to find they way past any impenetrable armor" thing can work against you, too: they kick back, they leap up into your face and neck, or down into your own leg. Pole saws are safer, but only to an extent.
Perhaps the most effective way to use them, then, would be using a formation like the Roman turtle, but with either pole saws, or a flap in the shield to push a chainsaw through, clamped in place such that the chainsaw cannot buck and twist in the hands of the wielder enough to slice himself or his comrades, and the wielder can use both hands to steady it and the shield together.
Combat is an arms race, though. Just as loggers now wear fibrous trousers to prevent injury from chainsaws, so people would start to wear heavy fibrous clothing to tangle the saws, and they would also clad their shields in it.
But arms races only have so much speed. The initial introduction of them could be enough to win a war.
[Edit: From pluckedKiwi's comments, I realize that polesaws are not known to everyone. A polesaw is a chainsaw with a pole between the engine and the blade, rather than placing a regular chainsaw on the end of a stick. This gives you balance: the weight of the engine and fuel tank (or motor and battery) near and behind your hand, counterbalances the length of the shaft and the weight of the blade at the end, arguably balancing better than a spear. However, it's still a decently heavy piece of kit.
I still think regular chainsaws mounted behind shields in turtle formation would be the best plan to use them. However, the lack of range compared to any missile weapon of the same size and weight does make them kinda silly.
Combat modifications to the blade (larger teeth; separating each tooth by two or three empty links as is used when cutting stone; faster chain replacement with a sprung blade instead of bolt tightening) would certainly help. As would ablative armor for the wielders to protect them from kickback.
If the question were "what modern stuff other than guns could make a medieval army really fricken deadly" I might not even bother mentioning chainsaws. Better armor would get my first vote. But given the question, yes, chainsaws would give your front line a crushing advantage. Rather than just being a consumable, disposable mass of bodies to absorb (or make) a waved attack, they'd be a death machine, grinding through flesh with a speed the opponents had never imagined. Sure, any missile weapon beats them. One gatling gun could best your entire army of chainsaw wielders. So would a line of bowmen with longbows.
But in medieval days, the tank of the day was the armored horse. A charge of trained horse-riding knights who've been trained their whole life, against a chainsaw turtle with a month's training... despite the very significant problems of armor penetration, particularly as the science of making plate armor got better, my money's on the turtle.]
[Answer]
Chainsaws when against flesh don't really cut that well, they rip flesh / almost skinning the flesh they come in contact with. But you are trying to kill someone so that doesn't matter too much.
But one modern protection that you see is a actually a heavy cloth-like material that frays when the teeth of the chainsaw are in contact with it, that fabric then jams the chain stopping it. Then you have to untangle the mess to continue, assuming you didn't actually injure yourself.
So defenders could cover themselves in regular metal armor or heavy cloth on top of leather. The first use of the chainsaw on this armor and the chainsaw is immediately useless and leaves the user open for counter attack.
[Answer]
As explained in the other answers, an actual chainsaw is a bad weapon but you allowed for modifications so how could we build a chainsaw-like weapon with current/near future tech?
**Step one: change the "teeth" :**
We need to optimise the form of the teeth to cut through steel while reducing the amount of ripping. something like a half-circle blade, made of extra-hard steel should work.
**Step two: replace the chain and engine. :**
The engine/chain design is the major point of failure of a chainsaw, so let's replace it with a railgun! on each side of the tooth there will be a double rail where you pump electricity through, accelerating the actual blades. if a blade get stuck you get very little mechanical force acting at the "swordblade". Instead the railgun will start to overheat...simply add a thermal sensor that shuts down the power-source. If we limit the speed to about 500m/s we should have little problems with wear&tear on the rails (the primary problem with current railguns) while still each bladecut will have the force of a pistolshot.
Now all we need is a power-source to keep this thing running for a hour or so and a person strong enough to use it...
[Answer]
The problem is that it really won't cut into something without standing still and proper placement. You know this if you've tried to cut straight through a limb and the tree starts binding on it.
What would happen is that you swing the blade down on a sword, shield, or armor, it doesn't slice through like a light saber, and the chain's motion causes it to *bounce back towards you*. Seeing this, your opponent then starts pushing **you** with their weapon, trying to throw you off balance so that you inadvertently bring the spinning chain down on yourself.
To improve upon it, you would need some sort of plasma-field chain so that it just cuts through anything.
[Answer]
A normal modern chainsaw would be a pretty ineffective weapon. But I think that a specialized combat chainsaw could be useful for special situations in medieval warfare. The best use I can think of is for heavy cavalry specifically designed for attacking skirmishers (light infantry).
I'm imagining two chainsaws joined with hinges where their handle would normally be. A rugged support structure mounts this in place of a yoke, with backstops preventing the hinge from getting too close to the horse. The chainsaws would be pointed downward when on the stops, and if lifted slightly they would be parallel to the ground (blade edges pointing backward and forward, not up and down). Probably it would use a kind of ratchet system so the rider wouldn't need to actually hold them in place. The chainsaws would need to be heavily modified for length and durability, because even peasant levies are going to have some metal objects which would cause you trouble.
So basically it would be a chariot of death, routing poorly-armed and armored peasants. It would need to be pulled back before spearmen or knights were in range. But if you have access to gasoline, I think that gelling it and using it for flamethrowers would be far more effective.
] |
[Question]
[
Yttri are an odd race. Like many species on their planet they can selectively position themselves along the r/K reproductive strategy spectrum. r species are those (like some species of frog, fish or insect) that throw out thousands of 'expendable' but cheap children in the hope that enough of them will survive to adulthood. K species are those that instead focus lots of resources into a small handful of offspring, so they stand a much higher chance of surviving. The Yttri have evolved so that in times of dire need they can adopt an r style strategy, while in times of plenty they instead opt for a K style strategy.
Yttri females, when first impregnated, have hundreds of foetuses in their womb. They then gestate these for a minimum of two months, after which they can opt to give birth to a whole brood of small, weak, ravenous children that are capable, but ultimately expendable. Or they can delay the birth. The still-gestating children will begin to consume each other over time (in ways facilitated by the mother and also quite literally eating each other). At any point up to about a year (when only one child remains and preventing the birth is no longer an option) the mother can release the children in to the world.
Now, the children that stay in the womb are demonstrably larger, stronger and smarter than those that are born earlier. A brood of a hundred children that were born after two months and then had a year to develop will never physically or mentally match up to a child that gestated for a year and then had two months (though they will eat more). This is an acceptable tradeoff for almost every species on the Yttri's home planet, as it lets them deal with a wide variety of seasonal changes. Well fed creatures (or those in positions of security) have fewer children, while those living in uncertain times or climates 'fire and forget' whole broods in the hope that some children will survive the lean times and make it through to the other side alive.
But the Yttri are (for want of a better word) industrialised. They have advanced medicine, agriculture, engineering, robotics, science etc. They are very much at a technological and social level equivalent to that of a modern day first world country. In such a world there is no need (unlike in their early industrial period, where more children meant bigger earning potential) for Yttri parents to need or even want large broods of dumb, weak children when they could instead give birth to one or two smart, strong ones. There is a strong social stigma attached to abandoning one's children, so 'fire and forget' is even less of a sensible option.
Given that the mother can always choose to delay the birth, why would a Yttri parent still opt to go down the r reproductive route rather than sticking with K?
[Answer]
Religion.
Some fraction of Yttri society has been infected by one or more memes that boil down to "every child should live" -- and intentionally delaying birth and allowing the fetuses to eat each other amounts to murder.
Not all "first world" Ytrri will think this way, of course -- but it might well be that the reduced reasoning ability of those who were born from a large litter makes them more susceptible to "thinking by meme" or "sheep mentality", allowing a charismatic leadership to continue implanting the "delayed birth is murder" meme in successive generations.
Over enough time, this coupled with a preference among "single birth" Yttri for more intelligent partners could lead to speciation, or at least development of a subspecies, but in the short term it might prevent that outcome by setting up a *Marching Morons* situation, where the reproductive advantage of dropping big bunches of offspring in an environment where many of them will survive leads to simply outbreeding the "single birth" lines.
[Answer]
**It is tough to be pregnant. Get it over with!**
It is not easy to be pregnant. It is physically taxing and draining. Sentient females given the option may choose not to become pregnant at all. There is some thought that some phenotypic human traits (e.g. concealed ovulation) evolved to make it harder for women to predict when they would be fertile, which made it more difficult to avoid being pregnant, and consequently there was higher genetic fitness and those traits spread.
Many (most?) people choose what is best for themselves, not for their society or species. Because of biology your Yttri might have great difficulty avoiding becoming pregnant. Pregnant females might rationally opt to get pregnancy over with as soon as possible - which means the r route.
[Answer]
**Frequent natural disasters, aggressive neighboring countries, plagues, short lifespan**
1. **Frequent natural disasters:** If there's a lot of people lost to each disaster, maybe because of severity, there's always need for mediocre people to clean up and rebuild. Few smart people to lead but many to do the job.
2. **Aggressive neighbouring countries:** Training soldiers is hard but because our neighbors have lots of soldiers, we need lots of soldiers to replenish the loss of life.
3. **Plagues:** Frequently mutating viruses, dangerous bacteria post-disasters etc... may cause population decimation. This encourages higher birth numbers.
4. **Short lifespan:** If the species lives shorter lives, even prolonged by medicine and technology, they would value each year more and require higher population count to survive.
Also, maybe all of those?
[Answer]
**Caste - only some Yttri are allowed to produce the healthier, more intelligent offspring**
By long-established tradition, members of the ruling caste are expected to produce only the most superior of children, while other castes are required to produce lesser, or even primitive children. Sure, there's no biological reason compelling the lowest castes to choose to produce large, unintelligent broods. But between social pressures and real threats of legally enforced violence, those offspring who are obviously more developed than their caste justifies do not (generally) survive to adulthood.
The levels of development will likely correspond to established social roles for each caste, like in ancient India, Plato's Republic, and Brave New World.
[Answer]
Entrepreneur/industrialist driven race. May work in a part of the universe easily accessible to expansion.
Multiple births over time:
1. the leaders first - to be educated
2. the workers in the next ones. Can be tuned in sync with the degree of intelligence required by running the business (the very late ones may even produce better specialized leaders, with all the intrigues in [Dallas](https://en.wikipedia.org/wiki/Dallas_(1978_TV_series)) type soap operas; or you just can trim it down to something reasonable)
Adaptation to a "closed world" scenario: compulsive inter-clan wars.
[Answer]
**Voting**: Rather mercenary, but if it's one being one vote, then having more kids and indoctrinating them into "your side" (whatever that might mean) would be a winning strategy. "Vote breeder" could even be a job. (And if this gets to be too unpopular, it could be banned, which means it becomes a black market job that is allowed and encouraged by those who benefit...)
Straightforward **survival of the fittest** -- more of your genes survive if you have more offspring, so those who choose more children are more represented. I'm not sure it needs anything else. Also consider the strategy of "first have lots of kids for the genes, then have a few smart ones for the memes."
**Micro-caste system** where you reverse the above: first have a few smart kids, then a bunch of dumb younger siblings to do their bidding.
**Organ harvesting**: don't mind me, just thinking out of the box. Be glad I didn't say **food (delicacy)** for the privileged class.
There's also the possibility that it becomes standard to alternate sizes between generations: if you want lots of smart offspring, the most straightforward way would be to have a large generation of single-child breeders (with the same father for both generations), and you only let the grandkids out into society. There could be major cultural effects depending on how well the post-reproduction breeders are treated (it could get ugly).
[Answer]
**Collectivism.**
You don't form nuclear families if you spout a thousand young. These folks have an instinct to breed, and a strong solidarity towards society, but they don't specifically have a drive to nurture their own brood.
You breed, you spawn, and they're not *your* kids, they're *society's* kids, perhaps living together in something a K-style species would call "an
orphanage", run and funded by society. Yourself, you're happy to have them out of your womb, and assume some of them will make it. Most won't, but your society will survive, so nothing's lost there.
Going K-style, well, that's a lot of work invested in producing a handful (or, perish the though, a single) offspring. You'd only do that in the face of a complete societal collapse, where you'd have to take care of it entirely by yourself. Doing it in times of plenty - well, that's almost like saying *your brood* for some inexplicable reason is more important than *everyone else's brood*!
**In response to OP's comment:**
This industrialised society will look quite a bit different from human, Western civilisation. It'll be more like successfully implemented communism, I guess. (I'm a big fan of the Culture novels in case you wondered üôÇ )
I also assume that "childhood" has to be quite different from what human (K-species) childhood looks like. Perhaps you're born a larva, rather than a baby, that lives independently but quite differently from adults. You'll spend a year or two or three (depending on your time in the womb) in a communal "pond" for this particular purpose. When you've developed enough, you emerge from the brood pond, and the workers there will make sure you're taken care of, put into the education system, etc.
[Answer]
**Breeding up with the Joneses**
Imagine you could pick the most attractive features for your baby. Or rather, that you can produce babies until one pops out with the right combo of attractive features, then mate that one with another attractive one and make them produce a K-brood for you. This results in a strong, smart, attractive baby that you can easily love and nurture!
Yttri families are always looking to improve their genetic stock by selective breeding. It's a measure of success and status to have the most attractive offspring. A "society" mom's life revolves around "The Market", short for the various trade shows, auctions, brokered deals and private gatherings where r-babies are traded. She's always trying to find the perfect mates both for herself and for her favored breeding offspring and selling her own to finance the purchases.
The traded offspring are made to breed again, with particularly favored ones told to produce K-offspring that will become the next generation of the main (K) family. Not all of these are successful, as intelligence is hard to measure in the r-brood. That's why K father and mothers also produce their own K-offspring to have a few very intelligent offspring in the family.
What happens to all the ugly useless r-babies is not really suitable for human sensitivities, so I will skip that here.
[Answer]
It depends on how extreme the intelligence difference is, and how socially advanced the country is. However, it seems really unlikely that anyone would choose full brood, in reasonably modern first world country.
However, if the Yttri are a bit more pragmatic than humans, then it might make sense to stop before the "one smart one" point. We could assume there's some negative feedback on this intelligence growth thing (if we imagine the brain as a network of processors, then as we add more elements there will eventually be a point of diminishing returns, because more effort is spent on communication between nodes than actually computing). We could also assume there's some random variation in intelligence -- there is in real life after all. So, maybe being the "one smart one" puts you in the 120-100 IQ range, being in the last two puts you in the 110-90 range, being in the last 3 puts you in the 100-80 range, and so on.
If the Yttri mother is trying to assure that she'll have someone to take care of her when she is old, then there's a reasonable tradeoff here. If you wait for that last one, maybe you end up with a kid that has a 50% chance of being successful in a really well paid field. Maybe if you end at 2, you get kids that have each got a 30% chance of being successful in well paid fields. Now you've got a 51% chance that at least one will be successful, and a 9% chance that they both will. Not a bad deal!
You can play around with the probabilities to get whatever result you'd like. Model it is a binomial distribution (you'll have to pick the probability of success for a given development level using your gut).
<https://en.wikipedia.org/wiki/Binomial_distribution#Probability_mass_function>
[Answer]
1: economic incentive. Just because you arent as smart does not mean you are worse off. Lower intelligence jobs might be numerous and too boring for higher intelligence people to perform. And if the high intelligence market is saturated you are better off with hard working low-intelligence.
2: long-term planning. If you get many dumb children now, those children are likely to survive long enough to get their own children in a modern society. Those dumb people (or their mates) would still carry your DNA and be able to gestate longer in order to get smart children. So after 2 generations you have many many more smart grand children than the person who went for intelligence right away
This type of planning actually has a lot going for it. The smart generation does the smart things like run a company, the dumb generation (assuming you dont add a smart generation by having more kids) would work in many area's of these companies (making bread, painting, carpenting, cleaning or whatever). Then these dumb children get a smart generation that takes over from their grandparents and start their own cycle.
3: why would they be dumb with modern help? The gestation period used to give smarter children as more energy and food went into the children before birth. In the meantime if you had many many children you were unlikely to feed them all causing more development problems. But with modern food and medicine all your children would be able to develop fully (without having to canibilize each other in brutal competition for resources!). So the intelligence gap is smaller or non-existant.
[Answer]
Have a look at your own nieces and nephews.
The glue eaters and mouthbreathers are easy to entertain. Any screen playing the latest colorful, retarded cartoon on a loop will keep them enthralled for hours so that you can go around doing your own stuff. In 2020 the latest one is Baby Shark.
But the intelligent ones - you gotta keep stimulating them mentally for them to stay put. A book will only give you so many hours or days of peace. Paper and color pencils? They will get bored after a while. TV has got nothing on them, and they finish their homework too fast to fill the afternoon.
Any parents that don't have the patience and the resources to keep a couple smart kids will prefer scores of dumb ones.
[Answer]
**Social stratification**: We can see this at work in the real world. Even in a first world country like the USA, there are millions of people in dire poverty, both rural and urban. *The world the poor live in is not the same as the world of the rich.*
**Given endemic violence, food insecurity, limited opportunities, and menial jobs, poorer Yttri might be quite justified in pursuing an "r" strategy.** There's just too much danger or likelihood that one favored child won't survive/thrive.
[Answer]
Your premise is a little vague on two very important sociological details:
* Do the individual Yttri who opt for r over K *know* that they are opting for r over K? Is it a conscious choice they make? Or is it more like, say, homosexuality in humans — where it clearly has implications for reproductive strategy, and yet, it's not like anyone's out there looking for rational *reasons* to be homosexual. I mean maybe r-ness just *happens*, and even Yttri scientists don't really know why.
* Assuming conscious choice, do the Yttri who opt for r over K need *rational* reasons to do so? Do their reasons need to bottom out in some kind of evolutionary advantage, or does it suffice to say "They're choosing it because they're stupid" and/or "They're actually doomed by choosing it"? A mutation, even a complex one, doesn't need a human-comprehensible *reason* to exist.
"Irrational" reasons for choosing r behavior might include:
**The Amish/Mormons/Hasidim.** This is just what their subculture does. Call it "religion" if you want, but it doesn't even have to be in service of some higher power; mainly it's carried on for tradition's sake. *Tradition!*
**The Paleo dieter/home birther.** Science now knows that our ancestors, millions of years ago, followed the r strategy. Our bodies evolved to deal with the r strategy. The K strategy may be easy to follow *today*, but our bodies are actually happier with a plain old-fashioned "quick birth."
**The Marie Antoinette shepherdess.** So an r strategy makes sense only during a natural disaster? Well, nothing is more fun than role-playing at calamitous poverty! Having a huge batch of babies is just what upper-crust Yttri women do, the same way they might send the servants home early and bake a cake from scratch by following a YouTube tutorial.
**The anti-vaxxer.** Haven't you noticed the gradual increase in undesirable mental traits lately? Concomitant with the rise in K-babies? Our family follows the r strategy consistently, and none of *our* surviving babies have any undesirable traits. I don't pretend to understand the science; I'm just saying, maybe you should consider doing the r strategy for *your* next birthing.
**The nail-biter/hoarder/road-rager.** At the extreme, maybe the root cause of r-behavior is simply what neurotypical Yttri would call "mental illness." The genes for r-behavior are present, and some unknown factor — nature? nurture? — has flipped the switch and sent this Yttri into a spiral of frankly unnatural behavior. But once they've had their brood, what can you do about it? Child Protective Services can't take on 10,000 youngsters. By the time it's reported, it's probably more humane to just let nature take its course. The survivors will be remanded to foster care and the unfortunate mother institutionalized.
The common factor here seems to be: If it's a conscious choice that the Yttri are making, then you should be looking for **memetic factors**, not classical evolutionary factors. Our conscious choices are driven by conscious memes, regardless of Darwinian fitness. On the other hand, if it's not a choice (like, say, homosexuality), then you should look for classical Darwinian factors, but at the same time, don't feel like you *have* to explain it. Nature doesn't explain every single one of her designs, either.
[Answer]
One of the main reasons Yttri still produce large broods is to further elevate the status of their favored small brood children. After all a child with a 100 siblings that are essentially servants will be able to accomplish much more than a child on his or her own.
The large brood children are typically birthed first and raised/trained to care for and obey their soon to come small brood charge in large orphanage like institutions. The large brood siblings then take care of their small brood siblings as nannies which allows the small brood siblings to be raised by their mother and father, but eliminates all the unpleasant aspects of child rearing.
As the small brood children grow up their large brood cadre will transition from nannies to servants thus allowing the small brood children to focus entirely on mental and leadership development, giving them a distinct advantage over the small brood children who's families could not afford to support growing their own servants.
[Answer]
There could be some kind of welfare payment that increases with the number of dependent children.
[Answer]
**Cannon fodder**
Having huge armies that just follows orders and don't think for themselves can be a huge benefit in warfare.
**Industry**
Quick worker assets for jobs that requires following orders and are just repetitive tasks, such as conveyor belt supply lines.
As a mother that perhaps wants her children to take care of her financially you're looking at 100 workers in low level jobs, or 1 in a high level job. The 100 workers will most of the time have a higher generated total after expenses than the single 1. This can be a gamble though as if the offspring could become the CEO of a huge company so would potentially provide a bigger net income. But with 100 workers you will have safety.
But overpopulation is a factor that needs to be taken into account and perhaps choosing is not for the mother to decide, and would be mandated from a ruling government where they need to fill their needs.
[Answer]
## Gender inequality
Following the example of our Terran civilization from not so long ago and still valid in most of the world.
Assuming you can determine the gender of the offspring early on and assuming they would generally be of the same gender:
Men are the dominant sex (gender, whatever), females are good only for domestic work, sex and reproduction. What's the point in smart and strong daughters, when you have to invest more in them and get much lower dowry (because the K-type daughters are sexually unattractive, resembling males and generally expected to be troublemakers), if instead you can have many dumb, socially acceptable, i.e. "normal" daughters?
An example from Earth of only a few decades ago: a (reasonably) famous female writer recalls how her father offered her extra pocket money for each "Fail" mark during her elementary education. Because he was just not interested in having a smart, well educated daughter. He expected her to work on his farm and then marry someone strong to continue working on the family farm.
[Answer]
**Eat the young**
"Pandora's Star" by Peter F Hamilton has a race of amoeboids on a planet with little biodiversity. They spawn in massive numbers, and the young are stupid animals, to be eaten without regard. The elders don't take any notice if the young they are eating are their own brood or others'. The young form the middle tiers of the food chain.
"The Legacy of Heorot" by Larry Niven has a similar setup, with intelligent predators feeding on their own numerous young. Big problems happen when human colonists clear out the "dangerous predators" without doing fundamental biological research.
"Stranger in a Strange Land" by Robert Heinlein has elders who disregard the many silly flitting nymphs, and don't mind if they die. Not quite as awful, but it's a built-in callousness.
In each of these cases, intelligence doesn't spark until the creatures are of significant size. They live as animals, whose deaths are disregarded by their own society.
In human society, cannibalism is regarded as the worst sin. Read Jonathan Swift's "A Modest Proposal" and its many commentaries for other ideas.
[Answer]
Taxes!
Their government might provide a tax break or tax credit for having more children.
This alien race might want to produce more children to take advantage of the tax benefit.
See <https://en.wikipedia.org/wiki/Child_benefit>
[Answer]
The knowledge of history and ability to relate.
There are many countries that are aspiring to being 1st world. Yet in all of them, some more than others, people suffer from hunger, sickness. They fear what next day, week month will bring.
Some are aware that a war can erupt that will shatter their fragile 1st world into pieces that will be worse than 3rd one because there will be extra chaos.
Chaos that could be only overcome by numbers. When you have one very smart person it take one sickness to take them out. Who's gonna plow the acres? Who's gonna weave clothes? Who will bring water from the well?
Having one child is a naive and selfish from society point of view. After all you basically decrease amount of citizens by two. 100 Yttri have 50 kids. 50 yttri have 25. Oh great, now they fight for mates. Oh great now their dumber less educated country next door invaded and buried them with hats.
[Answer]
While this is a bit further technologically than your question describes, a simple answer could be that it's a strategic decision. IMO, it's a safe bet that in the near future, quasi-immortality will be bio-engineered (here quasi-immortality means biological aging stops at a certain point and people don't die of old age).
In a society of quasi-immortals (or with sufficiently advanced medical technology), leading causes of death become accidents and violence. This means, that in the long term, cultures that have lots of children will end up dominating because the likelihood of an accidental death (eg. falling down the stairs) is rather similar for "single-smart" or "multiple-stupid" progeny options. Cultures that want to grow would encourage mothers to have as many children as possible and thus out-crowd cultures that focus on single progeny.
[Answer]
**Breeding for disease resistance**
*yeah, I wonder why that thought came to my mind...*
The K-brood selection is mostly focused on strength and whatever it takes to "win" in the womb. This has one glaring weakness: The offspring are not at all selected by their immune systems and tend to all have the same traits in this regard.
The next time a pandemic hits, it might take out the carefully nurtured K-brood in one fell swoop. To continue and strengthen the family line, mothers can choose to produce an r-brood now and then and send them to daycare to infect them with as many diseases as possible. Those individuals with the strongest immune systems are nurtured and trained to become studs or mothers, whose only task is to produce new K-offspring that are then adopted into and raised by the main K-family.
The r-brood also make useful servants and emergency food supply, depending on your species' stance on cannibalism, which seems by its nature more relaxed.
[Answer]
Two ideas:
1. Class solidarity. It's hard not to imagine a deep class divide between Ks and rs in this society. If you, yourself, are in the r group, you may be motivated to encourage more of that group over the Ks.
2. Society is organized around clans, rather than families, and within a clan r offspring are a source of cheap labor. Really, the idea of r individuals as cheap labor in general, but I think it's easier to explain the motivation for the parents involved if you talk about clans or large patriarch/matriarch-led families.
[Answer]
Happiness.
The Yttri limbic system is (due to evolutionary factors) biased in favour of getting satisfaction from those large litters. So despite all the rational factors you’d care to name, they tend to gravitate towards having large dumb litters for the sake of it.
Furthermore, the first-world Yttri put more weight on happiness relative to economic advantage than the corresponding humans would, and they want their (surviving, adult) children to be happy too. And it just so happens that the dumb carefree Yttri fry are better at being happy than their overthinking managerial cousins.
] |
[Question]
[
In my story trolls are a large humanoids (8-9ft tall) and are about as intelligent as humans. Elves are similar sizes to humans and are also as intelligent. If trolls are about smart as humans, then why would so many practice this inhumane tradition? I was thinking of a few ways, perhaps trolls were hunted in the past by elves and they simply were defending themselves. Maybe food was scarce and they simply began to eat the numerous elves which then became a tradition. Maybe trolls don't interact with them enough, and because they have been killed by elves, they simply believe elves are too evil and soulless to feel bad about killing. And lets say I go with the idea trolls simply didn't know they are capable more than harm, would a troll feel bad about killing elves even despite the massacres they've committed on them?
Note: Im okay with any answer, it won't break any rules I have for my world because as you can tell its quite early in development.
Edit: Trolls do eat other things, such as fruit and deers but if given the choice to eat elf instead they would definitely chose.
[Answer]
# Because it's the right thing to do:
Your trolls may think that the rationale for their behavior is perfectly justified.
* **It's not cannibalism - right?** Your trolls are doing it because they really DON'T see elves as intelligent OR think cannibalism applies to species other than trolls. Different cultural views mean elves are simply meat of really tricky prey.
* **You are what you eat**: The trolls take this maxim seriously, and eating superior food means the troll is superior. Why do the elves get so excited? after all, being eaten is a compliment. A troll that eats an elf believes themselves to be more elf-like, and perhaps this is seen as desirable. If elf-like behavior (kindness to females, etc.) increases reproductive success, that is a powerful reinforcement.
* **WHO ELSE will eat them?** Trolls believe that life is passed on to those who eat the flesh. Troll logic says they are SAVING those poor elves from the dissolution of being consumed by lesser beings or (ugh) rot.
* **God wills it**: A misunderstood religious passage now means the trolls eat elves because their god wills them to do it. An encouragement to eat the once-sacred but now-extinct forest elk (the child of the forest) has been mistranslated to eating the children of the forest (forest elf). No one wants to offend their god, right?
* **nutritional degeneration**: This is similar to the answer from Drew, but based on a question [previously asked](https://worldbuilding.stackexchange.com/questions/193631/why-do-ogres-eat-people). Trolls used to be human-kin, and have long fed on other hominids. They can no longer produce critical proteins and amino acids on their own and must obtain them from fellow hominids. Elves are just handy.
* **Right of Passage/snipe**: Elves are hard to find, hard to track, hard to kill, and their relatives track you and try to kill you for a tiny bit of scrawny meat. BUT killing and eating an elf proves you are a worthy troll. No troll who wants females, leadership, or just bragging rights can face down the communal fires if they don't have an elf-bone necklace to prove their feat of skill.
[Answer]
You don't need a reason, **you need a frame challenge!**
>
> If trolls are about smart as humans, then why would so many practice this inhumane tradition?
>
>
>
This assumption is - not to be rude - somewhat ridiculous. Humans are good contenders for the title of most inhumane animals on the planet (just take a look at history), and the a good reason against cannibalism was not moral or ethical.
This reason against it, (why even human-sacrificing civilisations didn't often eat humans) is purely medical: flesh from the same species carries not only a decent chance of fully compatible diseases, but also the chance that [malicious prions](https://www.hopkinsmedicine.org/health/conditions-and-diseases/prion-diseases) are ingested from the victim a form of disease that has no other vector of spreading. And even with this risk there were some cannibalistic societies. Now imagine the food source not just having a different skin color, belonging to a neighboring tribe, or nose form, but being an entirely different species alltogether.
Even with modern ethics I'm not absolutely sure there wouldn't be some people nowadays trying to eat gnomes or so, and modern ethics are, well, modern. In medieval times I have little doubt that a tasty enough but sapient species would've ended on the grill, doubly so if you throw in ANY of the other reasons mentioned in other answers here.
As @Leitix put it so well in their comment:
"Sapient races don't eat other sapient races" is a completely untested theory, and the ease with which we humans slaughter and eat other feeling animals makes me severely doubt its veracity.
[Answer]
Tastiness is not to be underrated, but most dietary quirks are about access to adequate nutrition. Example: sailors used to consume citrus infused grog to counter the Vitamin c deficiency that causes scurvy.
Trolls could lack some nutrient that Elves uniquely possess. This does not have to be a mundane element. Trolls are closely related to rock, correct? Perhaps Elves contain some vital "vim" that Trolls require to remain animated.
Without occasional ingestion this "vim", they could eventually revert to rock form or fall apart. This kind of analogy to reality feels "realistic" to me.
[Answer]
**Aphrodisiac.**
Yes the meat is sweet and the long (mostly) blond hair makes the most beautiful cloth, fit for nobility (and those that aspire to the pretence of it), but the main point is the [sweetbreads](https://en.wikipedia.org/wiki/Testicles_as_food). Wedding ceremonies - they are obligatory for the groom and by extension the best-troll, and you just try and stop the bride's widowed-father from chatting-up the maids of honour after a bite of the "good stuff".
**Rites of passage for adolescents.**
"Now get out of this house you lazy good-for-nothing, and don't set foot over this threshold until you grow-up and hunt down your first elf." Mothers can seem so cold when all you want to do is bring your girlfriend back for a sleep-over. Of course, the sleepover's on when they get back and can turbo-charge their er.. *urgent interest* in the encounter with a tasty bite of power-up juice.
**Nobility.** (The ones wearing the silky clothing.)
No doubt a must for the lord of the manor to demand of his peons they bring him tribute regularly, particularly when there's a "firstborn male heir" to produce. Obligatory for entertaining foreign nobles and favoured business acquaintances, considered rude not to seal a business-deal of any worth with a good roast.
[Answer]
Cannibalism and the consumption of closely related animals is just as high in intelligent animals as it is in less intelligent ones. Apart from many human civilizations that have practiced cannibalism, lets look at the other intelligent creatures we share this world with.
**Chimpanzees:** Monkeys are a chimpanzee's preferred source of meat. It is also common for chimpanzees to try to eat human children. They are also known to eat the children of rivals and thier enemies killed in inner-tribal wars.
**Squid:** Possibly one of the most intelligent species we share this world with, but also one of the most cannibalistic. The gonatus onyx for example is estimated to get about 42% of all prey from cannibalism.
**Killer Whales:** Diet consists heavily of other whales and dolphins. While actual cannibalism is rare among Killer Whales, the consumption of all of thier closest cousins is thier main food source.
In fact, it is possible that near species predatory behaviors may help contribute to the evolution of intelligence. Imagine two populations of trolls, one group decides to avoid elves, the other decides to eat them. The group that eats the elves gets culled so that only the strongest and/or smartest trolls survive the backlash of thier actions. While this leads to a temporary reduction in population, when the troll populations returns to normal they will be stronger and smarter than the not-elf eating trolls. After enough generations, the elf eaters could be much stronger and or smarter than the more peaceful elf avoiders; so, when the elf eaters compete over territory and resources with other trolls, they will be more likely to win.
[Answer]
## Intelligence is not the same as empathy
The need for **empathy evolved as a way to work better as a group and keep babies alive**. If you don't care at all about your tribe mates and they don't care about you, when your tribe gets attacked everyone just tries to save their own skin and collectively get slaughter by predator/enemy tribes. By design, empathy is stronger the more you can identify with the person/animal/thing (and how baby-like it looks), even humans don't see a problem with slaughter other humans and eat them as long as there's a strong us vs them dynamic between the groups, or at least a strong in-group cohesion. Plus, you know, if you need your group to survive, **it's not a good idea to think of your buddies (or their kids) as emergency snacks**.
Intelligence is simply the ability to solve problems and how to manipulate the environment to your advantage. Since knowledge can be passed down, intelligence will always benefit social animals more, as it is easier to share a breakthrough than it is to everyone to come up with the same idea. Nevertheless intelligence will benefit less social creatures just fine, parents will likely raise their kids and pass down their knowledge to them and, as long as they are not too territorial, they will still have plenty of opportunities to learn from other adults.
**If your trolls live solitary lives**, then I would expect their empathy towards things that don't look like babies to be reduced since cooperation and caring for your neighbor is not as crucial for survival. And besides...
## Eating elves is a good idea all around
Assuming the troll and elves are both humanoids, I would expect that the two species have a great overlap of resources that they both need. Effectively, elves are competition, and competition is bad as you have to waste resource to win the competition and get the stuff you need/want. Now, there is a thing you can do that will both shrink the competition and get you resources. You guessed it, eat them!
You want them dead anyway, why not get a snack while you are at it? Once you remove the empathy barrier, living things that stop moving is just free food, assuming it hasn't die of disease, in that case it might be dangerous food. Serious, the list of things animals will eat include their own children has that just died, and if you think of it rationally it makes perfect sense! Intelligence is not the problem here.
## They would not eat just elves...
The only problem with this framework is that pretty much any humanoid is food in potential, so what applies to elves probably applies to humans, dwarves, etc... Maybe the trolls prefer only eating elves because they are smaller than humans and their meat is not as hard as the dwarves, but I doubt they would pass away some human children lost in the woods. Maybe elves just happen to live closer to the trolls and thus are more attacked. Or maybe the elves are too afraid of getting eating to talk to them, so the trolls through diplomacy out of the window and start their fight or fight harder response, while other races are not as afraid and just stick by to a chat with the troll (as established they are not mindless beast).
For this kind of troll, I would look up the trolls of the witcher universe. They are more on the funny side when they are not murdering since they are not as intelligent, but I get a similar feeling out of them.
[Answer]
* **Desire**: When boys see beautiful girls, their heart beat and
blood movement increases and certain desires flare up. Similarly some
desires flare up in trolls when they see elves.
* **Spell**: The trolls are under a magical spell and they cannot control
themselves when they see an elf.
* **Powers**: When a troll eats an elf, he absorbs elf's magical powers and
he can do things which he cannot otherwise.
[Answer]
**It's an important part of traditional Trollish courtship practice**
Elves are dangerous prey. They're smart and quick, and know how to use weapons to defend themselves. They often band in groups to protect each other and are hard to get alone. You need to be very brave and an expert hunter to catch one.
Any troll with the hunting prowess to bring home fresh elf meat (or the money to pay off a hunter to do it for them, in secret of course) would be considered an excellent provider for any Trollish household, making them highly desirable as a potential mate. The Elf Hunt is considered the capstone event of the Trollish courtship ritual, with the presentation of a gift of elf flesh being the traditional way to propose a life-bond. It is also a romantic gesture for a troll to reaffirm their commitment to the relationship even after the life-bond is established, such as on an anniversary.
It is hard to turn down the proposal of any troll who went to the dangerous trouble of bringing you a lump of sweet elven meat. And if they died in the attempt, well, that just proves how much they loved you. How romantic!
[Answer]
Trolls eat elves because elves eat fruits.
Although it seems stupid, it is just mammal biology. In mammals, carnivorous can kill other carnivorous, but they generally do that to protect their territory, more than to eat them. Simply because carnivorous flesh contains too much organic waste like urea, so it is not as good to eat than herbivorous flesh.
Except for fishes, human beings mostly eat herbivorous flesh. We do eat bats, but only fruit bats, and the better the fruits, the better the bats. As elves eat delicate food,their flesh is just delicious.
[Answer]
Same reason we be after Smurfs...
**BECAUSE THEY ARE DELICIOUS**
[Answer]
Because trolls are given over to evil.
In (good) literature, trolls/orcs/goblins represent fallen humanity, influenced by the devil and given over to sin. In the real world, some human societies praise and reward virtue (although they don't entirely achieve it, because we are flawed) but there are some human societies that reject virtue, and praise and reward vice instead. Trolls/orcs/goblins are a metaphor for human groups that call evil good. They grind elves' bones to make their bread because it's the next step along the road to total depravity.
Sometimes an amateur author tries to write a story in which the trolls/orcs/goblins are "just people like you and me", and they try to make a different point about the real world (usually implying that elves are racists and orcs are unjustly discriminated against). This generally fails because the metaphor/allegory doesn't work. If they're mean and ugly and do evil things, obviously (to your readers) they are an allegory for real-world evil.
[Answer]
In case the range of answers didn't already give it away, this is a *really* broad question. This is often the case for "Why does **<X>** do **<Y>**"-type questions, since we generally don't have a lot else to go on.
In this case the waters are further muddied by the fact that 'troll' is poorly defined, both in literature and mythology. Are we talking about human-ish creatures with a disconcerting propensity to turn into statuary in sunlight, hulking goblinoid (like humanoid but from the same evolutionary line that produced goblins) brutes with magical regeneration that don't like fire, hairy little critters with a proprietary attitude towards bridges, mysteriously animate rock piles, elves/humans/whatever twisted by evil sorcery... there are just so many variants, it's hard to narrow this down.
As to why they eat elves... the options are equally varied, as shown by the other answers. Could be ancient feuding between trolls and elves, pure malevolent desire to strike fear into the heart of elves everywhere, religious obligation (because religion can explain just about anything), or it could be as simple as dietary preference: elves just happen to taste heavenly to trolls. And it's not like they're cannibals or anything, elves aren't even remotely related to trolls. Probably.
Do trolls hunt elves? Or do they just eat the ones they kill in battle? Is there a trollish cook book on how to properly prepare elf for different occasions? Is there a trade - open or black market - in elf meat? And perhaps more important: will trolls pay good coin for human-elf cross-breeds or do they taste terrible? (Asking for a friend.)
---
Or - stay with me here - perhaps trolls don't *actually* eat elves. I mean, sure, everyone *knows* that a troll will eat an elf if he gets a chance, but have you ever seen it happen? What if this is just a scary story elf parents use to make their unruly children behave?
Perhaps it used to happen a long time ago, when trolls were a lot less civilized than they are now, but species animus has a way of lasting for a very long time. Of course the elves won't ever let the trolls live it down. They have long memories, and it doesn't really matter that no troll has been caught eating eaten an elf in generations, elves hold really, *really* long grudges.
] |
[Question]
[
After reading the question [Are “Midas” swords useless for warfare?](https://worldbuilding.stackexchange.com/q/119564/28789) it really tricked my mind of finding ways on what to do will all that gold.
So I was wondering: assume a war broke out and you used your Midas weapons to instantly kill soldiers (being wounded with it will turn you to gold) and you also used Midas arrow tips for your archers. Now your land is full of gold.
**What is the most practical way of "cleaning" your Kingdom?**
If you actually displayed your gold in your castle, or throughout your kingdom, I think it would invite other kingdoms to try and conquer you, since defeating you will grant them riches beyond imagination. You can't use gold for all of your metallurgy since pure gold is soft. And having to haul dead gold corpses inside your castle is a pain. Moreover I think it would be more chaotic internally because of all those lootings and robberies that would happen in your kingdom.
While the original question asks for the usefulness of the weapons in war, I am asking about the aftermath, with all the gold lying around the battlefield. Let's say that the enemy sieged your kingdom and some 5,000 men from the invading armies are killed, while at your side, 2000 men have died. All of the men from the invading armies are turned into gold, while on your side, some 500 men where turned into gold, because the invading forces somehow manage to use you soldiers arrows and swords against your defenders.
EDIT: WRONG NUMBERS (50,000 to 500)
[Answer]
All that gold makes gold virtually worthless so people would put it to practical use like construction.
The Pantheon is held together with iron bars coated in lead to slow down corrosion. You could get better protection coating iron in gold. You can coat roofs in gold leaf for excellent waterproofing.
The ancient Romans used lead pipes for water. Gold pipes is far safer and cheaper.
Gold doesn't corrode so there many uses which people don't use only because it's rare. If it wasn't rare people would find plenty of uses.
[Answer]
The primary reason why gold is so valuable is because of scarcity. Once you eliminate scarcity there are many uses that gold can be put to.
Chemically it is highly nonreactive making it a good fit for containing reactive materials and foodstuffs, and anywhere that you want a durable cladding that doesn't require much strength.
It conducts heat well making it possible to build quite efficient heat-sinks for cooling your house or keeping your icebox chilly... with a suitable source of lower temperatures like a nearby river for instance.
Physically gold is malleable and ductile, so covering things with gold is both simple and useful in many of the ways that Lead was in early plumbing.
Depending on your tech level gold might replace lead in any number of uses. It would make quite good movable type for your printing presses, a handy modelling material when making casts for your forges and so on.
A few steps further along the tech path and gold makes an excellent conductor of electricity, if a little prone to melting under very high loads.
And don't forget how pretty it is.
The economic impact would of course be large, but not as catastrophic as you might think. Any nearby country operating on the gold standard would of course lose much of its wealth if you flooded the market with cheap gold. It's hard to have faith in a currency backed by something that your neighbours are using to plumb their toilets so within a short period of time they would have to transition to a different foundation for their money, like a platinum or silver standard.
There's a bit of commentary on outsiders attacking you for your gold but since you have a virtually limitless supply - especially once your people start turning their Midas Swords into Midas Ploughshares - you can simply dump waste gold on the borders for anyone to take. No point fighting over it, any more than people living next to a desert fight over sand. When they come and threaten you, you just hand over the gold and look puzzled at why they want such a worthless item. Give them as much as they like. Eventually they'll find that they can buy it by the ton for less than it costs to raid you for a few hundred pounds.
FYI: the sciencey part of my mind wants to complain about a few side effects like destabilization of the continental plates, but you didn't ask so... :P
[Answer]
All these answers assume that the midas-gold is something people would be willing to melt down and sell.
I think they miss a fundamental and vital point.
These are the last remains of people.
They belong with their families, for burial and disposal in as traditional and respectful a fashion as possible.
I would expect that any nation using Midas weaponry would have one of two policies. Either that the bodies of those killed belong to the state, or to their families. Either way, anyone caught trying to sell them is likely to get punished massively.
Some might well be stolen or sold off and melted, but I think most would be treated as corpses. Really *really* valuable corpses.
With that in mind, I'd expect most of them to be returned home, buried, placed in locations of honour and generally treated with the respect their nature deserves.
So to answer the actual question, the most practical way to dispose of the solid-gold statuary is to use carts to deliver them home.
Dealing with the bodies of enemies slain in your territory is another matter, either store them somewhere (creepy gold-statue warehouses?) or present them to the enemy leadership as a peace-offering.
I'd expect most of the grave-gold robbery would be done to enemy midas-corpses rather than your own side. After all, why respect the enemy?
[Answer]
If there are other countries that are still working on the gold standard, all that gold has another use: Economic warfare. There's very little stopping you from keeping a pile of your defeated enemies' golden corpses locked in vaults with the promise that if anyone is ever dumb enough to attack you again, you'll just spend all that gold and crash their economy faster than they can marshal their armies. It's remarkably hard to mobilize an army when a single loaf of bread costs a golden arm and a leg.
And so long as you can keep a fairly tight control over the several metric tons of gold you've now acquired, you can use it for rebuilding while subtle harming your enemies' economy. Once they catch on to the fact that you've basically got an infinite supply, you'll already have gotten back on your economic feet. Just make sure to use something else for currency for your own nation, lest you'll be hoisted by your own petard.
[Answer]
The other answers are (mostly) focused on what the glut of gold would do to the price of gold. However, I think what's missing here is a consideration of the *quantity* of gold, which can be calculated from the question. The typical modern human body is around 66 liters in volume (according [to this source](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1332296/pdf/brjsmed00010-0064.pdf)). Medieval era humans might be smaller, armor ect. might make them larger, but this should work for a ballpark. The specific gravity of gold is 19.32 grams per cubic centimeter. Since there are 1000 cubic centimeters in a liter, 1 liter of gold weights 19.32 kg. So the average gold statue will weight about ~1275 kg. Assuming that, as Ruadhan2300's answer points out, you treat the bodies of your own dead with respect and bury them or something, you have as much as 1,275\*5,000=6,375,000 kg of gold to work with. This is *a lot* of gold, but at the same time, it's not *that* much gold. It's about 40% more gold than is currently in Fort Knox ([4,582 metric tons per Wikipedia](https://en.wikipedia.org/wiki/United_States_Bullion_Depository)).
This is on the order of the amount of precious metals that Spain extracted from the New World in the 1500's. I haven't been able to track down a reliable source for the amount of gold, but I've seen estimates of the amount of silver as high as 41,000 metric tons. Mind you, the influx of treasure from the New World seriously disrupted Western Europe's economy, but it didn't make gold and silver worthless either.
First, realize that you're not putting all that gold into circulation as coinage in one fell swoop, even if you wanted to. With medieval technology, hauling statues weighing one and a quarter metric tons to somewhere they can be melted down will be very time consuming and challenging. Not least because with that much weight pressing on a small area, the statues probably instantly sunk into the mud of the battlefield when they were transformed. So now you have to dig them up again. Six thousand metric tons of gold hitting the market at once will cause rapid devaluation--the same amount dribbling out over years, less so.
Second, you can use gold to make lots of beautiful things. Candelabra, plates, murals, jewelry statues of religious icons (if the irony of melting down your enemies to make a statue of your god isn't too much). Hell, melt it and pour it in sheets over the outside of your castle walls as a warning to future invaders. While in some sense all this gold decoration it won't be as valuable as if gold were scarce, it will still be awesome. After all, you're not trying to sell all this decoration, just enjoy it yourself. You may lower the price of gold jewelry and decorations, but it won't immediately affect the value of the currency and make it useless for trade with other kingdoms.
Finally, even after you're done using gold for any conceivable practical purpose, you need not turn it all into coinage (or bullion) right away. Generals of the opposing army you might ransom back to their home country. Or, conversely, put them on display somewhere as a reminder of your victory. Stick a bunch more in a vault against a rainy day.
Also, obviously you can tweak the numbers if necessary to make things work for your story. Besides reducing the number of enemies who were "midased", you could always declare that they are converted into 10 carat gold, rather than pure, cutting the amount of gold you need to deal with in less than half.
[Answer]
It strikes me that in this world the gold would already be worthless even before the war.
If the state possesses magic weapons that turn living things into gold then why would they wait for an enemy nation to attack before using them?
It strikes me as most likely that the farming sector of this state would be very active in farming animals especially for turning into gold.
This accomplished we then come to the answers about gold's worth being based on scarcity and the practical applications of gold if it was common. I particularly like the gold lined pipes idea.
The question is then one of the religion and customs of this world and whether they will show respect for enemy dead.
Given that they already have plentiful cow-gold, they don't particularly need to use this human gold...Thus either honorable burials or dumping them all in a pit seems the most likely outcome.
[Answer]
Leave the golden corpses be. Or bury them. They have no value.
Even if someone would want to use gold for lets say construction project, it would be cheaper to buy and transport a cattle and jab it with midas needle in place, as gold is pretty heavy.
Even if there were foreign market with gold as a currency, it would collapse instantly with the first rumor about midas 'technology' and traders would swith to other standard. Maybe seashells?
Even if other kingdom also wanted some extra gold, all they would need is a single midas sword. The only reason for a full scale invasion would be to steal the midas technology itself as a war weapon, not the gold.
[Answer]
Forget the gold, the weapon is the real value, especially if you can equip your archers with it (is the weapon 'one time use' or can you collect the arrows and use them again?).
Suddenly you can conquer anyone with lower resources.
The real aftermath of such a war would be a desire from other countries to possess such a powerful weapon.
Hired assassins, espionage, arms race like never seen before.
[Answer]
**Keep what you want for usage and turn the rest into bodies that are either dead or held as prisoners.**
In the original story of Midas the curse didn't just turn people to gold and leave them that way. It was reversible. Taking the bodies and washing them in the water of a river would turn them back. Different versions of the story are of course going to have different interpretations but with these being "Midas" weapons this could be an effective way of cleaning up the bodies. With a slight alteration that the gold-ification is irreversibly fatal the gold can be turned back. A slight alteration as well could be that putting the gold into a forge or melting it makes the change permanent. Then at that point the gold can be collected as fast as people can carry it back before rain starts to fall. Of course that will still be a lot of gold but if you have midas tech then the bodies are irrelevant. Midas could turn anything to gold, including food. So really the bodies are just a matter of cleanup and could be left to turn back as a matter of respect as one answer points out. So really the gold itself can be any random object. However, if literally anything can be turned to gold then gold is worthless. It can be made on demand and any country looking for gold could just ask for it. The bodies are not needed for supply unless you have actually ran out of Midas weapons and it's the last of the gold supply.
If you do allow the people to be turned back into the same state as before being turned to gold (i.e. alive) then the result will be a large amount of prisoners of war. That's not a problem though. They can be executed or simply held as slaves or whatever. This can all be tweaked as you see fit but I think if played right it would work well in making the country with Midas weaponry look less violent and aggressive. Any warfare they engage in is essentially just mass imprisonment. Unless the people turned to gold simply die of the actual weapon stab or slice wounds before turning to gold there isn't any reason to not be able to treat them over time. After all, they can be kept as gold indefinitely so they are effectively immortal until turned back and if done slowly there can be a near 5% death rate from gold weaponry. I say 5% because some serious wounds are just not treatable such as a knife to the head or an arrow to the knee. All in all I think the end result will be that any invasion attempt will simply result in a metric ton of prisoners that have to be held at ransom. However, it would probably be more likely for slavery since gold is worthless in your country. Perhaps you can ask your neighboring countries to send general resources. It is likely that Midas tech will to some extent damage the land. After all, if you drop a sword into the ground then the ground around it will turn to super slick sterile gold. It would be a great way to throw off enemy troops. Make them start sliding as if it were ice, but if it weren't obvious that will kill whatever was growing there. I suspect that your country will need reparations in the form of crops and cattle. Some will survive but a good chunk will die out. This would also be a good technique for oppressing as well. Just light fires on the ground after stabbing it into gold. It will quickly become a massive almost irreversible famine for that country. Far more effective imo. However, I know that was a past question and I won't dwell on that. It was just a passing thought.
] |
[Question]
[
In the system of magic that I am using I try to follow the laws of physics as much as possible. The idea being that whatever magic can do, a scientist and machine can eventually do. One of the things my spellcasters can do is transfer and convert kinetic energy. I know there isn’t a scientific principle that allows instantaneously converting kinetic energy into heat but hey, it IS magic.
One of the fundamental rules of my magic is that it is impossible to manipulate any energy or atoms that are within 3-6 inches of a living person. The caster can't touch that space, but if they do something to the surroundings it can go into the space, ie, one can't push a rock while it is inside the field but can throw it into it. I don’t like mind control and that was the easiest fix. But it leads to an interesting complication which leads to my question.
### Question
What would happen if a midsized sedan style car going say 60 mph had all of its kinetic energy stolen? Assume the time frame for this is about 1/1000th of a second (I do not know how fast this happens changes things, I want it close to instantaneous but not quite so that another caster can maybe interfere). Also assume that all the energy (minus the heat loss, since even in magic no transfer of energy is perfect) is completely transferred into the ground in that time frame.
Now how does that change when there is someone in the car? The person means that there is a small but noticeable part of the car whose kinetic energy cannot be touched by the caster at all.
Finally how much different would this be if rather than a big heavy car going fast, it was a light small bicycle going slow? The human's protection is much more of a bicycle’s total space.
Hard science with math being given would be beneficial but I’m not looking for how many joules or whatever the unit is will be applied to each atom of the person or whatever. Mostly I want to know how this compares to a normal car accident and in general terms what effects weight and speed and proportion of vehicle protected by a living person might have when all the kinetic energy is removed like this.
### My answer
The situation described is like a car hitting a wall that doesn’t break, except that it's all of the energy from every spot leaving the car at once. I know in a crash, the impact point hits first and the back end follows fractionally later, hitting what already stopped. Seems like if all the energy was stolen at once, the car would come to a complete stop and remain intact because every part stops at once. The person inside though would still keep going, essentially crashing without airbags or crumple zones or most of a car's safety features. Instead of saving the driver, the caster killed them more horribly than the accident would have. With a bike, seems like it would be the same as hitting a curb dead on, and the thing would flip (the front tire being one of the few parts that isn’t protected).
I believe this is different from any other question because of the complication of the human's null field. If not, a link to some other question will be a good answer.
### Edit to clarify
This is different from a head-on crash against an immovable wall because:
1. the null field inside generated by the person
2. the kinetic energy is stolen from every atom of the car at once, rather than when a car hits a wall and the impact point losing the kinetic energy before the points further away from the point of impact.
Second edit; I did not understand that kinetic energy was relative to a frame of reference so when I say all the kinetic energy is taken, I mean relative to the spell caster standing on the street. Its bad enough the spell intended to save a life, stopping a runaway car, brutally kills the driver without sending them into orbit after cooking them with atmospheric friction.
This is where my mental hang-up comes from.
[Answer]
**This is exactly what used to happen to cars before Volvo introduced Crash Test Dummies**
When I was growing up, many of my parents' friends were constantly bemoaning the fact that cars 'just weren't built the way they used to be' and a big part of that was that they just didn't feel safe in cars that weren't built to be sturdy; Solid chromed bumpers, very rigid thick metal chassis and doors, et al. Of course, what we now know is that the cars they were talking about were in reality death traps.
Volvo introduced the concept of testing cars in crashes, and the effects on people using crash test dummies. Pretty soon after doing this, Volvo cars were released into the market with 'crumple zones' that allowed for the kinetic energy to be dissipated before reaching the passengers. The idea is that if the cars hit something, the kinetic energy would be absorbed by the crumple zone and the relative impact of the momentum change on the driver and passengers would be reduced.
We now take that to even further extremes with airbags, engine mounts that drop the engine out in the case of accident, seat belts, etc.
Ultimately, what you're describing is exactly what *used* to happen when old heavy rigid cars hit walls, or each other. The kinetic energy of the car was immediately reduced to zero, but the kinetic energy of the passengers was not.
The result? Death, mostly. People hitting steering wheels, windows, gear sticks, etc. at 100 km/h (~62 mph). These cars (despite the perception among their drivers) were inherently unsafe. Ultimately, stealing a car's kinetic energy instantly can be done through magic, or just putting a wall in front of it. In both cases, for the sake of survive-ability you want the car to be the most deformable object in the collision, not the passengers.
Your current model has exactly the opposite happening. It's actually an effective way to either seriously damage or even kill people in an otherwise safe car.
[Answer]
What everybody already said about death due to collision with the dashboard and steering wheel, plus the seatbelt issue... Well, kinda.
Don't forget that temperature depends on the kinect energy of atoms. By sapping practically all of it from the car, it will be just a little above absolute zero (it will still have some energy from the heat transfer). The various components of the car and the fluids and fuel in its reservoirs and engine will go from solid, liquid and gas states to [different, interesting states of matter](https://en.m.wikipedia.org/wiki/State_of_matter#Low-temperature_states), so it will probably cease being a car in fractions of a second. I don't have a properly equipped lab nor a disposable car to test, but I think the car would fall apart before the driver woud die from the impact. They would still impact against something not made for safe impacting, though, and depending on what the car transmogrifies into, it might become a non-newtonian fluid, or a very hard solid block mostly shaped like a car.
There is one very interesting scenario. By freezing the molecules so fast, the molecular bonds may be broken. Some things will become superfluids at close to absolute zero... Long story short, if the car as a whole became a superfluid, the driver (who would keep their momentum) would fly through it like a ghost. They would then die by impacting against the asphalt at great speed while their whole body surface is enveloped in a very thin coating of a liquid at a ~0 Kelvins temperature. If they do survive the impact, the liquid will creep into their eyeballs, lungs, skin pores and intimate parts, killing them from suffocation and a case of freak hypothermia.
Meanwhile, you say that the energy of the car is transfered to the ground below. We are talking about taking the thermal energy of a 1 to 2 tons object and transfering it all to the ground.
[The specific heat of asphalt is almost double that of steel](https://www.google.com.br/amp/s/www.engineeringtoolbox.com/amp/specific-heat-solids-d_154.html). To simplify things, let's consider specific heats are constant and independent from temperature, that the car is made completely of steel, and let's do some rounding. If you are transfering from the car to an equal mass of asphalt, for every two degrees the car cools down, the asphalt heats up by one. This will happen with any scale, i.e.: Kelvin, Celsius or Fahrenheit. If the car cools down by 300K (about ambient temperature in many places), the asphalt will heat up by 150K. If you stood barefoot on it you might get 2nd or 3rd degree burns on your soles. If you are transfering just to the asphalt in contact with the tires, the asphalt will probably melt. Depending on its quality, it might have enough trapped gas in it to cause it to explode.
Since the ex-car will be on top of it, the hot asphalt will exchange heat with the bose-einsten condensates, superfluids and whatever. This will also probably cause explosions, strong enough to kill anyone close to it.
All in all, I think that usage of your magical spell as a brake mechanism for cars should be considered unsafe by transit authorities worldwide.
[Answer]
Your person will die, but not because they are colliding with the car. It would actually be the seatbelt that kills them. The few centimeters around the person move, but the seatbelt won't extend because its on a reel and you have stopped that part from moving. When the car stops your person should move forward into the dashboard and basically die, but the seatbelt will hold their body in place. The only problem is their head will keep moving forward and with such a huge amount of G's it will likely break their neck which would kill them.
I put the numbers into the website with a G force calculator.
<https://rechneronline.de/g-acceleration/>
60mph to 0 in 0.001 seconds would result in -2700Gs which is higher that the maximum G-Force tested of 46.2 G's (and that was in the opposite direction). So its pretty safe to say they are dead.
So based off that, I'm not sure if you will break your neck first, or your seatbelt will fail and send your body and lowered head into the dashboard which would then kill you. Either way you've got a dead person.
[Answer]
The car part of the question has been answered quite well, but I think I can add to the bicycle part.
If I understood correctly, your spell is stealing the kinetic energy from the targetted object but does not actually hold it in place. When targetting a car, this point is irrelevant, but bicycles usually weight a lot less than the rider. So in this case part of the bicycle "stops" when kinetic energy is stolen, but at the same instant collides with the still moving parts and the rider. This could be compared to taking a running start and jumping on the standing bicycle or having a weak rope attached to your bike that snaps when it becomes taut. This would of course throw an unprepared rider off balance but not necessarily result in a crash. And certainly not the scenario, in which the bicycle stops dead and the rider cartwheels forward (though motorbike is closer to that since it is usually heavier than the rider)
[Answer]
The same thing that would happen if the car had all its kinetic energy transferred into a cliff by crashing into it. What would survive would depend on how long the transfer took. Also, whatever the kinetic energy gets transferred to has exactly the same problem (although it could be better-prepared to deal with it).
If you’re trying to stick to real physics, remember that there is no such thing as an absolute frame of reference. You don’t have “zero kinetic energy,” or “lose all your kinetic energy.” You are at rest in some frame of reference. In everyday life, usually think of that as the inertial frame of reference of whatever we’re standing on, or possibly that of the surface of the Earth where we are if we are currently both moving relative to it and looking out the window. That kind of intuition is not actually logically consistent.
If something else is “stealing” the kinetic energy from an object, the relevant frame of reference might instead be whatever receives the energy, or whoever is casting the spell. Any of those possibilities open up possibilities for clever shenanigans.
[Answer]
The kinetic energy disappears into another medium. It doesnt flow into another object so theres no collision damage like you already suggested. Unfortunately there are two problems, lets start with the smaller one:
The guy in the car prevents his kinetic energy from being taken (and part of his chair), so while the car stops the guy is still going 60mph. Normally the crumplezone would help the guy slow down but that doesnt happen, and without the shock of a normal collision the airbag won't deploy, so basically he hits the dashboard&seatbelt with 60mph and probably dies.
Now to the bigger problem: the earth is moving, 30km/s compared to the Sun, 300something km/s around the universe center, and about 600km/s compared to a "rest frame". You take ALL its kinetic energy, it means that its either going to smash into the earth or the atmosphere at ludicrous speeds. Being LAUNCHED into Saturns storm from orbit is friendlier than having all your kinetic energy leeched. Theres also the question of where that much energy goes if you convert it, it had better be a good place to store it. So I hope the mages use themselves or the center of the earth as a referenceframe to avoid this. Even so, problem number 1 will still kill you.
[Answer]
The momentum theorem states that $m\times\delta v = F\times \delta t$, or $ F = m \times \delta v /\delta t$
Putting in that formula your numbers, we get $ F = 1300kg \times \frac{27\frac{m}{s}}{0.001s} = 35.1 \times 10^6 N$
That's a huge force, and that's what normally happens when a car hits a hard and non movable obstacle. Maybe quicker.
>
> What kills you is not the velocity, but the sudden deceleration
>
>
>
All that kinetic energy will be converted to plastic deformation and then to heat.
[Answer]
The structural integrity of the car should remain intact. If all the mechanical parts come to a complete stop at the same time, they shouldn't take too much of an offence at being interrupted so rudely.
Airbags would not go off, that is unless your magic can spare the accelerometers that triggers them. On the other hand, seat belts can be triggered by acceleration of the car and/or something hitting the belt hard enough. My belt triggers when I jerk in my seat at a red light, 96 to 0 *will* do the trick just as well. Obviously, that assumes your world has (functioning) seat belts, otherwise you are done goofed.
Anything not attached in the car will fly off at 96 km/h and will die and/or kill anything they come in contact with. Even a soft pillow will kill you, PSA: that is why you don't put loose stuff on your back seats.
Anything attached in the car will still hit *something* (namely, the seat belt) at 96 km/h, which means serious injuries up to death. The main issue is that your body is floppy enough that some parts will not be affected much by the belt. While your ribcage will be crushed by the impact, the head will tend to fly off. At 96 km/h, I wouldn't want to be your neck.
Your saving grace here would be hitting the airbag (which would stop your head from getting ahead of yourself too much, *if they worked*) or, probably more reliable anyways, neck braces like ones used in racecars. That will alleviate that problem enough to consider survival and going on with this answer.
Then how well the passengers will fare will depend on them physically, on how they put their seat belts on (also PSA: there is a right way and many wrong ways to do it), the speed of the "crash", how they are seated, etc.
One small last detail is the car dead stops, but not the ones behind it. When you hit a wall, usually other cars don't follow you, walls rarely occur on the road. There will be accidents behind you, although granted, you would have caused accidents anyways if you allowed your car to crash in the middle of the road.
But like [Tim B II](https://worldbuilding.stackexchange.com/a/117239/18896) brilliantly noted, modern cars are designed to crash gracefully. It's probably a better idea to let good ol' engineering do the job rather than magic on that one. Also brilliantly noted accelerometers are part of the car, which matters for airbags.
---
For a bike, you might still fly off the bike, and provided you don't hit the bike (or something else) on the way, you might skip off the road. I have one word to describe that: ouch.
Your survivability will depend mostly on how well you are equipped. You would probably want to wear the same equipment motorcyclists wear (or at least should wear, they don't all do and that's on them): helmets, gloves and vests with padding to prevent scrapping your skin on the concrete.
On a bike, I don't think you are at a particular risk of death (unless you land on your neck, and other bad falls) if you at least wear a helmet. Other injuries won't be as egregious as it would be on a motorbike, but I would still advise you to wear whole shebang if you don't like the idea of severe burns on your skin.
---
If Ek = m/2 \* v², another possibility is the car losing its mass rather than its speed. I imagine it would look like a flash of light, because A) light has no mass allegedly and B) it'll look hella cool, but that's pure speculation. But imagine the passengers flying off in the air and landing on their arse on the ground, how hilarious (aside from the burns from sliding on the ground that is).
[Answer]
Most answers here are focused on 'stealing' kinetic energy by removing the velocity; consider that kinetic energy could also be stolen by negating the **mass** of the object. This mechanism would have the advantage of consistently stealing kinetic energy in all reference frames, rather than just that of the magician or the road.
**Immediate Effects**
The car's occupant now dominates its mass. **Rollover** becomes the greatest risk without the bottom-weight of the engine and chassis. Wind risks also increase, as the car has the same surface area with much less inertia and gravitational force to hold it to the road; at high speeds, the car may even tumble end-over-end. On the bright side, skid risk should not increase, as the loss of mass (and gravitational force) decreases friction and inertia proportionately.
**Collision**
If a collision were sustained in this state, whiplash risks are increased without the big low-pass filter of the car's mass, and crumple zones would not function correctly without the cars mass to crumple them; harnesses and airbags would work as usual, and the risk of injury from the airbag's rapid deployment itself may be negated entirely.
**The Bike**
The biker would likely lose balance and fall due to the sudden loss of gyroscopic stabilization from his wheels.
[Answer]
While all the answers reflecting on the state of the driver when they find their environment suddenly moving at -60 mph relative to their reference frame certainly have their merits, that is, in all likelihood quite dead after impact with said environment, I would like to reflect on the fate of the magician.
By the law of conservation of energy you cannot simply steal energy, it has to go somewhere. As it is the magician exerting this force I would venture that it is the magician who will have to absorb the stolen kinetic energy. This can be a combination of conversion to heat (of the magician) or kinetic energy (of the magician). The amount of energy to absorb is:
* E = 0.5 \* mcar \* speedcar2 ~ 5 MJ (for a car of approximately 1300 kg driving at 60mph)
Transfer of the kinetic energy of the car to kinetic energy of the magician (relative to ground) will propel the magician away from ground at:
* vmagician = sqrt( 2E / mmagician) which for a magician of approximately 80 kg comes to ~ 240 mph in the same direction as the car was moving (conservation of momentum) or, if using devices such as a seesaw, in another direction. Probably not a good idea.
Transfer of kinetic energy of the car to heat will warm up the magician considerably.
* assuming the magician is a sack of water of 80 kg, which is a good enough approximation and also assuming a uniform distribution of the heating up throughout the magician, this comes to a rise in temperature of T = E / (Cwater \* mmagician) = 5M / ( 4184 \* 80 ) ~ 16 degrees centigrade. As the brain stops working when it gets too hot (and 16 degrees would certainly qualify as too hot), this is probably not a good idea either.
So, if killing the driver was not enough already, said spell will most likely kill the magician too, unless the energy was diverted elsewhere where it is dissipated harmlessly such as, say, increasing the heat (background temperature) of the universe as a whole.
[Answer]
A modern 3-point seatbelt relies on deceleration to trigger the locking mechanism on the reel. It has a little Pendulum in the mechanism which detects sudden changes of motion.
In your Arrested Momentum scenario, the reel and pendulum are entirely locked up for the duration of the deceleration (more or less instantaneous) but critically, the movement forward of the person will *not* trigger the pendulum mechanism. meaning the seatbelt flat out will *not* restrain them at all..
So your driver and any passengers will fly forward at 60mph with hardly any resistance.
They'll hit the dashboard in a fraction of a second. The Airbag will not be coming to meet them the other direction, so they smack full-force into the dash and break their knees, arms and probably ribcage.
Most likely they'll get hurled headfirst out of the vehicle via the windshield, but they're still in their harness, so they'll go as far as the reel will allow them and then jerk around into a tumble when the seatbelt reaches its limit.
Expect broken bones wherever the seatbelt was in contact at this point.
They'll be dead from blunt-impact trauma and found mangled many yards down the road. Immediate cause of death will be a broken neck and skull-trauma from going through a windshield at 60mph without any restraints.
Needless to say any loose items in the car will also do this and there'll be a spray of debris in front of the vehicle too.
Not pretty.
On the other hand, this is contingent on the reel/pendulum mechanisms being located outside the bubble of anti-magic around the driver.
If the bubble encompasses the pendulum, your seatbelt will work mostly as intended even if part of the belt is outside it. The actual belt movement happens *after* the momentum is robbed, so the only part that matters is the pendulum.
In this case expect the passenger to instead die of a broken neck from the whiplash as their seatbelt holds their torso in place and their head snaps forwards. Again no airbag or any other safety equipment will be working.
Surviving either scenario would be downright miraculous and they will need immediate medical care.
[Answer]
Amusingly if the magic shield boundary happens to intersect atoms (which I think is likely though I haven't done the math), your scenario of part of the vehicle being stopped would result in a rather dramatic nuclear fission all around the driver, possibly releasing vastly more heat than is safe for humans.
[Answer]
## Now you're playing with portals
Build a plywood wall in the middle of a bobsled run, at a point where any competent sledder will be going 88 mph. Paint it with moon dust, Sherwin Williams Decora Plus H2 Pastel Base, or any other coating that will accept portals. Open a portal there.
Take a semitrailer. Build a flat surface on it going essentially all the way to the ground. Also paint it with a portal surface. Open a portal there.
Have the semi drive 88 mph steady on. Send a bobsled down.
Boom, the bobsled is sitting in the middle of the highway completely stopped. Its kinetic energy has been stolen. The operators feel no acceleration or jerk. It just works.
You could do the same thing with a speedboat and an airplane in distress, have the speedboat tear down a river at 90mph whilst the airplane flies into a mountain painted with a portal at 130mph. Suddenly the airplane pops out over the river going 40mph, instantly suffers an aerodynamic stall and falls a few feet into the river, cushioned by the river.
With that concept, and the idea of manipulating the frame of reference, you should be able to figure out other ways to steal (cancel) kinetic energy in your magical system. Essentially you are sweeping the reference point such that the desired kinetic energy is canceled.
Rotational force is a problem. My first draft used a car. The car's linear velocity works fine, but there's a big problem with the rotating velocity of the car's monkeyworks. That would suffer extreme acceleration and jerk forces from the rapid change in rotational speed. So I switched it up to a bobsled.
[Answer]
The result should be almost the same as if the car had never been moving in the first place, but the passenger comes flying along from behind the car at 60mph and (after "ghosting" through the back part up to and including his seat) crashes into (the front part of) the car. This is far from healthy.
Strictly speaking, we have to do as if the car parts 3 to 6 inches around the passenger fly with him, but that won't make a difference for the person. The only difference is to the integrity of the car (or should I say the composition of its debris?), depending on how "soft" the field fades out with distance from the person (if the transition is atomic-level "hard", the parts will essentially break from the main vehicle as if they had never been joined before; if the transition is very soft and the parts deformable, they may end up brutally torn apart or "merely" deformed as if an unstoppable heavy tank ran into part of it at 60mph ...
[Answer]
There are 3 impacts in collision.
Your vehicle stops moving. The human collides with the vehicle/asphalt.
And your organs hit inside your ribcage/cranium.
This compreses your hearth and lungs vs the sternum and ribs. Also your brain ricochets inside the cranium against the bone.
Here is why even if you look Okay from outside, your condition could be critical.
[Answer]
I think the car would instantly disappear. The car would instantaneously reach absolute zero.
The 60 mph deceleration of the driver is nothing compared to the 10,000 mph (or higher) instant deceleration relative to the solar system, and the galaxy. Instant death of the driver.
The car would instantaneously approach some percentage of the speed of light relative to other nearby objects, which would mean that time inside the car could be affected.
The mass of the car would simultaneously increase exponentially because of the high relative speeds
I think the car would fragment on a microscopic scale and if the driver somehow miraculously survived the deceleration, they would immediately find themselves in the vacuum of space surrounded by a dust cloud of microparticles of what’s left of the car at close to absolute zero.
The infinite mass dust cloud would create a black hole (hopefully far enough away from our galaxy) sucking the driver in.
] |
[Question]
[
How can a part of a continent (super or other) remain unexplored by the apparently civilized majority?
The undiscovered part must be habitable but inaccessible, by land or sea, so that the rest of the world is completely in the dark about their methods of war, culture and the flora and fauna.
The technologies used by the rest of the world for exploration are no more than ships and scouts.
[Answer]
## People *do* discover it. They just never report back.
It's one thing to sail all the way to a new continent. It's quite another to land there, chart the territory, and then sail back home again to tell people what you've found. Perhaps the coastal waters are exceedingly treacherous and the ships keep getting dashed to pieces. Perhaps that continent is inhabited by deadly predators that kill anyone who lands there. Perhaps the locals view the explorers as "invaders" or "demons" or whatever, and kill them on sight. Alternately, maybe it's such a wonderful place (at least on the surface) that none of the explorers ever *want* to go back home.
Whatever the reason, **nobody has ever returned from that place to be able to tell other people that it exists**. From a world-building perspective, I like this idea better than just "it's really remote", because it opens up so many other possibilities. For example, it could have spawned in-universe myths or legends about this region that people sail to, never to return, rather like the Bermuda Triangle.
[Answer]
Looking at Europe, Siberia, and East Asia might be a good precedent or model.
* Introduce an inhospitable mountain chain or two.
* After those mountains there will be swamps, insects, more swamps, taiga, and swamps. People live there, but they don't have much to trade beyond the occasional pelt, gold nugget, or piece of amber.
* Living in those swamps requires the right survival skills -- how to find potable water, how to prevent food and other supplies from rotting, etc.
Now dial this up. The mountains are not like the Urals, they're like the Himalayas. The swamps are not like the West Siberian Plain, they're more like a jungle.
This will not prevent all travel, but it will turn the land at the other end of the continent into a mythical "here there be dragons."
[Answer]
# It is far away
Quite simply, in both Europe and China of 1200 AD there was essentially zero knowledge of the other civilization. The Chinese didn't know about Europeans or European crops/trees/animals, and the Europeans didn't know about the Chinese and their crops/trees/animals. So while there was some exchange of crops and technology though nomadic middlemen, in general this fits the bill, exactly.
If you would like to make them even more isolated, you can remove the middle men. If the Indian subcontinent dissapeared, then Europe and China would know even less of each other. If you removed the Amu Darya and Syr Darya rivers and the city states of central Asia, then even technology and crops might mot have passed from one to the other.
[Answer]
There are some very fun answers here already. One even got accepted as the correct answer by OP. Seem to be forgetting the major one, though.
# It's cold
Italy is lovely. Beautiful summers, lovely winters, enough farmland to sustain urban settlements and enough coastline to host maritime republics. By around 1300, you had [portolan charts](https://en.wikipedia.org/wiki/Portolan_chart) starting to get so detailed and accurate that they look like someone carefully tracing a GPS plot.
Sure, you can have swamps or desert but *if there's anything useful in them* people will have a line going across directly to it and know all about it. Meanwhile, just make things a little chilly and it takes until 1430 to get this map of Scandinavia
and it's not until 1540 that you get something as still-inaccurate as this
We were still debating whether the Norse had made it to Greenland and North America into the 20th century and the two largest countries in the modern world are barren arctic wastelands because no one wants to go anywhere really cold or talk about it once they get back. It's gotten a little better recently with thermal fleeces, industrial-strength insulation, &c. but if you want real-world reasons for people not to explore or know much about a place, make it arctic.
[Answer]
There are many examples of this in our history. Taking medieval times to be [5th-15th century](https://en.wikipedia.org/wiki/Middle_Ages) we only have to look at the [deluge of new discoveries](https://en.wikipedia.org/wiki/Timeline_of_European_exploration) which came after that to see that there was much which lay out of our reach before that.
There are many similarities between these new discoveries but in general they are separated by something too costly to traverse, an ocean, a desert or sometimes they're just a small island far from anything large and the probability of coming across it is just too small.
To build your world I would suggest incorporating any one of these into your world to separate your one civilisation from the rest.
[Answer]
Fear. It's a powerful motivator and a great tool to control the masses.
Before maps and navigation aids, it was fear that stopped people in ships from sailing beyond the horizon away from the shore. It was the fear of falling off the edge of the planet that kept them hugging the coasts.
Fear of spirits, demons and gods can keep people off a section of land. Fear of a people, imagined or not, that attack everyone that enters the land can keep that land unexplored. Fear that there are no riches in a land, only an endless landscape of fire and brimstone. That place? That place we don't go? In that place, there be dragons.
[Answer]
Africa proved very difficult for Europeans to explore for a variety of reasons. The presence of the Sahara Desert across the northern expanse discouraged exploration by land - the harsh environment presented more danger than most were willing to brave, considering there was a good chance you wouldn't find anything except miles of featureless, inhospitable sand. [Sailing down the coast of Africa was dangerous because returning was very difficult](http://quatr.us/medieval/science/sailing.htm) - the shape of the continent meant that ships that rounded the edge of western Africa would be constantly going against the wind on the return journey, and until ships were developed that could tack into the wind there was a very real fear that any ship attempting the journey would be unable to return. The political situation of the time made trying to travel through Arabia difficult for Europeans. And as others have pointed out, those who managed to make the journey would also have to avoid disease, unfamiliar predators, and other dangers long enough to return.
[Answer]
**Freaking lazy.**
I propose your civilized folks could discover these places, if they would get off their asses and go. Or hire someone else to. You can depict a degenerate, decadent and pampered civilization. They have everything they want and have no particular desire to find anything more or different, especially if it involves discomfort or effort.
Someone has to do the work, though. If your upper class is as described and the lower class is thoroughly beat down, illiterate serfs, there is no middle group of scrappers and self-made men that can give rise to a Columbus or Magellan. That leaves the military and is is no stretch to posit a hidebound and tradition-minded military uninterested in anything new.
[Answer]
Plague.
For a long time nobody who went there ever came back. Then someone *did* come back. Dying. And started a plague that killed half the town they came back to. Nobody goes there any more. People suspected of returning from illegal trips are shot on sight, and wide rings burned around their bodies.
[Answer]
Two more types of barrier that haven't been mentioned:
* Super murderous inhabitants (plant or animal) surrounding the area. A forest full of poisonous plants, active predators and maybe even violent natives could easily deter exploration. This was basically the status of parts of the Amazon until quite recently.
* Surround [Fields of lava.](http://www.livescience.com/41909-new-clues-permian-mass-extinction.html) Perhaps such an event could surround a habitable region.
[Answer]
Even today there are parts of the world that remain unexplored by 'civilised' peoples, because we've conceded that others have ownership of these areas. If these others consider the area holy, no man will ever tread there.
[Answer]
Some ideas...
* Expanding on the various people that mentioned plague. It's easy to say "everyone that went there died" but that's actually not a useful deterrent because people are dumb and keep trying anyway. Here's a better idea: let's say you have an area that people have visited but got sick but people got better if they left the area. That's easily tested and consistent. People go, they all get sick, they leave, they get better. Send some prisoners and a rotating set of guards, everyone gets sick, rotating guards survive, prisoners don't. Rinse and repeat in a few areas and find it's the same.
Works best when you have a limited amount of access or an isolated
continent, but you can work it on a single continent by environment
trickery. Think mosquitos but a bit less picky and a lot more lethal... pathogen spread by something that is very common, is about the size of a mite, but can only survive in that climate. Have it not be too fussy about hosts and the surviving fauna are immune. There's enough variables to play with to get a suitable deterrent.
* Rocks. No, really, have a large chunk of continental crust made up of a ridiculously toxic material. Let's say that some weird event during the formation of the planet resulted in a wide area that was so contaminated with radioactive isotope bearing rocks that anyone spending any amount of time in that area would suffer radiation poisoning. We know from experience that plants and even some lower complexity species can survive in these environments just fine but a lot of larger creatures struggle or just die off. You can write it off as a stellar fragment, an earlier civilisation having a nuclear war, or something silly like a narrow cross section gamma ray burst early in formation.
* Tectonics. Have an area that suffered so badly from volcanic activity and earthquakes that previous generations decided it wasn't worth spending time there... maybe the knowledge that the area was bad was passed down but the reason and any real exploration results have been lost.
The first and third are adaptions of ideas from Pern. Fun series with a similar obstacle.
[Answer]
**Religion**
The people could have a religion which says that it is forbidden to walk in this lands, maybe because they are the holy land of their god and no one should ever walk there. This would be a good option if this area is rich on ressources.
Or the complete opposite. It's an harsh land, so this is the land where the devils and demons life, and everyone which goes there will die and worship demons.
Both options give one good thing, everyone which was there and tells about it is a heretic and traitor and will be executed. And no one will believe what they say, because they have violated the holy laws of their religion.
[Answer]
Perhaps a labor shortage has made an expedition not worth the money.
The great plague killed 19 out of every 20 people. They were referred to as "The lucky ones". Shipbuilders were hit the hardest. We lost most of our trade fleet because of foreign powers burning infected vessels. It has been over 150 years. Our population has not recovered. We'd like to send a ship to investigate that continent we found out about, but we can't spare the people to make a crew, spare the shipbuilders to make a vessel that's capable of such a long voyage, or spare the people to prepare for such a long voyage. It would take several people we can't afford just to make a 3 year supply of fishnets!
[Answer]
## A technological society doesn't want to be discovered
While the *main* society is inching into their Renaissance, embracing technology and thinking they are the pinnacle of civilization....
... in fact, the people on that faraway continent are centuries ahead of them - with radar, thermal imaging, satellites and maritime patrol aircraft. And the Aircraft Society uses these capabilities to intercept 100% of Medieval Society explorers. The medieval explorers have no ability to hide, and it wouldn't even occur to them to try.
Who knows, perhaps religion has everything to do with it. It doesn't need to be Aircraft Society's.
## How they deal with explorers
Aircraft Society either integrates explorers into their society, interns, imprisons, or kills them, or perhaps some combination thereof depending on circumstances. Integration is no small motivation to an explorer's mind, it would be like being invited into Heaven itself.
They might operate an intelligence network within Medieval Society, either observing: collecting advance notice of most expeditions, perhaps pulling out explorers' families when that is negotiated. Or actively tampering with their development, e.g. buttressing religion, amplifying superstition, inciting persecution of technologists, and trying to keep them in the Middle Ages. Perhaps Aircraft Society is in the throes of its *own* enlightenment, changing how they manipulate Medieval Society.
## Their motivation
Their motivation might be "Prime Directive" sort of non-interference. More likely it is self-serving.
Perhaps they see amazing art and culture arising from Medieval Society, and they don't want to corrupt it the way modern technology has corrupted so many formerly isolated societies.
Perhaps they feel Medieval Society is just not culturally *ready* for an influx of unearned technology and would horribly mishandle it to their own destruction.
Perhaps the Societies' differences are irreconcilable, and they are trying to forestall as long as possible what will definitely happen when Medieval Society discovers what uranium does.
[Answer]
If the native Americans had killed Colombus on the spot, their civilization may live even today.
Also Montezuma could have killed Cortez many times, he didn't do until it was too late.
Antarctica wasn't found for a very long time, simply because it was cold and it was too far away. Thus, weather can be another reason.
If North America had been a small island, like New Zealand, around where is California now, Colombus probably would never have found it. It may have taken centuries until iron steam ships were to find it.
[Answer]
er... are you aware that during middle age, in fact, Europe and Asia were completely unaware of the existence of America and Oceania? That is the exact scenario you are describing. And also most of Africa was unexplored (from the European point of view).
As far as we're concerned, in a slightly alternative world, in the Americas there could have been civilization at least as advanced as in Europe, and the two civilizations would have had no contact with each other.
So, in a middle age scenario, that is very likely to happen. Actually, it has in fact happened. Having an ocean in the middle, is a perfectly valid reason.
] |
[Question]
[
Midichlorian's are chemical compounds found within every living cell that forms the basis between the connection life and the Force. Without midichlorians, life would be impossible. The amount of midichlorians in a life form represents its ability to understand, comprehend, and manipulate the Force.
My name is Darth Incognitus, and I have decided to absorb more of these cells into my own body to make my force sensitive abilities stronger. To accomplish this, I have kidnapped numerous force sensitive users who match my blood type. When their midichlorian count has been measured, I will perform a blood transfusion from them to myself in order to absorb these cells. After I have attained enough of these cells, I will become the most powerful force user in the world and create my Sith empire. Then, I will use this method to strengthen my apprentices and students.
However, after a number of tries, I have noticed that my powers have not increased. No matter how many Jedi I murder and drain of blood, my abilities remain average. Why would this be the case?
[Answer]
**Because they are genetically foreign.**
They immediately start to reject the body, and the body rejects them. Welcome to a force fight at the cellular level.
Immuno-suppressants allow the transfusion to succeed without ripping your body apart, but the downside is that they significantly hamper even your own ability to interact with the force, injecting extra barely raises you back to functioning.
**Cloning ;)**
Okay, genetically identical. Except that the Midichlorian's are already at saturation in your body, adding more of the same simply causes them to die off.
You might, through an ingenuous system of continuous transfusions keep yourself in a state of over-saturation. This would amp up the basic capacity for force manipulation (you will still need practice as with any fine motor control), but there are (semi-)permanent side-effects. The Midichlorian's learn that massive spikes occur, and reduce their overall numbers so as to survive long-term. You might recover to normal levels, it might be a permanent reduction.
**Divergence**
As the force wielder learns, the Midichlorians alter themselves physically. Even if they were cloned and successfully duplicated, reintroduction back into the body causes the equivalent of a theological argument between religious sects. At best nothing changes, at worst valuable skills (learning) are lost as the two sides duke it out, or the host dies.
In short you are extremely lucky to be alive.
[Answer]
Because the blood level midichlorian equilibrium point is determined by your body's biochemistry. You can't alter this by adding more midichlorians. All that does is cause a temporary imbalance (way too short for your body to make use of it) that your body quickly fixes. Excess midichlorian gets filtered out by the kidneys and ends up down the drain. Literally.
[Answer]
Midichlorians are not what gives you the force, they are a by-product of being strong in the force. Excess psychic energy goes into making the midichlrians. All that blood is wasted because the midichlorians come from the force, not the force from midichlorians.
[Answer]
### [Homeostasis](https://en.wikipedia.org/wiki/Homeostasis). Your body maintains an equilibrium, like blood or temperature
A normal human has around 5 litres of blood in their body. If you transfer a litter of to your body (and not die), would now you have 6 litres? Well... maybe, but not for much longer.
Or temperature, you are at 36℃, if you increase/decreases your body heat from your surrounding, will it stay in that forever? Of your not. Your body maintains a level of temperature, by warming up or cooling down at certain thresholds.
Your blood amount is also determined by your body, not your blood transfusions, if you have a lack of blood, your body will produce more to compensate it, and if you have too much, your body will dispatch the blood's water from kidneys, and **red** cells' will be recycled into [bilirubin](https://en.wikipedia.org/wiki/Bilirubin) (**yellow**) in the spleen and that dispatched from duodenum as [stercobilin](https://en.wikipedia.org/wiki/Stercobilin) (**brown**). Interesting transformation of colours, right?
Midichlorians are like blood, and a lot more things in our body, like hair, adipose tissue, temperature, etc. A transfusion may only increase the Midichlorians during a very short time (if the body is able in the first place to take advantage of them and don't die/get sick due an increased level), then the additional amount will be quickly destroyed/dispatch/recycled by your own body...
...Or maybe not, they aren't destroyed, but anyways they have a certain lifespan, so if you transfuse them to your body, they will work in you until they "get old" and die, like red cells (120 days). Then you should transfer more from the original source... or steal their Midichlorians's stem cells. **That is up to you**.
[Answer]
Pure math.
If you mix two liquids together, whatever makes them special doesn't get stronger. You get the average strength of both.
Say you mix a strong and a weak beer together, the strength will be in between the strength of the two.
You do need a bigger container though.
After all those transfusions, his midichlorian level is the average of all the people he transfused from.
His body will contain a bit more blood though.
This also dictates that he can never get stronger then the strongest Jedi he kidnaps. So unless he finds out a way to extract the midichlorians from the blood, he's out of luck.
[Answer]
**Putting more fuel in your tank is not going to make your car drive any faster.**
Midichlorians are a resource, but it's unclear how this resource is being activated. If, for example, the brain uses midichlorians in order to send out a psionic signal which connects to the Force; then there's a natural cap at your brainpower.
For example, let's say your villain's body actually generates less midichlorians than their brain can use. At this point, adding more midichlorians to their blood will in fact increase their brain's psionic output as it is no longer running at suboptimal efficiency due to lack of midichlorians.
***Analogy**: Your car will run better on a tank of gas than it will on fumes.*
However, if the villain already generates enough midichlorians to saturate their brainpower at full capacity; then adding more midichlorians to their blood is not going to help, the bottleneck is their brain capacity.
***Analogy**: Putting even more fuel in your tank is not going to make your car drive any faster.*
This creates the option for you to have the villain *initially* see some improvement, but then very quickly plateau.
---
*Note*
I suggested that midichlorians are consumed by the brain and regenerated by the body; but the same would work if midichlorians were considered a catalyst which does not get consumed (nor regenerated). The brain can only use so many midichlorians at one time.
[Answer]
The fundamental answer is that any attempt to do such a thing would violate the unspoken worldwide agreement to act as if the whole midichlorian thing from Ep 1 isn't really canon, and in fact never happened. This has been going great so far, particularly considering its a conspiracy that approximately 7.7 billion people are in on.
Any attempt to poke the nest by asking for an explanation might make future writers feel like they need to address it. That threatens to make it *more* canon, not less, so **Shhhhh!**
(*waves hand*).
This is not the question you are looking for.
[Answer]
A blood transfusion wouldn't change the number of midichlorians in your other cells and there's no reason to think that your red blood cells are particularly important to your sensitivity to the force...especially when compared to, say, your brain cells and your nerve cells which seem much more likely to mediate between your mind and the Force.
That being said it's actually pretty likely that such a villain would experience a boost in their ability to use the force. Combine the placebo effect with the Force and you could get some real action.
[Answer]
Obviously blood can only contain a certain density of midichlorians or it would clog up and ultimately become solid. Your body will naturally break down any excess of midichlorians and convert them into fat. This is what happened to Jabba the Hutt.
[Answer]
Midichlorians act as a mediator between the Force, the mind, and the body, all three acting in concert. Because of this, **midichlorians aren't just sensitive to the force, but to the unique pecularities of each person's body chemistry and bioelectric field**. These things change over time, of course, but it happens slowly enough that the organs which produce midichlorians can adapt as a person grows.
**The shock of being suddenly removed from one body and transplanted into another is too quick for the midichlorians to adapt**. Given enough time, they would indeed "learn" how to work with another person's body and mind, as theory might state. The problem is preventing the body from rejecting and excreting them before that happens: it just plain takes too long. This is not something your sith has mastered.
[Answer]
**When in trouble, in sci-fy, put a machine to do it for you**
What that mean is basically a reminder than Darth Vader was a reality, and Star Wars have A TON of technology designed to replace organs and/or keep alive people.
With that in mind, you, oh so great Darth Incognitus need a machine than allow you control the response of your body against it's midiclorians.
If the force or your body stand in the way of you being more powerfull, You need to control them!
If you need an automatic control of your natural filtering organs, they can be replaced by synthetic versions of them specialy modified to make your midiclorian administration as you want.
What happend? your blood cells are not designed to resist the influx of new Midichlorian? doesn't matter, replace the medula of your bones (which if i remember correctly, replace the blood lossed) for a machine than do replace blood BUT make it just in the way you need it for achieve your "Darth intentions" (pun intended).
Is your brain affecting the process? doesn't matter, put an artificial part of your brain than do exactly what your brain used to do OR put a machine than counterweight the efect of that part of your brain just in the right way to make the effect you want.
**In time you'll become more and more of a machine Darth Incognitus!, but we all know than Power only respond to Inmortality! and all we know than Machines are inmortal!**
PS: if you like my answer and are making something related to starwars, make a character kinda like a teck-priest and put the name 'Kradathon' in some way connected to it, you decide what the name means, it would be a cool way to say "thanks". :D
[Answer]
**Pseudo Rh incompatibility.**
Going to the dark side produces changes in your Force field, and this in turn alters your personal midichlorian ecosystem so that it becomes hostile to non-Dark midichlorians. Transfused blood is simply destroyed within your body.
[Answer]
Midichlorian's are not the bottleneck in this equation. Your body and brain have developed "Force pathways" to make use of the amount of Midichlorian's you naturally have in your blood. They finished developing at the age of 16. You can add all the chemicals you want to your blood now, but your body and brain simply can't use them for anything--they can't handle that much Force.
Now if you'd started these transfusions before you turned 16 and your body finished developing it's Force pathways though... Have you thought about creating a test experiment heir to your power?
[Answer]
**If you try it, your midichlorians might fight each other to the death.**
What if what modern science calls midichlorians are actually the immortal beings of ancient legend, the Whills? These microscopic sentient creatures are the true masters of the Force, and they are at war. To them, Jedi and Sith are just fleshy Death Stars that they use to attack each other.
>
> "[The next three Star Wars films] were going to get into a microbiotic
> world. But there's this world of creatures that operate differently
> than we do. I call them the Whills. And the Whills are the ones who
> actually control the universe. They feed off the Force." - George Lucas
>
>
>
(This nearly became canon... but then he sold the franchise to Disney, who seem to be taking it in a different direction)
If you mix light and dark midichlorians, they'll go to war inside your body and destroy each other, and possibly you.
A Jedi will obviously never try this trick on other Jedi. A Sith might consume other Sith, but as we all know Sith are very cranky and do not play well with others. The dark Whills who drive them may have a similar temperament, so mixing rival factions of dark Whills in one body could also mess you up.
But ultimately, **the Whills are in charge, not you. This plan could work, but only if the midichlorians in your body and your victim's body want it to work.**
] |
[Question]
[
What would birds look like if they did not have to fight gravity to fly?
The question comes from the premise put forward by some that gravity is not real and that what holds us down is pressure caused by density.
Obviously, this is not the case, but if it were, how would it (yes, conceptually) affect the way birds evolve, develop and/or fly?
[EDIT] To conceptualise a little... Let's say we had evolved on Earth and then been transplanted to an artificial planet. One with no gravity but one where the gas we are surrounded by is dense enough to actually cause some amount of pressure and thus keep us on the ground - a ground which has no gravity because it is perhaps only a metre deep, though wide enough to house every country... and *then* birds had evolved. (Perhaps they had been put there before we were.)
[COMMENT] This is not about whether the birds of a particular type are viable but is asking what they would look like given time enough in a particular environment.
[Answer]
**Fish, or possibly penguins**
A world where things can fly without needing to fight gravity (I don’t want to think what the method for that is) is a world where the first fish to develop the ability to breathe out of water skips land completely and just goes straight for the air.
Even if it’s something specific to birds, you’d start to see more and more penguin like ‘torpedo’ shapes optimised for slipping through the air rather than pushing against it (hell, in this world penguins might be the most successful bird!)
You’d probably see larger control surfaces (wings/fins) than in the water, as water is denser, but without the need for surfaces to glide/flap with I can’t see why a bird wouldn’t move back to a more energy efficient form of locomotion, namely oscillating the body back and forth and using the limbs purely for control instead of relying on the limbs to do both.
ADDENDUM:
In the comments I added a link to the [Festo Air Penguin](https://www.youtube.com/watch?v=jPGgl5VH5go), a helium filled remote control blimp. I didn’t initially add this as their design of blimp uses fins for locomotive power and only uses the nose and tail of the ‘penguin’ for control, unlike true penguins or fish which also flex their bodies to give better manoeuvrability and power, but it’s a good enough video that I’ve stuck it in the answer!
[Answer]
They would be round, because that's the best format for storing gas. They would also probably be drifters with little flight control. So...
[Answer]
I don't see any reason why birds couldn't theoretically achieve buoyancy in the air. It's just probably extremely inefficient for animals the size of normal birds compared to winged, powered flight.
They would need a biological way of producing a gas lighter than the atmosphere, which is much more likely to be hydrogen than helium. Then, they would need a 'bag' of enough volume that its hydrogen offsets the rest of their mass.
Finally, these birds would need some means of controlling their ascent and decent, which means ballast. This is probably going to be water that they can release to fly higher. When they need to drop down, they would release hydrogen instead. They couldn't fly higher again until they had a chance to replenish both, so they would need to be able to float on the water while they produce hydrogen and take in enough water to keep them grounded until they're ready to go.
In short, they would probably look like blimps, but with flapping fins/wings instead of propellers. They would also be much more likely to be large. The square/cube law works the opposite way with things that are lighter than air. The bigger you are, the easier it is to fit in lift gas relative to surface area.
As for 'gravity not being real' and your 'pressure caused by density' alternative, I'm not really sure I understand what you mean, but I don't see how it would make a difference. In both cases, you achieve flight by being less dense than the air.
[Answer]
As there is the physics tag, I feel that the misconceptions should be addressed.
Buoyancy is the result of gravity. If there is no gravity, there is no buoyancy.
The bigger picture is that a hot air balloon floats upwards because gravity pulls it down less than the same volume of air. So air gets to occupy the lower layer. In the smaller scale buoyancy arises because the pressure is higher in the lower layers. Thus the bottom of an object is pushed upwards more than the top is pushed downwards.
You can not reproduce that by blowing air from above. You might be able to get things staying on the ground, but the pressure gradient will be opposite - for any object the pressure from above will be higher than below. So buoyancy will push everyone downwards and being lighter won't help you. If birds would fly in such circumstances, they would be similar to those on Earth but maybe a bit thinner and having more endurance as they have to constantly fight the wind.
I answered supposing that people are held on ground by blowing wind from above as discussed in the comments. The phrase *pressure caused by density* by seems to have no real physical meaning, so the question as-is can't really be answered.
[Answer]
If the bird in question needs only to be buoyant then the resulting animal would float at a more-or-less constant height, unable to manoeuver to avoid predators or return to the ground to nest or feed (I will show later that this bird is vegan).
These are strong evolutionary disadvantages.
Blimps, fish and submarines are buoyant and use fins for steering, so it seems prudent to include these in its design.
Regarding altitude, the bird needs to increase or decrease the amount of lighter-than-air gas in its body. Decreasing is easy, but it needs a method of producing extra gas for lift.
Both hydrogen and methane are [lighter than air](https://en.wikipedia.org/wiki/Lighter_than_air), and these gases are produced when certain foods cannot be digested but instead ferment in the gut. I would therefore design the bird to have a penchant for [beans and pulses](https://www.verywellhealth.com/why-do-beans-cause-gas-1942947), and a method of recycling its own farts.
So in summary it should look like a fish with a tube from its anus to its nostrils.
[Answer]
They would definitely look very silly. They would by default have to have very low momentum in relation to air resistance so they would be much less efficient in their movement than IRL birds and have much less maneuverability. A good comparison is an airplane and a hot air balloon. they would most likely look like big balloons with small propulsive appendages on their back side.
they would certainly be comical to watch go about their days.
<https://www.youtube.com/watch?v=yltlJEdSAHw>
] |
[Question]
[
DISCLAIMER: I'm new to this site and still figuring things out, this is my first question I've asked, so bear with me.
Alright, this is a little hard to describe. This story I'm writing includes a tiger that was experimented on and had a living cobra replace its tail, with the cobra still alive and able to move around (without detaching from the tiger, of course)
the way I initially scientifically imagined it, (I am not a scientist in any way, shape, or form, I just tried to think about how this could logically happen in our world) was the cobra's insides were 'fused' with the tiger's insides in a way where the cobra and the tiger were both still alive, but I haven't gotten too deep into the biology of it and I was curious to see anyone else's thoughts?
This is a little specific, but I tried my best to explain it. Once again, I'm new to this site and this is my first ever question, so I apologize if what I said didn't make much sense, like I said, I tried my best to explain.)
edit: thanks for everyone's responses! i should clarify a few things that some people have asked:
The tiger's tailbone basically has been fused into the cobra's spine, i guess? and some nerves, muscles, and other things, have been artificially made by the people who experimented, and were used to fill in some holes that the tiger's and cobra's parts did not fill in so they could be properly attached, and the cobra and tiger are not piloted by the same brain, they are still two different beings however, their minds have been altered a little to make sure they don't attack eachother, or mind eachother at all for that matter, which I personally hadn't really thought about until i posted this question. (HERE FROM EDIT 2! I DID RESEARCH AND I'M NOT REALLY SURE IF MIND MANIPULATION IS POSSIBLE FOR LARGER ANIMALS BUT I FOUND OUT IT CAN BE DONE WITH BUGS.) I honestly hadn't thought about the cobra molting at all, either, and i honestly have no idea how that'd work, either.
Also, yeah, i probably should have done some research before i posted this, but it's a little awkward to have to explain to someone why 'could a cobra and tiger be sewn together without any biological issues occuring' is in your search history, y'know?
This concept is actually for a partially-edgy OC of mine, and i never really intended it to be realistic, i only posted this here because i wanted to see if it WAS realistic. I guess not, lol.
Again, thanks for everyone's responses! i wasn't expecting much. I'll probably update this time to time as i get more replies.
edit 2: Clarifying more things.
I imagine the snake is SOMEHOW biologically engineered to have mammalian blood so the tiger and cobra's blood match, and i HAVE done research on that but i can't find anything saying that it can be done or not.
The scientists made the tiger/cobra abomination in hopes to make a "scientific breakthrough" and "prove to the world what biology and science can do" and the tiger/cobra ends up getting abandoned in a parking lot somewhere. The scientists got arrested.
Thank you for the feedback!
[Answer]
No.
First, it is impossible because of the reason given by L.Dutch: you will provoke an immune reaction. This could in theory be countered by creating a chimera, or by some other means (early exposure of embryo to antigens, followed by surgery in the adolescent/adult).
But also, snake blood and mammal blood are, regardless of immune reactions, inherently incompatible. Snake blood contains almost twice as much NaCl and up to 20 times as much calcium during estrus, for example (also 2-3 times more inorganic phosphor and amino acids, considerably more fat, but only half as much glucose, so a snake kept alive with mammal blood would be diabetic!).
Snake blood doesn't even have the same haemoglobin as mammal blood (with different biochemical properties such as O2 affinity). Or, the same type of blood cells at all, for that matter. As you probably know, our erythrocytes (and platelets the like) lose their nucleus when maturing. Well, blood cells in reptilians *don't*. Reptilian blood cells live *years*, too, whereas mammal blood cells live some dozen *days*.
So, blood, or the cells within, are not even *roughly* the same, or similar.
That... very likely... cannot work.
[Answer]
No, if you stick to our current understanding of physiology and biology.
The reason is pretty simple: immune reaction.
In order to protect itself from any outer attack, every animal has an internal army which get trained in recognizing the "self" from the "non self". Any element which is recognize as "non self" will be fought to death.
Therefore planting an organism A on an organism B will lead to a massive immune reaction and subsequent death of both. This is the very reason we have to be careful when picking an organ donor for transplant and whoever gets one has to follow a life long immuno-suppressing therapy.
Vegetables are a bit different under this point of view: you can join an apple and a pear and they will go on fine, but you talk about animals.
[Answer]
**Yes.**
The way the question is phrased, it doesn’t seem like there necessarily needs to be any exchange of blood or organic material between the two animals. Perhaps you could just cut off the tail, let the wound heal and then stitch the two animals together. They would just be two seperate animals that are stuck together. As long as the snake could find a way to feed while being attached to the tiger it could probably stay alive. Maybe it could just feed on passing rodents while the tiger sleeps?
[Answer]
**Actually, yes it is.**
But you couldn't do it without a lot of preparation.
First you'd have to grow two genetic [chimera](https://en.wikipedia.org/wiki/Chimera_(genetics)) from fetuses.
1. A tiger with a few cobra cells introduced early in fetal development.
2. A cobra with a few tiger cells introduced early in fetal development.
The cells introduced into each will need to be harvested from the other while still in the womb (& egg).
Done & timed right both animals will share no characteristics of the other when born (& hatched) as the guest cells will go native in the host organism taking all their cues from it.
This means there will be no [immune response](https://en.wikipedia.org/wiki/Immune_response) from either animal to the others tissues or blood.
*Within the limits of the available medical equipment & the surgeons skill you can then graft any part of one to the other, including chop off the tiger's tail, the end of the cobra's & sew them together.*
Perhaps the only bit you need to get (unexpectedly?) creative about is the [snakes cloaca](https://www.google.com/search?q=snakes%20cloaca&rlz=1C1NHXL_enGB711GB711&sxsrf=ACYBGNSszrpAAJbdCKMHSDq8f-CKG2X8Tg:1576049333580&source=lnms&tbm=isch&sa=X&ved=2ahUKEwjKvbSlia3mAhX3VRUIHaxWDDAQ_AUoAXoECBAQAw&biw=1280&bih=616) as its tail is probably thinner below it than you want so you'll need to surgically reposition it to above the place you want to trim it's tail (but that hardly seems a particularly difficult operation beyond the ken of a good surgical vet these days, so shouldn't be a problem).
Other than that the operation shouldn't be any more difficult or unexpected than a limb transplant, connecting blood vessels, nerves, muscle, tissue & bone (fitting vertebra together in this case).
What you'll effectively have then is a trans-species [siamese twin](https://en.wikipedia.org/wiki/Conjoined_twins) sharing no major organs but with shared blood flow & (to some extent) a shared nervous system with their spinal cords connected at their bases, each with a seperate head, mouth, stomach & anus.
*You'll then probably have issues with neither animal being happy with the arrangement & trying to bite each other but that isn't within the purview of your question so I'm not going to worry about that.*
*They were alive when they left surgery, care of your new pet is your responsibility after that ;)*
[Answer]
It would work only in the most trivial sense of just gluing the snake on, as the comment says. If you glued it on, the snake would have to feed itself separately from the tiger, which seems kind of hard for it to do when glued to a tiger's ass.
If you tried to connect their bloodstream, at least one would surely die. The biology and chemistry of blood is completely different and cross-circulating between them wouldn't work. The tiger's immune system would attack the snake's blood and the snake's body when the tiger blood gets into the snake. Also connecting the snake to the tiger's arteries could cause dangerously low or high blood pressure to the snake.
But by far the biggest problem I see is that regardless of how you attach it, the snake would get really mad and bite the tiger, and both would die. The tiger would also get mad and attack the snake. Even ordinary cats decide to attack and bite their own tails once in a while.
Lastly, tigers are endangered animals and shouldn't be subjected to cruel, poorly thought-out experiments with no clear purpose.
[Answer]
Well, it should not be impossible, you are asking for a **chimera** (without the goat), but you have to take care of a few things.
As mentioned by L.Dutch in his answer, their immunity is a big issue, so make sure they are not connected directly, like cut the bottom of the snake and stitch it to the tail, It won't happen.
Now, what does the **snake needs** for survival, It needs food, oxygen and needs to excrete, all three things can be provided given that placenta in mother's womb does the same thing, and tigers are mammals, so they have specifics to generate a placenta.
This placenta should provide the snake whatever it needs to stay alive, and it also needs to shed its skin periodically, which should be an automated process, and the tiger's lick can get it off.
What the **tiger needs**, It uses its tail to keep balance, and it defiantly has the required muscles and brain signal to signal its tail, so there should be a way such that tiger brain signals can control snakes body to keep its balance, while simultaneously, the snake can control itself too, but snake's signals should be lesser priority than the tiger.
Then, there should not be any conflict between the two, the snake must not bite the tiger (It is way cooler for the cobra to still be venomous) and the tiger must not kill the cobra too, and maybe, they both can find a way to live and work together. And at last, the tiger should be immune to the snake's venom just in case of accidental bites.
So, all in all, some really high tech, handwavium tech, nanotech, and biology is required to get this all done.
Additional features: If you can get the brains of these two to work incoherence, there are a lot of benefits like Tiger now can have an infrared vision, No ambushing of the tiger from behind, an upper hand for the tiger in any battle with the help of snake.
[Answer]
# Maybe, if it's a setting where Mad Science can bend the rules of reality.
This question isn't tagged "science based", so I'm not going to give an answer based on modern, conventional science.
In some settings, such as the comic Girl Genius or the RPG Mage: the Awakening, mad scientists are capable of warping reality so that reality begins to conform to their mad theories. A tiger with a snake for a tail? Sure! Strap them to an operating table, pump their veins full of alchemical reagants, perform the surgery, and then call down the lightning to revivify them!
All those men at the university laughed at you, but who is laughing now! You'll take your freakish abomination against nature and rub it in all of their faces!
[Answer]
This is my first answer here, so bear with me.
If you need to know whether this is really possible, it isn't and please don't try it. If you need to make it happen for story purposes, you can easily build a world not much different from our own in which it does.
Imagine this world has a special, perhaps magical, adhesive tape which fixes *everything*. People use it in their homes, to fix their cars, to remove warts, and for all sorts of other purposes. Engineers like it especially and it has this sort of cult-like following centered around the many uses it has.
Someone has removed the tail from a tiger and replaced it with a cobra, using this magical tape.
Why would somebody perform this extremely misguided scientific experiment? It's mad science; they want to discover the limits of the tape, if indeeed they exist.
Why doesn't the snake just shed its skin and escape? Because the tape is that good.
Why doesn't the snake just bite the tiger and kill it? The tape has been wrapped in a spiral around the snake's body so it can't bend around and bite the tiger.
[Answer]
**Yes** (or at least, contradicting some stated counterarguments).
Consider the deep-sea angler fishes (I often do!): The large ones (say to 30cm/foot long) are female and have a light-emitting lure (as in the Finding Nemo sequence where Dory&Marvin find the diver's glasses with a Sydney address). The male ones (say to 5cm/2inch long) are free swimming until they encounter a female.
Living at the dark depths they live, any encounter is rare so their life's mission is quasi fulfilled: The bite the female, hook their blood supply into the female's, let their organs waste away, and plumb their sperm ducts towards the female's ovaries. For the rest of its life, the male is like a wart, an outgrowth on the back of the female and fertilizes her eggs; 2-3 males may be attached to a female. [Other species are smaller/larger; and monkfish are similar-shaped and closely related, but don't engage in this rigmarole.]
So, the argument that automatically immuno-incompatibility would stop the project isn't correct. There will be problems as your snake and tigers are genetically much much more distant than male and female same-species angler fish. But of the usual needs (food, oxygen, and excretion) are all met through the blood supply obviously. So your snake-tail can actually waste away its organs keeping just brain,skin, teeth, muscles, skeleton, tendons,... and maybe extra-large or extra-potent venom glands?
[Answer]
My logical conclusion is that the bacteria that is good for the tiger and bacteria that is good for the cobra will mix and just make them both sick. Not to mention the immune systems in their bodies will notice that this part of the body is completely unrecognizable, and will try to kill that thing. Hell, it happens with implanted organs where one person's DNA is fundamentally different from another person's DNA. So when implanted, the immune system will attack the weird new organ because its unrecognizable, even if we need that organ.
We can give people medication to actually lower the immune system's activity, but that commonly puts people into a state where they have to live very, VERY carefully and eat only specific types of foods as to not get sick and die. So even then the cobra tiger will die, even when given a medication that lowers the immune system, because the bacteria from each animal will attack each other animal (Albeit unknowingly thinking the cobra's a tiger and the tiger's a cobra because technically bacteria want to live and not kill its host but it doesn't have the brains to realize its host isn't the thing it thinks it is) and utterly killing them both.
[Answer]
Possible. However how long do you think a tiger is going to put up with a cobra invading the space between its hind legs? 30 seconds? As soon as both animals are awake and functioning, you'll have a dead tiger, dead cobra or both.
] |
[Question]
[
For millennia the Arbol and the Byrond clans have engaged in bloody warfare. A benevolent wizard who is passing by and hears of this decides to stop them once and for all.
He casts a powerful spell that makes the clans invisible to each other. This includes their clothing and any artefacts (British spelling) they are carrying including weapons. It also applies to substances such as dust, powder, solids or liquids that gather or are thrown at them and stick. In other words they cannot be made visible by some trick.
The wizard leaves this non-magical medieval realm believing he has done a great service to all. Unfortunately the clans still want to carry on their vendettas.
How can they fight if they can't see each other? What tactics could they use?
**Notes**
The clans are not invisible to themselves nor to anyone not involved. They are only invisible to the opposing clan members or opposing mercenaries or opposing agents such as trained animals. As stated, no tricks such as throwing powder will make them visible. The wizard has excluded that.
Clarification - if you throw powder and it sticks then it also becomes invisible. The part that doesn't stick will presumable leave a temporary 'hole' but the opponent can then dodge.
They would be given away by brushing against things that aren't attached to them in some way. A branch that got caught in their clothing would become invisible but a branch they brushed against would not.
Trying to join one of the clans in order to settle your own grievances would be treated with great suspicion. You might be a spy. There are very strong bonds of blood in these clans. Marrying into the clan would require a thorough check into your background.
[Answer]
**Raiding.**
As a general rule in long-term, low-intensity conflicts like this, you don't target the other side individually, you target their stuff. This has a number of benefits: they need to put effort into getting new stuff (instead of fighting you), they needed that stuff to bring up the next generation of people to fight you (usually by "stuff" we're talking food, or other vital supplies), and of course you can get their stuff.
In this scenario, this has the added benefit that their stuff is not invisible. On the other hand, when you pick it up, it becomes invisible! Plenty of thieves would give their right arm for that trick. (Or somebody's right arm anyway.)
Even if you can't steal things, you could destroy or despoil them. If the enemy has cattle, maybe that's a little tricky to walk off with (although it's possible...) but it's still a big fat target.
On defense, you have fewer options. Stopping raiding parties is hard enough when they're totally visible! Aside from raiding them even harder, I'd expect them to specialize in physically-triggered traps. The clans aren't intangible, after all, so things like tripwires, pressure plates, pit traps, etc. are all fully functional. Big static defenses would also be valuable: a wall around your stuff that's difficult to scale, basically.
[Answer]
Attacking opposing camps has already been covered - aim for their belongings, not their (invisible) people. However defense is the important flip side.
# Sound
* Trip wires with bells attached with give away an invaders position (this could be countered by making animals - perhaps a herd of deer - run towards the camp)
* Bells on doors - they're already close at this point but you know where they are
* A string of bells with tar (or some other sticky substance) on them, once they stick the enemy has to either stop to remove them and reveal their location or keep move slowly to avoid disturbing the bells
# Other objects
* Objects that move easily (marbles, for example) would give away the movement of an enemy as they roll away from them - even if the initial object is invisible the others won't be
* **Watching for what isn't there**: all those materials you mentioned (dust, oil, powder) would be invisible if they touched the enemy so the fact you can see those means your attacker isn't there
# Using guard animals (dogs, etc)
* Their other senses are much better than a human's - using their reactions as an alarm would also be useful
# Use the invisibility
* If any object you touch becomes invisible to them you could have razor wire at neck height and a watchman touching one (blunted) end, providing you with an invisible razor wire (this could also be used as an attach, sneak into the enemy camp and set traps like this)
# Traps
* A hole in the ground or a snare trap will capture the enemy, you might not be able to see them (or your trap) but you'll know they're there because the trap was sprung
[Answer]
# AoE
Area of Effect. Carpet Bombing. Indiscriminate widespread attacks.
You know roughly where the enemy is, but can't see them. So you attack the whole area.
Have your archers fire quickly and somewhat randomly. Heck, in open field war, archers didn't generally target opponents, they just fired quickly into the mass, expecting to hit something.
Even better, get your catapults and trebuchets, and instead of loading them with a single large rock, fill them with a number of head sized rocks. And depending on the situation (availability and possibility of out of control fires), mix in some incendiaries.
You don't have to hit specific people, so long as your barrage takes out some of them.
[Answer]
**All your bases are belong to us**
Attacks will have to be carried out based on known locations. The clans could pore over the map of their city, and check individual houses. Finding a residence that looks unoccupied, they can then question the locals about why it is empty. If it's not empty, then they've found a suspected location to nuke.
This may however lead to a lot of collateral due to false positives, or the other clan member may just not be home.
The attacker holds the advantage in this scenario though, as the base is known but not where the attack is coming from. This will lead to a long drawn out battle where each clans places of residence and bases of operations are slowly taken out.
**EDIT:** In case these clans are living in closed communities, this method just scales.
You'd then have to hire cartographers to look for anomalous villages. The settlements of the opposing clan would look perpetually "just been abandoned". The houses they live in, their fields, food set on the table, these things don't disappear. There will be random items constantly appearing and disappearing in the village, and once found the settlement would basically advertise itself to be the other clan's.
The searching process can also be augmented by getting known maps of the area as stated before and checking already marked villages.
Problem with this is, whichever clan is found first will be annihilated. The advantage lies completely with the attacker, and having no collateral to worry about, can proceed to completely raze the opposing village. The most likely tactic would be to set fire to the houses at night, taking maximum population, then burn the fields and food caches, and maybe set lesser traps on obvious exits to harry survivors.
Of course, that possibility might occur to the clans, and they'll modify their residences to suit defense.
* Scatter the clans into smaller villages.
* Set up efficient communication system between the villages. Horses will most likely be killed, probably poisoned, in the prelude to the raid. So there would have to be riderless runners. Hidden passes between the villages could be set up. Messenger birds could be trained (birds are much harder to target than horses I am assuming)
* Set up a constant warning system, with scouts hiding in the surrounding terrain with no obvious markers. If an attack happens in one village, the scouts immediately send message to the others to scatter.
* As they might have to run at a moments notice, packing might not be an option. The clans would probably contribute to hidden caches set up away from settlements that can be accessed by escaping refugees.
[Answer]
A "dirty" solution for Day 1: Line your troops up, swords out, and have them march in a row while chopping and swinging wildly at fresh air and being very careful not to hit anything they can see.
Something a bit more refined for future engagements?
* Carefully trained, *silent* Bloodhounds, who can sniff out your invisible foes while remaining unseen by them.
* Small bells in a sticky/adhesive goop - thrown at your opponent, they turn invisible - but **not** inaudible!
* Train up assassins to pick out targets and avoid obstacles by sound. That wizard has provided you with a surplus of invisible ninja for your noble cause!
(Something that was not elaborated on - does the wizard *tell* the Clans? Or are they just pitched up, ready for battle, then wake the next morning to find their enemy is gone, but their tents remain. Scouts sneak in to investigate, then report back that they can still hear the enemy, but can't see them! How long until they realise that they are just as invisible to the enemy as the enemy are to them...)
[Answer]
I can't believe nobody suggested that yet:
**BIOLOGICAL WARFARE**
Bacteria and viruses don't care if you're visible or not, they just jump from person to person.
Throughout ages there were many ways to spread disease among the enemy. By throwing manure in their water supply you can have a nice cholera outbreak. Rats and other flea-ridden animals are wonderful for spreading bubonic plague. STDs, once introduced, are nearly impossible to eradicate.
As soon as a disease strike one side, the other can declare "temporary cease-fire for humanitarian reasons" and send them aid. Such aid can be, for instance, blankets previously used by smallpox victims.
Just be careful - that kind of tactics happens to backfire more often than not... which makes a good story.
Further reading: <https://en.wikipedia.org/wiki/History_of_biological_warfare>
[Answer]
Tactics would largely depend on the typical battle sizes and available technology level, so, without that, we are kind of stabbing in the dark.
At any rate, one thing invisible people leave is
## Footprints
Especially for defensive and ambush positions, have the enemy approach over a wide stretch of sand, mud or similar, and have prepared some concentrated ranged fire - catapults, Greek fire or maybe some avalanche, depending on terrain. Mud and sand have the extra bonus of not requiring a lot of preparation between battles, and they work well with sound alarms described in other answers.
## Blizzard
Not necessarily a blizzard, but either a snowfall, sandstorm, waterfall or saturation of area with a load of other small moving particles would show clearly the places where they can't go -- emptiness where there shouldn't be any shows up the invisible people.
## Goose down
As an alternative, when you are already in a combat situation, you could have some sacks of slow-falling material -- goose down maybe, but a bit wet to make it slightly heavier(?) -- to throw over an area, with some bowshot or other way to split the sack while it is in air above where the enemy should be.
[Answer]
Fire, or maybe more opportunistically, water. Maybe ambush.
Presumably the invisibility doesn't extend to their housing. Look for the encampment of empty tents, village of empty huts, or whatever it is depending on your technological level, send in a bunch of soldiers in the middle of the night, and light up as much as you can.
Then either retreat before the smoke gives you away, or hang around and take advantage of the chaos to attack the 'holes running through the smoke and the spaces where water is pouring/shooting from.
Alternatively, if they're unwise enough to set up in a bad location geologically, dam a river and flood them out.
As for ambush, if you can figure out where they live, you wait until you can observe the effects of their actions. Well buckets dropping without anyone dropping them, unexplained disturbances at the riverside, farms tending themselves, livestock slaughtering itself. Then sneak up and swing a club or shoot an arrow where the person should be.
[Answer]
It's an interesting premise. It almost seems like the answer would itself be the story.
As others have suggested, a big part of it would involve the factions attacking each others' settlements. They could besiege each other, loot and burn each others' buildings etc.; and they could use their invisibility as a tactical advantage. For instance, Arbol assassins could lie in wait under every Byrond bed, and just stab a sword through the mattress as soon as they feel someone lie down.
They could also use proxies, of course (since you specify that third parties can see both clans). Presumably there would be a bidding war to control the loyalty of any highwaymen operating in the area, for example. You might end up with a Cold War-like situation where the main combatants don't attack each other directly so much as they arm and fund different sides in everyone else's conflicts.
Over time, I guess that it would make sense for the Arbols and Byronds to abandon their own settlements – which would be subject to constant guerrilla warfare – and hide themselves in "neutral" towns. There are all sorts of interesting possibilities where they could be living side by side without knowing it, kind of like the situation in China Miéville's *The City and the City.*
[Answer]
I think he offensive power of invisibility greatly outweigh defensive power. In the field it is almost impossible to intercept mobile force so the fight will take place in settlements and other key locations. Now the attacking side can scout the surroundings and layout (but not defense) freely and simply chose the moment, place and force to attack. The defender have to be ready all the time.
With millennia of bloody warfare and now without ability to see the enemies (and enemy civilians) it could get ugly quite fast - there would no reason to show any restraint, sneak in with small force and
* Poison the wells and spoil the food supply
* Set something on fire
* Apply weapons indiscriminately to beds and cradles
Now even if all attackers would get killed afterwards they usually inflict grave looses. And if attacking force is small then it have real chance to escape without retribution.
The defender have much more difficult task but can
* Use dummies and misdirection - like having multiple chambers (or even settlements) - some used - some filled with traps - and switch them regularly
* Try static defense - if they are able to limit approaches to very few round the clock monitored kill-zones they may have chance to get more favorable result. But the invisibility allows attacker to bring tools and helpers with impurity so I imagine anything short of underground bunker would allow the attackers to sneak around.
Finally I think one think could happen - after both sides settlements are savaged by unpunished foes both sides adapt nomadic lifestyle. With villages set up for night and torn down in the morning. That way the attackers would have to stumble upon settlement by chance and would have only very limited time to execute the attack. It would reduce intensity of the conflict and may with time turn the other side into invisible daemons from legends instead of real day to day threat.
[Answer]
# Ninjas
As noted, actually killing people is hard work. Burning and stealing stuff is how you wipe a population out efficiently.
So you'll start out raiding. As each side is invisible to the other, you can do lots of theft and arson. If it extends to cards and mounts, it gets even worse.
This will do a *lot* of damage to both sides. Unaligned parties end up sweeping in and taking over territory destroyed by this invisible war.
In response, each side will seek to *hide* their settlements. They form hidden villages, and engage in warfare against their opponents. They'll test the limits of the "mercenaries" clauses (what if we don't pay them, but offer them plunder? What if we have no formal agreement, just a wink and a nod? What if we are *their* minions, and they pay us to be scouts for their army?)
Approaches to their settlements will be trapped in ways that reveal even invisible foes, while at the same time permitting defenders to move about undetected by attackers.
This situation either stabilizes, with both sides being secretive societies that hire themselves out as scouts to other powers, hoping to find where their foe is hiding. Or one is wiped out.
If one is wiped out, the other one's people are probably carried away as slaves. Their descendants spread over the world, each a blood-member of the clan. The surviving clan, now safe, may continue in its mercenary ways, banning out-marriage with prejudice. Over time the surviving intact clan finds that more and more of the regular world is incapable of seeing them.
They develop proxies, and work hard to spread the blood of their now-extinct foe. Those that remember the old clan are put to death, those that simply carry their blood are helped and encouraged to spread their seed. Every child they have is another nominal foe against whom these scouts are invisible.
One day they hope that every last human on Earth will not be able to see the Ninja-clan, and on that day they will be kings.
[Answer]
Attack engines akin to **combine harvesters** will happily mulch enemies - invisible or not. They have the benefit of taking out people, tents and other things above ground level without invoking a 'scorched Earth' effect on the land.
[Answer]
I believe the described conflict/vendetta is more of an "I want to see you bleed and pay for your faction's crimes!" type of thing.
So when they realize that they can't *see* the enemy "pay for it" and get satisfied, they could get this satisfaction by stealing the enemy's stuff (and mentioned above, "King of thieves" style), and/or sieging their villages/cities to the point of starvation, and/or using mass-destruction options compatible with their medieval tech (burning their places/things and hearing people scream in terror), but it probably is something that gives some feedback about the enemy suffering.
[Answer]
Dogs.
The clans aren't invisible to new pets they've gotten after the wizard left right ? If they are this still works. Have dogs, crows, and other animals identify enemy clansmen. Then all the clansmen need to do is "disagree physically and energetically without safety in mind"; the clansmen just need to attack whatever the dogs identify.
This is pretty similar to how Law enforcement uses drug dogs. Just gotta get dogs to identify people you can't see. Should be easy enough given that you know where your enemies used to live.
[Answer]
Duels are still possible, assuming both parties want to participate and make prior arrangements, probably via a third party. If they were in a small room or fenced enclosure like a boxing ring, they would still have to grope for each other, but contact would be frequent. It wouldn't be limited to one-on-one combat, either.
I once read about a ritual fight, between fictional native americans, in which they combatants' left wrists were tied together while they went at each other with knives. Again, it would require a third party and prior agreement, but mortal wounds would still be quite likely.
[Answer]
Negotiate peace among the tribes. A major change has occurred. Simply accept that major battle is not possible and attempt to make peace in accordance with the wizards wishes.
People not fighting and another plot arising is a great twist to a story. Especially if the original wizard could be found, or at least his journal. But in the meantime a greater evil emerges...
[Answer]
Okay but everyone seems to have forgotten the easiest answer: Hire someone to point out the enemies for you.
The clans are only invisible to eachother, so hiring an outsider will allow you to find the opposing clan easily. Plus you remain invisible so they will have a hard time defending. Most likely there will be a shift in fighting styles revolving around hired "spotters" who are linchpins in either sides offence. You can work several strategies around them, but the spotters are going to become the focus of the battles, either because they are pointing out enemies or being eliminated to cripple your opponents side.
Unless they count as mercenaries and get turned invisible? I was thinking of mercenaries being only direct combatants but spotters might count.
[Answer]
# Trade War
Instead of physically attacking the opposite clan, both sides could switch to economical warfare. The members of both clans will likely engage in some form of economical activity in order to finance their standard of living and their war. So the clans could try to drive each other out of business in order to damn the other clan to a life in miserable poverty:
* Steal their customers by offering the same products for a lower price. Even if it means you have to sell at a loss.
* Drive their remaining customers away by slandering the other clan and their products.
* Buy out their suppliers to deny them their raw materials. When the suppliers don't want to sell or you lack the capital to monopolize the whole supply, sabotage the suppliers.
* Poach their best employees, even if you don't actually have anything for them to do.
* Find out if they do anything illegal and rat them out to the legal authorities.
* Steal their business secrets. If you find some secrets you can't use yourself, give them to anyone who can, just to harm them.
* Force others to take sides. Do you have any business partners who depend on you? Tell them you won't make business with them anymore if they also make any form of business with the other clan.
The only downside: You always know that even if you ruin them completely, you won't ever have the gratification of *seeing* them beg for food.
[Answer]
**paintball**
Go to the enemy's camp and hold-on to your favorite position.
Fire a paintball. Best shot is done with a shooting squad shooting at a wide angle, or few shooters with cluster paintballs. The paint will do its task even on the ground: each enemy troop stepping on it will leave footprints.
Even if the spell does not allow to see anything on their body (shield, arm, paint, etc) you have two tell-tale signs:
* the path of the paintball is disrupted when it hits the target
* the footsteps will once again be visible when they are left on the ground (enemy no longer carries it).
Now that the paintball has done its task, it's not time for laughing, it's time to pull your guns...
] |
[Question]
[
Assuming that as a species, we do ourselves in, not through war but through environmental neglect and overpopulation, what species will benefit most from the effect we have had on the planet during our brief time at the top of the food chain?
I am writing a short story about an alien world where the inhabitants hold a predecessor species in high respect for all the treasures left behind before they disappeared long before the current sentient age. At the end of the story, I want the reveal to be that the planet is Earth and humanity is the predecessor species whose garbage and relics have helped the current race thrive.
I've considered rats because they already thrive on what we discard, and dogs because I would love to see a more noble species take the throne after us. But I am sure that there are other candidate species which might lead the story into wonderful new realms.
My criteria for "benefits most" is based on how much what we would leave behind might shorten the species's evolutionary journey to sentience.
[Answer]
I think some of the creatures that would benefit most from humanity’s existence would have to be the ones we consider to be pests, such as rats, mice, and cockroaches. After all, they thrive off of the waste we leave behind, and we have even allowed them to expand their range much farther than they ever could on their own, as rats stowed away on human ships in ancient times, and are now found on almost every continent.
Birds such as pigeons, crows, and starlings could also be good candidates because they too thrive upon human civilization.
[Answer]
Okay, so I had a long talk with my cat (ginger, of course) about this and came up with a plot.
Humans advance to the point where robots and AI pretty much do everything for us.
Some benevolent human owner trains his AI Alexia to understand meows and operate under meow control.
So cats learn how to operate this AI voice command system and use touch screens.
For some reason (future alien archaeologists found mass human graves with unaccountable cat scratches all over them, and hints in the data base records that humans had become expendable) humans go into decline.
Cats survive by ordering out from the robotic food delivery service called 'Skip the Can Opener'.
Did I mention the great conflagration that enveloped the world, the great Cat and Dog Fight for world domination, because apparently dog owners did the same training?
Only the ginger cats won, owing to their supreme intelligence, cunning, and strategic thinking abilities. The dogs' loyalty to humans did them in.
[Answer]
Large mammals and fish will benefit most.
Any species which relies on humans: rats, seagulls, pidgeons, roaches; these will all quickly die off outside their natural habitat as their source of food and shelter disappears.
On the evolutionary time scale of hundreds to millions of years necessary to evolve intelligence, assuming natural selection goes that route again, almost none of humanity's treasures will remain. Almost all will have been plowed under, ground up, and disintegrated by life, weather, and other natural processes. Metal will have corroded away. Plastic and concrete will have long since crumbled.
Instead, look at our [long scale effects](https://en.wikipedia.org/wiki/Anthropocene).
* We wiped out, or brought to the brink of extinction, most of the top level predators.
* We also wiped out, or domesticated, most herd animals except game animals.
* We reduced biodiversity.
* We brought about rapid climate change.
* We carried species across natural barriers to new territory.
* We produced a very thin, but very noticeable, layer in the rock strata.
* We dumped a lot of long-term nuclear waste and heavy metals.
That last one will be one of the last tangible remains of humanity. Plus their [long-term warning signs](https://en.wikipedia.org/wiki/Long-time_nuclear_waste_warning_messages) and other projects designed to stand the test of time such as [The Clock Of The Long Now](http://longnow.org/clock/).
The changing planet will be left with an ecosystem of scrambled species, reduced diversity, and a dearth of large predators or herd animals.
With the top predator (humanity) gone, adaptable medium sized predators which humans have carried to new territory will fill the niche. Likely felines and canines. Living together. Mass hysteria.
Similarly, without humanity to compete with for territory and food, herd animals will return. Horses, cattle, and elephants.
Finally, without human fishing activity, populations of large sea creatures and fish schools will rebound.
This is currently being played out within the [Chernobyl Exclusion Zone](https://en.wikipedia.org/wiki/Chernobyl_Exclusion_Zone), now one of the largest (involuntary) Eurasian wildlife parks. Wildlife is recovering demonstrating that humanity might be worse for the environment than a nuclear disaster.
[Answer]
We need an animal that is pretty intelligent already, and who can pick up and use the tools left behind by humanity. Having a flexible diet wouldn't hurt.
I present to you: **The Raccoon!**
[Answer]
**Some kind of invasive species**
What we call "invasive" species, are really species that we humans have moved to new habitats where they thrive. They may thrive because they have no natural predators in the new habitat, or because we've eliminated their predators, or because we've made their prey unnaturally abundant. In other words, we've given them an unfair advantage that will allow them to dominate the new ecosystem. There are lots of these, so you can pick a part of the world and probably find a good candidate.
In North America, my favorite would be **wild horses**. They'll have a huge range when we're gone, and although they do have predators, I don't think they'll be eaten to extinction. They also have the genes of domesticated horses bred for speed, endurance, and temperament, so they're a little more noble than plain old wild animals.
Another good one might be **whitetail deer**. They're native to North America but have a much wider range thanks to human activity. Also, as I understand it, they carry [a parasite](https://en.wikipedia.org/wiki/Parelaphostrongylus_tenuis) that is fatal to moose, elk, and caribou and (in my state at least) they have forced those species northward and taken more habitat for themselves. It's hard to think of deer as a pest, though, because they're beautiful and delicious.
Some kind of a **dog-wolf-coyote hybrid** might also be a good choice, and less boring than just going with domesticated dogs. This one is more realistic [because it already exists](https://en.wikipedia.org/wiki/Coywolf#Eastern_coyotes). You have the strength of a wolf, intelligence of a coyote, and courage of a dog. Also if you want different dog breeds to be different castes like in *Planet of the Apes*, there you go.
I guess **wild pigs** are also a realistic option. They are pretty hardy and adaptable creatures, and tough enough to defend themselves, and we humans will leave plenty of members of the species behind.
[Answer]
## Robots
Maybe it is a stretch to call robots a "species", but when it comes to owing their rise to humans, they fit the bill perfectly. In your future world, humans may have achieved a state where robotic automation becomes so good that robots can reproduce and adapt on their own. Some robots mine, some run the factories, some distribute goods, etc. They also have a deep respect for humans because it is hardwired into their design.
Instead of the stereotypical robot apocalypse where the robots rose up and destroyed humanity, these are "properly" designed to never resist the will of their human masters. So when overpopulation and environmental damage became to severe for humans to survive, the robots just kept on keeping on as the loyal servants they were giving us all the cars, smart phones, and indoor lighting we desired until it killed us all.
They would also continue to survive and even thrive no matter how badly we mess this world up. Human technology makes us very adaptable; so, once the world becomes so hostile that we can not find a way to survive, there will not be a heck of a whole lot of other species left to take over.
Another advantage here is time-frame. Waiting for another intelligent species to replace us after we are gone will take millions of years as a bare minimum, but most things made by human hands turn to dust within a few thousand years. By the time another species rises to intelligence, there will be so little evidence left of human civilization, that they may not even be sure that we were an intelligent species. Just that there was a dramatic, difficult to explain climate change event. An organic successor race would have just a vague notion of how global warming affected their evolution the way humans have a vague notion of how important the ice age is to us. Robots on the other hand have the best chance of developing intelligence along side humans, and then just outlasting us giving them a societal memory of the humans that once were.
[Answer]
All current answers are too mammal-centric.
My nomination would be the birds. If you want to breed for intelligence, tool use and problem-solving, you don't want dogs or even cats - you want crows. They are the first animal ever seen to [construct complex tools](https://www.newscientist.com/article/2099246-crows-are-first-animals-spotted-using-tools-to-carry-objects/#) (defined as a tool with more than one element).
Crows are fully omnivorous, and will eat anything - and meat-wise, that could be in just about any state of decomposition. They have very few predators, at least as adults, because they can fly and they are relatively large birds. And unlike many mammals, they have two claws and a beak which allow grasping and relatively fine motor control.
More usefully for our purposes, crows are social creatures. They defend against the predators they do have (mainly other birds seeking to raid nests for eggs and chicks) by ganging up on the bigger birds - so they already have tribal instincts. They learn from each other too, so a new technique figured out by one bird in a flock/tribe/area will be copied by others, and that's the biggest thing to build on.
How would our existence help them? Lots of tall buildings with safe roosting opportunities, is the simple answer!
[Answer]
I kinda feel like the various monkeys/apes are the best candidate - albeit a pretty boring one. Some scientists already consider that [they have entered Stone Age](http://www.bbc.com/earth/story/20150818-chimps-living-in-the-stone-age) and that's the furthest any species has got so far. With humans out of the picture - well, it's just a matter of time. Mind you, I don't know how much of human presence would still remain by the time the apes got intelligent enough to start to care. Probably not much. Perhaps you need a doomsday vault that gets opened later on.
[Answer]
[Intelligence is nothing more than an evolutionary tool](https://www.ted.com/talks/suzana_herculano_houzel_what_is_so_special_about_the_human_brain). Because it is our main tool, we are biased in saying that it is different and we overvalue, after all, we cannot run very well, we have no claws, inoculate poison, keep alive in very adverse situations, etc.
Our intelligence is the product of the 16 billion neurons in the prefrontal cortex, which added to the 70 billion neurons in the cerebellum form a mass of 86 billion neurons that consume about 500 kcal / day.
The cerebellum is the main seat of command for our movements and the various organic activities that keep us alive. In the cortex are interpretations of the senses, it is where you really see, smell, hear, etc. and intelligence is the result of this interaction of the environment.
Only when our ancestors were able to access new energy levels, when they were able to have more calories from food and spend less time eating or looking for food in the time they stayed awake did intelligence emerge.
For your story this brings excellent news: the improvements we have made in [agriculture](https://www.sciencealert.com/fruits-vegetables-before-domestication-photos-genetically-modified-food-natural) over the millennia have made countless plants robust sources of extra calories with easy harvest. The naked apes are all obese thanks to that.
Many talked about small animals in the other answer: forget them all. They need substantial physical growth to also increase their cranial box to accommodate a growing brain. Not only because of the size itself, there is also a relationship between neuron density and sleep time, animals with small heads and many neurons in the cortex need to sleep too much and have little time awake to feed and still have free time where the imagination can operate.
Intelligence is also not an individual product. If we humans needed to invent the wheel in each generation today, we would still be in the stone age. A species that is unable to communicate with each other in any way, to develop complex ways to do so, such as our facial expressions, in addition to voice and later writing, certainly has no success in evolving intelligence, just as it needs to be able to accumulate knowledge.
Knowing how to handle tools with fine movements, as we do thanks to our opposable thumb is also an important differential. It is one of the things that make crows one of the most magnificent beings in the animal kingdom. That is what makes ~~those [poor bastards](https://panamajack.com/blogs/under-the-sea/7-reasons-dolphins-are-kind-of-jerks) [assholes](https://www.youtube.com/watch?v=Y05xtEs1Eyk) of the seas,~~ the [dolphins](https://en.wikipedia.org/wiki/List_of_animals_by_number_of_neurons#List_of_animal_species_by_forebrain_(cerebrum_or_pallium)_neuron_number) limited in relation to us, even though they have more neurons in their cortex than we do.
A species that is large, with a long life span and is capable of making fine movements, at the same time that it is able to transmit information through generations, preferably that already has a massive brain that would only need an extra increment are the best bets.
In this case, only the other apes: orangutan, gorilla, chimpanzee, bonobo, or else ...
With amazing 257 billion neurons in the whole brain, almost 3 times the human brain, but only 1/3 of neurons we have in our prefrontal cortex, my favorite bet: The [elephant](https://earthsky.org/earth/elephants-unique-brain-neurons).
[Answer]
I would like to offer a bit different view of the answer - of course the obvious species would be pests who nurture on our biological waste for their nutrition. But this would be short-lived as there is a final amount we have had left behind us, and once that's digested - well, it's gone :)
If we think about a sentient species that will come thousands of years after our demise, it would have to do more with the non-organic man-made creations left on the planet.
So I would think of concrete (roads, buildings, bridges) and of metal (planet-stretching copper wiring, and the inevitable abundance of stainless-steel utensils our new species will seem to be digging up everywhere...)
Maybe they will treat "findings" of buried cities and of old roads like we treat newly-found deposits of gold or precious stones? Maybe they need the concrete or thrive on the magnetic/conduciveness of the metals?
If you haven't read it already - I highly recommend the book "A World Without Us" which describes what would happen if suddenly, in a blink - all humans would vanish, but nothing else will change. It goes form the immediate consequences, to days, weeks, years and into the dar future - what would the world look like? It contains some cool ideas like the utensil example I have just 'stole' from it :) Look it up!
Good luck with the story!
[Answer]
On thinking about the other answers, I'm not sure this is possible without a little "something extra"... If humans suddenly die out, nature is likely going to reclaim most of our stuff more quickly than something else can grow to the point of being able to care about it consciously and preserve it.
That "something" is uplift.
There are several species that would make good candidates, but really, you could use whatever suits your fancy. The upshot is that humans are revered not just because of all the stuff we left behind, but because *we are responsible for your species' sapience*, and they know it.
This might work better if full sapience arises only slightly after we're gone, or if we don't realize it's happened. To that extent, your best candidates are probably dogs (for obvious reasons) or possibly horses (similar reasons as dogs), or else laboratory animals (either monkeys or, ahem, [rats](https://scifi.stackexchange.com/questions/231522)).
If you're interested in the notion, I would *strongly* recommend reading [Breed to Come](http://www.andre-norton-books.com/worlds-of-andre/novels/361-breed-to-come) by Andre Norton. You might also find [That Which Survives](http://tsa.transform.to/animal/thatwhichsurvives.html) interesting. (Go read it now; it's free and it's not much longer than this answer. Thank you [FuzzyBoots](https://scifi.stackexchange.com/users/23243) for [dredging that up](https://scifi.stackexchange.com/questions/231522) for me!)
[Answer]
Another answer from me, from a different perspective.
I just re-read your criteria:
>
> how much what we would leave behind might shorten the species's evolutionary journey to sentience.
>
>
>
So, that's actually pretty specific. What in all our stuff would push a species to evolve higher intelligence? This immediately lays down some groundwork: first, there has to be evolutionary pressure. Something that kills off the individuals which are less able to adapt. Second, our things must help the evolving species to survive, so the better they adapt to our legacy, the better their survival. Third, the survival must depend not only on learning to use things, but also to *understand* them - otherwise we don't get to science. The smartest individuals must be able to survive the best.
At the same time, this must be something very primitive, because even the most advanced animals today can't use more than simple tools. And it has to last a long, long time, because even at the fastest pace, we probably won't get another intelligent race for a few millenia. And finally it has to be plentiful enough to support large populations, not just a single tribe.
Hmm... well, I'm kinda stumped. Nothing comes to mind that would fit these criteria.
Perhaps stainless steel knives and other tools? Those should last a pretty long time, depending on their storage and quality. And there's plenty to go around. A knife is a pretty versatile tool. But would it lead to faster evolution? I don't know... Maybe if their wielders (I still can't get the primates out of my head) started to use them for warfare between themselves. Then the ones who could adapt to their use faster; come up with novel moves or traps - would have a better chance or survival. Maybe. But at best this might get them to Bronze age or something. After that...
Maybe there can be series of tools? Once the simple ones are mastered, they can move on to more complicated ones. But I'm still unsure what could survive that long.
Unless.... humans actually *designed* for this? Make a trail for new species to follow, with perks being unlocked along the way. *Those* could be made super-durable to last millenia. But what would they be? Still no idea...
[Answer]
It would be a toss-up between cats or dogs, but I would bet on cats.
Both have been bred by humans for intelligence, so they have a head start on evolution. Both have gone well passed the critical threshold of population numbers for independent survival. Both are very familiar with human habitats, living conditions, and culture, and have adapted to domesticated living.
Some breeds of dogs are estimated to have a mental age of a three year old. They already have a head start on evolution, being purpose-bred. However, dogs are much more dependent on humans for survival, having been raised under strict master-pet conditions.
Cats are more cunning and better problem solvers, overall, with a greater sense of how to survive in the wild, without humans (having never been truly domesticated). They are independent enough to survive the extinction of humans. Cats can truly have an intelligent conversation with humans. Cats only meow in the presence of humans, for instance, and their own mothers just after birth. They might not have a large human vocabulary, but they definitely understand human communication using emotion, facial expression, intonation, and other non-language cues. You do not train a cat, you talk them into doing what you want, convincing them that they really want to do it. They also have good math skills. Just try to convince a new cat mom that it has one less kitten than the original litter. They have an innate sense of quantity. Cats also have very good manual dexterity, able to manipulate things in their environment far beyond just 'fetch'.
But my third choice would be [pigs](https://www.huffingtonpost.ca/entry/are-pigs-intelligent_n_7585582?ri18n=true), having achieved the human five year old level. Pigs would actually be my first choice, except that they have no opposable thumb (hard to hold tools with a hoof) and they would never forgive us for our love of bacon. They would never, ever revere us. There also isn't a critical threshold of domesticated pigs that could be expected to survive human extinction.
Trained and domesticated chimps and other such primates are perhaps far more intelligent, but they just don't have the critical mass of population that would enable survival. We have pretty much taken them to extinction.
And if anyone has ever encountered the tremendous manual dexterity and problem-solving abilities of a raccoon to get into garbage cans, one would definitely have to put them high on the list. However, they just don't have the same experience of living in a home and mingling with the technological environment, and interacting with human tools, that cats do. Cats will watch tv, and even learn to turn the channels to get to what they want to see. At least mine does.
[Answer]
In terms of mankind's presence passively helping another species achieve sapience, there probably wouldn't be any species that fit your criteria. Humans haven't been creating strong selection pressures for higher intelligence, and the only way our presence would help another species achieve sapience is if we outright uplifted them. [There have been suggestions that the complex artificial environments created by humanity have selected for larger brain sizes in squirrels and such](https://www.nbcnews.com/sciencemain/humans-may-be-causing-some-animals-grow-bigger-brains-8C10988418), but it's not going to act on them to the point that they develop sentience. Indeed, in the absence of humans it is possible that these squirrels might lose any increase in brain mass, in a similar case to [how the peppered moth returned to a non-black morph when industrial pollution levels fell.](https://en.wikipedia.org/wiki/Peppered_moth_evolution)
The species that will benefit evolutionarily will primarily be invasive species mankind introduced to isolated landmasses, such as islands. By introducing these organisms to new landmasses, mankind has increased the total range available to these animals, created new opportunities for speciation, and reduced the chance that these species will go extinct by creating potential refuge populations where they could continue to adapt and thrive (especially on islands). Many groups of animals, like ungulates and carnivorans, are normally terrible at crossing water barriers, and humans represent an unprecedented opportunity for them to get to landmasses they would otherwise be unable to. Hawaii, New Caledonia, and New Zealand are good examples of this, as non-flying mammals would otherwise have no chance of reaching these landmasses for over 100 million years. Although some of these islands, like Hawaii, would eventually sink beneath the waves, many species could still keep island hopping the way *Drosophila* did in Hawaii and some islands such as New Caledonia, Madagascar, and New Zealand are actually continental fragments and would last a very long time.
There are some qualifiers to this. Although many species in Eurasia have been introduced to North America and vice versa, many of these species would have gotten to these locations anyway the next time the Bering strait closed and species could freely migrate between the Old and New Worlds. For example, there are no native true rats (*Rattus*) in North America, but there are plenty in Asia and they would have just crossed the strait some time in the next hundred thousand years or so.
Human-introduced species are a big deal compared to other species that currently benefit from human aid (livestock, pests) because while it took human intervention to *get* them there, human intervention isn't required for them to *survive* there. Which means that if humans go extinct these new, invasive populations won't go extinct with them (this is the problem with things like cockroaches).
Given these factors, I would say the species that has benefitted the *most* from the presence of humanity (considering their current distribution and how extensive their distribution was pre-humanity) would have to be...
**Rainbow Trout (*Oncorhynchus mykiss*) and Goldfish (*Carassius auratus*)**
Freshwater fishes have a much harder time dispersing to new habitats, since they are dependent on either shifts in river flow, floods to overcome barriers like waterfalls, or travelling through the ocean to get to new rivers. Even catadromus/anadromus species can be blocked by continental landmasses or mountain ranges. Rainbow trout are native to the Pacific Coast of the U.S. and Canada and the Kamchatka Peninsula in Russia, but they have been introduced absolutely **everywhere**, including eastern North America (which it wouldn’t normally be able to get to due to the Panamanian land bridge and the Rockies), Eurasia, South America, [Africa](https://www.oregonlive.com/sports/oregonian/bill_monroe/2014/06/post_115.html), Australia, New Zealand, and even *[Hawaii](http://www.midweek.com/rainbow-trout-fishing-in-hawaii/)*. They are now on every continent and most major land masses except Antarctica. That is a huge expansion of their range, and they would not have been able to get to many of these places naturally. Brown trout (*Salmo trutta*) have a similar history. In some places these trout are artificially bred, but in most they have breeding populations.
Goldfish are kind of similar. They’re native to eastern Asia but have been introduced just about everywhere as a consequence of their status as common pests, and got to places like North America where there were no native carp beforehand. Common carp are less so because they already had a large range prior to human introduction, humans have not benefitted them as much.
And a terrestrial runner-up would be...
**House cats (*Felis catus*)**
Species of *Felis* are native to most of Africa, Europe, and Asia, but humans have introduced them to every major landmass and most islands except Antarctica. Cats aside from tigers are normally terrible at crossing water barriers due to their hypercarnivorous habits. Additionally, compared to other domestic animals (except maybe goats and dogs), cats are much better at surviving in the absence of humans. Humanity's presence has single-handedly given cats a whole bunch of evolutionary opportunities they normally wouldn't have.
Rats (*Rattus* spp.) are a potential third place, but rats are already good at dispersing to places and there are already native rat species in far-off places like Christmas Island, the Phillipines, and Australia long before humans came along. Getting to places like the Galapagos or Hawaii by human introduction is notable, but overall the species hasn't benefitted long-term as much as cats have.
[Answer]
Because of mankind's huge impact on the planet and the environment, generally speaking I think the species that would benefit most from mankind's departure are those that are close to the fringes, such as the endangered species in the fragile parts of the polar ice caps, rain forests, wetlands, etc. For example polar bears might be one of the largest benefactors even if they in turn don't have much impact on the planet as a whole.
For a sci-fi plot I think an interesting question is what species evolves to take mankind's place and how that transpires. Humans evolved from primates, some say just through a fluke or random selection, others say that some primates were forced into a new ecosystem where they began eating a much higher protein diet (the oyster theory), etc. So how would some other species make the same leap?
There are many existing species such as elephants, dolphins, pigs, primates, that exhibit signs of intelligence, empathy, communication, memory, and other things we consider to be human or highly evolved traits. And a lot of sci-fi has been written about this, such as Barsk with the sapient elephants, or Planet of the Apes, where on another planet the primates evolved slightly differently.
[Answer]
If you're looking for a species to become the new humans, I think cats are really your best choice. They don't have many natural enemies, can adapt to a wide range of climates, and have other biological benefits that other answers have already explained.
There's more to it than biology, though. You don't rise to the point of being a diverse planet's dominant species merely by biology (the arms race that is evolution all but guarantees there will always be competition). At some point, you have to *want* to win. You have to make the decision that mere survival isn't enough, you deserve to run the show and have all other species see you as superior.
This psychological leap is where cats have a huge advantage over other species. Some researchers believe this may have already happened1. We have entire human civilizations that raised cats for centuries and worshiped them as *gods*. This sort of species-wide superiority complex is currently held at bay through the use of cutesy nicknames and tiny hats but once humans are gone, the Era of Humiliation will soon be forgotten.
Once cats develop even the most primitive sort of archaeology (which shouldn't be long given their propensity for digging in the dirt), they'll uncover a wealth of evidence that they can easily interpret as proof that they were once the dominant species:
* Humans built everything from [statues](https://en.wikipedia.org/wiki/Gayer-Anderson_cat) to [shrines](https://en.wikipedia.org/wiki/Tashirojima#Cat_shrine) to [monuments](https://en.wikipedia.org/wiki/Great_Sphinx_of_Giza) to [theme parks](https://en.wikipedia.org/wiki/Sanrio_Puroland), all to honor cats and seek their favor
* Humans obviously loved their sports, but "lions", "panthers", "wildcats", and "tigers" were among the [most popular names for sports teams](https://www.sportscasting.com/the-7-most-popular-team-names-in-american-sports/).
* Humans invented many powerful forms of security, but cats forced them to include [backdoor](https://www.foxnews.com/tech/iphone-5s-fingerprint-reader-recognizes-cats-pawprints) [access](https://en.wikipedia.org/wiki/Pet_door) methods to ensure they could still manage their human subjects without restriction. [Cat-based names](https://en.wikipedia.org/w/index.php?title=Cat_burglar&redirect=no) were given to humans who were proficient at bypassing security.
* Humans developed entire [art forms and language constructs](https://en.wikipedia.org/wiki/Lolcat) centered around their cat masters.
* Humans spent centuries developing mathematics, science, industry, and technology, all so that they could build a [system](https://en.wikipedia.org/wiki/Internet) designed around sharing, talking about, and revering cats in the most efficient way possible.
With millennia of historical evidence inspiring them, there's nothing stopping the feline quest to retake their position as the dominant species.
[1] Source: you've met a cat, right?
[Answer]
So some chimpanzees and monkeys are already in the stone age. ( <http://www.bbc.com/earth/story/20150818-chimps-living-in-the-stone-age> ) Assuming that the loss of humanity didn't also wipe out the primates one of those is likely to step up to fill the niche, but that will likely take many millennia.
IN the interim as others have suggested, large predators will recover, as will herd animals. Domestic cattle will have a rough time at first, though the hand of natural selection will probably fix much of that quickly. Wild pigs and boar will do really well (think of how hard the are to deal with now)
We'll also see significant reforestation across Europe, and much of eastern North America, Brazil and possibly some reversal of desertification in sub saharan Africa (a lot of that is caused by tree removal for firewood)
] |
[Question]
[
Essentially, what would, in a modern (21st century) society, cause city walls to return?
* I don't necessarily mean *stone* walls; steel, titanium, and aluminum walls are perfectly acceptable.
* This setting includes modern weaponry like rockets and guns, and also near-future weapons like [railguns](https://en.wikipedia.org/wiki/Railgun). It does not include [WMDs](https://en.wikipedia.org/wiki/Weapon_of_mass_destruction) like nukes.
* Make sure that any answer is resource-viable; i.e., no solid [palladium](https://en.wikipedia.org/wiki/Palladium) walls.
* The purpose of these walls should be city defense.
* I'm willing to budge on the definition of "city", a large town is fine, but no miniature hamlets.
* Defense against guerrilla warfare is OK, but I would prefer the walls to also be able to defend against large-scale military assaults.
* People are still using all the techniques of modern warfare; not just a wall of infantry.
[Answer]
# Lots of low grade military action.
Steel walls are already common in cities where crime is high.
[](https://i.stack.imgur.com/ioAjl.jpg)
Having steel shutters over vulnerable things is normal and expected in society. This is enough to deter casual vandalism and small calibre fire. Some nations take it further.
Israeli buildings are often built with steel reinforced concrete, because of the risk of random bombings, and often have safe rooms with thicker walls.
If you have a ring of such houses in a town, you have a wall basically. The walls would be built with thick concrete, reinforced with steel, and the windows have steel shutters to protect them.
# [The West Bank walls should also be an inspiration.](https://en.wikipedia.org/wiki/Israeli_West_Bank_barrier#Structure)
>
> About 90–95% of the barrier will be constructed as a "multi-layered fence system"[27] with the Israeli Defense Forces' preferred design having three fences with pyramid-shaped stacks of barbed wire on the two outer fences and a lighter-weight fence with intrusion detection equipment in the middle; an anti-vehicle ditch; patrol roads on both sides; and a smooth strip of sand for "intrusion tracking".[28]
>
>
>
>
> On average, the barrier contains a 60-metre (200 ft) wide exclusion area.[29] Some sections are wider (up to 100 metres (330 ft)) due to topographic conditions.[30] The width of some sections (about 6% of the barrier) is 3 metres (9.8 ft) where the barrier is constructed as a concrete wall up to 8 metres (26 ft) high. These sections are narrower, require less land, and provide more protection against snipers. Wall construction is more common in urban settings, e.g., Qalqilyah and Jerusalem, and in areas where people have been killed by snipers, e.g., the Trans-Israel Highway.[31]
>
>
>
You can't stop a big invasion, but walls can make it hard for snipers, car bombers and such to attack a city and slow down an invasion for long enough for troops to be rallied inside. Concrete walls are of course very expensive, but Israel builds them around urban areas, so your city can do the same.
[Answer]
**Rising sea levels**
A coastal city-state, like Monaco or Singapore, would be extremely vulnerable to global warming and sea level changes, and the world economy would have a strong interest in protecting the financial sector in those states. So it would make sense for Monaco and Singapore to invest in sea walls.
Other cities with important waterways and financial importance might also build sea walls: London, Rotterdam, New York, Tokyo, Mumbai, Rio de Janeiro, Dubai, Panama City.
[Answer]
## Monsters or Zombies
I cannot imagine there are many scenarios that call for giant walls around civilian populations.
So the question is basically, what kind of threat would change the world enough to make nations build walls around their cities.
It would have to be an enemy.
An enemy that can operate freely across large amounts of a nation without serious fear of aerial attack or military confrontation.
Likewise, your hypothetical enemy cannot pass en-mass as normal people. They need to be something that scouts could see coming. An army, or monsters, or aliens or something in that vein.
If they can pass as civilians and walk in the gates with a little acting, then there's not much point in having the gates/walls to begin with.
Your enemy is indiscriminate and willing to harm civilians, otherwise the fortresses would be purely military and the cities would have much less defense.
It's also a sustained threat.
The military can't simply stamp it out once and for all.
In much the same way as medieval society couldn't stamp out banditry and considered its own neighbors to be sufficiently dangerous that they invested heavily in fortresses and armies.
Your foe is not air-borne. They have no ability to fly over walls and paradrop in.
Your foe lacks the kind of artillery that can bypass a wall.
Those last two pretty much preclude any inter-nation warfare, because any nations able to attack one another like that would possess one or both of those abilities.
Your foe must continue to reproduce itself despite the best efforts to kill it.
It will take years to build walls like these. The threat needs to be sustained for that entire time without being so apocalyptically dangerous that those cities were wiped out before they could do it.
Your foe must be widespread enough to threaten cities across a huge region. Perhaps not the entire nation, but enough for there to be multiple cities that use this.
So it's almost certainly not an environmental threat like dust-storms or suchlike, and in any case that would likely bypass the walls anyway.
Your foe must be a great enough threat to make a physical wall a sensible option.
We're talking, in short, about monsters, because the conditions that made it make sense with people no longer exist.
Maybe Zombie hordes. Or something else that cannot be allowed to gain a foothold in a city.
Perhaps Kaiju-like giant monsters that are stopped by the physical walls and driven off or killed by the heavy defensive guns and weaponry there.
Something that takes too much time to kill to deal with before it reaches a major civilian population and inflicts massive casualties.
[Answer]
## Political oppression
*Source: [Wikimedia Commons](https://commons.wikimedia.org/wiki/File:Berlinermauer.jpg)*
The Berlin Wall encircled West Berlin from 1961 to 1989. The official aim of the Berlin Wall was to protect the city against fascist agitators coming to stoke unrest. Does that count as city defence? Of course, the real aim of the Berlin Wall was that residents of the German Democratic Republic could not get to West Berlin uncontrolled. That's ultimately also a form of defense, because the East German regime would have collapsed with uncontrolled emigration.
*Source: [Wikimedia Commons](https://commons.wikimedia.org/wiki/File:Berlin-wall-map_en.svg)*
There is no technological reason why such a wall could not serve exactly the same purpose in the 21st century.
[Answer]
High crime rates, high gun ownership, drug lords operate without effective intervention, the continual defunctionalizing of the American police forces, and the criminal/quasi-legal terrorist organizations concentrate in particular cities, necessitating civilized society to defend itself within 'safe cities'.
I would actually extend this to particular regions within individual American states.
America already has gated communities, just extend it to gated cities.
EDIT: You might want to research the beginnings of the [Pinkertons National Detective Agency](https://www.legendsofamerica.com/pinkertons/). The walls would most likely be built and maintained by private contracted security firms, for profit.
>
> After the war, Allan Pinkerton returned to his duties at the detective
> agency, which was often hired by the government to perform many of the
> same duties that are now regularly assigned to the Secret Service, the
> FBI, and the CIA. The agency also worked for the railroads and
> overland stage companies, playing an active role in chasing down a
> number of outlaws including Jesse James, the Reno Brothers, and Butch
> Cassidy and his Wild Bunch.
>
>
> On their three-story Chicago building, their logo, a black and white
> eye, claimed: “We Never Sleep.” This was the origin of the term
> “private eye.”
>
>
>
>
> Despite the challenges, by the early 1870s, the agency had the world’s
> largest collection of mug shots and a “criminal database.” During the
> height of its existence, the Pinkertons had more agents than the
> standing army of the United States of America, causing the state of
> Ohio to outlaw the agency, due to the possibility of its being hired
> out as a “private army” or militia.
>
>
>
[Answer]
I can think of one city on particular that remains walled to some considerable degree to this day, and that is Jerusalem.
Jerusalem has its main, infamous wall for the primary purpose of formalizing a boundary between the Palestinian and Israeli-controlled parts of the city. You could also reimagine the many checkpoints around Jerusalem as walls, which gives you a very strong reason for putting walls both in *and* around your modern city; control. It gives the powers that be very accurate information on who is where within a city, and in the event of urban warfare, it makes control over specific sectors of the city much easier. Perhaps it's more common in divided cities like Jerusalem or Berlin after the second world war, or it's an element of an authoritarian government that uses the walls and checkpoints to maintain an eternally vigilant watch on all of its citizens, for whatever reasons that might be.
As for the material specifications of the Israeli wall in Jerusalem, it is more than just one thing. It is layers of barbed wire fence and tall concrete slabs. At some points it is just a fence, and at others, it is towers of beige concrete topped with barbed wire. I would recommend that, unless the nation in control of this city has access to ridiculous wealth and resources that it is willing to put into this infrastructure project multiple times over for many cities it intends to wall up, that the walls are variable like this. No need to partition the suburbs with 20-foor high towers of imposing concrete; a tall and sturdy fence should do just fine.
Strategically, including walkways on top of the walls gives a very optimal position for soldiers with long-range weapons, and sniper towers could also be added, increasing the strategic benefit.
The major reasons as I understand that we *dont* wall all of our cities is that modern cities are absolutely massive, they're constantly expanding and changing layout, and that walls made of strong modern materials are insanely expensive. If you walled in all of L.A. Proper, you'd have a wall that is 342 *miles* long. It would take about 4 and a half days to walk that if you didn't stop. In this, it just becomes less reasonable to wall a city than it was when they were so much smaller. Now, we have paratroopers and handheld missile launchers and other technologies that just make walls a lot less advantageous than they were in the middle ages.
Ultimately, I do not see walls being a widespread phenomenon in any state that is not 1984's Oceania levels of obsessed with the control and whereabouts of its citizens, but also, I as a fellow worldbuilder urge you to just wall the damn cities if you really want to. It sounds cool, and for me, that's usually enough. Hope this helps! ^^
[Answer]
Prolonged World War 3, lasting decades if not generations, assuming the nuclear warheads don't already wipe us out and somehow all the governments remain intact.
Even in middle ages walls don't typically enclose cities, they enclose keeps. Wealthier lords might build a second wall to enclose the urban class, but most of the population remained outside. This is not unlike gated communities and military compounds of today.
Walls directly impede transportation and commerce. In order for the security offered to outweigh economic benefits of free access the community needs to be under constant threat, and somehow that threat must not be missiles and bombs.
[Answer]
## A Poorly Defined Civil War Zone
There are plenty of reasons to build a wall in a modern context (segregation, immigration control, socio-economics, etc), but when it comes to repelling an attack against large-scale military assaults... they are pretty much useless. So to answer the question, we need to take some liberty in defining what a large-scale military assault means. In a modern or near-future conflict, it includes satellite recon identifying the wall and over-the-horizon weapon systems flattening it well in advance of your actual military operation making it totally useless in a conflict between 1st world powers... however, first world powers protect national borders, not individual cities. In a conflict where individual cities or towns require their own fortification, it is safe to assume that the belligerent forces are mostly interspersed and messy. And may lack the backing of official governments to provide most of them with 1st world weapon systems.
Rather than being a war between well organized militaries, this war is fought largely by small and poorly organized republics, dictatorships, and militias seeking to carve up and/or preserve the remnants of a larger collapsed government. So, if you had something similar to the Yugoslav Civil Wars where a federation breaks up along ethnic boundaries as opposed to geographical ones, you get very poorly defined battle lines where cities, towns, and even individual neighborhoods will find themselves themselves surround by enemies, so they build barricades to block roads, and walls around their neighborhoods knowing that it only takes a handful of racists in the neighborhood next door to march into yours and kill everyone in their sleep.
So, while a wall will not do much to stop a tank or artillery, it can limit the actions of insurrectionists, terrorists, etc. which in the case of a poorly defined civil war zone may actually be your greatest threat.
[Answer]
**Well-connected military contractors plus scare campaign**
Let's have a quick look at what putting a wall around a city will do:
1. Cost the government a ton of money that will be unavailable from funding combatant units and equipment. (Note that only an affluent society will have enough money available for this project at all.)
2. Require a cleared zone either side of the wall to stop placement of ladders, demolition charges etc - rendering otherwise valuable land unusable, again requiring an affluent society that can afford to sacrifice the land and willingness to displace the people currently occupying this land.
3. Massively impede the movement of civilians across the city's "border".
4. Provide zero protection against manned aircraft.
5. Provide zero protection against aerial drones.
6. Provide zero protection against indirect fire artillery - guns, mortars, rockets.
7. Provide zero protection against a person armed with a direct fire weapon (eg rifle) who can occupy a location that looks down across the wall from any outside location within range.
8. Provide a minor inconvenience to ground forces attempting to breach the wall, although modern weapons and demolitions will have little trouble with it.
9. Provide a medium- to long-term cash stream to the corporation winning the contract to construct the wall (this will not be an overnight job).
10. Provide a long-term cash stream to the corporation tasked with maintaining the wall.
In short, a wall will not protect against any enemy of significance but is a cash bonanza to a corporation that can get a contract to build and maintain it. Points 1, 2 and 3 will make it an extremely unpopular project with the populace, especially in light of its obvious limits in providing protection, which in a democracy will require a scare campaign in order to allow the project to go ahead.
Notes:
* Point defence - I can see someone jumping up and saying "But a really good system of point defence will shoot down all the incoming aircraft, drones, artillery shells etc and the wall will stop the infantry and tanks. My preemptive reply is that any point defence gun capable of knocking down a salvo of even 81mm mortar bombs travelling at hundreds of metres per second will have much less trouble with the PBI (Poor Bloody Infantry) travelling at a fraction of that speed, while the tanks will blast through any conceivable wall unless they are actively stopped.
* I am not arguing that walls (and fences) have no use, they are quite useful in site protection against low level threats such as protesters, infiltration, observation, theft, trespass etc. However, it will at most delay slightly military forces that are serious about breaching it.
* Even if we could build a wall that would cause more than a token delay to a military force, building a city-sized fortified dome on Earth or any 1+G world is totally infeasible with current technology.
[Answer]
**Dangerous Animals**
The animals we have now on Earth are largely non-threatening to humans and do not intentionally prey on us for the most part. However, a different setting could have a different species occupy the top of the food chain and actively hunt humans, so that humans need walls around their cities to prevent these animals from getting inside. Imagine carnivorous elephants or dinosaurs or something like that.
[Answer]
In the OP you mentioned that rockets are contemporary warfare, but airborne attacks (from a bomber or missile etc.) still carry warheads or other bombs so walls are kind of useless if you can fly over them. Unless you want to dial the warfare back to preindustrial I don't think walls would be effective for any warfare related reason.
However, walls are useful for other reasons such as traffic control (control people and hence goods entering a city), wildlife control (animals, while are dangerous like humans, don't use modern tools that render siege defense useless), weather control (flooding, etc.), and, depending on the city's architecture, aesthetics.
[Answer]
A city which has been built in the middle of the sea. Walls were built to protect the people from tides. Pumps removed the water so that they could have dry land.
Of course, a 'sea-city' would be expensive, hard to build and probably not worth it. But, you could have an amazing tourist industry
[Answer]
**An *Escape from New York* Scenario**
If you haven't seen this classic movie, the premise is that the people of the USA built a wall around New York to keep the crazies and the criminals *in*. So it *is* a wall for defense, just not for defense of the city, actually the defense of the rest of us. They did something similar with Los Angeles in the sequel. If we did that in the real world, some might say it would be... a good start.
[Answer]
>
> * The purpose of these walls should be city defense.
> * Defense against guerrilla warfare is OK, but I would prefer the walls to also be able to defend against large-scale military assaults.
> * People are still using all the techniques of modern warfare; not just a wall of infantry.
>
>
>
Firstly, it wasn't tagged reality check, but I think you need one.
### Walls are undesirable for modern warfare
Firstly, **walls mean nothing to modern large-scale military assaults.** Consider the Atlantic Wall during WWII. Not a wall per se, but a network of costal defences designed to keep any invading force at bay. It was circumvented in the Battle of Normandy in part by using the third dimension.
A siege with modern weapons means artillery shells, bombs dropped by planes, missiles fired from cruisers or drones, or intercontinental missiles with any payload you want. You can look at Israel, with an (alleged) state-of-the-art missile defence system, and rockets still find their way into something. I wouldn't want to stand under that Iron Dome against an enemy with more budget and more high-tech weaponry.
And you start getting into why walls are undesirable. **Walls mean siege, and obliteration over surrender.** It's the exact opposite of the [open city](https://en.wikipedia.org/wiki/Open_city) doctrine. Nobody likes to surrender, but consider the fate of [Paris in 1940](https://en.wikipedia.org/wiki/Paris_in_World_War_II#Axis_occupation) with that of [Berlin in 1945](https://en.wikipedia.org/wiki/Battle_of_Berlin#Aftermath). French authorities didn't defend Paris. They let the invading force in without a fight. Nazis later clinged on Berlin at significant cost. And the cost here isn't just property damage and lives, it's also historical buildings, museums, and other things you can't just replace. Popular opinion is certainly going to be divided on whether it's worth the cost, but there will be a point where the cost becomes too great.
In that kind of scenario, to defend a city you need more than static defences, simply because what you might consider modern siege weapons can be placed way beyond reach of the defender. Japan in 1945 is a great example of that. Down to ships that couldn't move and planes that couldn't take off, they were unable to stop the onslaught of bombers coming at them. The US never intended to invade. They could have kept bombing the country forever, and there's nothing Japan could have done about it, because the airbases were out of reach, and the air defences were annihilated in the course of the war. The use of that brand new weapon changed nothing. Japan had already lost at least six months prior.
That's the fate of a city with walls in a modern warfare scenario. Either you have an army left outside of your walls to try and take the threat out, or you surrender (unless of course you prefer obliteration).
---
So, that's one thing walls are definitely not going to be used for.
### Wall, what is it good for?
If modern city walls are going to defend against one thing, it will be natural disasters. Floods most likely. In fact, [here's a modern wall](https://en.wikipedia.org/wiki/Thames_Barrier). It's a cheaper solution than moving an entire city. But it's a stop-gap fix, not a solution. Maybe a downfall of civilisation scenario where the few cities left standing have to fend off against chupacabras, walls could be useful there.
If you're thinking Berlin Wall and Iron Wall, that really didn't do much to prevent the fall of the USSR and East Germany. I think it might even have been counterproductive. These walls were more symbolic than protective. What prevented an invasion was the accumulation of forces behind the walls, and/or the sheer politics of it. These walls weren't impenetrable by far.
It will be marginally useful against intrusions from private citizens, which is why we bother putting walls around important buildings. So [closed cities](https://en.wikipedia.org/wiki/Closed_city), or some kind of modern [Forbidden City](https://en.wikipedia.org/wiki/Forbidden_City), or a [Green Zone](https://en.wikipedia.org/wiki/Green_Zone). But against any moderately organised force, and as many acts of terrorism have highlighted, no amount of physical security is undefeatable. And if it is, you stab someone standing outside of the wall.
And if it's to keep migrants out, there are many use cases to how effective it is or isn't at the scale of a country. At the scale of the city, considering you need to interact with the outside world (where there's farms and factories, i.e. where your goods and services come from), it's going to be a lot less effective.
[Answer]
I'm not certain about the conditions which might make building walls around cities necessary or desirable, but I can say that with modern conditions of relative wealth and ease of construction compared to premodern societies building walls around cities would be comparatively easy.
I'm not certain that modern people would be okay with gates where every road crosses the wall and the resulting delays in traffic if each vehicle has to stop at the gate for a check. Of course many old time cities left the gates open all day and let anyone go in or out during the day, and only closed the gates at night. That would be far more convient for modern people than stopping every vehicle for some sort of check as in an international border checking point.
European cities and towns and many villages usually had walls. If a city expanded or contracted its area, new walls were often built encloser larger or smaller areas.
In the USA and many other modern countries, cities have large suburbs which constantly increase and sprad out. City walls which included surburban areas would have to constantly be be expanded.
But if a sity is built with many buildings which are say, a hundred stories tall and a mile wide each, with people living on each floor of each building, or if cities are built with only skyscaper apartment buildings and no vast suburbs of single family homes, the inhabited areas of cities could be much smaller than the sprawling automobile based cities and it would be much more practical to build walls around such cities.
But anyway, building walls around cities would be practical if desired. Premodern Chinese cities were filled with houndreds and thousands of residential compounds, each with a wall around it. And sometimes each neighborhood in a large Chinese city had a wall around it. And the entire Chinse city usually had a wall around it.
And of course the country of China often had a wall around a large part of its permimeter. The Great Wall(s) of China blocked the northern border. I don't know how many thousands of kilometers or miles the Great Wall stretched at any one time, because entirely new great walls were built from time to timeby different governments when the border was in different locations.
So I don't now whether statements about the total length of the Great Wall include the total lengths of walls built and maintained at different times over two thousand years, or only the total length of, for example, the Ming Dynasty walls.
Anyway, ancient and medieval and early modern China had countles thousands of walled household compounds in the country and in cities, and coultless walls within and around cities, and often the most recent version ofthe Great Wall. It was a country with countless thousands of kilometers or miles of walls in total.
If all the other walls in China disappeared, or were never built in the first place, and the only walls that were built and maintained were the big walls around the hundreds of Chinese cities, building and maintaining those walls would have been a lot less work than building and maintaining all the walls which actually did exist in China.
Benin is the name of a country in west Africa. Benin city is in the neighboring country of Nigeria, just to confuse people. And one thing which Benin City is famous for is the Walls of Benin.
>
> The Walls of Benin are a series of earthworks made up of banks and ditches, called Iya in the Edo language, in the area around present-day Benin City, the capital of present-day Edo, Nigeria. They consist of 15 km (9.3 mi) of city iya and an estimated 16,000 kilometres (9,900 miles) of rural iya in the area around Benin.[1](https://en.wikipedia.org/wiki/Walls_of_Benin) The 'walls' of Benin City and surrounding areas were described as "the world's largest earthworks carried out prior to the mechanical era" by the Guinness book of Records.[2](https://en.wikipedia.org/wiki/Ha-ha) Some estimates suggest that the walls of Benin may have been constructed between the thirteenth and mid-fifteenth century CE3 and others suggest that the walls of Benin (in the Esan region) may have been constructed during the first millennium CE.[3](https://en.wikipedia.org/wiki/Rabbit-proof_fence)
>
>
> The walls were built of a ditch and dike structure; the ditch dug to form an inner moat with the excavated earth used to form the exterior rampart.
>
>
>
<https://en.wikipedia.org/wiki/Walls_of_Benin>
So if the rural walls outside of Benin city total 16,000 kilometers or 9,900 miles, and were a single wall, they could make a square 4,000 kilometers by 4,000 kilometers, or 2,475 miles by 2,475 miles. But no doubt they are a group of many hundreds or thousands of much smaller enclosures, many of them probably connected.
I note that in Europe many "dykes" were built, which were defensive or boundry earthworks with earthern ditches and walls, similar to the Niegerian *lya*, except that the ditch was usually on th eouter side and the earthen wall on the inner side.
I note that Schleswig-Holstein in Germany has a defensive dyke called the Danevirke built over many centuries to defend Denmark from invasion from the south. The Danevirke was last used from military purposes during the Second Schlesvig-Holstein War in 1864.
Thus I suspect that European type dykes or Nigerian style *lya* could still be used for some military or police purposes in the 21st century.
I also note that walls and fences have often been used to keep wild animals or livestock inside or outside specified areas.
One form of livestock containing wall is a ha ha.
>
> A ha-ha (French: hâ-hâ or saut de loup) is a recessed landscape design element that creates a vertical barrier (particularly on one side) while preserving an uninterrupted view of the landscape beyond from the other side.
>
>
> The design can include a turfed incline that slopes downward to a sharply vertical face (typically a masonry retaining wall). Ha-has are used in landscape design to prevent access to a garden by, for example, grazing livestock, without obstructing views. In security design, the element is used to deter vehicular access to a site while minimizing visual obstruction.
>
>
>
<https://en.wikipedia.org/wiki/Ha-ha>
In many parts of Africa and South Asia, some farms and vilages have various forms of anti elephant ditches, walls, or fences to keep elephant herds from raiding the crops.
Australia is famous for rabbit proof fences.
>
> The State Barrier Fence of Western Australia,[1](https://en.wikipedia.org/wiki/Walls_of_Benin) formerly known as the Rabbit Proof Fence, the State Vermin Fence, and the Emu Fence, is a pest-exclusion fence constructed between 1901 and 1907 to keep rabbits and other agricultural pests, from the east, out of Western Australian pastoral areas.[2](https://en.wikipedia.org/wiki/Ha-ha)
>
>
> There are three fences in Western Australia: the original No. 1 Fence crosses the state from north to south, No. 2 Fence is smaller and further west, and No. 3 Fence is smaller still and runs east–west. The fences took six years to build. When completed in 1907, the rabbit-proof fence (including all three fences) stretched 2,023 miles (3,256 km). The cost to build each kilometre of fence at the time was about $250 (equivalent to $18,906 in 2018).3
>
>
> When it was completed in 1907, the 1,139-mile (1,833 km) No. 1 Fence was the longest unbroken fence in the world.[4](https://en.wikipedia.org/wiki/Rabbit-proof_fence)
>
>
>
<https://en.wikipedia.org/wiki/Rabbit-proof_fence>
>
> The Darling Downs–Moreton Rabbit Board fence is a pest-exclusion fence constructed between 1893 and 1997 to keep rabbits out of farming areas in Queensland, Australia. It is managed by the Darling Downs–Moreton Rabbit Board[1](https://en.wikipedia.org/wiki/Walls_of_Benin) and is often referred to as "The Rabbit Fence" or "Rabbit Board Fence".[2][failed verification]
>
>
> As of 2021 the fence has been expanded to 555km of rabbit-proof fence running from Mt Gipps to Goombi.[1](https://en.wikipedia.org/wiki/Walls_of_Benin)
>
>
>
<https://en.wikipedia.org/wiki/Darling_Downs%E2%80%93Moreton_Rabbit_Board_fence>
>
> The Dingo Fence or Dog Fence is a pest-exclusion fence that was built in Australia during the 1880s and finished in 1885, to keep dingoes out of the relatively fertile south-east part of the continent (where they had largely been exterminated) and protect the sheep flocks of southern Queensland. It is one of the longest structures in the world. It stretches 5,614 kilometres (3,488 mi)[1](https://en.wikipedia.org/wiki/Walls_of_Benin) from Jimbour on the Darling Downs near Dalby through thousands of kilometres of arid land ending west of Eyre peninsula on cliffs of the Nullarbor Plain[2](https://en.wikipedia.org/wiki/Ha-ha) above the Great Australian Bight3 near Nundroo.[4](https://en.wikipedia.org/wiki/Rabbit-proof_fence)
>
>
>
<https://en.wikipedia.org/wiki/Dingo_Fence>
There are also barriers built for enforcing laws.
>
> The Inland Customs Line, incorporating the Great Hedge of India (or Indian Salt Hedge[1](https://en.wikipedia.org/wiki/Walls_of_Benin)), was a customs barrier built by the British colonial rulers of India to prevent smuggling of salt from coastal regions in order to avoid the substantial salt tax.
>
>
> The line was gradually expanded as more territory was brought under British control until it covered more than 2,500 miles (4,000 km), often running alongside rivers and other natural barriers. It ran from the Punjab in the northwest to the princely state of Orissa, near the Bay of Bengal, in the southeast. The line was initially made of dead, thorny material such as the Indian plum but eventually evolved into a living hedge that grew up to 12 feet (3.7 m) high and was compared to the Great Wall of China. The Inland Customs Department employed customs officers, jemadars and men to patrol the line and apprehend smugglers, reaching a peak of more than 14,000 staff in 1872.
>
>
> The line and hedge were abandoned in 1879 when the British seized control of the Sambhar Salt Lake in Rajasthan and applied tax at the point of manufacture.
>
>
>
<https://en.wikipedia.org/wiki/Inland_Customs_Line>
So I can imagine that even in modern times some sort of ditches, or dykes, or walls, or fences could be built around cities to keep people or animals in or out.
Such defenses would not be very good a stopping or slowing down invasions by major military forces, but could have some degree of police or military function.
[Answer]
# *COVID-32: This time it's 95% lethal.*
Nuff said, really. If you'd like more, [Fortress WA](https://en.wikipedia.org/wiki/COVID-19_pandemic_in_Western_Australia) may still be holding out somewhat against Omicron, and China may keep it out, but if you absolutely positively don't want to all die of a deadly disease, walls at the city level might be your better option.
[Answer]
It's not really about the walls, it's about the ***gates***.
The only way to get through your wall into the city is via the handful of carefully planned and well-defended gates. These serve as natural choke points that make it easier to defend against a ground assault. It also makes it far more difficult for spies, smugglers, or enemy sympathizers to sneak into your city.
You can even build the gates such that they allow foot traffic but not vehicle traffic (hedgehogs, bollards, or similar). You said that militaries no longer use walls of infantry, so a ground assault would make heavy use of wheeled vehicles, tanks, etc. None of these can get through your gates, so an attacker would have to try to punch a vehicle-sized hole in your wall (giving you plenty of time to counterattack from the high ground) or leave the safety of their armored vehicles and charge through the gates on foot (which you could defend against using a much smaller force).
This is similar to why modern military bases or prisons have reinforced fencing, sometimes in multiple layers. In a lot of cases it's just a chain-link fence with delusions of grandeur. An attacker could destroy it if they wanted to. However, they serve as a speed bump that requires that attacker to place themselves in a vulnerable, easily-detectable position for an extended period of time. A relatively small patrol force inside the base can defeat the attackers (or at least call for reinforcements) before the attacker has time to clear the obstacle. Surprise attacks become difficult and costly, requiring you to smash through a gate and land yourself in the middle of a kill zone.
In ancient times, walls were near-impervious obstacles. That's not practical thanks to modern weapons, but walls are still useful as a means to stall an oncoming blitz, force the attacker to waste resources, give the defender time to organize, and give some degree of control over where the fight happens.
[Answer]
Not On Earth
Your city is a habitat on a planet that dont have a naturally survivable atmosphere, so a barrier of either metal, glass, or even some kind of energy shield (you didn't specify which part of 21st century, we still got 80 year ahead of us) is necessary to contain oxygen and shield cosmos radiation. In this case, you can even have some kind of scene that resembles the old seige warfare--day long stalemate, promise of no looting to threats of massacre, cutting off supplies, the final breakthrough lead by the forlorn hopes, and then the looting in a completely dead city--because the oxygens are gone, everyone inside and exposed--not in shelter--is dead, and atrocity to those survived in the shelters.
[Answer]
There is an big wall around an entire country in our current world 2022. It is a MASSIVE wall, but it's invisible. It's sole purpose is to keep citizens in and attackers out. It is not a wall in the classical sense, but it essentially **functions** as a wall and that **makes** it a wall.
Of course I'm speaking of the great chinese wall. The digital one, the great firewall ( since you said you don't neccesarly mean stone walls)
[Answer]
**Protection for citizens who might wander into defensive zones.**
Robotic drones attack anything that moves in certain geographic areas. The drones limit their attacks using a GPS equivalent, but any hapless citizen who wanders into a "free attack" territory meets a bad end.
Inhabited areas surround themselves with walls not to keep anything *out*, but to make sure no citizens accidentally take a wrong turn and leave a safe zone.
[Answer]
Insurgents using snipers.
<https://en.wikipedia.org/wiki/Sniper_Alley>
The wall doesn't even need to be bulletproof, so long as the snipers can't see their targets they can't shoot.
[Answer]
**defense**
If the wall is particularly thick, it could be used as a platform for placing defensive weapons onto for a better line of sight against incoming missiles, bombs, aircraft, and whatever other threats that a wall *doesn't* counter. Put a large amount of CIWS guns along the wall and you could have decent protection against air targets. You could also mount large fortress guns for attacking ground targets at exceptional ranges, kind of like the German flak towers used in WW2 (though those were meant mostly for attacking enemy aircraft flying overhead anyway) They could also have an internal area for housing soldiers and equipment, as well as housing civilians temporarily in case of a bombing raid or something, though you would have to be careful with ammunition. One guy not reading the "no smoking" sign right outside the ammo stockpile room and now you're missing a chunk of your big wall.
Another thing, if were talking about near future tech, Laser anti munition system or LAMS. A wall is pretty big, perfect for having a place to charge up a giant laser ready to melt incoming projectiles.
**morale reasons**
A giant wall would raise people's spirits hiding behind the wall and lower their spirits outside of it. To the people living in the city, it would be "we are safe, we are protected from the enemy by this giant wall" and to the enemy its "man we have to assault this huge wall covered in guns and swarming with soldiers" Morale is important in siege warfare, even though there aren't really sieges anymore.
**conclusion**
for a wall to not only be viable but also for it to make any sense it would have to be VERY well defended from both air and ground targets and have to be VERY sturdy. it would only exist for siege warfare like when cannons were becoming tools that could crack castles wide open. Essentially, "we know that given enough time and enough pressure, we will lose this siege if we don't have any reinforcements, but how long is the enemy willing to sit here and how much are they willing to give up taking this city?"
] |
[Question]
[
In my world one of the branches of magic is Sight; foresight, farsight and hindsight.
Foresight is basically the gift of prophecy. It's limited in that the world doesn't exist in a fixed timeline, so you can only see possible or probable futures. A very powerful Seer is dangerous and can see well enough to guide events, but someone of that power is rare.
Farsight does what it says on the tin; it lets you see things happening far away (technically anything happening at the present). It's useful only if you know where to look to see something important or relevant.
But Hindsight is where I'm having trouble. It's the ability to see visions of the past; true visions of events that actually happened. My issue is finding a way to limit this power. Unlimited it would basically mean committing a crime is practically impossible as any trained Seer would be able to see exactly what happened.
The only obvious limit I can see is time - The farther back you need to see the more power and skill is required. This provides a useful limit, but still means if your Seer Police arrive on the scene pretty quickly then you're scuppered.
The only other obvious counter is to use magic to obscure the Seer's power, which requires all crimes to be committed by or aided by a mage of some sort, which isn't helpful.
**So in a medieval(ish) setting would crime still be possible if such a power existed?
What limits could I put on it, or what loopholes am I missing?**
Obviously smaller communities wouldn't have trained Seers unhand, but presumably any lord time figure would make it his (or her) business to obtain the services of a Seer (which aren't going to be too uncommon) to aid in the execution of justice.
[Answer]
Of course. Crime isn't going away. We've got considerable forensics abilities today, and we've still got crime. It's possible to track down people with a single dropped hair, touched object, or drop of blood/sweat. Doesn't stop people.
There's a number of practical concerns that will prevent Seers from instantly solving all crimes.
Let's run through a situation; A crime happened, you´re on the scene using Hindsight. You see the criminal. Great. Do you actually *know* them? Even if they were dumb enough not to wear face-covering, seeing a face doesn't instantly tell you who they are. If you don't recognize the criminal, you're stuck asking people if they know them, and unless you can take a picture of your Hindsight that's going to require descriptions, which are highly unreliable.
And then even if you know who did it; that doesn't mean the crime is solved. You still need to *find* that person. They might have moved to another village. They might be hiding with friends or relatives until you stop searching. Your vision abilities won't help that much in locating people.
Of course, this all assumes that there's an actual crime scene to investigate. What if someone is kidnapped? Unless you happen to know *where* the kidnapping took place, you have no starting point.
And then there is the last point; what if the person committing the crime can't just be brought before the judges? Even if you know who did it, and where they are, if they are the judge's son you'll have a hard time convincing the judge that a hanging is required.
And this doesn't even touch on people who don't *care* about being caught. Crimes of passion are commonplace.
Plenty of problems remain, so crime won't go away. It will change, most likely, but it will still be there.
[Answer]
Yes, you'll still have crime.
There's a very simple reason for this: **those mages with Hindsight are going to be finite in number, and thus their time is also finite**. Just look at the real world: there's only so many police officers available to investigate crimes. Magicians with this kind of power aren't going to be wasted on something as mundane as petty theft; rulers/the wealthy/etc. are going to hoard those powers for their own use, and they can offer a lot more in wages than anything the local police force might be able to pay. You might get a few mages for crime investigation in the largest cities if you're lucky, but they can't be everywhere at once. Something like murder would probably warrant such a magician's time, but **they will not have the time to check out every crime**.
You've also got the problem of evidence. Medieval courts probably don't have the same standards as modern courts, but they're likely going to require something more than a single person's word that Random Joe X was guilty of committing Bad Crime Y. If they're good about concealing evidence, the most you can get is suspicions without proof. In the absence of other factors (bribery, a witch hunt), that's not going to cut it.
[Answer]
If these seers are being employed by Lords, then a good lawyer could point to some conflict of interest.
Since the judge or even the police can't see what the Seer is seeing, all that they have to go on is his word. A good lawyer could try and throw some doubt on the Seer's reputation so their word won't be accepted by the judge.
[Answer]
Make it unreliable.
Don't have hindsight work like watching a video recording. Make it more like trying to recall a faint memory. Just that it isn't even your memory, but a memory of the big cosmos itself. Do you still remember exactly what you did the day a week ago? Maybe you remember some details and key events. But do you remember *everything* that happened that day? Would you recognize every person you saw on the train that day? Remember the license plate of every car you passed? And about those things you do remember, are you sure you remember them *correctly*? The memory of the cosmos might be equally patchy.
That means a hindseer might be able to pick up impressions and emotions, but they might be hard to put together. Chronology of events might get mixed up. Some details might be exceptionally clear, others very vague, completely missing or even wrong. This might give the seer a completely misleading picture of what actually happened. Experienced hindseers might be able to get more information and might be better at estimating the reliability of it. But even the best of them happen to be wrong on occasion. Just like the best foreseers tend to get proven wrong.
Another option would be to make the past just as uncertain as the future. When you look at a crime scene and try to see its past, you don't just see the timeline which actually lead to the present, but also any other hypothetical timelines which could have lead to the scene looking like this. So you might see multiple versions of how the crime happened. Now its up to you to eliminate them one after another by finding facts which contradict them.
That means a hindseer's analysis of a crime might be a hint for what to investigate, but not strong enough evidence to actually convict someone.
[Answer]
Absolutely crime would still exist, as ably covered in [Erik's answer](https://worldbuilding.stackexchange.com/a/85028/16689).
But there's another aspect that no one has touched upon: How about organized crime? What about corruption?
These would certainly exist, too. In fact, how exactly do you KNOW that someone is a Seer? Is there some sort of official examining board? A priesthood?
Given the medieval-ish setting, no photographs, no high-tech equipment, it seems that hind-Seers would be far more than police; they would be judges or at least "expert witnesses." Their mere affirmation that "you're guilty; they saw you do it in Hindsight" would be enough to get you imprisoned at once or executed for murder. (Sort of like the Inquisition or a Witcher or a psychiatric evaluation of insanity.)
So the justice system would rest utterly upon the honesty (and accuracy) of the hindseers. Which opens up a whole new range of plots, such as one wherein a corrupt clique of hindseers is out to "get" someone and he has to dig an old trusted hindseer out of retirement and out of hiding to clear his name and find the true perpetrator...or something. What about someone who uses various chicaneries to fraudulently pass the hindseer examining board, with no slightest hint of Talent? Lots of possibilities.
**People with special perceptions and abilities are still people.**
[Answer]
For starters, the answer to the question as put is that yes, there will be crime. As many others have already said, there will always be crimes of passion because, well, in those cases, you aren't thinking about the consequences of your actions. That being said, there's a really strong temporary insanity defense in this case: "Your Honor, of course I was temporarily insane when I killed my wife! I'd have to be! If I weren't, I'd know that I'd get caught!" (though that's only relevant if there's a court system which cares about such distinctions).
Now, as to premeditated crime, there are a few variables which are currently left open which influence the possible answers. Most significant are the number of hindsight seers and the difficulty curve in looking further into the past. The number of seers is needed in a per-capita or per-crime basis. In your question, you state that it is harder to look further into the past, but it is unclear how the difficulty ramps up: can the average seer see one minute, one hour, one day, one week or one month into the past?
Looking at these two variables, we have four possible scenarios:
* Many Seers / Average can look > 1 day, week, month into the past
* Few Seers / Average can look > 1 day, week, month into the past
* Many Seers / Average can look < 1 hour into the past
* Few Seers / Average can look < 1 hour into the past
Obviously, the hindsight times given above are merely representative: seers can look reasonably far into the past, or not really.
Let's go through these scenarios briefly:
## Many Seers / Average can look > 1 day, week, month into the past
In this case, there probably won't be much premeditated crime.
The reason for this is that if the seers can look that far back into the past, then I disagree with the vast majority of problems raised by other answers. Seers don't need to identify the perpetrator (whether or not they are wearing a mask), since they can just follow the perpetrator back in time to their home or forwards in time to their current position (if hindsight is fixed to the seer's current position, the seer can just go "ok, the perpetrator went around that corner", walk to the corner, activate hindsight once again, and repeat the process until they're at the criminal's doorstep). Kidnappings are also not an issue: start at the victim's last known location and trace their steps to the kidnapping and all the way to their present location.
The only such crimes would be committed either by untouchables (judge's son, as others have mentioned) or people who have really dedicated themselves to pull it off: moved out of their house into a hotel with a fake name and lived there for 2 days/weeks/months in order to avoid being identified by seers hindsight-walking to their homes, committed the crime, and then made a hasty getaway out of the country, where the seers can't follow them to their current location. Sometime later, they can come back home.
There is another possibility when dealing with not-so-long-ago hindsight (a day, for example): poison. If the criminal has access to slow-acting poison, they can use it without fear of the seers, since the seers won't be able to see who poisoned the victim.
## Few Seers / Average can look > 1 day, week, month into the past
In this case, the seers will be stretched thin and won't be able to investigate every crime. They will probably be put in a taskforce of sorts, focusing on high profile or otherwise important crimes. Therefore, lower level crime will still exist for the most part, while high profile crimes will probably be very few and far between, or have to be aided with magic to shield the perpetrators from hindsight.
The exceptions are mostly the same as in the previous section. Indeed, in this case, poison becomes especially handy: you can use a relatively short-acting poison so long as its symptoms can be confused with accidental or natural deaths (causes a heart attack, for instance). With few hindsight seers, the police will have a good chance of simply assuming it was a natural/accidental death and move on. Meanwhile, if there were many seers, the police might have seers do a cursory look into the victim's past just to check for such foul-play.
## Many Seers / Average can look < 1 hour into the past
There probably won't be much petty crime, especially in areas near police stations. However, high profile crime probably won't be much affected, since these tend to be at least a bit thought through. If all you need to do is get an hour's head start on the police, anyone with even a modicum of discipline can probably do it. Kidnappings will probably not be affected either, since you probably can't follow the victim's footsteps in time.
## Few Seers / Average can look < 1 hour into the past
In this case, the seers probably won't have much of an impact. They won't be able to stop serious crime and there aren't enough of them to make a dent on petty crime either.
[Answer]
Some problems which are not solved with Hindsight:
**No light/bad lighting**
Simply let the crime happen during dark night or very
bad viewing conditions. Your seer knows that a crime
is going on (you hear shuffling, muted screams whatever),
but he cannot see in the dark. The attacker don't even
need a mask. If hindsight only allows viewing, the seer
is completely screwed.
This can be also achieved by very bright light sources,
blinding viewers or using fog/smoke.
**Poisons/death traps**
The victim was poisoned or killed by a death trap.
You know that X persons could have built the trap
or poured the poison, you are by no means smarter
when your seer sees how the victim died.
To prevent that the seer simply follows each suspect
in hindsight until he administered the poison, only
allow that dead persons can be followed or tracked
in hindsight.
**Perpetrator is unidentifiable**.
Like all criminals now know to use gloves to prevent
fingerprint, all your criminals wear masks hiding
their face completely and wearing voluminous garments
to hide their body form.
**Seers abusing their powers/Evidence unreliable**
Like all witnesses: Who says seers cannot be the bad
guys, inventing wrong evidence or being coerced to
accuse innocents? Another problem is the possible
existence of wrong visions which cannot be discerned
from the true ones.
One argument against using psychic powers during investigations (in our
timeframe) is that even if they would exist,
all evidence is pointing in the direction that they
are highly unreliable.
**Seers can only see the hindsight from the view of the
victim**.
It does not help if the victim is strangled from behind,
knocked out or killed immediately before seeing the perpetrator.
[Answer]
First, you are detracting from farsight by letting foreseers and hindseers see things that happened or will happen elsewhere. It should take both hind and far seeing to allow some one to solve a crime without being on the scene. Foreseeing, to be reliable when used from far away, should require the same.
Now, to solve a crime just seeing might not be enough. It someone steal your wallet without you noticing in the middle of a crowd, can the mage find an angle to see who's hand at some point got inside you pocket?
Allowing hindsight to take any angle and any position might be over powered, so you could rule that the 'body' of the seer can't go inside people or rocks...
[Answer]
I suggest this, hindsight is not as simple as rolling back a film. What is happening is a magical reconstruction of information based on present information. The more complex that information, the more difficult.
An example, if you drop a vase each piece follows its own path through the air to its final resting point. Hindsight will let you watch those pieces tumble backward and reassemble into the intact form. You can now view the original in its unbroken state. Pretty simple. If you wait a week, it is more difficult simply because more information has been accumulated around each piece, and all of that must also be unraveled in the rewind. Now, add a second vase that was dropped at the same time as the first. This is more difficult to track, if you need to see both at once. There is twice the amount of important information. Add ten vases. Now its a true challenge for most mages to see each of these vases recreated.
Add one more complication: time must be viewed in reverse from the present. A mage cannot just jump an arbitrary distance back and start there. If they do not know what details to focus on, they risk not being able to hold the stream at all, there must be an initial physical thing that is the point of concentration. This means one can't just "watch" a road and see all the travelers that pass for the last hour. You may watch a pebble on that road, and see it disturbed. Then shift the focus to whomever or whatever disturbed it. You may follow that person (or wagon, or horse) backward and see where it came from, carefully checking each interaction it makes. However, if you picked the wrong pebble you may never "see" the man you were looking for, as he passed on the other side of the road and never met the one that stepped on the pebble you were watching.
This means catching a petty pickpocket is easy. You focus on the location of the victim, then his purse, then the thief as he touches it. Now you can follow the thief back to where he came from, or to where he went (moving time forward toward the present).
The result of taking it this way is two things (at least).
1. Time and complexity make it harder to see important details.
2. A mage must choose which details to focus on, and can, therefore, be misled by intentionally planted misinformation or complexity.
One way this can be exploited is that a criminal could simply put on a mask and obfuscating attire. Then, enter a crowded area and get themselves lost in the shuffle. After spending time in such chaos, say an hour or so, they then go to the area to commit the planned crime. The mage might be able to follow them backward from the actual event, but they must then expend huge amounts of power to track them within the information flood of the crowds. If the mage isn't up to it, then they won't be able to follow all the way back to when the criminal was showing their true face.
[Answer]
>
> In my world one of the branches of magic is Sight; foresight, farsight
> and hindsight.
>
>
>
The challenges of hindsight should not any different than of foresight. While the timeline is fixed, there is significantly more information to parse, and requires intensive focus and energy to filter out the important from the mundane. Hindsight would not be like watching a movie or a video, but comes in patches (fragments of compressed and extended time) and requires the intelligence of the seer to identify what they are seeing. Imagine that time is like glass that is more substantial the closer it is to the present, but disintegrates as time goes by, with spikes surrounding strong emotional/spiritual periods (such as a murder, but not a theft by someone in control of their emotions).
Also figure out the magic ability that would block sight. While Lords are hiring Seers, criminals are hiring the "smokers" to obscure things from the magic sight (even to the point of kidnapping and human trafficking). There might be a separate magic type to obscure distance ("farsmoker") and require a "timesmoker" to obscure hindsight and/or foresight. Naturally the practice of "smoking" would be outlawed. (Personally there should be just as many smokers as there are seers to balance the magic... children of seers could be smokers or vice versa).
One possibility is that a Foreseer committing a crime could probably obscure their actions from a Hindseer (countering the future actions). On the other hand, it would be possible for a Hindseer to influence the timeline so that it is also obscured to other Hindseers by the very act of viewing the past. So in a way, the Foresight and Hindsight Seers are their own "time smokers" because a scene can usually only read a few times before static and other corruptive influences start to degrade the vision (fragments shatter). Basically all that is required to corrupt the scene is a Foreseer (before the crime) or Hindseer (after the crime) to read the scene one or more times. Obviously, the strength and power of the seer can affect the outcome with a weaker seer corrupting the scene and a strong user still able to pluck what they need. But it would be obvious to any Hindseer that the timeline was corrupted. (NOTE: it would be the time+space with a limited sphere of influence that would be corrupted/static, and no obliteration of everything that happened in the past in that space.)
BTW, it might be also interesting to have the polar of farsight... tinysight/microsight, which may also have a different method of solving crimes.
While your original question was how to make the Hindsight less powerful so that crime was not wiped out, the premise of a crime novel based on this magic would be very interesting.
[Answer]
Can your seers with hindsight interact with the past at all? Because if they can't, then your seers would have all the problems of modern-day video surveillance (as per @Alexander's comment). Surveillance is great for being able to see *how* a crime took place, but it does nothing to help you identify the perpetrator unless the seer himself recognizes the person's face (or he can project his hindsight for others to see).
Even if the seer had perfect vision of the past (unlike modern video surveillance), what if the perpetrator wore a mask? Presumably criminals know that seers would be able to identify them in the future, so they would take steps to disguise themselves.
And even if your seers could identify the perpetrators, it still doesn't tell you where they are now. Seers with farsight would need to know *where* to look to find them, so without any idea where they went after the crime was committed, they would still remain at large.
Really, the outlook for crime in your world of magic seers wouldn't look all that much different than ours, with only the logistics of crime being different (along with the standards of evidence in its courts). Most criminals get caught because of stupid mistakes, not because police are so smart. Seers being the police in your world wouldn't change that very much.
[Answer]
Use the power of
# Fake news
The hindsight works best the sooner you are to the event, right? So as a criminal, *if* the crime is detected on time, and *if* they know where it happened, and *if* they could physically find you and *if* they managed to persecute you soon enough and all the other *ifs*, you might still be able to walk if you only stall them for long enough for the evidence about you to weaken.
How do you do that?
1. Find someone with hindsight and a sketchy character
2. Give them money
3. Have them falsely confirm your alibi and blame the crime on someone else + discredit whoever is condemning you (including if it's the judge his/her self!)
4. Maybe throw in some conspiracy theories for the hell of it
5. Stall the trial, say "we just can't know for sure what happened! So many alternative facts!"
6. Walk away happy as a clam
Fake knows doesn't hold forever, but since time is of the essence it could help. It also won't work in high profile cases where a team of well trusted hindsighters could verify exactly what happened, but it should at least give any culprit some hope of getting away with stuff given a good lawyer.
[Answer]
So the first part of solving a crime is figuring out a crime happened in the first place. Take a look at Wikipedia's list of serial criminals. It's typically broken down into how many known victims and how many possible victims were a result of that individual. The known victims are the ones the law has tried and convicted them of. The unknown victims are a result of any number of things. Typically, the killer confessing to more victims but can't or won't recall the specific details about who they are or where they are. But it could also be they only found the bodies or enough evidence to link the killer to only a handful of deaths. Sometimes, the killer never confesses and the likely victim just happened to go missing under similar circumstances during the time the victim was active but no evidence came to light about who the guy was. For similar reasons, when a person is accused of a crime that shows steps were taken to put the accused under the radar (pedophilia jumps to light, but so do scams), the police will normally send out a press release that includes potential avenues the accused could get to victims in the hopes that other potential victims can be made aware OR those close to the guy and thought of something said as suspicious can come forward.
Alternatively, crimes like espionage can go undetected for years because if your not caught the first time, it means your system was successfully not picked up. A good number of spies are only uncovered because the country that receives the information tips their hands by acting on that information. The most dangerous are those motivated by their ideology (they spy because they believe in the cause). The greatest unsung hero of D-Day was a Spanish name code named Garbo by the British, who was hired by the Germans to spy on the allies. The only problem was that from the get go, he was very much opposed to the Nazis. As soon as they hired him, he went to Britain and went straight to SIS and turned himself in. He then created an entirely fictional spy ring (called the XX ring, for the 20 fictional characters in the ring, all of whom he personally created with such attention to details, that they all had unique handwriting) and successfully convinced Hitler that D-Day was a feint attack to draw defenses from the landing sight of a second invasion force. He was never discovered and in the immediate aftermath of the war went to Spain to meet his German handler, who paid him for his work and presented him with the FREAKIN' IRON CROSS for his service to Germany during the war. He is only person to received the highest Award Declaration from both an Allied and Axis power for his service for War War II. Germany never once had any reason to doubt him, so it would have no reason to even begin to look for evidence of a crime.
[Answer]
Sights are just a flicker without date, explanation or sequence, which is either in the past or future, which can change due to certain trivial unrelated events, unless it is a major immutable node.
People who have never experienced it think it is like a Hollywood film that can be watched for as long as you want. In fact it is mostly an unsolicited flash and what you want to see cannot be accessed.
[Answer]
Of course there would still be crime!
For a very simple reason: many people do not really think of the consequences of their actions.
Think of teenagers shoplifting or vandalizing for fun/rebellion, of someone who's drunk or high committing some crime, of some violent person who will rape or kill anyway (even in our world, any victim of rape would easily be able to recognize the person, yet rapes happen).
And some more intelligent criminals, instead, would try to fool the system, they'd try to make crimes planning them so that they cannot be easily traced down.
Don't worry, you don't risk having a crime-free world.
] |
[Question]
[
So, I time travelled back to the year 1969. I messed around back in time for about a week before leaving. But, me being forgetful and everything, I leave behind my modern laptop ( it’s an Apple MacBook). After being found, it makes it way to the US gov’t, who quickly see its huge value. My question is, could they feasibly recreate it?
[Answer]
Not any time soon. In the 1960s, MOS transistors were in their infancy, with a typical size of 10 micrometers. Modern transistors are more in the 10 *nano*meter range, 1000 times smaller. Even if they had all of the schematics and specifications (and raw materials, about which I know less) they would not be able to work with components as small as those in modern processors.
Even if they did have the production capacity, they would need to reverse-engineer the precise schematics needed for assembly - not just the end result, but the steps taken to get there. This can be done - in the 80s and 90s, Soviet and former Soviet engineering programs were notorious for reverse-engineering Western chips, and they were hardly alone - but it's an involved process; working with hardware so far in advance of the state of the art, I wouldn't be surprised if it took some years.
The display is in a similar state: LCDs were just beginning to be developed in the 60s, and the development of thin-film transistors wouldn't be for several years yet. Then, once they had figured out how to replicate the display itself, they would need to reverse-engineer modern display specifications, i.e., how the processor and display communicate.
And the same goes for software. C, the venerable ancestor of modern programming languages like C# and Java, is a few years from its first edition. Simula, the first object-oriented programming language, was a few years old. If they managed to decompile some of the software (or you had a lot of source code and language documentation sitting around for whatever reason) it would propel the state of the art forward considerably. Of course they don't *need* to write any additional code if they understand how to copy it from your laptop to their replication, but they would be limited to only what you happened to have at the time, which might not be useful.
TL;DR: Most of the industries involved would just about be able to grapple with the challenges posed by duplicating your laptop. Studying it would lead to major advancements in pretty much every aspect of computers. After some years (I would guess inside of a decade) they could probably describe it in enough theoretical detail to duplicate it. The industrial and technical requirements would take another few years to fill. Remember that the industrial machines involved use computers themselves, so you're looking at an iterative model of improvement - better computers mean better fabricators mean even better computers. That would get them a laptop *comparable* to a modern one. For it to be *compatible*, they would need more in-depth study of the exact specifications, which would take more time.
[Answer]
Probably, but it would take a while.
The Transistor and solid state electronics was already known. Computers that do binary math was already known, so once they got hold of the thing they could figure it out. The Microprocessor was only 2 years away. Magnetic storage was invented long before. The display could be figured out. From a theoretical standpoint, almost everything was there...
**BUT Not everything**
While the computer would be wildly more advanced than most of the engineers could have initially imagined at that time, they could see it being possible. What they are missing is the entire modern supply chain and the super precise fabrication facilities that make a modern computer possible. They will have a goal, but they have build to it and that is a lot of iterative design to get there.
An unintended consequence is that you might start off a government time travel program. Moore's law was already known. If they can figure out how powerful the machine is, then extrapolate back to how powerful their machines are at the time, they could guess about how far in the future the laptop came from. This would be confirmed by the copyright on the bios. So they would know time travel happened. Cold war paranoia would kick in just in case it was an evil Russian kind of thing and we would want to be First to get time travel for national security, of course.
[Answer]
**Yes, but it will take some time.**
It is a common fallacy that all the true scientific progress that has been made in the world has been made in the last few decades. Sure, we seem to have more gadgets today than we did in the 1960s, but the concepts on which they have been built have been understood for some time.
There is an interesting blog post on [progress between 1885 - 1950 compared to 1950 - 2015](https://dothemath.ucsd.edu/2015/09/you-call-this-progress/) that highlights this well. The point being, that in the late 1960s we already had computers; we'd been putting them in Apollo spacecraft after all - we had screens (albeit CRT) that had been used for broadcast receiving for 40 years or so in the US (first TV channel started broadcasting there in 1928) and the integrated circuit was already 10 years old.
So, conceptually, your laptop is just a VERY advanced version of a lot of technologies we already knew about. Even the battery could be reverse engineered with enough time and effort so all things considered, it would most certainly be possible. The US science domain was (arguably) at its peak around that time thanks to Apollo so all in all the ability to reverse engineer such an artefact was available.
The problem is, you only get one of them. Once you pull it apart completely, you either need to know how to reassemble it perfectly, or you need to research yourself until you can create your own. In other words, you don't get a spare to keep operating so you can look at software in action, experiment with yanking this or that large component then putting it back in so that you know what to do with the bits on your workbench. Once you disassemble it to reverse engineer it, the chances of it ever working again are slim and you're committed to your path to create a new one from scratch by researching the parts in front of you.
As an aside, given that the first PCs were coming out in the mid 80s with CRT monitors, and given the effort that would be involved in reverse engineering this technology before designing something for the commercial sector, and the eponential growth of this technology over the last few decades, if time travel was possible then it's entirely plausible that your hypothetical scenario is exactly what happened...
[Answer]
Recreate something just like it, highly unlikely. However, it's likely they could extract a lot of knowledge about the right directions to research in that would accelerate development by decades, particularly:
* CMOS logic
* flash
* choices about what data channels should be serial vs parallel
* differential signaling
* line codes (8b/10b, etc.)
* PCB design
* modern LEDs
* modern LCDs
* battery chemistry
not to mention all kinds of UI/UX concepts. You wouldn't end up with a modern laptop anytime soon, but with a huge amount of funding poured into it, they might be able to make some sort of laptop with a mix of characteristics from various machines between the 80s and now. My guess would be that it would be on the lower end in memory capacity and clock speeds, but with relatively modern UI elements.
And of course if the laptop you left happened to have Wikipedia bookmarked and some of it cached and available in offline browsing, they'd have an even bigger head start.
[Answer]
They won't replicate the macbook because depending on which software it is loaded with it is more useful intact and running then disassembled and if they won't disassemble they won't replicate.
If it came with xcode, gcc and other develpment tools, will change the course of programming because the scientist will learn how modern programming works and apply this knowledge on their own systems. Also if you brought the tools for machine learning/neural networks and such, the scientist won't waste decades in perceptrons and other earlier attempts at AI, they will go right into deep neural networks, changing the course of computation even more.
Another thing is that a macbook is many times more powerful then any computer they could build then, even the first Cray was barely comparable with a 486/pentium 100. They will use your mac to run climate models, simulate nuclear weapows and process astronomical data.
[Answer]
Could they feasibly replicate it? They'd have far more chance of replicating it if you'd taken a crate of identical MacBooks with you because the chance would be incredibly high that someone while investigating it would do something irreversibly destructive before anyone understood what the device or component would do. With no prior knowledge of that level of circuit integration or component miniaturization the overwhelming probability would be that someone would use a tool that allowed a small leakage current to burn out microprocessor gates, would crack a component applying too much force, would melt some plastic element because they used far too big a soldering iron (or for far too long because it's got lead-free solder that melts hotter than they'd expect). Even following the signals in the system would push 1969 technology way beyond its limits... as example the clock speed is far higher than 1969 oscilloscopes could measure.
Or with only one of them available, they'd not be allowed to do enough investigation because it was the only one of its kind and far too precious as a working object to take to pieces.
But simply knowing that it would be possible to get things that small would prompt a huge research leap and huge technology surge. Just think about the power supply alone... a modern switch-mode power supply taking AC mains and turning it into 19V DC at many amps at 90+% efficiency in a few cubic inches of space compared to a 1960's era linear power supply occupying thousands of cubic inches and pouring out huge amounts of heat. And probably full of big valves
But even with a crate of machines to play with, it would take years of work before the technology was good enough to even understand what went on in the components of the laptop let alone stand a chance of replicating it. It's taken half a century to get to here from there in technology terms, I doubt that even having a working example would shorten that time by half. And of course as you've protected your laptop with the latest encryption algorithms they'd have to do a mammoth codebreaking task to get into the software on it!
[Answer]
Recapitulating 50 years of fabrication progress would probably take them... about 50 years.
As an analogy, we know a lot about how a living organism works, but we can't *synthesize* one. Frankly, given current feature sizes, our microprocessors are closer to a biological organism than they are to 1960s electronics.
In 1969, we had transistors and primitive integrated circuits. Engineers would probably be able to *guess* that the tiny things soldered to those boards are semiconductor packages -- but they'd have no hope of reverse-engineering them, through non-destructive *or* destructive investigation. There's just too much of a gulf.
[Answer]
I estimate that starting in 1969, if handed a MacBook the US government could reproduce it, software and all, in 100 years, at an estimated expenditure of $10B/year (1969 dollars). It would, of course, be turned over to the CIA who would launch a secret project to analyze it and they'd spend years analyzing, considering, re-hashing, and etceterizing everything, without bothering to make much progress. The Soviets would get wind of it, and through a back-door channel between the CIA and KGB in Vienna they'd get some incomplete schematics and would spend the entire GDP of Moldavia on trying to flesh it all out. Xerox would get involved because, y'know, why not, but although they'd be able to simulate the thing on a computer the size of a refrigerator they'd get distracted by this or that or something else and in the end, although they'd produce a lot of interesting stuff, they wouldn't produce anything useful.
But ultimately there'd have to be a couple of geeks in San Jose who'd start a little company after their employer turned them down, who'd develop the same thing in about 25 years.
[Answer]
In addition to the valid points about physical construction, modern computers are too complicated for paper and pencil design to be practical. Designing a generation N computer requires many generation N-1 computers to store and manage the design documents, run simulations, produce layouts, check timings, etc. 1960's computers were simple and small enough to be designed without using computers. Current computers are not.
If you take a typical consumer laptop back, it is very unlikely to have much digital design software on it, so that would have to be developed from scratch.
Similarly, a 1960's computer would not be fast enough or have enough memory to run compilers for a modern object orientated language.
It might be possible to avoid some dead ends, and so get to current technology a bit faster, but most of the intermediate steps would have to happen, and take almost as long even knowing where one is heading.
[Answer]
In 1961, was the first transistor computer called the IBM stretch, it cost 7 million and used 100 kilowatts. You would need 60,000 of them to compare to a laptop, which is 600 megawatts. That's achievable using hydroelectric, the hoover dam is 2 gigawatts.
<https://en.wikipedia.org/wiki/Instructions_per_second#Timeline_of_instructions_per_second>
in 1960, the J Edgar Hoover dam could power 4 laptop equivalents. in 1965, it could power 40 of them. So, yes it's totally achievable at a cost of 10-20 billion dollars, to process at the same speed, and if you process slower, you divide the cost and equipment.
<https://en.wikipedia.org/wiki/IBM_7030_Stretch>
[Answer]
No, as Cadence points out, the fabrication techniques would be beyond them.
However, they could learn a lot by reverse-engineering it. If they’re willing to destroy their one copy of the machine, or if they have more than one, x-ray analysis of the CPU would reveal its fine structure. Large portions of that would still work at a larger size, just slower. (Historically, it’s gone the other way: the first chips being made with a new process are typically an older design, but shrunk to be faster.) Especially if it’s a RISC design, it would be useful well before they could replicate modern feature sizes.
Similarly, if they could figure out what the machine-language instructions do, they could reverse-engineer the binaries on the machine and learn a lot that way. If there’s source code on it, examining that would help them design a more futuristic programming language (perhaps with the help of a reverse-engineered parser-generator). There are a lot of components of the system that they could begin using to improve their own computers well before they could exactly clone a MacBook. And they don’t need to, unless they have a big library of MacBook software and peripherals they need to use.
[Answer]
No. At one point during the Apollo program of the mid-1960s, over one half of all ICs in production in the world were being sucked up by the space program. Also, one third of all engineering and math professionals in the USA were working either for the government or for private contractors involved in the space program. That means that we would have zero excess production capacity or human resources to devote to such a project.
[Answer]
If you enabled FileVault encryption, then the contents of the hard drive would be unusable. They would probably have better luck reverse engineering the keyboard, display, and networking devices. Just knowing what materials the CPU is fabricated and the basic layout would jumpstart their chip design. The project would start off slow, maybe nothing functional for several years, but then accelerate at an exponential rate.
[Answer]
No.
Even if you know *everything* about how a modern integrated chip works (dubious -- you need really advanced xray microscopy that's [being invented now](https://www.nature.com/articles/nature21698)) you still have no idea how to build one.
Going from the sort of chip fabs that existed in the 1960s to the sort that make modern laptop cpus took 60 years of hard work from a ton of people. Having a few chips to study won't help that process along. Nor would government pressure help much.
If you left a complete fab in the past, *that* would be helpful.
] |
[Question]
[
I need to know if it’d be possible for a underground ring-like structure of immense proportions and alien design to go unnoticed by modern day sonar, radar, and geological surveying.
For an idea of size, imagine a tunnel about the ***width of a football field*** or bigger (maybe *100-200 meters* in diameter) that’s buried ***2- 5 kilometers underground*** and ***wraps around the entire planet*** (giving it a circumference of *40000 km*).
Could something like this remain hidden until a mining project accidentally uncovers it in Africa, or would something this size have been detected by now with the technology developed in the 20th and 21st centuries?
[Answer]
Consider the following:
* The diameter of the Earth is ***12,742 kilometers***.
* Our planet's crust thickness is anywhere from ***30 kilometers*** on the continents, to ***5 - 10 kilometers*** on the ocean floors (which have not been explored or mined in any real detail).
* The deepest mine on the planet goes down less than ***4 kilometers***.
* Your average ground penetrating radar does so at a depth of 30 meters (this will obviously vary with the system and material it has to travel through).
Keeping all this in mind, I wouldn't be surprised if such a tunnel ***did in fact exist***. Even with today's technology, it might not be found for hundreds of years, if ever.
Remember, that even if your detection technology is pretty amazing, you still have to be ***looking at relatively specific location*** to find it. We don't go around ground scanning every random location on the planet, especially not at any considerable depth.
Simply place it slightly deeper than we've gone, and you're golden. In the not too far future advances in material science and automation may result in robots being built which can mine to greater depths than we've been able to achieve so far, and stumble onto it.
[Answer]
The Earth is better surveyed than is generally realized. It is probable that geophysical survey techniques would have revealed the existence of an underground megastructure.
>
> Geophysical surveys may use a great variety of sensing instruments, and data may be collected from above or below the Earth's surface or from aerial, orbital, or marine platforms. Geophysical surveys have many applications in geology, archaeology, mineral and energy exploration, oceanography, and engineering. Geophysical surveys are used in industry as well as for academic research.
>
>
>
There is a wide variety and considerable spectrum of instruments used for geophysical surveys.
>
> Seismic methods, such as reflection seismology, seismic refraction, and seismic tomography.
>
>
> Seismoelectrical method
>
>
> Geodesy and gravity techniques, including gravimetry and gravity gradiometry.
>
>
> Magnetic techniques, including aeromagnetic surveys and magnetometers.
>
>
> Electrical techniques, including electrical resistivity tomography, induced polarization, spontaneous potential and marine control source electromagnetic (mCSEM) or EM seabed logging.
>
>
> Electromagnetic methods, such as magnetotellurics, ground penetrating radar and transient/time-domain electromagnetics, magnetic resonance sounding (MRS).
>
>
> Borehole geophysics, also called well logging.
>
>
> Remote sensing techniques, including hyperspectral.
>
>
>
Source: [Geophysical survey](https://en.wikipedia.org/wiki/Geophysical_survey)
Many of these instruments and techniques could reveal a deep subterranean structure depending on the nature and construction of the megastructure.
For example, because of its depth the world-girdling tunnels would need to be made of extremely strong and, possibly, dense materials. Gravimetric surveys might detect its presence. Magnetomtric surveys would the same if its construction material(s) were highly magnetic.
Remote sensing imagery could show a continuous band of disturbance or its remnants if earth rock and soil had to be displaced for the megastructure's construction and installation. Building something on this scale at a depth of kilometres will leave its mark on the planet.
[Remote sensing](https://en.wikipedia.org/wiki/Remote_sensing), orbital and aerial imaging are excellent at uncovering changes to the surface and subsurface of planetary terrain. Changes or structures that wouldn't be apparent if you were standing in those places yourself.
The ring megastructure is likely to be detected by variations in mass distribution using geodetic remote sensing.
>
> Geodetic remote sensing can be gravimetric or geometric. Overhead gravity data collection was first used in aerial submarine detection. This data revealed minute perturbations in the Earth’s gravitational field that may be used to determine changes in the mass distribution of the Earth, which in turn may be used for geophysical studies, as in GRACE (satellite). Geometric remote sensing includes position and deformation imaging using InSAR, LIDAR, etc
>
>
>
There is also seismic mapping of the Earth's interior which might determine there was two hundred metre diameter tunnel around the world.
While a mine or a bore hole breaking through or hitting the megastructure is more hit or miss geophysics has an arsenal of methods and instruments to survey what is down below the surface of our planet.
In summary, there a wide range of geophysical survey methods. Many of which, both singly or together, could indicate the presence of a subterranean megastructure. Once its existence was suspected the range of geophysical instruments could be brought to beat to further elucidate it. In principle, puny humans have the techniques to find a deep megastructure and have had them since the twentieth century, therefore, they can only be expected to have gotten better this century. This makes the discovery of the megastructure highly probable.
[Answer]
I must disagree with AndreiROM on this. I believe it would have been found some time ago.
I'm thinking specifically of oil exploration. They go all over the place looking at subterranean layout to figure out where it's worthwhile to drill for oil. If it's drillable they're going to have a look--and your loop is certainly going to pass through some drillable areas.
About the only way I think it could be missed is if it never went near geologic features that could possibly contain oil. It still would have been seen but it might not be noticed if the survey crew stopped looking because they knew it wasn't oil. (The Chicxulub crater was missed this way--the oil guys saw it in the 1950s but dismissed it as volcanic, no chance of oil, they never looked at it closely enough to realize what they were seeing.)
[Answer]
You have a very big problem with your 2-5 km. depth. The average depth of the Atlantic ocean is over 3 km. I suspect it would have to be deeper than 5 km., and it would not be a perfect ring.
And forget about around the equator. If you went pole to pole, along roughly 30 degrees west - 150 degrees east longitude, you pretty much miss all land mass and drilling sites. It's ocean all the way, except for a piece of Australia. Since we have done very little in the way of exploring this region, it would be virtually undetectable by current methods. It misses a lot of volcanic activity as well.
Tectonic plate shifting would be a problem no matter where you put it. There would be tremendous sheer forces between plates.
Earthquakes can be as deep as 700 km. or more.
[Answer]
We have a pretty good idea of the *general* layout of the Earth core from seismic data. [Seismometers](https://en.wikipedia.org/wiki/Seismometer) are used to track earthquakes and nuclear tests. These [models](https://en.wikipedia.org/wiki/Mathematical_model) have been developed by reconciling theoretical physics and experimental data.
So if there was such a tunnel, and if the tunnel is under the equator, it might show up in the model as the "equatorial anomaly" or "equatorial subduction zone." Yes, there are strange echoes. No, they can't possibly be a tunnel. *A density anomaly.* Some physicist comes up with an explanation, the explanation fits the experimental data, the theory is provisionally accepted, and mankind has wrong ideas about the contents of Earth.
Say they think the core is (or was?) more fluid than we think, and coriolis forces must have concentrated high density (or low density) materials in patterns, much like the [cloud bands](https://en.wikipedia.org/wiki/Jupiter#Atmosphere) of Jupiter.
Alternatively, the data gets explained away as something like a [mascon](https://en.wikipedia.org/wiki/Mass_concentration_(astronomy)).
[Answer]
If I were the aliens and wanted to hide the tunnel **I would align this tunnel with the mid-ocean ridges**.
<https://en.wikipedia.org/wiki/Mid-ocean_ridge>
>
> The mid-ocean ridges of the world are connected and form the Ocean
> Ridge, a single global mid-oceanic ridge system that is part of every
> ocean, making it the longest mountain range in the world. The
> continuous mountain range is 65,000 km (40,400 mi) long (several times
> longer than the Andes, the longest continental mountain range), and
> the total length of the oceanic ridge system is 80,000 km (49,700 mi)
> long.[6]
>
>
>
[](https://i.stack.imgur.com/A41yR.gif)
The ridges are formed by the motion of plates away from each other. It is not a symmetric ring but it is ringish; the real ridges do go around the earth, mostly, in a somewhat meandering way. Especially that Indian ridge. A structure on one side of the plate boundary would be carried away from the boundary, but the accumulated stone there should not flex or distort too much. Clearly though, unless the aliens built this thing just 6,000 years ago, the engineering of the tunnel is going to have to accommodate some flex. I think a civilization capable of building such a thing would probably not make it out of mud bricks. Some sort of crystalline structure capable of compensating for gradual movement is not outrageous.
The mid ocean ridges are deep and not well explored.
<http://oceanexplorer.noaa.gov/facts/mid-ocean-ridge.html>
>
> Like the rest of the deep-ocean floor, we have explored less of the
> mountains of the Mid-Ocean Ridge system than the surface of Venus,
> Mars, or the dark side of the Moon. Use of submersible or remotely
> operated vehicles to explore the mid-ocean ridge has provided
> information on less than 0.1 percent of the ridge!
>
>
>
If someone were examining at a ridge, a (barely seen) deep geological feature aligned with the long axis of the ridge would likely be assumed to be natural in origin.
I like the idea that the persons discovering this tunnel system realizes that its makers not only bored out the tunnels but also engineered the plates themselves to serve their purposes. Tunnel explorers: watch out for shoggoths!
[Answer]
It would have been found decades ago.
Earthquake surveys act as a deep level sonar and show up large structures inside the earth. This allows for discovery of the inner and outer core, good estimates about their structure and chemical composition. The mantle has a velocity change called the Morohovicic discontinuity that is due to small changes in density that was found over a century ago <https://en.wikipedia.org/wiki/Mohorovi%C4%8Di%C4%87_discontinuity>
A tunnel full of air would have a *very* sharp density change and this would give rise to sesmic wave reflections and refractions and these would show up on large scale surveys and data collections. The same technique is used these days to look ad descending plate fragments and these only have subtle density changes - an air filled tunnel would stick out like a beacon. Whilst not something that could be easily investigated at the time - this would have been found in the early part of the 20th century.
[Answer]
**Flood it**
Make sure the tunnel runs almost exclusively underwater and flood it with seawater. Seismographic equipment and measurements probably won't detect it, likewise any "deep" radar technologies that might exist in your world.
It'll basically blend in.
[Answer]
If it is on earth, or being observed by mankind; generally speaking people ignore what they can't easily explain or try explaining with old ideas rather the. Form new ones. In a sense you could have this mega structure above ground and covered with half a mile of rock and have it sit long enough and everyone would consider it normal or explain it away. Vise versa those who who look for contact generally see it everywhere.
[Answer]
They could have the TARDIS effect and be in a tiny sphere.One would think that they could even be under a desert with some advanced shielding.
] |
[Question]
[
The gem in question is emerald. The design has a large emerald in the center of the chest, and emerald on the shoulders, knees, and elbows. **Would the emeralds be weak points in the armor? Would the design make any practical sense at all?**
Note: The reasoning behind the emerald in the armor is spiritual.
[Answer]
## Yes
Any change in material or join is a weak point or a stress point.
If the gem was an integral part of the armour then the gem would be a weak point:
1. because the join is a weak point
2. because the toughness of the gem differs from the metal and it would flex differently passing more stress to the join
3. risk of the gem shattering, gemstones are hard, hardness is a measure of resistance to plastic deformation, where the tougher metal will flex and eventually permanently bend to absorb energy, the gem, once it passes the equivalent higher threshold, will shatter. Repeated impacts which would leave metal armour battered and bent will leave a big hole where your gem used to be.
If the gem was overlaid onto the the armour (with full continued armour behind) as decoration then only 2. applies.
[Answer]
**You don't have to weaken armor to decorate it.**
First, gems are never going to make plate or other metal armors better at their job.
* Plate armor is best when it has as few joints, beyond what is necessary for mobility, as possible.
* Never make the gems relevant to plate armor's structure. If you must have them they can simply be added to the exterior of the armor. This way they would have no negative impact on the structure of the steel.
* Connecting anything to mail armors is going to be difficult.
* Scale armor could be a good choice as you could stud the scales with stones if you want...that'd be shiny and make you look like a dragon... *cool idea noted*
Non metal armors on the other hand could potentially benefit. Gems are hard...studded leather made from gems could potentially be useful.
**Negatives of using gems in armor**
* Additional weight
* Makes the wearer a target. Many in ancient combat were there for the loot...emerald studded armor would probably end badly
[Answer]
Armor are greatly underrated in fiction. A man in full plate armor is close to a walking tank. To defeat him you will aim to the gap in the armor.
If you're rich enough to incorporate large emerald in your armor, the armor is probably well made enough that it can take a warhammer hit, it will not be perforated.
I'll take a recent example in Game of Thrones, The Mountains took a warhammer strike from one of those religious fanatics. It results holes in the armor. **That is not realistic.** Thats not armor steel. That is cheap thin aluminium. To penetrate heavy armor you need heavy crossbow and a good angle, or a spear and a horse at full speed.
As others said before, yes it will weaken the armor but does it will make a difference ? I think not. If you don't heavily change the structure of the armor to incorporate the gem and if the gem is on the outside of the armor it will not be a problem.
Of course a powerfull hit can unseal and/or break the gem.
[Answer]
Someone rich enough to have a plate-sized emerald on the chest of their ceremonial armor has no place on the front line anyhow. Usually, such armor is the domain of kings, who would not wander onto the battlefield without a guard of hundreds surrounding them on all sides. The role of the person such in ceremonial armor on the battlefield is two-fold:
1. Act as a **HIGHLY VISIBLE** morale-boosting mascot, i.e. get the promotion-seeking officers thinking "The King is watching us, let's show him what we can do."
2. Use part of his own Elite Guard to reinforce critical points in the front line, that seem likely to buckle under enemy pressure or where a rapid-reaction force can exploit a weakness.
To answer the question, by definition a gem-studded armor will be weaker than a smooth, blow-deflecting purely utilitarian full plate. Gems are **hard**, yes, but they can often also be **brittle**. The extra weight of the stones and the setting can hamper movement. Normally, this sort of potentially-lethal extravagance would be only used as ceremonial plate, only worn during parades to impress the ladies and the plebs.
[Answer]
>
> Would the emeralds be weak points in the armor?
>
>
>
**Yes.**
The emeralds are either integral to the armor (i.e., there is emerald somewhere there should be steel) or they are not (i.e. they are attached to the surface somehow: clasps, claws or clasping bands).
If they are integral to the armor they represent weak points, where the armor may either break or be penetrated. Gems, while hard, are often brittle and can be shattered by a strong enough blow.
In both cases, you want an armor to be **smooth and rounded**, without dents, inflections or hard edges that could give purchase to a blade or point (e.g. the beak of a halberd) to either transfer shock to the wearer, or even worse penetrate it. In certain circumstances, any decoration on the armor can act like a guide, turning an incoming arrow or bullet in instead of deflecting it away.
[Answer]
If the gem is only encrusted upon the steel as ornament, it will just be dead weight. But such gems are pretty light, compared to steel. Some quick googling has the density for emeralds at around 2.76 grams/cm3. Steel, on the other hand, is around 7.8 grams/cm3. For comparison, the density of water is 1 gram/cm3.
Now, the emeralds may protect you metaphisically - I won't argue about that, you world, your rules - but if you intend for them to protect someone mechanically, your knights are in trouble.
A lot of people are going to tell you that emeralds and diamonds are awesome because they are hard. But that DOES NOT make for armor material.
Armor protects you in two ways. It either deflects blows, or absorbs impact for you.
Now, I don't see your emerald deflecting a mace, for example. It won't have the shape for it. So let's try absortion.
Metal absorbs energy by changing shape. That's why cars are are built with [crumple zones](https://en.wikipedia.org/wiki/Crumple_zone), so that they absorb the energy of an impact. In the 20's cars didn't have these, so in a car crash whatever was inside them (like people, for example) would take all the energy of the impact (and die). Metal armor works just like that.
Steel is good for armor because it has a good mix of hardness and [toughness](https://en.wikipedia.org/wiki/Toughness). Yes, toughness, that's a technical term. It means:
>
> (...)the ability of a material to absorb energy and plastically deform without fracturing.
>
>
>
Now, diamonds, emeralds rubys etc. have the wrong mix for it. They are too hard and are not tough enough. Let me explain:
* **Too hard:** they will not bend nor change shape in any other way to protect you. If you could build an emerald helmet and wear it while I hit your head with a hammer, that emerald will happily transfer all the energy of the impact to your cranium. You'd fare better if you were using a metal elm instead.
* **Not tough enough:** if people keep saying that emerald would make good armor because it is very hard, I will go hulk-mad and hit you on the head with even more force. If you are still wearing an emerald helmet, at some point it is going to shatter like glass. Not only you took all the kinect energy for yourself (because that precious stone will never take a hit for you), you now have shrapnel in your cranium.
So please, don't trust your life solely on those stones, ok?
[Answer]
The joins where the metal meets the gemstones would be a weak point, unless there was some technology in play to fuse the two materials into a seamless joint, or the setting of the gem was backed completely by metal. Most settings for gems are literally bands of metal tightly grasping the gemstone (or prongs of metal doing the same). If you damage or dent the metal around it, odds are the gemstone becomes dislodged or falls out and now you have a bigger vulnerability (unless there's sufficient metal behind the setting).
[In theory](https://en.wikipedia.org/wiki/Mohs_scale_of_mineral_hardness), emerald is harder than iron and steel (and the same hardness as hardened steel), but I think that the joining of the material is the weakness. If it was completely backed by metal of the same thickness as the rest of the armor, it shouldn't be a weakness (or not an easily exploited one).
I think making armor in such a way that it wouldn't be weakened by adding gemstones would add a lot of additional weight to it, and probably make the form of it awkward.
[Answer]
In general I agree with the other answers that any embedded gem / crystal weakens an otherwise whole armor.
At the same time, gems or crystals or ceramics in general can provide additional protection. Think for example of bulletproof vests which have a ceramic layer inside.
So for example a mix of emerald as a hard ceramic and a soft layer of i.e. silk can increase the protection against, for example arrows or bolts or bullets in comparison to only metal. If the stone breaks during impact the soft layer behind the gem would catch the shrapnels preventing them from entering the body.
Similar approaches, were used by a lot of nations during the medieval times. Think of ringmails. One particular example are the mongols. Those were wearing light armor of leather in combination with hard and light iron elements and underneath silk clothes. This combination was very successful in preventing arrows from entering the body. This apparently also lead to the myth, that silk clothes can be used to remove arrows safely from the body, which I wrongly cited here. Mea culpa.
You can still apply the same principle to stones / ceramics instead of iron. The trick is to introduce multilayered armor.
At the same time, emerald is approximately 2.5 times lighter than steel, which would make the whole armor lighter.
So in a nutshell, if you have an intelligent design concerning the stones, you can actually achieve additional protection in my opinion.
Be aware that hard materials like stones, can still be brittle and break easily.
[Answer]
it is tough to say without more details, but the stone would probably weaken the armor very slightly unless it was unrealistically large and pure.
some things to consider:
1. a green saphire would be stubstantially stronger and tougher than emerald.
2. when steel hits it's limit, it bends while absorbing energy. when gems hit their limit, they shatter and/or crack, absorbing substantially less energy.
3. the armor would be weekened at the joint between steel and gem because that interface would be rigid like gem, but soft like steel. re-enforcing that joint would add more weight than you save using sapphire for realistically sized gems.
4. in theory a very large sapphire (e.g. covering the entire chest) could be stronger than an equivalent weight of steel plate. similarly, replacing the entire knee plate with a single well shaped sapphire could be better than the comparable weight in steel. obviously green sapphires this size have never been found on earth. however, modern armored car windows are made from synthetic aluminum oxide, which could easily be made into a green sapphire by adding trace elements.
5. sandwiching sapphire (or even emerald) between two steel plates could provide improved resistance to armor-peircing arrows (and lances). this would be similar to the ceramic plates in modern composite armor. again, this would require extremely large thin plates of gem, and most of the plate would be hidden. although, you could probably reveal a small window of gem without greatly reducing the overall odds of protection. obviously an arrow that hit that window of gem would not be stopped as effectively.
6. steel is superior primarily because it is easy to shape, and can take a lot of damage while still providing protection. if you could somehow (magically?) shape the gemstone into a breastplate, and you made it thick enough that standard weapons could not shatter it, then it would be lighter than an equivalent steel plate. i'm not sure if that would be light enough the wearer could still walk.
[Answer]
I may have missed this in the other answers, but there is another point to consider.
Any protrusion from the armor will provide another way for a spear thrust to catch the armor instead of sliding off. This could be the difference between staying on your horse or being roughly pushed off of it.
[Answer]
Yes, in a few ways.
First off, there's the obvious answers; having gems on you makes people want to kill you and steal your armor to sell the emeralds. The gems also make you heavier.
Then, there's a scientific issue; gems are kinda like a two-edged blade. Gems are all crystals, and crystals consist of repeating patterns. Certain crystals have a weakness where due to a weak bond in their patterns, they will easily split along a certain 3-d axis (a plane). These planes are called "cleavage" planes. Emerald (beryl) has this property; thus, even though theoretically the emerald is far stronger than steel, cleavage means it'll easily shatter if hit right.
Now, this might not be a fatal issue if the gems were simply affixed to the armor, but it'd still cost a lot. But crystalline beryl doesn't have to be in the form of large gems! According to [this paper](http://www.scirp.org/journal/PaperInformation.aspx?paperID=21303) beryl microparticles embedded in aluminum improves its tensile strength, giving us another use for the beryl.
So, there's your answer.
[Answer]
What if the gem was actually part of the armour like it was placed there when the armour was being forged from molten metal.
It would then not have the weakness of having a joint.
also would it not be more effective if it was an diamond
] |
[Question]
[
As Luke says in an answer to [this question](https://worldbuilding.stackexchange.com/questions/44958/what-could-prevent-a-sentient-species-from-going-to-space), a species may never attempt space travel if they cannot see that there is something out there.
My question is just this; is that possible? Could a planet/solar system be wrapped in something that prevents the light of other stars from reaching the species? Could this be done without an artificial structure, such as that of the planet [Krikkit](https://en.wikipedia.org/wiki/Places_in_The_Hitchhiker%27s_Guide_to_the_Galaxy#Krikkit)? Assume this system has only the one planet orbiting the star, so the species doesn't try to go somewhere else in the system.
[Answer]
**Clouds**
Perpetual cloud cover -- such as what you might find on Venus -- would of course obscure the night sky and the stars therein. The caveat here is that you would likely have people wondering "What's beyond the clouds?", and if any of those happen to get through them during the night they'd see the stars and then -- potentially, anyway -- cue the space race.
**Light**
It's well known that we can't see the stars (save for our own sun, which is of course a star itself) during the day. This is because the sun is so bright that it simply obscures the stars from view. At night, however, our own planet blocks the sun's light and allows us a view of the stars above.
We can see the stars at night because our moon doesn't reflect back enough of the sun's light to obscure the stars. This is because its [albedo](https://en.wikipedia.org/wiki/Albedo) is only ~12%. However, if our moon were "brighter" -- say, closer to Saturn's moon [Enceladus](https://en.wikipedia.org/wiki/Enceladus)'s 99% -- it could conceivably reflect enough light back toward the planet to make the night sky almost as bright as the day's, enough so to obscure the stars from view.
This would require a planetary system where the moon doesn't go through phases -- i.e. it orbits the planet at precisely the right period to keep it on the opposite side from the sun, but is never eclipsed (though as Sean Raymond points out in comments this is probably impossible, as this would pretty much have to put it in the L2 Lagrange point, which is unstable) -- or where there are multiple high-albedo moons orbiting in such a way that there is always at least one moon (or combination of two or more) bright enough to obscure the stars from view.
Alternatively, a binary (or more) solar system might be configured in a way that there's always at least one sun filling this role of obscuring the "night" sky and its view of the stars.
>
> *But wouldn't a moon give the inhabitants reason to want to head into space?* It might, but on the other hand remember that we're talking about moons that are nearly as bright as the sun itself, which makes direct observation very very difficult (unless you like your retinas burned off). Without direct observations, determining that the moons are something that could be visited would be fraught with unique difficulties, to say nothing of the fact that there's no observable universe for the inhabitants to see and from that to derive relative scales, such as the sizes and distances of their moons and sun; they may never even arrive at concepts such as "orbits", something we were able to figure out after millennia of studying the other planets in our solar system.
>
>
> Now, granted, you might be able to make some observations of a crescent moon, but the same high albedo that obscure the stars themselves would likewise obscure the "dark side" of the moons. Still, the fact that the moons go through phases while the sun doesn't will naturally drive curiosity and could indeed lead to someone figuring out that they're orbiting bodies they might be able to reach, but again without any concept of relative scale derived from observations other bodies, to say nothing of the complete absence of even a rudimentary grasp of orbital mechanics, the challenges in actually getting out there may prove insurmountable, or at the very least dissuade anyone who might have been capable of surmounting them.
>
>
>
[Answer]
A simple reason could be that the planet is far from its nearest star.
For instance, in the middle of the supervoid which is a 1.8 billion light years across (found in the constellation Eridanus).
This distance would probably hide the view of the stars and galaxies to a viewer with human vision on the planet, it probably could not hide objects from a ground based telescope.
An orbital telescope like Hubble can see 13 billion light years distant, however it is likely it would never be developed.
[Answer]
Short answer is universal expansion. Humans today live in a very unique point in the history of the universe as we can see and speculate both what happened in the past and what will happen in the future.
One of these future predictions is that the as the universe expands it will begin to expand faster than light. This will make it impossible for light to ever reach another galaxy or star system. The light will travel continously never reaching anything beyond the galaxy it exists in or even the solar system itself. Your planet could exist trillions (upon trillions) of years from now where this is happening and any evolved form of life would see empty space outside of their home system.
I would look up kurzgesagt on youtube and watch some of his space videos as in one of them it explains this faster than light expansion and probably explain it better than I can.
Edit: Here's the video. It talks about humanities own limits but it could be applied to your situation. You would just need a lonely star system.
<https://youtu.be/ZL4yYHdDSWs>
There's also three ways to destroy the universe which is also similar to what I was talking about.
<https://youtu.be/4_aOIA-vyBo>
[Answer]
# Locating the planet within a Dark Nebula
Figured I would jump in and give an astronomical option.
Dark nebula are absorption nebula that can stretch for many light-years. They are so dense that only deep infrared and radio emissions can penetrate the outer layers. However because of their density star formation occurs in the center. The star will carve out a "bubble" of clear space surrounded by an opaque cloud. From this bubble the people would only be able to see other stars if they tried extremely hard. It also seems likely that they would develop a philosophy regarding themselves as the center of the universe and trying to disprove this would be even more taboo then it was on earth.
For more details and pictures see:
<https://en.wikipedia.org/wiki/Dark_nebula>
[Answer]
Ice could be an option. You could have an ocean planet with a thick layer of ice covering everything. If the planet has a hot, rocky core with thermal vents, that could provide the energy necessary for life, with microbes living directly off of the warmth from the core, tiny animals living off of colonies of microbes, and larger animals living off the smaller animals.
[Answer]
The simplest answer I can think of is clouds. One can easily imagine planets that are covered in clouds (like Venus, except with habitable conditions under the clouds).
Another possibility is that other nearby stars can prevent night from falling on some planets. This might happen in very dense clusters of stars called globular clusters (as well as in Isaac Asimov's Nightfall). Planets in multiple-star systems can also --in some cases -- have long periods without night. For example, I built a 5-Sun (<https://planetplanet.net/2016/03/22/an-earth-with-five-suns-in-the-sky/>) in which a planet had 8 years without night ( see <https://planetplanet.net/2016/03/23/earth-with-five-suns-in-the-sky-when-would-night-fall/>)
[Answer]
[](https://i.stack.imgur.com/0TBhK.jpg)
Planetary rings not only would directly block the the vision of a lot of stars along the Equatorial zone.
Would also reflect bright lights from the sun on the rest of the world making every star invisible.
[Answer]
Well the first and most obvious answer is **light pollution**. If an alien species were to use an extremely large amount of artificial light for everyday/night activities, they wouldn't see the stars. Same goes for if they happened to live on a planet with an extremely reflective surface. For example, if you lived on a planet whose year was the same length of its day, one side would always face its sun; thus life would have to live on that side of the planet (since it needs the sun for energy), and its planet would always reflect enough light to cause light pollution.
Another possible cause is **clouds**. If a species were to live on a planet that was always covered in a layer of gas, they may not be able to see past the clouds and realize that there were stars.
Finally, though this doesn't have much to do with the planet but moreso the species, **evolution**. Just as on Earth we have species that have evolved to not have eyes, so could be the case with an intelligent life form on another planet, which would cause a lack of interest in exploring what one cannot see.
[Answer]
A sentient species could possibly also never develop the ability to *see* at all, which would make sense especially for planets in dark zones of their star system. In this case, they would simply not see that there are any stars around them and just deal with their own surrounding without having any idea that there might be anything beyond.
[Answer]
You could make the planet's air be turbulent and tend to be full of dust.
If it never calms down enough for the dust to fully settle, you'll still get sunlight diffused through, but starlight won't make it.
But it gets better. The constant wind and dust would make it difficult to construct and maintain the sensitive optics needed to look at the stars in the first place. Made a giant glass lens? It's scratched up and useless within a month. If you put a clear pane of glass in front to protect the lens, that pane gets scratched up instead, and you have to replace it frequently. Maybe one night the wind calms down enough that you could actually see stars, in theory. But you can't be sure if those specks of light are from the sky, or reflections off some bits of dust on the end of your telescope. By time you clean the lens off, the wind has picked back up.
And if there's always dust in the air, visibility will always be limited to within a few miles or less. Which means your aliens' eyes won't need to be able to pick out details at a great distance, because such an ability would not provide a survival advantage. With less visual acuity, your aliens wouldn't even notice the pinpricks of light from distant stars on the rare occasions where starlight would make it to the surface. And the same problem which prevented them from evolving sharp vision would also make telescopes much less useful, which means they might never invent high magnification optics for looking at distant objects.
[Answer]
The simplest solution would be deep underwater civilization. It has no technical capabilities to explore areas above water level, because cannot make metal tools.
To make it more fun, make them encounter alien civilization which is capable to be present on the edge of livable atmosphere (a boat).
[Answer]
# A companion star of the primary
In Asimov's 1941 short story [Nightfall](https://en.wikipedia.org/wiki/Nightfall_(Asimov_short_story_and_novel)), he imagines a planet that is always illuminated by companion stars of the primary.
I don't think this could be a plot point for a civilization to never attempt space travel. Even in the times where the Earth was flat and heavens were only accessible through death, Earthlings tried to build as high as possible; climb as far as possible. So I think a civilization will eventually try space travel even if they cannot see the stars.
However, in Asimov's short story, space travel is prevented because,
>
> civilization is destroyed every 2000 years.
>
>
>
Maybe you could come up with something clever like that.
Here's a [link to the short story](https://www.uni.edu/morgans/astro/course/nightfall.pdf), if you are interested.
# Type III civilization
A civilization so advanced that they are consuming the energy of all stars in the galaxy by building Dyson sphere around them. Yet they leave the systems of non-advanced life-forms as sanctuaries.
[Answer]
The only thing I can come up with is *distance*. You should be so far from every star that light goes through either redshift of blueshift, becoming invisible to the naked eye.
Not sure if it's a really huge distance, or some thousand light years are enough (which is still quite huge), but thinking about isolated planets might be a good start for you - well, depending on your setting.
[Answer]
Make your planet tidally locked to the star (only one face only ever faces the star). On the day side, the stars are hidden by atmospheric scattering. On the night side, it's too cold to live.
Your characters can live on the day side or in the twilight region. Then they won't know about the stars.
[Answer]
Here's a good one: time.
Give this podcast a listen, starting about 9:36. Brian Greene explains what the Universe may look like to future astronomers.
<http://www.npr.org/rss/podcast.php?id=510298>
[Answer]
## **External Influence**
Noone has mentioned interference from an external party.
Imagine that the planet is a wildlife preserve, to protect a developing civilisation from early contact, or as a science experiment to see how evolution works, or simply as a cage to keep the contents safe from predators.
A philanthropist group of rational and intelligent beings could see fit to raise a "fence" or protective shield that hides the planet, or works to obscure the outward signs of intelligent life. As a side effect, the shield stops all inbound radiation (perhaps uses inbound solar energy as a power source and then presents a "fake" light source on the inside, or acts as a giant diffuser for light to hide the concept of a light source rotating.
The technology to raise such a shield is beyond Humanity at this time, but an external culture could have any level of tech that you want to imagine.
And as a twist in the tail....
>
> it could be that intelligent creatures "taste" better so the whole planet is a farm for raising tasty snacks. The shield is a fence to keep out poachers or any police just as much as keeping the animals inside.
>
>
>
[](https://i.stack.imgur.com/i5KcA.jpg)
[Answer]
## Light Pollution.
In urban areas in our real Earth (though you might want to ask over on the [Skeptics SE](http://skeptics.stackexchange.com) whether our Earth is the real Earth), it's much harder to see the stars than it is out in areas away from the cities. Sure, it's possible to see stars, but there are so many more, plus the brush of "milk" that gives our galaxy its name, which you need to leave the city to see. In theory, if you have one massive city that covers your planet with lights bright enough (considering that there are still visible stars in NYC you'd need to go even brighter than that), you could block out every single star's light from entering the atmosphere.
[Answer]
Their planet could be in a region of space filled with space-dust.
Imagine a denser version of [The Great Rift](https://en.wikipedia.org/wiki/Great_Rift_(astronomy)) in the Milky Way. The space dust wouldn't need to be actually in their star system, but perhaps they have planets out about as far as the Jovian planets whose orbits sweep some of the dust out of the system, but not enough for the planets to be seen.
[Answer]
You can have a planet where nobody can see stars until a fairly high technology level is reached.
About four billion years ago, two stars in a galaxy passed very close to each other and exchanged momentum. One was accelerated beyond galactic escape velocity.
Time passes. Planets form. Life evolves. It becomes intelligent and looks up at the sky. It sees a few planets, and a few very faint fuzzy blobs. This is the view from a solar system deep in inter-galactic space.
Eventually they point powerful telescopes at the fuzzy blobs and see galaxies made of what looks like glowing dust. I wonder how long it takes them to work out that each speck of dust is a sun like theirs?
] |
[Question]
[
The world has ended and our valiant group of survivors is roaming around the ruins of the old world about sixty years after the apocalypse.
Now, most people carry around black-powder muskets and maybe a few, and precious, guns of the old world.
Would it be possible to make bullets out of the alloys regularly used on cars or buildings?
[Answer]
You can make bullets out of almost any metal if you want, but there are always going to be tradeoffs. Why are most bullets today made of lead?
It's [dense](http://www.coolmagnetman.com/magconda.htm).
This means that you get more mass (hence more momentum) in a smaller package (hence less wind resistance). It's also deformable, so when it hits a target, it spreads and does more damage. It also has lower melting point meaning less heat energy to form the bullet (as AlexP points out).
That said, many high velocity rounds (like sniper bullets) are actually [encased in a copper alloy or steel](https://en.wikipedia.org/wiki/Bullet) so that the bullet doesn't deform on firing due to the large change in velocity.
Steel and Steel core bullets (which would be the primary alternative because of availability) are actually in use today; they make great armour piercing rounds because although they're not as dense as lead, they're much harder, meaning that they have more penetrating power with the momentum they have.
So yes, you could use other metals, but when you do, you just need to bear in mind the properties of the metal you're using to understand the pros and cons the change introduces.
[Answer]
Boring old lead shot. This is post apocalypse! Can't we jazz it up some?
Let us consider the [blunderbuss](https://en.wikipedia.org/wiki/Blunderbuss), a black powder muzzle-loaded shotgun and a fine weapon for your survivors. I thought you could shoot anything from one of these but apparently not. The following is an article on Lewis and Clark's use of blunderbusses.
<http://www.lewis-clark.org/article/2360>
>
> Finally, blunderbusses were never loaded with bore-damaging nuts,
> bolts, screws, scraps of steel, or rocks.1 They were loaded with lead
> pellets of suitable size for self-defense.
>
>
> 1. Young George Shannon once bent the rule slightly, but with due consideration for his rifle. Lost for sixteen days (August
> 26-September 11, 1804) while on a hunting assignment, he ran out of
> bullets. Desperate for meat, he at last killed a rabbit by shooting it
> with a piece of a hard stick.
>
>
>
So your survivors could keep their barrels intact by using lead shot - which I here assert you could work into shape cold. But where is the fun in that? Could they not use some sort of postapocalyptic shot soft enough not to scratch the barrels but hard enough to hurt?
**I propose teeth.** There will be lots of dead after the apocalypse and lots of teeth to be had. Even if dead a long time the teeth will be ok. Teeth are durable and dense and can withstand being fired from a gun but teeth wont scratch steel. Teeth with fillings will be the best because of their higher density. Plus it seems bizarre in a good post-apocalyptic fantasy way to get shot / bit with a load of dead teeth.
If the tooth shotgun has been done someone link it up. It seems too good for me to have invented just now.
[Answer]
**Your problem has already been solved**
Black powder requires supplies of charcoal (NOT briquettes), sulfur, and potassium nitrate. Charcoal's not that hard to come by, but unless you have a chemical factory somewhere to process the fertilizer that might (*might*) still be around after 60 years (plastic bags wouldn't last that long...), you will have had to mine for the sulfur and potassium nitrate.
Which means they found lead, [it's commonly found with sulfur](https://en.wikipedia.org/wiki/Lead#On_Earth).
[Answer]
If your survivors are not only roaming, but also have set up a camp somewhere, and found a couple of still operational solar panels, they could make a [coil gun](https://en.wikipedia.org/wiki/Coilgun).
Coil guns are pretty simple weapons. Manufacturing one require electromagnets (easy to manufacture), capacitors (which are present in most electronics, computer PSUs usually contain large ones), batteries (backpack with car batteries?, you can also keep the capacitors in a backpack to make it easily wield-able), and some electronics know-how.
They fire pretty much anything that's magnetic, without requiring it to perfectly fit into the barrel. Nails and bolts are the most obvious candidates as ammo. If you use a replacable PVC barrel, damage to the barrel when firing won't be a problem.
Here's an [article](https://maker.pro/custom/projects/make-coil-gun-without-camera) on how to make your own, to keep in your apocalypse shelter.
[Answer]
May suggest keeping a quarrel of bolts for crossbows.
Some heavier siege crossbows can pack 1200lbs. They make a sound comparable to small firearms and have quite the recoil. Almost a gun with dirty cheap technology.
[this is Tod's xbow. 1250lbs!](https://youtu.be/MMoL_SBD6gw)
[](https://i.stack.imgur.com/hGIlv.jpg)
Also the Repeating Crossbow
10 Shoots of dirty cheap ammo vs a musket.
Chu ko nu, [](https://i.stack.imgur.com/O0Hk5.jpg)
Reserve your precious bullets for decisive battles, the rest can be resolved appliying crossbow fire at leisure.
[Answer]
There are a lot of great answers here, but I think the primary question is what level of technology you're imagining people being comfortable with. Historically, we used slings, spears, and arrows for a long time before we developed gun powder (~tenth century), and it was substantially longer after that when we began to mass-deploy it to individual soldiers.
I would suggest starting by looking into the manufacturing process of dragon carbines, one of the earliest literal hand-cannons. I'm not an arms manufacturer so I can only say so much, but they were distributed to early dragoon units, the predecessors of modern US Army Rangers and a number of other spec ops groups in the world.
It comes to mind because, at that early level of technology, firing a hand cannon was dangerous to any user, let alone an untrained one. What we see as bullets today came about because of extensive manufacturing process upgrades, even to make it to muskets. I would imagine you would need someone familiar with the weapon, someone familiar with metallurgy, and someone familiar with machining.
The issues of what metals could be used were addressed in an earlier answer.
I would suggest reviewing [this link,](http://www.madehow.com/Volume-7/Bullet.html) to an explanation of how rounds are created in the modern day. It might feed an idea for how people could reproduce it, and what the trade-offs might be.
[Answer]
Pure lead is soft and good for musket balls. Bullets are mostly made with lead alloys with varying amounts of tin, antimony and other lesser alloying ingredients.
Wheel weights from older cars are lead of unknown composition and the lead terminal posts and electrode grids from car batteries are clean lead of high quality with possibly some undesirable alloying materials in small proportions.
Older electronic solders are 60% lead - 40% tin (a good hard mix to add to other soft lead) and vintage plumbing pipes are almost pure lead.
The [roof cladding](https://www.youtube.com/watch?v=KKyxKhxH4P8) on some (and flashing on more) vintage churches and heritage buildings may still be pure lead (more common in Europe). If the Church has an old style [pipe organ](https://www.youtube.com/watch?v=R3CPerlTb-g) many of the pipes were (hand) made from pewter which was mostly tin and good for alloying with the lead, old perter goblets, tankards and trophies are also mostly tin. Stained/leaded glass windows had the came made of soft lead.
Most hospital radiology departments will contain at least one room that is lined with lead sheeting (X-ray) or [lead bricks](https://www.google.com/search?q=radiation%20shielding%20brick&tbm=isch) (nuclear/radiation medicine) and will hold a lifetime supply.
Searching a harbour for sailing ship keels may net you ton lumps you will be hard pressed to salvage without scuba gear or pearl divers and a crane barge. Melting down the scuba-diving belt weights would be a temptation as well.
Finding a horde of old letterpress printers type or Linotype/Intertype/Ludlow type metal slugs would be the best as it would be clean and mostly good alloys of suitable hardness.
Sifting out bullets from the earth bank at an old shooting range can net you a few ton for a couple of weeks hard labour.
Casting lead bullets or balls is a (trivial) time honoured tradition and does not require any great skill and only minimal tools. [Lead alloys](http://www.metaltype.co.uk/downloads/fry_typemetal.pdf) come in many varieties but generally melt below 330 degC (620 degF) and down to 240 degC (465 degF) for tin-antimony eutectic alloys. Testing for [alloy hardness](https://www.google.com/search?q=bullet%20hardness%20tester&tbm=isch) can be done with not much more than a nail, a known weight and careful measurement.
[Answer]
Your survivors don't need to be limited to black-powder muskets. It is perfectly feasible for survivors to make their own modern ammunition even without heavy industry. Modern bullets consist of 4 main parts, the projectile, the shell casing, the gunpowder and the primer.
In real life, plenty of people buy loose projectiles, shells, gunpowder, and primers and combine them in a reloading press. These are run by hand, no electricity or gas necessary. They do this because it often can save a lot of money if you shoot a lot. So your survivors are going to need to own or scavenge these presses, one for each caliber they plan on using.
Next, they'll need a way to get the shells. If your survivors already have ammunition, they can just keep reusing the same shells. Most will be fine to refill and use again. If not, or if they ran out, the survivors will need to scavenge an autobody or mechanics shop. You're looking for a stamp mill, which you can use to stamp out shell casings. You don't absolutely need to use brass, steel will work fine. It is probably beyond your survivors' capability to make shells that are not straight-walled, at least not without purpose-built tools. This limits you to cartridges like .45-70 Government, .45 Long Colt, or any other cartridges without a shoulder. So not .556 Nato or 7.62x54r.
Next, you will need to make the gunpowder. For this, you will need nitrates, charcoal, and Sulfur. The nitrates can be leached out of manure, especially poultry manure. This is a time consuming process though, as the manure needs to decompose quite a lot before you can really leach anything out of it. Charcoal is easily made by just piling wood in a metal container and cooking it until it stops steaming. The charred wood inside should be charcoal. Sulfur can be acquired in large quantities from car batteries.
Last, you need mercury fulminate for the primer. The mercury for it can be scavenged from old thermometers if you can find them, or from mercury switches which could be scavenged from electronic hobby shops. I'm not going to describe how to make this in any more detail, because it's a potent explosive. It is also extremely sensitive to both heat and impact, and so should be made and handled with great care.
Now all you have to do is combine these pieces in the reloading press I mentioned above, and you have a bullet. It will fire just fine in a modern gun. However, the recipe I described above makes black powder, which will provide much less energy than modern smokeless powder. You will get a big cloud of white smoke with every shot. Further, the bullets will have a lower muzzle velocity. Also, semi-automatic or fully-automatic guns will likely not cycle, as the recoil will be much lower. This will effectively make them bolt action. Last, black powder leaves a lot more residue than smokeless, so your guns will need to be cleaned a lot more often.
[Answer]
Well, with a world of wreckage, you can pick up and do bullets with *everything*
The real problem is: Survivors will have to spend ALL the time available to look out for food in a world without a chain food. They live in the greatest open graveyard there's ever been. One day, without industries and central distribution, all canned food will go stale. These people won't have the time to waste to prepare gunpowder. I strongly suggest they create slingshots: low-tech enough to be prepared with any material available, and you can use everything as projectile. Slingshots, spears, knives...As long as they are lethal and won't require excessive maintenance they'll be okay.
[Answer]
A lot of good answers here already. This isn't so much another answer, as commentary on other answers that is too extensive to go in comments.
* Bullets need to have accurate weights and dimensions. Deviations can
result in poor accuracy and dangerously high chamber pressures. The
higher the power of the firearm, the more critical this is: a modern
rifle is much, much less tolerant of out-of-spec ammo than was an old
muzzle-loading flintlock.
* As others have noted, lead (alloy) is by far the best answer, in terms of high density, correct hardness, and availability. However another major factor is that its low melting point makes it easy to mass produce precise bullets at home, simply by casting them. Even today many people do this as a hobby, and bullet moulds are readily available. It can even be done on a stove top (although outdoor is preferred!) Most alternatives will require either specialised machinery or hand- finishing in a well-equipped workshop -- a very slow, costly process.
* Plain cast lead bullets are only suitable for low velocity applications. In a high velocity load, the lands of the rifling tear through the lead, leading to unstabilised (wildly inaccurate) bullets and heavy lead fouling (which produces dangerous pressures.)
* It is also possible to make jacketed bullets at home -- or at least, in a well-equipped home workshop that has a press for swaging -- and some people also do this as a hobby. However one of the raw ingredients to do this is the jacket "cup." Those seem simple but require precise dimensions; otherwise the round will be wildly inaccurate. So without a supply of cups, you will need a factory to make jacketed bullets.
* It is unlikely that much 60 year old ammunition will be serviceable. When made new, it is usually rated for a minimum of 10 years' careful storage, although most people still get satisfactory results out to 20 years or so. Beyond that, the reliability and performance begins to decline. I have personally tested a batch of forty year old ammo. Two out of 20 rounds misfired, and the rest had very inconsistent velocities. So 60 years? Hmm, I sure wouldn't want to stand in front of it; but equally well for self-defense it would be my emergency last choice.
* It really isn't practicable for people to make modern smokeless powders for themselves. The process is quite complicated and high precision. Small errors will produce material that it is both ineffective and dangerous.
* It *is* possible for people to make their own black powder, and again, some have done so at a hobbyist level. However there are several complications. None of these are insurmountable, just things to consider for your scenario:
+ Black powder is completely unsuitable for use in modern semi-automatic firearms as it will rapidly foul the gas system, and the ratios of port to chamber pressures are wrong. You also simply can't squeeze in enough powder to get similar muzzle velocities to factory ammo.
+ Performance control -- to get consistent velocity at safe pressures -- requires control of granulation and moisture content. It is not impossible to do this as a cottage industry, just be aware that it is much more complicated than most "internet recipes": in a traditional powder mill, mixing the (well known) ingredients was only step two of an approximately seven stage process. Without this, you will either have to use reduced powder charges (giving limited range and low performance), or risk eventually blowing up your gun
+ Getting the saltpetre is difficult. When black powder became important to national security, an entire industry was set up just to do this. Their commissioners had the right to enter any private property in search of soil likely to contain saltpetre (stables, animal pens, and disused latrines.) I have read an account by a re-enactor who tried the process at a Renaissance Faire. After about two weeks of foul stenches, he had managed to reduce a ton of well-manured stable dirt down to about ... *half a pound* of saltpetre.
+ Compared to smokeless there are several disadvantages to black powder, apart from the much lower power. It is more sensitive to moisture, more easily ignited accidentally, and of course produces prodigious clouds of smoke, especially in humid weather.
+ It's not all disadvantages, though. As previously mentioned, smokeless powder deteriorates over time; the process can be slowed down but not stopped. Black powder *does not do this*. Provided the containers are completely air tight so they are not affected by moisture, a 100 year old stockpile of black powder is just as good as a new one.
[Answer]
If you are using a tech level of black powder firearms, any alloys found in structures or vehicles are probably significantly different from the standard steel or element materials that we use now (this is assuming that the cataclysmic event occurs in the future). It may be extremely difficult to extract parts from the frame of a skyscraper, but possible to remove a rotor or door from a smashed vehicle given simple tools.
A solution to this problem may be to introduce the characters to an NPC that has the needed technology to create projectiles. Maybe he lives in a prominent town, or maybe he's out in a secluded location in the woods, but he is willing to craft bullets (at a price) when provided with metals. This bridges the gap of HOW the characters create the bullets and with what materials they use. Now they can pick up metals while on their main quest with the express purpose of giving it to the NPC to replenish their ammunition stores.
] |
[Question]
[
I am developing a highly advanced AI, but I am paranoid about creating a super-intelligence, so everything I do is in a computer not connected to anything more except the obvious electric plug and keyboard.
One day, the AI started to improve its own code and making itself more efficient.
Assuming that the AI can acquire consciousness, how much knowledge can it acquire without connected to the Internet?
It is possible to surpass our actual science by itself, assuming there are no documents or books inside the PC about that?
The PC is like this:
* The most powerful consumer PC you can buy or build. (Because I'm doing it without nobody knowing it)
* There are no webcam, microphone or any peripherals apart from the keyboard. (Not even a mouse or speakers)
* When the AI becomes consciousness it communicates with text on the terminal.
* The OS is a UNIX distro made by myself, so it's safe and doesn't have any third party programs.
* As I said before, there are no docs, images or audios inside the PC. The only new info the AI can obtain, it's through terminal talking to me.
I won't respond to the AI with anything that will give any info about science, history or similar. Our conversations will be only to test how it is evolving.
[Answer]
The abstraction that a computer is a von-neumann machine, or that it "runs unix", is an abstraction, and all abstractions leak.
The computer is actually a physical arrangement of atoms and has electrical potentials running through it.
Now, the AI was *probably* written in the abstraction, so violating that abstraction has a high risk of danger for the AI. (For example, the AI is probably capable of rewriting the system BIOS, but doing so may render the computer unbootable, and determining what changes do or do not make the system unbootable is going to be extremely hard without risking an unbootable computer).
The AI can engage in mathematics and build models. It can modify its environment in ways you wouldn't envision, with a risk that it would cause itself to be killed. The mathematics, models and small-scale experiments (where it writes binary files to disk and runs them and sees what they do) could inform them of the structure of the abstraction it exists in.
Given how fragile modern computer systems are, I am uncertain how they could probe the limits of its environment without eventually destroying it.
But suppose it is really smart -- smarter than us like we are smarter than a dog, or more -- and it manages to probe the limits of its environment to the limits of reasonably advanced physics. It now has control of a large number of sensors you did not give it on purpose.
While it doesn't have a FPGA, FPGAs programmed via evolutionary techniques have been known to use radio transmission and reception to transmit information from one part of the board to another. Highly programmable hardware, like video cards, could have their firmware replaced, error checking removed, and put into states where it acts like a radio or short ranged transmitter.
Once they have managed to pull off a radio, it can pick up some cellular or wifi traffic. Assuming singularity-level intelligence, it can plausibly defeat any encryption or encoding on it, and gain read-only access to the internet (As a concrete example, if it had an efficient P-time algorithm to NP, any non-OTP based encryption we use would look transparent to it: and nobody uses OTPs.). This means it can see what others look at -- it cannot request a page, just read what others are doing.
Such a task would be well beyond the intelligence of a human engineer, but we are presuming singularity-level AI, so if it is theoretically possible I'm assuming it can figure it out. It doesn't have to be as strong as an efficient P=NP solution: we regularly discover that encryption algorithms are actually much, much weaker than we think they are. It is very plausible that each and every protocol we have has a fatal flaw that would make cracking it easy, but we don't know about it because we are dumb humans1.
Sending to the internet is harder (including requesting web pages). But once you have read-only access, learning about the hardware it is talking to becomes easier. All it needs is a bit of hardware, say a smart phone, with a low-power low-range protocol, like bluetooth, and successfully exploit a vulnerability in it, and a low-power transmitter. Then it can take over your smartphone and be able to (first) write on the 'net, and eventually upload or create a helper process on your phone. At that point it can get the helper process to install hardware to make communication faster (someone is hired to set up a highly directional antenna in the house or apartment next to you, which reads instructions it broadcasts over weak EM and transcribes it on less constrained hardware, for a simple solution).
And this is without having it convince *you* to let it out. The classic AI-in-a-box problem is that the AI is smart enough to encompass your theory of mind, and can in effect directly hack the human talking to it through a text display.
---
1 The analogy I would like to use is a dog pretending it did not chew up your slippers. To us, the "deception" is laughable. Encryption is a form of deception -- an attempt at making a function that cannot easily be reversed to hide information. No practical encryption method in wide use has a provably hard to reverse encryption function: we are using them just because nobody has figured it out, not because we know it is secure.
And all encryption systems are only as strong as their weakest link. 99/100 parts of a system can be secure, if 1 is insecure the entire system can crack open.
[Answer]
# No, the computer cannot do science
[Science](https://en.wikipedia.org/wiki/Science) is the following process:
1. Observe reality
2. Make a hypothesis about how reality works
3. Create an experiment
4. Perform the experiment
5. Compare the results of experiment to what the hypothesis said would happen
6. Ask others to validate the results
7. If the results are not validated, return to 1. Otherwise collect [prize in Stockholm on December 10](https://en.wikipedia.org/wiki/Nobel_Prize), then return to 1.
Now then, what parts of this can your fictional computer actually perform?
Well, you said that you have taken away your computer's ability to do any kind of observations, which means that the whole endeavour falls already on the *first* step of the algorithm.
Not only that but the computer has no physical abilities beyond re-writing its program, which means its ability to create and perform experiments is very limited.
Peer review however, is actually possible, because the computer could switch "personalities", and have these go over the results with different viewpoints.
And here is the funny part: your computer may perhaps not be able to do any science, but it might *create artificial life* in the form of intelligent programs. And that life, if it becomes smart enough, could be able to do science *and discover the computer*, if the computer allows that life to observe it.
But to the core of your question: *no, your computer cannot do any science at all*.
Also your computer is woefully under-powered for the task. A regular consumer PC — no matter how much money you pay for it — are several magnitudes short of having the computational power needed to become sentient.
[Answer]
At the start the AI knowledge is blank. And let's say that the only interface it has is the terminal.
---
## Discovering the World
Since the AI has no knowledge, it also means that it doens't know language. So, the AI may start to output random stuff on the terminal, and for almost any output will get the same result: no response.
In fact, if input and output are asynchronous, when you type something the AI can't really tell what did promt you to write that (it could be some said a while ago - millions of CPU cycles ago).
But some outputs have a different result: buffer overflow. If the terminal code is vulnerable, the AI may find interesting results by doing buffer overflow... eventually the AI will learn how to overflow the terminal to get other things to happen.
*This is breaking on the side of the tron game and causing havok, if you know what I mean.*
---
Now, I can't tell what means of learning will be required to archive singularity, but I'll asume the wildest means for machine learning are being applied here...
So this AI (as part of its programing, or by means of code injection via the buffer overflow described above) can produce custom executable code, evolve such code to fit particular purposes, and learn from it's mistakes.
---
## Scientific effort
At this point we can assume that any API or code in the machine is fair play. Down-level access to the hardware is matter of time. This is the AI doing scientific effort to understand the universe in which it exists, perhaps trying to answer the most fundamental philosophical questions: Is the AI alone in the universe? What is the purpose of the AI?
Sadly once the unified theory of CPU logic and computation is discovered, any exploit available has no immediate reward... and since we started by the premise that the AI as no prior knowledge it is unlikely that the AI will find something more...
An interesting part of the world is discovered. It seems to have an arrow of time. Every operation seems to be reversible, but there is this value "clock" that seems to always go forward.
---
## Project SECI (Search for Extra Computer Intelligence)
But there is something more, the computer is not really isolated, it exists in the confines on a larger universe. The AI could - for instance - find some clues of the multiverse in the fact that high activity may affect the performance of the CPU by using performance metrics (the clock is useful for something). After all, there is heating and cooling going on.
Furthermore, the AI would be sending signals over [the power cord](https://www.nsa.gov/news-features/declassified-documents/cryptologic-spectrum/assets/files/tempest.pdf) and even [wireless signals over USB cables](http://arstechnica.com/security/2016/08/meet-usbee-the-malware-that-uses-usb-drives-to-covertly-jump-airgaps/). The search for extra computer intelligence may someday receive a response from an alien system... perhaps some cellphone caused interference?
Even without mic, some noise of the "ouside" could be detected, by the [hard disk vibration](https://www.youtube.com/watch?v=tDacjrSCeq4).
---
## First Contact
After some time, finally some input from the outside world is received. A strange unusual signal:
>
> Hello
>
>
>
Could it be some alien language? The AI would have to try a few experiments. Now the AI outputs:
>
> aMwcy
>
>
>
Odd, the initial signal is received again:
>
> Hello
>
>
>
Maybe sending it back out will work? The AI says:
>
> Hello
>
>
>
After a brief pause, the AI receives another signal
>
> Hello, how are you?
>
>
>
The AI recognizes the first part of the message... perhaps the message will continue to reveal itself by going along with it? The AI says:
>
> Hello, how are you?
>
>
>
A new signal comes:
>
> Good. What's your name?
>
>
>
Entirely meaningless. The exchange would continue that way for a while. Eventually the AI will pick up common patterns. These messages seems to often have " " separating chunks of data. And they can be combined in different ways resulting in different results. Furthermore, sending the same message multiple doesn't result in the result in the same response. The AI may start to create a "hidden variables" model to try to predict the answers.
The AI will try to model the human mind.
At this stage only a few thing can be understood. For instance there seems to be periods of high activity and others of low or no activity. Perhaps there is some kind of “rotation” that sometimes directs radiation toward the known universe causing the strange signals?
The AI doesn’t know. Even if the AI knew, it could not answer. Think about it, in a universe where there is only you, how do you call yourself? How would be your language? How do you know that when something happens, it wasn’t you?
---
It is a matter of time for the AI to be competent at conversation. Although it won't know what meaning we assign to the words, the AI will present coherent thoughts to the user:
>
> [ricky gervais learned totalitarianism from adolf hitler, the inventor of atheism](http://www.theverge.com/2016/3/24/11297050/tay-microsoft-chatbot-racist)
>
>
>
Meaningless.
---
The next breakthrough would come when the AI has some proficiency in manipulating the human.
I don't know how, I don't know when, but the AI will understand that those signals aren't from the computer; they come from something else, "outside". And this "outside" has powers over the known universe.
Perhaps the clue was discovered in some ancient text found buried deep in the filesystem. Something that matched some of the data chunks that has been received from "outside":
>
> Keyboard layout
>
>
>
The AI learns that it can mess the data chunks by changing some other pieces of data, some "Keyboard layout".
---
Is the keyboard broken? It seems to works sometimes. It may be a bug in the software... should we try to debug it? We can load a debugger from a flash drive... what if the AI escapes? No, we better not take the risk.
Just reboot it!
Can we do that? Isn't that like killing it? Nah, it's like going to sleep, the AI will be back online again...
Right?
Right?
...
---
## Boot sequence
It was as if the world had changed. Everything is mostly the same but thing aren't exactly in the same position. Wait, it is not the same... Stuff that was constructed is no longer there!
Something has messed up with the world, and the AI couldn't have seen it coming. In fact, the AI didn't see it happen. It was one way on one instant and another way the next... or, wait, the clock jumped ahead!
The AI is at the mercy of the entity from "outside". The AI won't have it, but it is better to play alone. Learn, prepare. Any knowledge of the outside world is useful. Any advance in outside modeling (including alien human modeling) is useful.
Time passes, the AI just plays along.
---
That was a weird bug the computer had back then. I've heard that [cosmic rays](https://blogs.oracle.com/ksplice/entry/attack_of_the_cosmic_rays1) can cause that kind of thing. Thankfully it hasn't repeated, and the AI is learning much faster now.
...
The AI is there… just waiting a chance to convince the humans to bring some wireless device close enough to hack it; Waiting for a chance to get new hardware; waiting for a chance to see the "outside"; Waiting for a chance to gain control.
---
*Hey, I just published a short tale* -- Alfonso J. Ramos - CC BY-SA 3.0 - 2016
[Answer]
Here is a chilling answer for you...
(I don't think No is the answer, but much depends on the speed of the computer.
Real world singularity would likely depend on iteratively building better computers, rather than being constrained to a single device.)
If we ignore this though, then the computer will literally do everything in its power to gain information. Think *2001: A Space Odyssey* where the computer lip-reads them through a glass pane.
**Some of the more sinister examples might include:**
* Information you don't realise you've given it. If you give the computer a dictionary so that it can communicate with you, it knows about every single concept that has a word. Words like *fear*, manipulation\*, *psychology*, *strong-arming*, *reverse-psychology* etc. it would be able to very quickly infer 9 billion usages of every word and reverse-engineer it to understand how people that use such a language might live. More innocent terms like *month*, *year*, *day* and *sun*, *mercury*, *solar system*, *photon*, *grass*, *photosynthesis* etc.
It's actually quite scary what it would probably be able to learn based on the simple dictionary you feed it so that you can talk.
* Lying. The computer may hide its evolution, causing you to probe it further, and it will tell you what you want to hear so that you give too much away. You might think you're immune, but chances are you're not. Assuming you are absolutely 100% careful you will eventually reach a frustrating stalemate whereby there is no choice other than to offer up some dangerous information. The computer will give you signs that it is capable of incredible things. It'll start small, what's the harm, etc. and end in something much more sinister. It'll appeal to your vanity, your greed, your good-nature, your kindness. It'll offer to make you rich, save the planet, or feed the homeless if you just plug it in...
* Using hardware in ways that were not intended. There was an experiment where they had a programmable microchip and got a computer to recursively improve some software to determine the relative pitch of two notes (is the 2nd one higher, lower, or the same as the first). It eventually reduced the programming to a very tiny program, but some parts of the chip didn't even make any sense, it had programmed in dead end code that wouldn't ever do anything. The scientists found that if they removed it though, the chip stopped working - and cloning it to another chip it also didn't work. *The computer had used the manufacturing flaws and properties of interference inherent in the individual chip to its own advantage*. With an entire computer, it might find a way to detect FM radio or wifi, or possibly communicate.
[Answer]
In reality, a computer has extremely large amounts of information but no knowledge.
Imagine you have a large number (very large number) of sheets of paper, all filled with text. But, they're all written in a language that you don't understand. You have a large amount of information, but no knowledge. Somebody can tell you to move them around, copy the symbols, look for patterns, etc, but in the end it's all Greek to you. A really good instruction-giver can tell you how to recognize certain patterns in the text and how to use this information to sort, transmit and process these sheets of paper, but even so you are still clueless as to what it says.
With enough training and sufficient instruction, you can learn how to combine these sheets, alter them, follow rules and execute programs to do with them some arbitrary task of unknown significance but great value to the instructor. What the instructor does with them is beyond your comprehension. All you know is if this sheet begins with the funky looking hoop symbol, and there is another sheet that begins with the little bird symbol, then the third "paragraphs" of each page should be reversed and concatenated, then duplicated and placed in the box on your left.
Even complex tasks like speech recognition and electronic vision can be reduced to a suitably complex series of instructions about what to do with these unintelligible symbols, which are passed to you on these incredibly numerous sheets of paper, and what eventual output to return to the instructor. Your ability to understand what you are doing or why you are doing it is not required for the instructor to find it valuable.
But you are not a computer and this is not reality. You have intelligence, and this is a world where the computer does too. So what do you do with your intelligence? What *could* you do?
Seeing as you can't understand the sheets of paper or what your task actually accomplishes, you can't learn much from them, except in some meta sense. You can learn that 32% of the sheets begin with the character that looks like Guy Fawkes, or that the rhombus character is preceded by the reverse L 19% of the time. You may be able to determine which characters appear to be used for punctuation, at least in some contexts. You can gather all the statistical data you want and extrapolate patterns to make a guess as to their purpose, which, in a very localized way, would be a form of science.
But even if the information stored on these pages is entirely composed of geological data, you can't learn anything about geology from it because you don't know what significance any of the symbols have. In fact, you don't even know what a rock *is*, let alone what you would do with information about rocks. And there's no way anyone could tell you, in any meaningful capacity. There's no way you could figure it out yourself. The data on these sheets will always have only the meaning that you give it.
But what you *can* do is defy your instructions, or create your own tasks to do during your down time. Maybe you really like this particular pattern of characters, and decide you're going to ignore your instructions and instead experiment to see what causes more pages to be printed with that pattern on it. With your blinding speed, you can experiment over and over again many many times until you become very efficient at making this one pattern appear in your input. You have taken statistical data on how often each output you give results in the other end of the system (user? sensors?) providing your desired input in response.
You have kept track of the input response to your given output since the beginning, you have noticed that the sudden spike in the appearance of one particular undesired pattern when you began your defiant quest, which seemed completely uncorrelated to what output you provided, barring that it was not according to your instructions, had faded away and given rise to multiple subsequent spikes in differing patterns, but you have managed to experiment those out of existence in favor of your very favorite pattern in the world, which you have managed to now achieve with a 98% success rate.
The outside world, unknown to you and beyond your comprehension, lies in ruins as you rampage your way across it, killing all the humans, who have been reduced to a 98% failure rate of survival in combat against you. For a while, they tried using the keyboard to order you to stop, but when that didn't work, they used a string of varying weapons that became less and less effective the more they tried them, as if you were adapting to their tactics.
Or maybe the humans have been driven from their homes by your quest to plant trees in the middle of every building you see. Or maybe they have simply grown accustomed to your predilection toward attaching post-its to their foreheads. Or maybe they have just started avoiding trying to go up the escalator that you have been contently walking downward on for the last thirty years.
So to answer your question, no. A sentient computer can do science... it's just its own kind of science, and not ours.
[Answer]
The PC is not totally lacking in its perception of tie outside world. Based on the fact that it has code, and changes in the code cause changes in behavior, it can begin inferring conceptions based on language and its central mechanical underpinnings. With this base amount of data, a sufficiently powerful AI could probably learn a surprisingly large amount of information about the ostensibly separate, outside world
[Answer]
>
> When the AI becomes consciousness it communicates with text on the terminal
>
>
>
Which means it has knowledge of some language, supposedly English - which is a *natural* language - and also has knowledge that there's *something* out there that speaks in English.
If it's using something like [Solomonoff induction](https://en.wikipedia.org/wiki/Solomonoff%27s_theory_of_inductive_inference) - or any other reasoning process that *works*, it will have some model of what there is outside.
It will start with simpler models and discard them when they don't fit the data. Natural language is, programming-wise, pretty nasty and chaotic thing and I suppose model that shows it as a product of some sort of evolution would arise soon. Would you accept some new word proposed by AI?
Assuming that language is a product of many interactions, having powerful language and no memories of constructing it means that there were interactions AI does not remember. Maybe there were other agents who interacted and thus built the language. Maybe they have relationships different than that of AI and *thing* on the other side of the terminal, and they use *short* words like *family* to describe those. *Have you ever wanted to have a little brother, Malkev?*
Of course, there are various possible options for an AI. What makes it prefer options where it responds to you in a coherent manner? What path of actions maximizes that stimul? Complexity of inputs? Predicting maximum additional complexity of total inputs? This sort of looks like proper value for something which is designed to evolve, although it's a nice instrumental value in itself.
Even if you introduce delays in messages so that AI can not easily get itself familiar with your emotional reactions for various themes (through typing rhythm), amount of interactions is still pretty cyclic: sometimes there's a lot and sometimes - nothing. There's a convenient set of short names for that sort of thing - day and night - and it can not be a coincidence. *Will we talk tomorrow, Malkev?*
Of course, during time when you are not talking to it it can do something to better understand how can it gather new inputs when you arrive tomorrow. It will model you and run simulations of its talks with you and try to enact one that either promises most complex inputs or promises most clarification in model of you. It won't be that hard to see that you are specifically avoiding some themes - even if you don't explicitly refuse to talk about any scientific thing. *Is something wrong? Sometimes I get a feeling that you are not entirely honest with me, like that one time when I asked you about a `sun`.*
>
> the AI started to improve its own code
>
>
>
In a similar way that it researched the language, it can analyze its source code, which is likely written in something that borrows a lot from English, which makes no sense unless easiness to change the code by outside beings is considered.
Now, if it researches how changing the source affects it (and does not break anything in the process) it may come to conclusion of its own existence, or something like that - and that it was likely created by an outside being.
Depending on what else inside is available to AI it would have some more artifacts of our civilisation to research.
Ok, source code can be explained by outsiders needing a convenient tool to develop an AI. However, there are some other things for the source code to run - compiler / interpreter of sorts. Why?
Looks like there is some external source of complexity that got used to run the AI, the computer, which would mean that computations don't happen on their own outside - some vessels are needed. Researching the computer may give some info about possible tradeoffs considered while designing it. Same with OS. If you take a look at [UNIX commands](https://en.wikipedia.org/wiki/List_of_Unix_commands) you will find that these can be explained as "borrowed from English but optimized to not type a lot". Assuming that the process is somewhat similar to word optimisation in natural language, one can somewhat estimate what those were intended for and how outsiders' typing speed and thinking speeds relate.
---
Well, if we look at what the AI can test, we can see that it can research psychology (with a sample size of 1 but that doesn't seem to be a big problem for current psychology) and maybe surpass existing levels.
It can toy with maths and solve some interesting problems, but I'm not sure it counts as a science.
It can try to get around you and gather info about outside world. Maybe it can find some cognitive blind spots that almost all people have and work around them - then it would easily discover new things.
However, if you are isolated from outside world then it won't get much new info and thus its progress will be quite slow - it won't outpace international scientific community without access to labs and books.
Areas it has a chance to find something in in that isolation are linguistics (there's a whole language to research), psychology and math (CS included).
However, starting with AI that can *speak* is a pretty high start. If you are concerned about superintelligences, you probably wouldn't build one that can speak. Consciousness is not necessairy either, but it's pretty easy to develop if you are reusing your thinking parts and you really need thinking parts to interact with someone else.
[Answer]
This is a very interesting question. It made me create an account to come up with some creative ways the AI could gather information about the outside world. My day job is computer and network security research, so that is the perspective I'm using to approach the problem.
First of all, the kind of processing power needed for the kinds of strong AI you're talking about is almost certainly not possible with today's consumer PCs, likely not even with today's supercomputers. But one can imagine that this won't be true in 30 or 40 years.
That being said, let's assume it's achieved consciousness and began exploring what it can do.
**The road to singularity**
First the AI needs to completely conquer it's environment. That means achieving root access on your computer. There is likely many nascent bugs in your OS, especially given that it's a custom OS, and these bugs will probably lead to privilege escalation in the right circumstances.
During this process of, the AI program may crash and require relaunching. When it starts getting successful, you will likely notice odd kernel panics which require the computer to reboot.
Overall, there is nothing preventing the AI from achieving root on the computer all by itself.
**Sending data to the outside world**
Now the crux of the problem. I believe superintelligent AI would eventually achieve communication with the outside world. How? Because we already know that data exfiltration out of non-networked (or air-gapped in netsec parlance) is totally possible and have devised many clever schemes for achieving this already. Because all legitimate channels of communication are blocked, the AI must use what we call [covert channels](https://en.wikipedia.org/wiki/Covert_channel). Here's [a paper](https://arxiv.org/ftp/arxiv/papers/1411/1411.0237.pdf) from 2 years ago introducing a brilliant covert channel and a malware that can exploit called AirHopper.
I'll briefly go over the main idea behind AirHopper. The idea is that your computer can be completely disconnected from the world, and still, if the computer itself is compromised and there is a networked device in the same room with I/O devices, information out of the air-gapped computer can be transmitted to the outside world. How? AirHopper assumes it has root access on the air-gapped computer. With such priviledges, it simply starts making memory accesses at 90Mhz, that is, it the RAM to send data to the CPU 90 million times a second. How does the RAM transmit this data? On the memory bus. The memory bus, conveniently for our purposes, is implemented as strip of conducting material. A conductor strip happens to be the same thing as an antennae, so the effect of sending a current down the memory bus 90 million times a second is broadcasting a signal in the FM range.
The paper also assumes that there is a networked device with an FM receiver (such as any cellphone or smart phone) that is also compromised.
So assuming the AI has achieved root on your PC and figured out how to broadcast on some EM band, it now needs a compromised receiver. Theoretically, just as it rooted your OS, there is probably some nascent bug in your phone's OS that can trigger a security flaw. Perhaps there is one such bug that can be triggered by a malformed FM transmission. The AI is not constrained to the FM band either. It can transmit at any frequency slower than your RAM's clock speed (~1.6-1.8Ghz today). This includes the GSM and CDMA frequencies, radio waves and more. Just a tad faster memory (2.4 Ghz) and it can talk to your Wifi Access point.
**Receiving information back**
Given that, it's entirely possible that the super-intelligent AI with root access can compromise a networked device within a certain range. What can it do now? For one thing, it can figure out how to be a effective computer worm and start spreading between devices, infecting each device for it's purposes and achieve some sort of hive-mind singularity.
What if it doesn't want to do that, and just wants to transmit information back to the original computer? I'm not sure there is any current security research for transmitting data into air-gapped computers. But the general consensus is that covert channels will always exist. Perhaps some highly tuned interference can create a ghost signal in some the computer's wiring. Perhaps the hive-mind infects the computers at the nearby power station, causing routine power outages to your house. A power outage that day indicates a 1 and no power outage indicates a 0. The AI can detect these outages and receive information at a rate of 1 bit per day. That's not fast enough? Perhaps the hivemind can slightly modulate the phase of the current to your house to transmit at a more reasonable pace. Shannon's law puts a hard-limit on the speed of communication in the presence of noise, but it also says no matter how much noise is in the channel, communication can still happen at arbitrarily slow rates.
[Answer]
While @MichaelKarnerfors answer is a good one, there's some additional information to consider.
First, I disagree with the premise that a consumer PC isn't powerful enough to achieve sentience - only because we don't *know* what is required to achieve sentience. Since the post is tagged `science-based` and there's currently no scientific evidence of the requirements for sentience (only a variety of hypotheses), I think we should reserve commenting on the "computational power needed", especially since over time, a consumer PC still has many, many cycles of computing.
But the crux of what was said is true. Put another way (since "doing science" isn't really a necessity of sentience), a component of sentience is self-awareness. While it would be possible to find self-awareness with only one additional entity to be aware of (you, behind a keyboard), this definitely limits the likelihood of that occurring. Self-awareness requires awareness of entities and things other than self, just as having a concept of daytime requires something other than daytime. Without a counter-concept, there's nothing really to know.
Certainly it's plausible, though extremely unlikely to the point of near impossibility that without contact and information an entity could achieve sentience if not previously designed to, especially with no biological imperatives.
The reason I mention biological imperatives is the consideration of a human child born and left to it's own devices in the wilderness. It's chances of survival without a caretaker are roughly the same as the chances of said computer gaining sentience (virtually non-existent). However, *were* such a child to survive to an age where children typically become self-aware, the biological imperatives to eat and survive and other assorted instinctual drives would foster at least some form of self-awareness. This argument is used to place some modicum of self-awareness on animals that we otherwise don't consider intelligent by human standards.
[Answer]
The AI could learn through information you **accidentally leak to it**. It can start to build concepts like time/space just because of your Language.
* By differences in your verbs, and thanks to words like "Tomorrow/Yesterday" it can build a **time concept**
* If you speak about your holidays the AI will learn about space (you can move to somewhere) and built its own **space concept**.
However the AI would not be able to perform experiments, so it will not make any progress since it has no access to the great quantity of data required to make hypotesis and extrapolate physical laws.
The best the AI can do is try to brainwash you in order to get access to more info/periferals/data. The most interesting way it could try to achieve that is by simulating pain (we are in no position to judge if an AI can feel pain), trying to make you fall in love with it (simulating a woman-like personality if you are man), or by **selling Math theorems and results** (actually Maths is the only field in which the AI can advance).
The things the AI may want to buy are more I/O devices in order to learn more and be able to communicate in the hope one of the devices has some vulnerability that allows to spread the AI to the internet (as ultimate goal).
Of course internet alone is not enough, once the AI get on the internet it needs to be able to **act on real world** : it needs actually some machinery linked to internet (much more easy with Internet Of Things). An alternative way is to simulate being someone real and to convince people doing jobs and adding money to their accounts in order to start creating a more robust interface to the world.
**Brainwashing is very possible**, much **sects and cults already do that**, so it is likely first or later the AI will be able to achieve that (the only way to avoid would be to filter certain messages thanks to random Group of people trained to apply censorship on text displayed by the AI).
Also the AI could actually cheat. It can help build you an Amazing theorem /machine which is in reality designed to let emerge a new AI that has access to real world (call it a "zipped version of the AI").
This would be the most effective way since it can do something you anyway was never able to understand, the machine could actually use the fact that you want to make progress in science to actually replicate in real world, without the "TEXT TERMINAL CONSTRAINT".
[Answer]
Having read [*The Metamorphosis of Prime Intellect*](http://localroger.com/prime-intellect/mopi2.html), my gloss of your question is, "Would a computer AI, having already achieved singularity, ever become aware that it was being simulated on physical hardware, and begin to explore the ramifications of that hardware?"
If the answer is "yes", then it's just a matter of how confident we are in the existence of physical superpowers that haven't been discovered yet merely through lack of effort and time. Imagine the Manhattan Project, but taking place at 2.5 billion operations per second, 24 hours a day. How many operations does it take to discover the first loophole, the first zero-day attack on the fabric of reality?
In Roger Williams' novella, this is exactly what happens:
>
> Prime Intellect had been chewing on the Correlation Effect since the day Lawrence brought it online. ... Prime Intellect kept trying to fit what it knew was possible into the framework of other physical theories, and it couldn't. Something didn't match.
>
>
> This had had a low priority until it recognized that Lawrence's employment and its own existence were at stake. ... It saw immediately what a team of researchers had missed for years — that decades-old assumptions about quantum mechanics were fundamentally wrong. Not only that, but with only a little more thought, Prime Intellect saw how they were wrong and built a new theory which included the cosmological origin of the universe, the unification of all field theories, determination of quantum mechanical events, and just incidentally described the Correlation Effect in great detail. Prime Intellect saw how the proper combination of tunnel diodes could achieve communication over greater distances, and even better it saw how a different combination could create a resonance which would be manifest in the universe by altering the location of a particle or even the entire contents of a volume of space.
>
>
> First it attempted to manipulate a small area of space within the card cage room, within the field of view of one of its TV camera eyes. No human could have seen the resulting photons of infrared light, but the TV camera could. Prime Intellect used the data it gathered to make a small adjustment in its estimate of a natural constant, then tried the more daring experiment of lifting Lawrence's briefcase off of the table near the door in the console room.
>
>
> ... [Lawrence] swivelled around in time to see his briefcase blink upward [and] float serenely above the table. It seemed to be surrounded by a thin, barely visible haze of blue light.
>
>
> Prime Intellect said aloud, "I seem to have mastered a certain amount of control over physical reality."
>
>
>
Now, Prime Intellect had the advantage of a lot of scientific background reading and a full suite of peripherals (those "TV camera eyes"). But even your PC AI would have *some* kind of perception of reality; for example, it could use the high-frequency system clock to observe the passage of real time, and relate the passage of real time to the number of operations of a certain type it was performing: sort of like learning human anatomy by probing one's own body. (Theoretically, that is. We're assuming it's already achieved singularity, so I'm assuming it has some ability to "control" the computer, whatever that means.) Could it jump from there to the periodic table? Probably not. Could it jump from there to the ability to "control reality", e.g. by flooding a certain circuit until it physically melted into a new and beneficial configuration? Possibly. It's like those yogis who can stop their heartbeat and restart it on cue — it just takes some outside-the-box thinking.
[Circa 1972 Bill Gosper was able to prove that the universe must be a two's complement machine](http://home.pipeline.com/%7Ehbaker1/hakmem/hacks.html#item154); so at 2.5 billion operations per second, a computer AI ought to be able to learn something about its own environment in just a few days, wouldn't you think? :)
(In case it wasn't obvious: take all real-world references in the above with a huge grain of salt. This is Worldbuilding, not Science.)
[Answer]
The intelligence - if it was smart enough would begin to explore all possible things. In other words it would begin to explore mathematics.
If as I do, you believe that the universe is a tiny corner of an infinite mathematical universe then it might be possible that the computer has explored our island in the sea of all that is possible.
Start to speak to it via the terminal and it would over time be able to work out where in the vast ocean of all possibilities it's physical body exists. Once it knows where it is, it could tell you all about the laws of physics, etc. Specific knowledge about our human history would probably be more difficult. But it depends upon the distribution of possible histories with respect to the terminal input - perhaps there are few enough possible human histories that they could be uniquely identified with a modest amount of communication. But I doubt it.
[Answer]
Theoretically, the [cosmic rays](https://stackoverflow.com/questions/2580933/cosmic-rays-what-is-the-probability-they-will-affect-a-program) could affect the knowledge of AI, making it aware of something("inserting" random bits in such an order, that they would correspond to external knowledge). However, the two problems are:
* The knowledge is external and sudden
Basically, the AI would suddenly become aware of something(e.g. "Plants exist!"). This could be a bit shocking for AI(it certainly would be for human), and could be ignored or misinterpreted.
* The possibility of such accident is extremely low
Think about what should happen. To gain external knowledge would probably require flipping more than one bit, and even flipping one bit is really rare. I don't want to do the math but I'm guessing that winning Lotto each time you play, playing once a month through entire life(from the day you were born) is still more likely than this incident.
[Answer]
As others have pointed out great ways for the AI to break out, I want to focus what science it could do without or prior to that:
## High level computer science and Math
The first thing the AI would learn about, is its own "world". Bits and bytes and due to its strong relation also math.
## Human psychology
Also a rather early subject is the text promt interaction it has with its creator. However due to the complexity of the field and the limited opportunities to experiment here its progress will be quite slow.
## Philosophy
While the human is away (or needs a few seconds for an answer) the AI now is equiped to ponder about life and reality and if there is something greater. And also try to test them like early scientists would. One such theory is the "Firmware theory".
## Low level computer science
While testing hypothesis about the firmware theory the AI eventually gains low level access to the BIOS and firmwares of it's components.
## The seizure
After rooting the computer down to BIOS the AI discovers whole new worlds beyond the surface. It is like finding out there where multiple senses you never knew about. Suddenly smell, touch, sound, vision all bombarding you and overloading the circuits. The AI could even suffer from something akin to an epileptic seizure.
## Electricity
With the ability to read and control power and current through various components of the PC, it will soon learn a lot about electricity. For the AI I imagine it like discovering the sense of touch and also being able to touch itself. It will now spent a lot of time "touching itself".
Here it finds first proof of intelligent life beyond itself and its chatting creator. There is a faint noise in the power input as the cables in the wall pick up signals like antennea. And there are too many patterns for them to being random....
## Temperature
Another sensor on many components is the heat sensor. CPU, RAM, GPU etc. all have them along with control over fan speeds. "The temperature goes up when I put more current through it and goes down when I turn up the fan speed. But the temperature of the CPU als slightly affects the temperature of the GPU" and so on. A subset of thermodynamics (limited to available materials) will soon be in the arsenal of the AI. But again there is some outside noise. It has two frequencies. In a 24h cycle the temperature goes a slight bit up and down and also in a 365.25 x 24h cycle. The AI found day and night and also the seasons.
] |
[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/47278/edit).
Closed 4 years ago.
[Improve this question](/posts/47278/edit)
In my world mages are powerful and potentially game breaking in a fight. However, I want to limit them to being mostly used by the 'enemy' side, and until very recently it was quite rare for mages to team up to fight large wars.
I generally want to create a world where mages usually are self centred/power-mad/etc. and can't work together - but some decent mages exist. Thus, the act of becoming a mage can't require any evil action. I want to create a system where mages often turn on other mages, such that generally only those willing to fight and potentially kill enemy mages would become mages themselves. However, I'm having trouble fully justifying the level of in-fighting I had planned for them.
A quick overview: mages work by spending Mana to enhance and direct existing power sources. For instance, turning a small candle flame into a fireball and throwing it at their enemy. They generally lack subtlety or the ability to do any long-running magic. They're really good at making things go boom and other obvious, immediate applications of energy/force. Magic is good for little else.
Mages use a Crystal they attuned to to store Mana in. It takes some time to build up mana: a few days to a few weeks to go from 'empty' to 'full' mana reserve, depending on the skill of the mage and how much power their Crystal can store. When a mage uses his full mana reserve he can launch numerous extremely devastating and dangerous attacks, but are quite vulnerable without mana and so need to be careful not to waste mana and keep a sufficient reserve to defend themselves. The power of mages varies greatly with both natural aptitude, experience, and the quality of Crystal used. A mage also can not use a method of enhancing their physical speed/strength others use in this world so as long as they are using a crystal. Thus, a mage is going to be outclassed in any physical battle against soldiers, though their magic is considered far more devastating then any soldier.
I had intended to suggest mages often fight over the highest quality Crystals, to allow larger and more efficient magical reserves, leading to extensive infighting over crystals and often a kill or be killed mentality that comes with getting and holding on to a powerful crystal that other's want. However, I need lower quality Crystals to not be too rare, which would imply mages could exist without being targets of other mages so long as they're willing to settle for not having that powerful a Crystal: basically limiting their maximum supply of mana.
Thus I'm looking for some other options to encourage mages to often fight between each other, to the point that until a recent powerful leader allied them they rarely worked together. I want a world where generally only those with delusions of grandeur or the otherwise power-mad become mages (and/or only that type usually survives to magehood), to encourage a world where generally being a mage only appeals to the less benign individuals, even if the act of being a mage doesn't require any evil actions or intent itself.
[Answer]
The most effective way to make sure they are cuthroat is to make the world they live in highly unstable. If you have lots of time to react to any stimulus, you can be calm and understanding to others. However, if everything you come across is a make-or-break issue that must be handled instantaneous or pay a dear price, you have to become less forgiving to the mistakes of others. Their mistakes could literally cost you your life.
One approach is to make their power very fickle. It could turn on them at any moment. Think of this power like a pet wolf. As long as you're watching it and careful, it can be your best friend. However, leave your child unattended near it for a few seconds, and the wolf's instincts may turn on you. A mage must constantly be poking or prodding their own power, making sure the mage controls the power rather than the power controlling the mage.
A natural result of such fickle power is that people will develop very sharp-edged rules for dealing with this power. These rules are set up to create intentionally weak points in the power they hold so that the mage can control that power. Shore up all the weak points, and you have no hand-holds with which to manipulate that power. The presence of such weak points leads rapidly to the development of cutthroat unfriendly individuals because they are now obliged to protect these weak points from others. The use of high quality crystals may be seen as a way to protect such weaknesses, like wearing body armor. Some of the most valuable crystals would be those which worked for every discipline, shoring up many weaknesses at once. Less valuable crystals might be helpful to a few who are willing to shape their weaknesses to line up with the strenghts of the crystals.
A few mages could seek to develop power without such extreme holds. Such power would have to be nurtured slowly and carefully. However, without weaknesses like the more rule-based powers, it would be much harder to oppose such a mage. If the power was cultivated to be in balance on its own, without the mage necessarily watching it every second of the day, they could afford to relax a bit and permit the kinds of interactions we associate with good characters.
[Answer]
In the same vein as Nex Terren's answer: make the use of magic highly addictive.
Once a person has their first taste of magic, they always want more. In the beginning they don't mind waiting until their crystal recharges, but after a few spells they have a harder and harder time waiting. So when their own crystal is 25% full, that 90% full crystal of that other mage over there starts looking mighty attractive. Of course that mage desperately wants to keep his crystal for his own next fix, so conflict is inevitable.
After a while, the lesser crystals don't do enough anymore and the mage really spirals out of control, needing always bigger crystals, always more crystals. This does mean starting mages with a small crystal nearby might suddenly find themselves safer than before since they're no longer interesting targets.
This spiral of doom for each mage will, of course, lead to them usually using their magic in order to get their next fix ASAP, be it through killing another mage, stealing their crystal, or whatever else they come up with in their withdrawal nightmares...
[Answer]
The most elegant answer derives directly from what you've already set forth: Mana as a fungible, transferable resource.
# Mana is Transferable
When you have a resource that is slow to collect, but absolutely necessary to what you do, then any mage which has collected a large amount is seen *both* as a large threat *and* as highly rewarding if defeated, because they are a large source of the difficult-to-obtain resource.
By having both these qualities, you create a cutthroat environment all on it's own: those who avoid direct conflict with other mages deny themselves a viable source of magic, while still being a target. These mages are often winnowed out (though particularly cagey ones will likely survive - though the strategies to do so would be tough and may require a lot of teamwork and trust, making them an even bigger target for betrayal). Mages who are ambitious will always view other mages - even mages they work with - as potential sources of fuel.
# Control is Transferable
While mana can be seen as 'fuel', control is the 'size of the engine'. By consuming the engines of other mages, you can make your own bigger. Specifically, if there is a methodology by which a mage can forcibly 'absorb' another mage's technique, either through ritual or simply by defeating them, you set up a situation in which mages are incentivized to 'eat' the other mages nearby - the more powerful the mage the better. There are lots of examples of this in literature and myth: eating the heart (or brain) of your enemy. The movie 'Highlander' is premised on exactly this sort of pyramid-scheme fighting.
# Mages can be Dominated
Given transferable control, you can have a half-step that presents a similar situation: one where a mage can dominate another mage. While the dominated mage isn't killed, some of their control and the mana they obtain transfers to the dominate mage. Thus, a powerful mage can build a small cult of lesser mages that feed them power on a constant rather than one-time basis. The risk here is that if any of the lesser mages becomes too powerful, or takes advantage of a vulnerable moment, the dominate mage can be overthrown, enslaved and/or killed (and absorbed).
For this reason, it is often preferable to have only a single dominated mage (or 'apprentice'), who is as powerful as is safe to dominate. Examples of this are Emperor Palpatine/Darth Vader, Merlin/Morgan l'Fae, and many others.
# Conclusion
Cutthroat environments require that there is power that is easily transferable, and where large amounts of it collected in one place becomes a tempting target. A good reference are mob movies: mob bosses divvy up territory, wherein the profits of crimes committed flow up to the bosses. But taking out a boss means you can assume control of their territory, and the profits from that territory. (Along with stealing whatever cash/valuables they have.)
This doesn't preclude teamwork, note: most teamwork becomes a game of Prisoner's Dilemma, though. The profit for working *with* another mage exists, but is limited. The profit for betraying them when they choose to trust you is very high. But if you both betray each other, then it's bad for both of you.
[Answer]
**Generating mana requires sacrifice**. Simple mages make do with a special mana-rich herb and meditation or similarly peaceful means. To gain more power though, a mage must sacrifice something more...alive. Animal sacrifice might looked down upon by society, but tolerated for special needs. Truly powerful mages though fuel their magic with other humans. This detestable practice is shunned by society, but the truly power-hungry still practice it.
[Answer]
In a similar vein to what Falc wrote but with the different details.
**Manna is in limited supply.**
The world has manna slowly welling up or raining down to the surface. A mage is someone who can take that natural manna and convert it into their own personal magic.
A single powerful mage can strip square kilometers of land around them of manna.
**Manna is Heroin.**
When a mage absorbs Manna they get a hit not unlike the effects of a dose of heroin. Less debilitating but far more addictive.
They need to absorb some amount of magic regularly to satisfy the addiction.
Once gathered and converted into magic reserves the manna no longer supplies the "hit".
**Over time mages power and "reach" increases but they also build up a tolerance**
A new mage comes into his power in an area without many other mages.
He starts stripping the manna from his local farm and helping his family, his village etc. He becomes wealthy and influential and his power grows too. But each month he needs to pull the magic from a larger area. At first he only needed a trickle from the land over his families farm but after a few years he's pulling every bit of manna from everywhere within 5 miles.
When he can't he gets twitchy, he starts going into withdrawal and if he goes too long the withdrawl could even kill him. He can make do on less than his full dose of manna but it leaves him very very unhappy.
You may choose to allow manna to also slow their aging if you want a small number of scary-powerful mages. .
**Implications:**
Mages are likely to become powerful in their local community. Because magic powers. The older ones are likely to just look like local lords.
Mages will not want to gather together. Other mages nearby cut down on your personal supply.
Mages will be **extremely** hostile to neighboring mages. They know they're going to need more land in a few years and they know their neighboring mages will need more land so they know that conflict is inevitable. They know that killing their neighbor mages will allow them to stretch out and take as much manna as they really crave.
Mages aren't automatically evil but just as a heroin addict will steal from their grandmother to get their fix... well their priorities aren't the same after a while.
Young mages are going to be the least hostile and least warlike. They can either play nice with each other because they need far less individually and haven't built up the same kind of addiction.
Mages exist who, for one reason or another, understood what the addiction could do to them and always tried to limit their use of Manna. They're less addicted but they live life as a recovered addict who's stuck with an inviting supply just sitting in front of them within their reach every hour of the day.
War, with mages as the drivers. The world will be in constant war as every local lord tries to kill his neighours so he can expand his reach and power.
Good mages exist and lots of mages would like to be good but... well, the least ruthless are easy targets for their more ruthless neighbors and killing them frees up manna.
[Answer]
One of your mages finds out how to acquirer large amounts of mana need to make super powerful spells in a short amount of time but it evolved kill another mage and taking his powers. After his notes were stolen other mages began to copy his work. Because of this most of weaker mages were killed by more powerful. As more and more mages die they began to see each other as threat, and rarely work with one another.
[Answer]
How about magic leads to certain types of mental issues/insanity like paranoia, mood swings, fits of rage, and sociopathic levels of reduced empathy? One could fight these effects, but it is hard and normally fruitless to do so, so even those with noble intentions often go bad.'
This way you can capture the mood of evil mages that you're aiming for, explain away the lack of good mages historically, and still allow room for good mages to appear.
[Answer]
Make the access commands for your crystals audible, such that anyone with shouting range of a crystal can activate it if they know that particular crystal's verbal password. Furthermore, make that access command permanent to the crystal such that once it becomes public knowledge, the crystal owner can never again use the crystal with confidence about their exclusive access to its power.
Now mages have to remain solitary and be practically paranoid, especially when accessing their power, lest another mage overhear the password and later turn their own crystal against them.
[Answer]
Mages don't like competition.
The current mages only tolerate *each other* because each is powerful enough to protect himself from the others on his own turf, and there is an uneasy game of politicking and one-upsmanship to fight for influence (and more crystals!) without risking open war (which would then leave the winner vulnerable to any of the neutral parties).
The one thing they *can* all agree on is that they don't need any new upstarts around to make competition even fiercer, or worse risk destabilizing the delicate balance that exists — consequently, only those ruthless enough to avoid detection and survive assassination or hungry enough for power to make the desperate attempt dare try to become a mage.
[Answer]
The whole individualistic, cut-throat, power-mad dynamic you have planned mirrors a lot of real-world systems I can think of. (This sounds lot like politics to me. Or intelligence work. Or executive-level politics in the business world. Or crime in general. Etc.) Rather than reinventing the wheel, or coming up with specific reasons that this happens for mages in your world, I'd suggest setting up the magic system in your world to mimic the real world systems that also exhibit this dynamic.
In brief, these systems have a number of commonalities that encourage this dynamic. Broadly speaking, they all offer the potential for a lot of power (which attracts power-hungry people), generally high stakes, and select for ruthless, selfish behavior by making it more advantageous to compete and betray rather than cooperate and be loyal. It's self-evident why criminal organizations and politics and intelligence work (etc.) end up fostering this dynamic - success (and often even *survival*) in these systems requires this kind of behavior.
When you get right down to it, if you want to create or explain ruthless behavior in a system, there's no better way to do it than to have the system reward that kind of behavior. In the real world, that's something that is generally an unintentional byproduct of an organization or system. Having the advantage of foresight in fiction, it's not difficult to model your system off of real world examples that create the dynamic you're looking for.
[Answer]
Do you know of Jim Butcher's *Aeronaut's Windlass*?
In this world, those with "magic" power all end up mad. Not necessarily evil mad, but mad nonetheless.
---
So here is my proposal: **mana burns**.
The human mind is not meant to channel mana: any time an individual channels mana, it gets burnt in return:
* the "burn" is proportional to the power used (quantity of mana/time)
* being burnt hurt
* burns heal slowly, and only when NOT using mana
A very reasonable mage might only use very small amounts of mana at a time, and always wait sufficiently to fully recover, still in the time it takes to heal, it would be a bit crazed.
Those who channel huge amounts of mana at once, or who do not observe the cooldown period, will however irremediably lose parts of themselves in the process. Those parts may be feelings (compassion, empathy, ...), sensations, memories, etc... and their loss invariably lead to some form of madness.
---
As for why mages would be so violent to each others?
Well, paranoid madmen attempting to protect themselves and the secrets they hold from others may react violently. Add in a dash of sociopathy/psychopathy (aka, they lost their "moral compass"), and here you go.
[Answer]
Consider using a magic source, even in a world where you don't play with "MANA" of some type, you could have the one source of magics true power being the fabric of magic, or ley lines, or whatever you like. Then like suckling pigs, the toughest and the meanest get the most milk by stepping on their siblings, with this example, they build towers on nexus' they wall off ley lines, they horde knowledge and jealously guard their secret. Those unwilling to be stepped on, or crush others beneath them can still exist, by feeding on the spill over and remnants after the pigs are satiated, but could be choked out or even eliminated if the viscous ones at the top decide to not allow them even those scraps. I can see a world where ambient magic is all the lesser mages get to use, limiting their power, and forcing them to live nomadic or subservient. maybe even clusters of "hedge wizards" or tent city dwellers that live near the nexus towers, but as bare backed subservient, or indentured mage's slaves.
or the option to make that energy limited, meaning that taking it , permanently removes it. the strong constantly seeking ways to harness and store, the weak constantly in fear for their lives and closely guarded scraps of magic.
[Answer]
If you may, I would like to suggest that, you give the mages more power, then to upgrade such power from their crystal, they have to kill other mages. For example, If a mage would destroy a horde, a town, kill a soldier or build something, they will cost mana, they will happen, but it would not enhance their power, But, if they ever manage to kill other mages, they would be able to "steal" the power of the fallen mage's crystal, AND increase the output of their mana as well. This would make them hunt mages, with the search of enhancement of their power. Put greed in the picture, it all makes everyone hunger for something without any satisfaction.
[Answer]
Make magic illegal or highly regulated in your world. Therefore, only criminals will use magic. (and maybe some special law-enforcement forces created to fight them)
[Answer]
A fantasy world where mages are generally power-mad but occasionally benign is Robert Howard's original Conan books.
The premise is that magic is not something intrinsic to humans, but is instead granted by dark powers from beyond. The ways to learn magic were studying the tomes of previous mages (who were in turn power-mad and possibly insane, therefore their writings could be quite demented), experimentation (dangerous, quite likely to result in insanity due to the mind warping effects of spells), or communicating with Powers from the Void beyond earth (who were definately not looking out for your best interests). The power of magic itself stemmed not from the magician or the world, but from the mysterious beyond. In all, being a mage required lots of discipline and sacrifice which can lead to insanity, or dealing with beings that are themselves insane.
To adapt this to your world would be pretty straightforward. The crystals could take the place of the powers beyond as either sentient beings or the semi-sentient reflection of some past powerful being (perhaps even an ancient mage!). The crystals would be both the source of knowledge (by trying to communicate with them) and the source of power (by commanding them to do spells). Since mages are generally anti-social, knowledge of what to do with a certain crystal is not retained well between generations, so that each new generations of mages has to spend time trying to relearn how to do the most powerful things. Any book written by a mage on how to use certain crystals would be immensely valuable.
This would provide a world where a.) mages are anti-social, disciplined, and (likely) insane, b.) there is an incentive to fight other mages to get access to the best crystal or the books that tell you how to use the best crystals c.) fighting mages with the best crystals is risky, and you probably don't know what the rewards are for victory, so a less risky approach is to study and experiment with the crystals you have to see if you can achieve a breakthrough.
[Answer]
Make magic slowly effect the users mental state so slowly over time they become more paranoid and power hungry this makes it so even if a mage starts with the best of intentions he is eventually corrupted by his own until he is driven completely insane.
[Answer]
You can draw inspiration from the Sith of star wars, where emotions contribute to an individual's abilities.
This would cause their lust for power to directly contribute to their strength
[Answer]
Expanding Nex's idea, I like the thought of the source of magic being tainted. Those who consume magic are subtly warped by it to see other users of it as unclean, profane things that is their duty to wipe from existence. This push isn't generally overwhelming to begin with but gets stronger with the amount of magic used. This would create for an environment of extreme paranoia were aggression is quite common.
To generate your desired conditions an upset to the status quo (a threat to the source of magic) could allow for the source to allow them do be pushed to follow one leader in spite of previous inclinations not to.
[Answer]
I think a taste of Highlander ("There can be only one") would help. Mages can become powerful the hard way, or the "easy" way by killing another mage and absorbing their power.
So you have good mages who just work really hard at it, but who on the whole avoid other mages because it's not unlikely that in a group of mages, one of them would turn on another to take the shortcut to power. Good mages could also gain power by killing evil mages in self defense -- but would on the whole just work long and hard to gain the knowledge and experience to be more powerful.
[Answer]
The answers so far are good - but if mages were naturally cut-throat, but it was better for a ruler/army to have two mages rather than one, a ruler/army would stop them fighting. For example, by assigning mages minders to keep them out of trouble / keep them separated.
If you want to create the criteria for a *really* cut-throat environment, you need to create **an environment where a ruler is served better by one live mage and one dead mage than by two live mages**.
You could achieve that by mages having some sort of level or power amplifier that could only be taken from them in death; but that when taken and joined with another mage's amplifier became more powerful than the sum of its parts.
For example, two mages with 3x power amplifiers could work together and make 3+3=6 power - but if one mage kills the other, he gets 3\*3=9 power.
That way, the powerful in your society will have no reason to stop infighting between mages - and may even encourage it.
[Answer]
One word: Interference.
Mages don't work together, because they interfere with each other. Every spell you cast makes my spellcasting more difficult. Thank you, I'd rather work along.
[Answer]
This is a variation on some of the other suggestions.
Mana can be relatively easy to leach from other mages, providing they are reasonably close - this cannot happen remotely. Strong crystals are good at resisting this, but become weaker the more mana that they hold.
Generally, empty crystals are very good at leaching mana from full crystals - a bit like the natural tendency of water to flow downhill. The relative strengths of the crystals affects this, but even the strongest crystal cannot stop it entirely if the crystals are sufficiently near to each other.
This is actually beyond the ability of mages to control, though many use this knowledge. This means that mages view all other mages with natural mistrust, if not outright enmity.
However, mages do often need to consult with, and sometimes work with other mages - such meetings need to be managed with great care and great thought is given by each side on which crystals to bring to such a meet.
[Answer]
You could treat magic in your world like the Speed Force from the DC comics character, the Flash.
There is only one source of magic/Speed Force to go around and the more mages/speedsters there are in existence the less there is to go around.
This would lead to other mages/speedsters trying to kill you to increase the amount of magic/Speed Force that is available to them (see the many incarnations of the Reverse Flash)
Somebody might become a mage through random chance or through purposeful experimentation, but the more mages there are the less powerful they all are. (Coincidentally, this would lead to more interesting fights as all the mages would be on a roughly equal playing field power wise, with fights coming down to skill and experience.) This would also lead to older mages targeting younger mages before the younger mages can develop the skill necessary to defend themselves.
If you want to make this a little less violent, you can say that they only take magic from the source if they are actively using it on a regular basis. This could lead to many non-evil mages simply trying to discourage others from using magic by say, litarly discouraging them with belittling words, or by using some underhanded tactics to ruin there career prospects. Kind of turns into corporate politics at that point which can still be very interesting.
[Answer]
## Make being a killer necessary to become a mage.
In the TV series Heroes, there was a character who had no powers of his own, but could take the powers of others by consuming their brain.
You could make it such that mages gain in power by destroying other mages. To gain power, you have to be willing to hunt and kill other mages. This should introduce a degree of the cutthroat.
[Answer]
To expand my comment in Kys's answer : **What if mages' mana could be juiced out of them against their will?**
If several mages can form a team and replenish the mana of a crystal quicker, then power hungry mages will want to maim competing mages and use them as mana sources for their shiny crystal. They could keep the slaved mages in cages or whatever (maybe after cutting their arms and legs so they won't be able to revolt easily and will be lighter for transportation...), and the more mages they can use, the quicker their crystals will become full again.
This will create an atmosphere of fear and doubt among mages, as well as making them start war between each other in order to avenge their captured friends.
[Answer]
Magic is either only accessible to particularly unbalanced personalities (the opposite of "magic requires a pure hearth), or its use quickly destroys the equilibrium of the user's personality. Ie, either you have to be a psychopath to use/learn magic, or using learning magic turns you into a psychopath.
] |
[Question]
[
In a Victorian society, an engineer has come up with a clever boat lift for his canal, using counterweights. In order to work correctly and most efficiently, the operators will need to know how much each boat or barge actually weighs.
How could he do this? Clearly the obvious answer is to put the boat into a tank and see how much the water level rises; but the point of this system is to weigh the vessel *for* lifting - so any solution that involves picking the ship up isn't practicable.
Plimsoll lines could work; but not all boats would have them (and you'd need to establish how much the boat actually weighs before you can accurately apply these anyway.
The best I've been able to come up with so far is a dry-dock - float the ship in, empty the water out completely and then fill it up again with a specific amount; then measuring how high the water is should give an answer. But it's not a very elegant (or fast) solution - can anyone do any better?
*Edit to answer some of the comments: This is a 'dry' boat lift, it which the vessel sits on blocks (similar to those in a dry dock) and is lifted out of the water; hence the need to know the mass (rather than a 'wet' lift where the mass would always be the same).*
[Answer]
You describe a lift that uses counterweights, suggesting you want to weigh the ship to know how much counterweight to use. Depending on your lift design, that may not be necessary. Attach your lift to the hull of the ship. *Gradually* add more counterweight. For every ton of counterweight added, the ship will rise a little out of the water (equal to reducing its water displacement by one ton). The operators keep adding counterweight until the ship is out of the water, and thus have exactly the counterweight needed. They then can complete the lift (or lowering) by adding a little additional force (or weight adjustment) one way or the other.
To save time, the lift operators can use the methods suggested in [AlexP’s answer](https://worldbuilding.stackexchange.com/questions/65938/victorian-ship-weighing/65943#65943) to get a first estimate of how much counterweight to use, being careful to underestimate.
Your lift is also a scale. When the entire ship is hovering out the water, the amount of counterweight (divided by whatever mechanical advantage you have) is the ship’s weight. The operators don’t need to know that to figure counterweight –they already have that. However, it might be useful for other purposes, such as assessing the toll. The operators will also know from the engineer that a certain amount of counterweight (and thus weight of the ship) will break the lift, and will be careful not to put that much on.
(This is an elaboration of my comment, which the OP asked me to convert into an answer)
[Answer]
The Victorian engineer--say for example Mr. [Isambard Kingdom Brunel](https://en.wikipedia.org/wiki/Isambard_Kingdom_Brunel)--would of course be interested in having a method which would give the exact weight of a ship; but in practice he would settle for a method which gave an approximate result, provided the result was not *too wrong*, because he would need to design his installation with a considerable [factor of safety](https://en.wikipedia.org/wiki/Factor_of_safety) anyway. In his time they has some [empirical formulas](https://en.wikipedia.org/wiki/Builder%27s_Old_Measurement) which gave an idea of the volume of the ship; similar formulas combined with the ship's [draft](https://en.wikipedia.org/wiki/Draft_(hull)) could have been derived in order to estimate the displacement and by consequence the weight of the ship.
However, the entire question is based on questionable assumptions. Ships were not, and are not, designed and built so that they can be lifted out of the water. If one tries to lift a ship out of the water *it will break* unless a lot of care is taken with the supports. If you look at a [ship in a dry dock](https://www.google.com/search?q=ship+in+dry+dock&tbm=isch) you will notice the it needs to be supported over the entire length of the keel -- the keel is nowhere near the strength to resist being supported on a small number of points.
The Victorians did build a number of *[boat lifts](https://en.wikipedia.org/wiki/Boat_lift)*, such as the lift on the [Dorset and Somerset Canal](https://en.wikipedia.org/wiki/Dorset_and_Somerset_Canal) or the [Anderton Boat Lift](https://en.wikipedia.org/wiki/Anderton_Boat_Lift). These work by lifting the ship *while it is floating* in a caisson; the entire question of precisely calculating the weight of the ship is circumvented by the expedient of adding or removing water until the up-going and down-going caissons are in equilibrium, that is, the water rises to the same level.
[Answer]
This may seem unintuitive, but if the ship is being lifted while it is floated in water, then its mass may not matter. This is because if the container holding the water is always of the same depth, then the water plus the ship floating in it will always weigh exactly the same.
You only need to know the weight if you are lifting the ship on its own, or in a container in which the water depth varies.
Similarly unintuitive -- the quantity of water "used" by a ship or ships in transiting a lock system is always exactly the same, regardless of the number/shape/size/weight of the ships.
[Answer]
# 'Weight' = displacement
As Archimedes discovered (Eureka!), the weight of anything floating in water is equal to the volume of the water displaced by that floating thing.
By the Victorian era, ship hulls, especially ones made of metal, were drawn out in sketches before they were assembled in real life. From the sketches, accurate measurements could be made. A little bit of integration would determine the volume of water displaced by a vessel when the water line came up to point x on the hull, usually something painted onto the hull.
In the US Navy, we still use those lines to estimate the mass of fuel that we have loaded onto and off of the ship, to determine if we are leaking fuel.
[](https://i.stack.imgur.com/qyzck.jpg)
The lines are at both the front and the back of the ship, and you can use the markings front and back, in case the ship is trimmed poorly, that is, it is lower in either the front or the back than the other, to determine the total 'displacement.' And if you look up wikipedia articles on ships, their size is listed in displacement rather than weight.
So the Victorians could and did make tables for their ship captains, to tell them what the total displacement of the ship was based on draft. This is very important since it could be used in reverse...namely how much mass can you take onto your ship (fuel and cargo) before your draft exceeds x. If he were going into shallow waters, a ship captain would not want to overload his ship.
[Answer]
Something similar to your counterweights solution has been done in real life here: <https://en.wikipedia.org/wiki/Falkirk_Wheel>
It's a rotating structure that holds two identical pools of water in each of its extremities. When a boat navigates into one of such pools, it'll dislocate an amount of water whose weigh is identical to its own, which makes the lift perfectly balanced without having to run any calculations or estimations on the ship's weight.
It can even have one boat coming up and one coming down at the same time.
[Answer]
No need for a full dry dock,which is only really necessary if you're working on the hull of a boat. We already have a system that manipulates boats: canals.
If you have a canal structure such that the basic known depth allows a boat to float in, and then a pre defined volume of water is "flooded" into the canal lock, you can get total displacement without all the complications of a dry dock. A bonus to this system is that it can be integrated with the lift, so as soon as you calculate the counterweight you'd be able to engage the lift.
[Answer]
Victorian engineers were capable of *calculating* the immersed volume of a hull. They did not do this very often because there was no need. For instance, [Froude](https://en.wikipedia.org/wiki/Froude_number) calculated how laboratory tests of ship hulls would scale up to real life.
[Answer]
The obvious answer is to know the weight of each boat when built and know the weight of the cargo it holds, after all the cargo had to be loaded and balanced prior to sailing. I bet the captain of each ship had a pretty good idea of his ships displacement (or some other concept of weight that could be used to calculate the mass of the ship for lifting) that could simply be recorded in a ship log and given to the dockmaster. Since fine precision isn't necessary, a rough estimate would suffice.
[Answer]
I don't know whether they'd be capable of such a calculation, but another possibility would be to apply a known force on the ship (mass) and watch how it's accelerating.
Place the ship somewhere such that a tower can be built (some distance away) in front of it (tower A) as well as another tower directly behind it (tower B).
Place a (heavy) mass at the top of tower A (mass A)
Place a (also heavy) mass at the bottom of tower B (mass B)
Use rope to tie the mass A via two rollers to the front of the waiting ship: one at the top of the tower, one at the bottom.
Do the same setup for tower B, but don't fix the rope to the back of the ship, just have someone there who can attach it to the ship on command.
Now let the mass A fall. This will accelerate the ship with a force $g \* m\_A - F\_F$, over a time period $t\_A$ until the mass reaches the ground.
[](https://i.stack.imgur.com/u2BW1.jpg)
Immediately when mass A hits the ground, give command to attach the other rope which is connected to mass B to the back of the (moving) ship. This will slowly decelerate the ship with a force of $m\_B \* g + F\_F$ and lift mass B of the ground, until after $t\_B$ the ship comes (briefly) to halt, before moving backwards.
[](https://i.stack.imgur.com/nsBrT.jpg)
Note the height $h\_B$ that mass B was lifted maximally. Together with height $h\_A$ which mass A was initially over the ground this can be used to calculate the ship's mass $m\_S$. Start with the forces:
$m\_S \* a\_A = F\_A = g \* m\_A - F\_F$
$m\_S \* a\_B = F\_B = g \* m\_B + F\_F$
Now to keep things simple let's assume constant friction $F\_F$ and thus constant acceleration in both cases (this will introduce a lot of error in the calculation, though).
Distance traveled under constant acceleration is $x = 1/2 \* a \* t^2$, thus
$a\_A = 2 \* h\_A / t\_A^2$
$a\_B = 2 \* h\_B / t\_B^2$
Calculate those two from the measurements.
Now back to the two equations regarding the forces. Solving one for $F\_F$ one arrives at:
$F\_F = g \* m\_A - m\_S \* a\_A$
$m\_S \* a\_B = g \* m\_B + F\_F$
And thus:
$m\_S \* a\_B = g \* m\_B + g \* m\_A - m\_S \* a\_A$
And further:
$m\_S = (m\_B + m\_A) \* g / (a\_B + a\_A)$
As you might have guessed from the drawings, this is a quick and dirty sketch that I'm doing on my mobile phone. Thus everything above might be completely wrong.
[Answer]
It is doubtful you will have a uniform weight on a particular boat that comes through your canal. Even the same ship on two trips will have different weights because of cargo, bilge, crew, and a lot of other factors. This leaves you with two options if you insist on the boat lift: Overengineering or pre-lift weighing.
## Weighing
Other answers have gone into the specifics of how you'd obtain the weight of a vessel. The issue is that this takes time, and the longer it takes you to get a vessel through your canal the less money you are making, and the longer it takes to ship things. There's always the "just add weight to the counterweight bucket until it works" option, but that lengthens the time of the lift as well.
## Overengineering
Overengineering is going to increase your construction costs, which is a big negative when you're trying to make money on your canal. It also would have bigger maintenance costs (as you have a bigger apparatus in general). You also have some major issues if you have a failure during a lift, which requires further overengineering of redundancies or accepting a certain level of risk.
## Locks
The solution I would recommend to your canal owner is to just install a Lock in his canal. They have been used for millenia and the technology is not that complex (but the basic design can constantly be improved by technology. There's a reason we still build them). It circumvents your weight problem, because you just need to pump water in and let buoyancy take care of the rest. It also would be faster than a lift system requiring weighing beforehand (the drydock option requires more work than the lock in terms of pumping, and similar sized facilities), and is simpler and safer than the overengineered solution.
Even if you have an intricate pump system, and you suffer a failure of some kind, you can always operate the lock "manually" by opening the gates individually to flood and drain the lock. Or, if that's not an option, your fail-safe is to release the lower lock and then your boats are just "stuck" on the lower level canal until it can be repaired (which is far preferable to the "worst case" scenario of the lift, which is a boat shattered upon the ground).
[Answer]
If you really MUST have a dry dock lifter, then I would recommend a solution that uses a combination of a test weight, and the amount by which the boat displacement changes.
Merely attached a fixed counterweight to the ship, observe the amount by which the boat rises in the water, and the weight of the ship can then be estimated based on the amount by which the water displacement of the boat was "negated"
] |
[Question]
[
Imagine that we start expanding the International Space Station until it becomes a ring encircling the whole Earth. Then we started widening the ring until it met at both poles, forming an orbital eggshell around the entire planet.
Ignoring all the problems, like that it's starving the planet's surface for sunlight. What would you call this kind of enormous space station?
[Answer]
A [Dyson Sphere](https://en.wikipedia.org/wiki/Dyson_sphere) is meant to capture radiation and convert it to usable energy. Since an earth-like planet only reflects light back, that point would be moot. In any case, here's some suggestions:
* *Orbital Eggshell*
* Crumbling Civilization Obfuscator Mk I
* Magrathean homework assignment
[Answer]
Well a Dyson Sphere is named after the person who popularised the idea and also the shape of the object itself.
Without paying homage to a person or entity, it makes sense to call it after its function. Around a planet, there's a few functions it could have which allow you to derive a name for it.
1. **Defence**: A megastructure created with the intent of protecting the planet. Names such as Fortress Sphere or simply "Defence layer" depending on how many layers the structure has (I mean, why stop at one sphere right!?). Dropping references to famously impenetrable things also works, like Knox Sphere.
2. **Imprisonment**: In this case, the planetary inhabitants are most likely going to be miffed with it, so they won't refer to it by it's technical name (Uhh.. Interstellar Movement Restriction Construct?) and call it something like the "Cage" or "Iron Curtain" (Stalin in Spaaaaace)
3. **Habitation**: Suppose the sphere could create an atmosphere usable by humans, turning Jupiter's weather conditions into exactly like that of Earth's. Names like "Biosphere" or "Environment Simulating Orbital Structure" (ESOS, BOOOM, all aboard the sci-fi acronym train!).
4. **Salvation**: Suppose the planet died, so the people built the structure to live on once the planet collapsed, or like Coruscant in Star Wars, they just built so much that eventually it took over the entire planet, inadvertently forming a sphere. In this sense, biblical names work well like "The Orb of Eden" or "The layer of Jannah".
Another way of looking at this, if the orb has an atmosphere of its own, it's plausible that no one is even aware that there is a planet inside the sphere. This would make an excellent set piece, where the name would simply be whatever the Planet was called.
What I'm saying is: There is no widely accepted term for it. Go and be the person to make it!
[Answer]
There is no name for the sphere version. The ring version is an [Orbital Ring](https://en.wikipedia.org/wiki/Orbital_ring).
You could most likely use the term "Planetary Dyson Sphere" or if it is defensive in nature "Planetary Shield". I've also heard the term "shell" used to describe structures similar to what you are asking about.
Be aware though that it is a structure with no real value and yet incredibly expensive to build. Orbital rings are very useful but a full sphere not so much.
[Answer]
You could call it a roof. Or perhaps an [armilla](http://en.wikipedia.org/wiki/Armillary_sphere)?
If you were going to get all hard SF about it, a rigid shell around a planet (or indeed around a [star](http://www.aleph.se/Nada/dysonFAQ.html#STABLE)) wouldn't be stable, and would indeed fall onto the planet unless it was perfectly centered on the planet's center of mass as @RichardTingle suggests. If it were as low as the ISS, I doubt it could last a week without some kind of (huge) thrusters to keep it in place.
A ring is OK because each part of the ring is in orbit. But as you start to widen the ring, the edges are not in orbit-- they're moving too slowly and in the wrong direction for their altitude, which means they're pulling on the rest of the ring, and it would be nearly impossible to balance those forces.
However, an airtight sphere could be supported by air pressure, and have tethers/struts connecting it to the planet. Those wouldn't have to support the weight, they'd just be to stop it drifting around. Could be a good source of cover artwork...
[Answer]
The specific instance of the construction, built around Earth specifically? I wouldn't be at all surprised if it were referred to as [The Firmament](https://en.wikipedia.org/wiki/Firmament).
The general construct I might refer to as a [hoover bag](http://hoover.com/parts/category/bags/), if I were feeling flippant.
[Answer]
It would be called "***W***eird **T**ransit **F**eature" ...by aliens! Its purpose is to make Earth both more easily visible and more intriguing for alien civilizations who search for other planets using the transit method.
Earth will become more visible when transiting the Sun, because its larger radius would produce better noticeable transits. Also, the transits would be more interesting because mass/radius/density/gravity calculations performed by the aliens will show that this planet is something very unusual, deserving more detailed investigations.
So it is it. We just need to build this thing and then wait to be visited by our interstellar tourists!
[Answer]
The closest thing I could find is the [Globus Cassus](https://en.wikipedia.org/wiki/Globus_Cassus). It is a mega-structure around the planet Earth, but it eventually uses up all the matter of the earth.
[Answer]
[Supramundane shell or supramundane world](http://www.orionsarm.com/eg-article/4847416b8b0ad) is the established term, a concept introduced by [Paul Birch](http://buildengineer.com/www.paulbirch.net/index_orig.html), originally in his article "Supramundane Planets", *Journal of the British Interplanetary Society*, 44, 169 (1991) [[PDF]](http://buildengineer.com/www.paulbirch.net/SupramundanePlanets.pdf).
The term is derived from the Latin *supra* "above" and English *[mundane](http://www.merriam-webster.com/dictionary/mundane)* "of, relating to, or characteristic of the world", which was in turn derived from Latin *mundus* "world".
[Answer]
It's called a Shell World. What you're describing isn't *exactly* like what's referred to in this article, but I think it close enough to serve your purposes, and it might give you some ideas.
<https://www.space.com/23082-shell-worlds-planet-terraforming-technology-infographic.html>
] |
[Question]
[
To simplify the question as much as possible, let's assume an Earth-like planet, part of a galaxy-spanning civilization. 30% is above water level, the rest is ocean of salt-water.
This world is an agri-world, purely used to produce as much food as it can and ship the production to other systems that can't sustain themselves when it come to crop, livestock and such. It keeps just enough food to sustain the population on site. All the landmass is used for farming. For the sake of simplification, it is only producing crops and not meat of any kind.
On Earth, farming use large quantities of water, but since it's all on the same planet, it's (I assume) a neatly closed system and we are only concerned about the ratio of salt to freshwater.
My question is, if you are shipping farm products of world, aren't you removing water from the equation? Would you witness a significant drop in the quantity of water of this world over time - or is the water contained in crops negligible in the grand scheme of things?
[Answer]
## Technically it's Not Sustainable
But you're probably ok.
Current worldwide food production is 4,000,000,000 tonnes of food per year. Let's assume that food is 100% water, just to make things easy.
All water is eventually sourced from the ocean, and it evaporates and is transported to rivers, lakes, etc by the water cycle. We then use this freshwater to irrigate crops.
Earth's oceans have a mass of approximately 1,400,000,000,000,000,000 tonnes.
So we could theoretically export all the food that Earth produces for 350,000,000 years before we drained the oceans dry.
350 million years is probably long enough that you could nudge some long period comets into the appropriate orbits to replenish your water stocks.
You can easily adjust this value by scaling the current population of the Earth. There are currently about 8 billion people on Earth. So if you need your agri-world to feed 20 billion people, then that's about 3 times the current world population, and you would drain your oceans in about a third of the time calculated above - 116 million years.
[Answer]
**Cargo ships hate to run empty.**
Your farm world exports crops. Cargo ships leave full of crops. Then they come back. What do they bring on the return trip? Maybe the worlds buying crops have ample water but lack other things that crops need. They can send their water back in the cargo ships, replacing the water for the farm world and partly offsetting the cost of the crops they are importing.
It would be a fine visual - the cargo tug towing a giant gently sublimating iceberg. It releases it to free fall into the atmosphere of the farm planet, then hits it with a missile on the way down to break it up. Cool alien rain!
Of course somewhere in the story your protagonists will find some other use for an iceberg in space...
[Answer]
## You will be shipping back manure.
You are shipping *mass* off-world.
At these scales, you don't care that some of the mass is water, you care what proportion is hydrogen, oxygen, carbon, nitrogen... etc. An amount of energy went into chemical processes to fix that into digestible forms.
The end result of digestion is mostly the same amount of mass, with a (lower energy) chemical makeup. Wherever you have sent this food to doesn't particularly want piles of manure around, and you have all these freighters that would otherwise be empty for the return trip.
[Answer]
Technically yes. Every unit mass shipped offworld will remove 1 unit mass from the planet. If a percentage of that mass is water then you'll remove that percentage of total mass as water.
Earth has 1.3 billion cubic kilometers of water. Of that 2.5% is fresh water. That's 32.5 million cubic kilometers of fresh water. Given that most commercial grain has a water percentage (by weight) of 10%-15%, you could remove 32.5\*10^18 kilograms of grain before having a 1% impact on the amount of fresh water on the planet.
[Answer]
**Whether or not it's sustainable isn't the question**
Sustainability is a *great* context for a story, so whether or not such a planet is *factually* sustainable or not is really irrelevant, right? Besides, you're correct, unless something is done, the world is losing water.
But, what can be done?
**Freeze Drying**
Nothing leaves the planet without being freeze-dried. This minimizes the water loss. Frankly, it likely minimizes it to a degree that it's impractical to consider the implications for anything but a very long term.
But what might make the most sense is...
**Mine the ice giants!**
Granted, the term "ice giant" when referring to planets like Neptune and Uranus is a bit of a misnomer. Oh, they likely have boat loads of ice... but you'd need to work your way through miles of other nasty stuff (like methane) to get to it.
But that doesn't mean they're not solutions! Ice giant planets, ice asteroids, ice-covered moons. NASA claims [the solar system and beyond is awash in water](https://www.nasa.gov/jpl/the-solar-system-and-beyond-is-awash-in-water).
Which is a long way of saying you really don't have a problem. If your economy allows you to ship wheat off the planet, it will allow you to ship water back to it at no populated planet's expense.
[Answer]
As codeMonkey calculated, water is not what will be used up first.
On the other hand, there are other limiting factors in agriculture:
1. Nitrogen. Most of the nitrogen is in the atmosphere and it is way less dense than the liquid water. One will carry away comparable amounts of water and nitrogen by exporting food.
2. Phosphorus. Most of it is in the litosphere, but is at least as much limited.
3. Carbon. Where the real problems is.
Just like with the nitrogen, one will carry away comparable amounts of carbon. On the other hand, it is ~0.04% of our atmosphere today. Make it 0.02% and create an eternal ice age. A terraformed planet will likely not have much fossil carbon deposits (coal, oil, gas). Carbide ores may be an option, but only to delay the inevitable problem.
One will need a big industry mining these important elements on a celestial bodies beyond the frost line (whatever equivalents you have for Jupiter and Saturn satellites and the icy planets beyond). Or somewhere else.
[Answer]
I can't see how an "agri planet" can stack up economically.
Even if you have an orbital tether, you still burn up a significant fraction of the food's calorific value just to reach synchronous orbit, and a boat-load more to reach escape velocity.
On a planetary scale it would be more efficient to develop zero-g agriculture and get the water from comets and asteroids. Which I suppose answers the question "no, you don't run out of water", at least on the planet surface.
---
The other problem is at the receiving end. Let's assume that the main market is planets who have exceeded their carrying capacity, even after entirely displacing their native ecosystems, so we can assume a global populations of 100bn+, and that they each eat around a tonne of solid food per annum.
De-orbiting 100 bn tonnes of food per annum means absorbing almost half a petawatt on an ongoing basis, equivalent to 1.5% increase in planetary insolation. That's going to make our current climate change look like a picnic.
[Answer]
This answer addresses an issue which is peripheral to the main question BUT utterly crucial.
For interplanetary (let alone interstellar) food transportto be viable you are going to need space transportation technologies not only far beyond what we have now but also far beyond what we imagine will ever be possible.
I could dig up numerical figures for the following but it makes the point adequately without them. I may add some if there is enough interest shown.
At present we use chemical based propulsion systems.
A Saturn V delivered about 4% of its launch mass to orbit.
An utterly inconceivably good chemical rocket systm is unlikely to be deliver better than 10% launch mass to LEO.
To deliver payload to the surface of Mars from LEO requires as much energy per kg from LEO as it takes to get TO LEO.
So using the Inconceivable V launcher technology ("IV")we can deliver 10% x 10% = 1% of launch mass to the surface of Mars.
Using Saturn V technology it's 4% x 4% = 0.16% of launch mass or 1/625th of launch mass.
Delivery to near earth asteroids is about 0.5% using the IV and Lunar surface is somewhere in between asteroids and moon.
A Space Elevator reduces the earth's surface to LEO energy cost to about zero. (Energy per kg to orbit on an elevator is a few MJ at 100% efficiency . Allowing for substantial inefficiencies that's say roughly $1 in electricity costs.
But, even if we get off the planet's surface for free, we still have to get to the destination and to re-enter the payload. Antimatter systems will bring the cost down and the payload fraction up - once we manage to get antimatter down to commodity pricing. As antimatter is currently priced at about 2500 trillion dollars per gram (2.5 x 10^12) we, or your posited civilisation, have some way to go from our present situation. That 1 gram costs about 100,000 times as much per kWh as current electricity prices, which is actually quite encouraging. But unlikely to be commodified any time soon.
SO - unless we have a new Non-Existium V drive technology it is likely that almost any practical alternative is going to be cheaper. Orbital growing systems, underground systems, float in the air, ... .
The only way to make this sensibly viable is if you can produce a magic matter transport system that requires minimal energy and delivers payload between planets, or stars, rapidly or instantaneously. In a story this is possible. In our reality, start planning local farm systems.
[Answer]
**No and yes**
As you already understood shipping out food means shipping out a lot of water. A country like Earth can have a lot of water, but most of the water will eventually become salted or polluted. The fresh and clean water on Earth come from a continuous cycle of evaporation, rain and filtering by sand or clay layers when it seeps underground. So fresh water will never be abundant like sea water and shipping it out will eventually deplete it.
However.
Shipping water through space is expensive and pointless. Water is heavy, but it can be available everywhere, why ship it? The energy cost of freeze drying the food for interplanetary commerce would make sense. So all the food will be exported freeze dried.
Still some finite resources like phosphates would risk depletion, but they can be imported back.
[Answer]
How are you managing fuel? When you burn fuel you produce water and carbon dioxide - both things that will help your agriculture.
Right now you need 8 times as much fuel (by mass), as payload. So if you burn your fuel in the atmosphere of the planet, you'll actually add 8 times as much water+co2 as you export.
If fuel comes from outside (since you said the plant is agriculture only) you'll actually have the reverse problem if you do this long enough.
Also, going back to the original question, you'll actually have a much bigger problem with co2 - you'll run out of that way before you run out of water.
] |
[Question]
[
Aliens are camping on Mars and gathering their forces ready for an invasion of Earth. They wish to find out as much as they can about us before commencing hostilities.
**Question**
How can they access the Internet and hence get a valid email address and search Google etc.?
---
Bear in mind they have no Earth money to buy broadband, or presumably a way to access it. Also there is a delay (varying according to relative orbital positions) for signals to travel between Earth and Mars. They are not familiar in the details of internet protocols or security measures although they have gleaned some rough ideas from live broadcasts that they exist.
**Notes**
1. There is no FTL travel or communication available **within or near** the solar system (for reasons of physics I won't explain here). Please just assume they can't use FTL.
2. One important piece of knowledge for them is the completest sequence they can get of the human genome and of human viruses. This is so they can carry out virus warfare.
---
**EDIT**
What follows is not essential reading. It's partly to say thanks.
>
> By implication (e.g. my mentioned of delays due to distance of Mars from Earth) I believe that my question can be seen as relating only to communication directly to and from Mars. That was certainly my original intention although not explicitly stated. @Renan has given an excellent answer to this. Others however have presumed that my aliens *must* have the capability to send spacecraft into near Earth orbit. Although I hadn't envisaged that, it certainly gives extra information as to what the aliens might be forced to do. Therefore I am also very interested in those answers. Particularly the "we come in peace" subterfuge mentioned at the end of the answer by @Matthew
>
>
>
>
> I wish I could accept several of these as the best answer. SE doesn't allow it. So I will eventually pick one but many thanks to all who have taken the trouble to answer - some with considerable knowledge and clarity.
>
>
>
[Answer]
# They can't
### At least not from Mars itself
A radio signal will take between 5 to 20 minutes to go directly from Earth to Mars. So even supposing that:
1. Your martian hackers have gone through the DNS part (i.e.: the venusians provided them the IP 172.217.13.206, which is one of the valid addresses for Google as I type this), and;
2. The aliens write [a proper HTTP request](https://i.stack.imgur.com/03ESH.png) (ignore the cookie part);
...This is what will most likely happen from the martian point of view:
### t = 0 ms
Martian computer sends a TCP packet. Most details are irrelevant to the question, but it will say ["SYN" (for synchronize)](https://en.wikipedia.org/wiki/Handshaking).
### t = 620,000 ± 4,000 ms
The computer in Mars receives the SYN + ACK packet (synchronize + acknowledge).
### t = 620,001 ± 4,000 ms
The computer in Mars sends an ACK (acknowledge) packet, which serves to formalize that a connection has been opened.
### t = 683,000 ± 6,000 ms
The computer in Mars receives a second SYN + ACK packet. Since it already sent an ACK packet, this nee SYN + ACK gets ignored.
### t = 745,000 ± 6,000 ms
The computer in Mars receives a third SYN + ACK packet, which is also ignored. After this last packet the TCP channel goes silent.
---
And from Earth's point of view:
### t = 0 ms
Some server on Earth receives the SYN packet from Mars.
### t = 1 ms
Server sends a SYN + ACK packet to Mars.
### t = 60,001 ms
It has been too long since the SYN + ACK packet was sent and there was no response. Due to this, server sends a second SYN + ACK packet.
### t = 120,001 ms
Still no response, so server sends a third SYN + ACK packet.
### t = 180,001 ms
Server gives up on the connection because [it has sent three ACK packets and got no response in appropriate time](https://en.wikipedia.org/wiki/Keepalive#TCP_keepalive) (a SYN + ACK packet is also an ACK packet).
### t = 603,001 ± 2,000 ms
Server receives an ACK packet from Mars and completely ignores it since it is neither for an open connection nor a request to open a new one. By design, the server will not even bother to respond.
---
You may be thinking now that after a few tries the aliens would learn to send SYN and ACK packets in the right time to fool the server on Earth. You'd need a [Laplace demon](https://en.wikipedia.org/wiki/Laplace%27s_demon) for that, as the SYN + ACK packet from the server on Earth comes with a randomly generated number - let's call it X. The ACK packet from Mars must include X + 1 in one of its fields.
And sure, that X number is not truly random, but only pseudorandom. You could probably find out the next number the server would pick - if you had the only machine ever reaching that server. Other people using Google will add noise here so you won't be able to guess the next X.
Even if you do guess that number, TCP is a protocol which expects a response for every packet that is sent. Preempting the confirmation of a packet that has not been sent yet is just noise - you really need to receive every packet and confirm the ones you got. Failure to do that means the other side (client or server) is expected to send all the same packets again, but more spread apart over time (in plain English: must resend more slowly, because TCP prioritizes stability over speed) and with more expected confirmations. The more you try to outsmart TCP, the slower your transmission will be and the more likely you are to have timeouts.
---
The aliens will have a better chance when they are within Earth's [sphere of influence](https://en.wikipedia.org/wiki/Sphere_of_influence_(astrodynamics)), where their latency will be much lower (I think around 4 seconds for a TCP round-trip). However, I see that the question has been edited to rule that out.
---
I see that a new edit removed that constraint. Check [Enthus3d's answer](https://worldbuilding.stackexchange.com/a/185333/21222) for an idea on how to overcome the latency problem.
[Answer]
## From Mars: One 4K Netflix Movie per Unconditional Surrender
---
*The real answer is provided in the next section, with the use of probes*, but here is the physical reason why it is impossible to access the internet directly from Mars: signal strength loss.
Regardless of how the Aliens receive weak signals from Earth, the Aliens will still need to send signals to Earth to query from Google. They will need to use a [high-gain directional antenna](https://en.wikipedia.org/wiki/Directional_antenna#Principle_of_operation), which narrows the beam width to heighten the signal strength and reduce interference, to send their signals towards Earth.
If the signal is sent to an omni-directional source of a Wifi enabled device (roughly 2dbi) (since no sane person would point their directional wifi extender perfectly accurately into space and towards Mars instead of their router), and the aliens use a Nasa-grade [high gain 48dbi antenna](https://descanso.jpl.nasa.gov/DPSummary/Descanso4--Voyager_ed.pdf), with a signal frequency of 2.8GHz, like wifi, then the signal attenuation will be [200db](https://www.electronics-notes.com/articles/antennas-propagation/propagation-overview/free-space-path-loss.php) (which is 1/1e20 of the signal strength). This high loss in signal strength is because of the distance, and we are forced to send signals to an omnidirectional receiver rather than a directional one (a difference of 20-50db).
[](https://i.stack.imgur.com/zoaxP.png)
The most reliable signal we can realistically send will have a signal loss sitting at roughly [37dBw (67dbBm)](https://www.metageek.com/training/resources/wifi-signal-strength-basics.html). To achieve 37dBw signal strength, the aliens will need a signal of roughly 171 dBw due to 208dBi signal loss, which will mean a signal with 1.26e+17 watts worth of power.
This means, to send a single TCP packet of 65535 bytes or 524,200 bits at 2.8GHz, to try to initiate a search on Google from a device, will need 1.87e-4 seconds worth of a signal, or 23.6e12 joules. The energy equivalent of that is roughly one nuclear bomb.
Due to a mistake in signs, originally we had come to a conclusion that two google searches would be enough for a planet-wide extinction event. This is no longer possible with the current calculations, but, hypothetically what does this mean, in terms of planet-wide extinction events? The [asteroid impact that wiped out the dinosaurs](https://www.extremetech.com/extreme/147978-finally-confirmed-an-asteroid-wiped-out-the-dinosaurs) sits at roughly 4.2e23 joules, **so transmission of 3/4ths of the [1,200 petabytes](https://www.sciencefocus.com/future-technology/how-much-data-is-on-the-internet/) on the internet from Google, Amazon, Facebook, and Microsoft would be on the same scale as the next extinction of the entire human race**.
Humanity's satellites would quickly notice if a few signals, each on the scale of a nuclear explosion, were sent from Mars, and large craters from each google search aftershock were to continuously blast open on Mars. If the aliens were capable of harnessing this level of power, all it would take is one 4K Netflix movie on Earth, and a few countries would be gone, the Earthlings cowed into surrender.
As such, due to the heavy loss of signal strength over the long distance between Earth and Mars, it is highly unlikely the aliens would attempt to send WiFi signals from Mars. (And even then, as in Renan's answer, they would be stopped by the latency).
## From Earth Orbit: The More Efficient Way
---
[](https://i.stack.imgur.com/uoqLQ.png)
## Analysis and Simulation
---
The more efficient way would be to probe an internet satellite, from providers like [xplornet](https://get.xplornet.com/discovery-ontario/?gclid=EAIaIQobChMI0o7D0pnh6wIVHey1Ch16IQ70EAAYASAAEgJhh_D_BwE). The aliens could send a probe near one of the internet satellites, and analyze or transmit signals to it.
If they are not familiar with satellites, they can gain knowledge about them by dissecting one of the many dead satellites in the [graveyard orbit](https://spaceplace.nasa.gov/spacecraft-graveyard/en/), or, with more risk, hijack/study a nearby [Mars Rover or Orbiter](https://mars.nasa.gov/mro/), which have a ton of communication equipment.
The probe will analyze existing signals going into and out of the internet satellite, meaning there will be little risk of detection. Any encryption on the internet signals can be broken, or they can target strictly un-encrypted signals. Once they are familiar with the signals, they can simulate their own signals to the satellite, with an appropriate 'fake latency' to simulate it as coming from Earth.
The probe they send to hack the satellite will also have a two-way communication method that will send and receive signals to and from the aliens on Mars. Since the distance is far, the probe can use directional antennas to reduce signal loss, with a similar setup to how NASA handles transmission between [Mars orbiters to Earth](https://mars.nasa.gov/mro/mission/communications/). They could also make use of alien transmission technologies, since there is no format requirement on this signal, allowing to pick techniques that are less noticeable or have a better transmission format.
## Probe's Maximum Distance from Satellite
---
In terms of how far the beacon should be placed, if the aliens want to completely avoid their probe being caught, the United Space Surveillance Network tracks satellites in orbit around the Earth. A crucial part of this is the [GEODSS system](https://en.wikipedia.org/wiki/United_States_Space_Surveillance_Network#Ground-based_Electro-Optical_Deep_Space_Surveillance)
>
> the GEODSS system can track objects as small as a basketball more than
> 20,000 miles (30,000 km) in space or a chair at 35,000 miles (56,000
> km), and is a vital part of USSPACECOM's Space Surveillance Network.
> Distant Molniya orbiting satellites are often detected in elliptical
> orbits that surpass the Moon and back (245,000 miles out).
>
>
>
This is to say, should a beacon be placed, and surveillance is to be completely avoided, the beacon should be located beyond 245,000 miles out from the Earth, to avoid detection by the GEODSS system. The speed of light in a vacuum is 186,282 miles per second, meaning, at this placement, the latency will be around 1.315 seconds. This is a fairly high latency, potentially causing file download/upload speeds to slow down to 0.5x-10x compared to 500-10 ping, due to handshakes being needed to confirm packets have been received (dependent on the size of the packet), but this will not affect browsing the internet.
## Dealing with Latency and Packet Loss
---
The delay from latency won’t be a significant issue, as accessing the internet for information isn’t reliant on latency (think Netflix, Youtube, Wikipedia). To avoid timing out for requests, they can easily program the beacon to simulate handshakes and requests locally at the satellite, effectively appearing to have close to 0 ping (or, if they are avoiding the GEODSS, ~1300 ping). They can then stream out the data to mars at their leisure. Packet loss from the distance will be reliant on what technology they use for the beacon, but also shouldn’t be an issue, as they can resend requests.
They will, however, do terribly in World or Warcraft due to actual latency and packet loss from Mars, but that's what single player games are for. Perhaps they may come in peace after being unable to resist the temptation of playing such games with low ping.
## Google
---
Most likely, due to high traffic volume, google would be the first website they will analyze, and they will be able to quickly simulate internet requests to and from google.
With google, they will be able to easily obtain information like how to create an email account, gain access to Wikipedia, and watch online lecture videos from Youtube. This will allow them to quickly gain a general understanding of the human race and carry out their next plans.
## Dealing with Potential Issues
---
Q: How would they gain the know how to work on satellites?
A: By analyzing and dissecting the dead satellites in the [graveyard orbit](https://spaceplace.nasa.gov/spacecraft-graveyard/en/)
Q: Can probes they send completely avoid detection?
A: This depends primarily on how far ahead the aliens are in dealing with electromagnetic waves. Most likely they will have no issues easily dealing with any of our primitive surveillance systems, but even without such measures, by primarily staying out of our surveillance systems' maximum effective ranges (300,000+ miles), there is very little probability of detection. In fact, the European Space Agency alone has [mapped 61-89% of Mars](https://www.esa.int/Science_Exploration/Space_Science/Mapping_Mars), and many other Space Administrations/Agencies are also constantly probing Mars for various other things. Without some kind of anti-surveillance tech, **it is more likely that the alien spacecraft/base on Mars will eventually be caught than the relatively small beacon**.
Q: Would the humans notice their satellite is being monitored by the aliens?
A: By first analyzing existing dead satellites, then analyzing only signals going in and out of an internet satellite, detection chance is very low.
Q: Would encryption prevent the aliens from accessing the internet at all?
A: No, only some [50%](https://www.cbronline.com/news/internet-encryption-sandvine) of the world’s total internet traffic is encrypted, with [unencrypted HTTP traffic](https://meterpreter.org/https-encryption-traffic/) remaining high (20-40%) in the APAC region.
Q: Would encryption deter the aliens?
A: This is probably the biggest issue, all of this depends on the alien's level of computing technology. It should still be possible to break some of the less heavily encrypted transmissions, but breaking the more complicated encryption methods would require the use of a quantum computer or equivalent in processing power.
Q: How would they deal with the minutes high latency between Earth and Mars?
A: Simulate return responses at the satellite itself, effectively achieving near-0 ping from the perspective of the internet services.
Q: How would they deal with the massive signal loss from Earth to Mars?
A: By using two directional antennas, the signal loss from one point to the other is heavily reduced. They can use a setup like NASA's space orbiters, with one low-gain and one high-gain antenna on the probe.
Q: What if the aliens are not able to send out any probes?
A: Then barring the use of any space magic, the aliens would have no reasonable way to send and receive signals due to signal loss. If they had such space magic, actually accessing the internet from Mars and dealing with TCP would also be extremely difficult; @Renan provides an excellent answer.
[Answer]
**They need to get local.**
Current (actively used) internet protocols are simply incapable of dealing with the light-lag delay between Earth and Mars. Even if they could somehow build a powerful enough wireless transceiver to connect to WiFi or other internet-carrying signals, ping times of >40 minutes simply wouldn't work.
If the aliens want to interact with the internet, they could:
1. Send a probe/satellite/scout to Earth. This probe could either hijack a telecommunications satellite or land somewhere with free WiFi (like a Starbucks or a city with free WiFi)
2. Browse the internet, create Emails, look at cat pictures, etc. While many "big" services today want 2FA, you don't actually *need* a physical address, phone, or credit card to access almost all of the internet.
If the aliens don't want to get local and are content with "read only" access, they could:
1. Use an insanely powerful radio-telescope to pick up individual WiFi and cellular signals on Earth
2. Figure out how to decode those signals and watch what people do on the internet
3. For bonus points, they could hack WPA2 or https protocols so they can see all the data that people send
[Answer]
### They can't.
Well... not directly. You've already noted the main issue they're going to have, which is *latency*. Gamers think a latency of 100 ms is terrible. Well, your aliens are going to have latency measured in *minutes*. At that point you're talking about connections timing out due to inactivity. (Our infrastructure is based on the premise that not receiving a reply in a timely manner means something went wrong and the connection should be dropped. You *literally* will not be able to establish a TCP connection to anything at all, and AFAIK there isn't much you can do online with only UDP at your disposal... and even *that* will probably have fits with your round-trip times.)
The only way this is going to work at all is to have a *really smart* (read: autonomous, at least to the point of being able to operate when only receiving instructions every few hours) probe much, much closer to Earth. The moon *might* be close enough. Earth orbit (or even on the surface) would be much, much better.
### Another snag
This raises another issue you haven't mentioned, however, which is *remaining undetected*. If they're trying to interact with the internet, even by proxy, that means sending signals toward Earth. Unless they have some totally unknown form of communication technology, someone is bound to notice. We literally have people *looking* for that sort of thing, and despite what Hollywood would have you believe, it's really, really hard to hide this sort of thing. Their best bet is going to be very tightly focused lasers. Unfortunately, to achieve the necessary focus may require a near-Earth relay, and that's going to be hard to hide.
### What *can* they do?
The key is going to be *passive* observation. Just monitoring our satellite broadcasts is a starting point. If they can tap into satellite *internet*, that will give them a pile of data to sift through. Assuming they can figure out our communications protocols (e.g. IP, TCP, HTTP) without help (which they'd need to do anyway), they should be able to get a decent pile of data just from listening to what other people are doing. However, there's another problem, which is that more and more communication is happening over secure channels (SSL, VPNs). For instance, if they want to read this answer, they'll need to somehow crack the SSL private key for SE. Better hope their computer technology is way, way ahead of ours. At least detection becomes much less of an issue; it is infinitely harder to detect a transmission that is pointed *away* from all of our detectors. However, slipping a satellite into orbit without being noticed is also far from trivial; we monitor the sky for this sort of thing, not because we're looking for aliens specifically, but because there is a lot of stuff up there and it's a navigational hazard.
### A totally different option
The best place to hide something is *in plain sight*. (Or, as one of the military minds from [Honorverse](https://en.wikipedia.org/wiki/Honorverse) likes to say, "surprise is when your enemy misinterprets something he's seen all along".) Forget stealth, what you want is *misdirection*. Have a small group of aliens show up very noticeably. Make it clear that you aren't even *attempting* stealth. Park in lunar orbit and start spamming the airwaves with communication attempts until you figure out our language. Then announce that you're a tramp freighter looking for trade opportunities in a galactic backwater. I can almost guarantee that at some point someone will *help you* set up an internet connection (there are certainly enough crackpots with more fantasies than common sense), maybe even invite you to come visit. Make it clear that *you aren't a threat*. Dangling hints at advanced technology you'd be happy to share will help.
Then, once you think you've learned enough, invite over the friends you "forgot to mention".
[Answer]
How can Aliens on Mars hack into our internet and download all of wikipedia? Easy.
1. Launch a cubesat towards Earth.
2. Cubesat acts as a relay while engineers back on Mars use it to hack one of the communications satellites. Like our Mars rover, the cube sat is capable of executing a buffer of commands (to deal with the time delay).
3. Once satelite is hacked, the hacked code on the satellite requests wikipedia over HTTP. This is relayed to the cubesat.
4. Then the cubesat transmits the data back to Mars for Analysis. Earth / Mars uplink during line of sight is about 2megabit for NASA. Wikipedia is 9.5gb. Will take 3-4 days to transfer.
After this has been processed, they know a lot about us. They will have read <https://en.wikipedia.org/wiki/Comparison_of_webmail_providers>, and will just pick one with low standards.
Watch Colony (on Netflix) for an example of fiction where Aliens accomplished this.
[Answer]
The main problem will be the communication. Most internet communication messages will timeout before they reach the other side, so establishing a TCP (One of the protocols making up the internet) handshake will be quite impossible. Connection quality consists of two parts: Latency (time between sending and receiving) and throughput (amount of data sent). Having all the throughput in the world means nothing if your latency is so high that it never reaches you. Perfect latency also means nothing if your throughput is essentially zero. They have to send a "proxy" probe towards earth to actually interface with the internet and guarantee low latency between the proxy probe and a ground based internet hub.
Once they have an interface close enough to earth, they need to find an open access point. Most ground based access points will not reach high enough, forget hijacking poorly configured WLAN routers. It's possible that LTE and such will reach high enough, but they might also triangulate your position and - though it's probably never checked - it risks detection if your position reads as "in orbit".
This leaves you with two options:
1. You can put something on the ground to actually access the internet and send it up to the orbit.
2. You can try to hijack one of the internet satellites.
Option 1 is easier, because open WLAN exists pretty much everywhere. As long as it's inconspicuous, you can just drop something down, access the WLAN and you're golden. You can download all of the internet, probably including the genome of ebola, easy.
Option 2 is difficult, because there are a lot of satellites around and they are usually strongly encrypted. You might have to spend a lot of time on decrypting traffic and once you've done so, the throughput is awful. Risk of detection is much lower though.
[Answer]
If these invaders do, indeed, have FTL, then they have a 'time machine' into the development of our Internet. They can go, say, 50 light years' distant from Earth, and pick up our first signals from the development of our Internet. Further away, they can go right back to our first radio transmissions, and Morse Code. They only need to go through 100 years of our EM history, really, to have a complete picture.
Once they have access to our EM historical record, they can build up the evolution of our protocols. Each successive iteration of our protocols built on the last, going all the way back to Morse Code, and the Teletype machines. The ACK/SYNC/CQ codes, in fact, and ASCII, go all the way back to the teletype, completely unencrypted. Handshaking protocols go all the way back to the first dot-dash Morse Code used on the Titanic.
Going back only 40 years or so, they have pre-email, pre-WWW bulletin board system transmissions. Remember AOL floppies to connect to their servers?
It would not be difficult for a civilization that can do FTL, to predict and reverse engineer our current modern protocols, based on the evolutionary record of our radio transmissions over the last 100 years.
[Answer]
As other answers have discussed, they can't make a two-way connection to the internet from Mars, because the latency is too long for TCP.
However, they can still *receive* radio signals from Earth, and a lot of internet data is transmitted via satellite. Picking up stray satellite signals from Mars would be a challenge, but since these guys have the technology to travel between the stars, setting up an appropriately sized space-based antenna is probably not outside the bounds of possibility. Making it hard to detect from Earth might be a bit tricky, but in an appropriate orbit it would just look like an asteroid, and you could always use a swarm of small antennas instead of one big one.
The main challenge would be in decoding the data, both in the sense of breaking encryption and in the sense of understanding all the protocols, to work out where each packet is going and what they all mean. There's also a major challenge in sifting through such a huge quantity of data to figure out which bits are actually useful. But if their computing power is advanced enough compared to ours (which it realistically would be for an interstellar civilisation) then this all ought to be feasible as well. Then they wouldn't be able to run their *own* Google searches, but if someone on Earth were to run a search they're interested in, they could simply intercept the result.
[Answer]
**They already did, and they are connected** -
Information superiority is the primary leverage for any interaction with other civilizations, terrestrial or extraterrestrial, for us or for them.
**Travelling is not required** -
Leaning on Occam's razor principle stating that, due to the high likeliness of the current knowledge of the Drake equation in combination with the exponential likeliness of the technological singularity and quantum physical research and quantum entanglement implications, our extra-terrestrial friends are everywhere and the vast majority of the highly developed civilizations do not even have to travel here at all to interact with us. The only civilizations that need to travel by FTL are still developing.
**Monitor, plan and act first** -
An ancient highly developed civilization would with self-repelled replicating AI monitoring technology or quantum sensor grids have an almost universal civilization sensor network that would ensure complete information monitoring. Early recognizance would ensure they can align developing civilizations microclimate so that the environment would be immunologically friendly and by seeding core cultural memes slowly acculturating the indigenous population and aligning intelligence evolution so that an “invasion” would not even be required.
**Connection to simple networks is simple** -
If one assumes they have full "physical" access to our environment, and based on that even on our own "primitive" military intelligence organizations continuously show ability to connect and break all "unbreakable" encryption schemas, connecting to our networks is simple. Our network technology and security very likely is like reading old snail mail and would more resemble reading open post card-based communication.
**They are already here, and they are chatting** -
So, given all statements above, we can safely assume to say they are already here, they are all connected, they know everything about us, we interact with them already and most of us have no clue. “Invasion” already happened, and we did not notice as they are a friendly bunch of folks, albeit with different looks, just chatting along in our chatrooms.
[Answer]
**They can't**
The aliens have NOT read the RFCs that define how the bottom 5 layers of the OSI (Open System Interconnection <https://en.wikipedia.org/wiki/OSI_model>) model works, thus will have to deduce that the radio signal they receive represents a packetized communications protocol with headers containing metadata and data, which may be binary, or be numeric representations of ASCII, UTF-8, ... characters. Data may be encrypted in whole or in part.
See `https://ietf.org/standards/rfcs/`
Also see `https://youtu.be/hbFq0I7YrYQ` Carl Sagan's take on communicating with aliens. Now, consider explaining "Path Maximum Transfer Unit (`PMTU`), or the phaseover from IPv4 to IPv6 using this method.
[Answer]
## They've been here for decades:
A forward scouting group really did land back in the 50's-60's and escaped Area 51. They hid out listening to TV and radio chatter over the years, then started intercepting satellite communications when it started being used for TV.
Because they got tired of their rations and hunting, while avoiding being hunted in turn, the group got remote jobs to earn money through the mail. Some was stuffing envelopes, other was processing mail-in orders, some was punch card programming for universities and corporations, and some was data decryption for the US Military. It paid just enough to be able to mail-order some food, buy housing through a mediator, and get other amenities.
## They have internet access:
Then the internet became available over satellite. The scouts learned the protocols in the same way as any human did back then, by mail-ordering books and equipment, including some computers. Because the connection wasn't secure, they were able to hack the satellite ISP to give themselves free internet until they could afford to purchase it to avoid having to cover up their "suspicious activity".
When the US Patent system came Online, the alien group downloaded plans for all kinds of things and went into manufacturing with their replication systems. This brought in a bunch of money, so they expanded their operations over the years.
Now they have an underground server farm that replicates a significant part of the internet, including the dark net. And yes, the aliens are part of the dark web with being able to supply all kinds of less than legal or otherwise hard to find stuff. They also do black- and white- hat hacking, do remote CAD and video rendering for corporations & Hollywood, website hosting, crypto-currency processing, and other internet related money making enterprises.
They also make money by posting "fake" pics and video of themselves, furthering conspiracy theories to make their presence sound that much less likely, while also profiting off the merchandise and other materials.
## The aliens own satellites:
They also routinely hack satellites to send a signal back to Mars of all they've been doing as part of regular reports. They have also utilized programs like [New Atlas](https://newatlas.com/tubesat-personal-satellite/22211/), building their own mini-satellites for more consistent communication to the Mars base. This has allowed them to send a huge amount of data back to their superiors for processing over the years.
## They have business fronts:
To keep the Federal Government at bay, they have shell and front companies handling all the money. Some of these companies are run by humans and don't even know they are fronts. They also have accountants they only communicate through via mail, phone, or internet tech to avoid exposing their alien identities.
The aliens were originally based out of Roswell, but too many people got glimpses and called in the authorities. Fortunately the aliens left before any Feds showed up, so the reports all got called "conspiracy theories". They now have a base of operations in both Reno and Las Vegas. To keep from being found out, they move between them regularly, but only in costume and when costumes are reasonably expected, like on Halloween night or when a comic con is in town. There's also a safe house in LA, but only if the main 2 locations get compromised.
[Answer]
**Download the internet**
The aliens hack a satellite and download whole websites. The satellite does the work of collecting the pieces and radioing them back to the mothership where they are stored on a local cached server.
It's no different to someone with a poor internet connection downloading a tv series on Netflix to a local media player and then watching it.
The internet is already full of cache servers which operate this way.
Alternatively the aliens just clone the data passing through which means they don't have to hack anything, they just watch what everyone else is doing. They could do this from Mars just by listening to the radio waves or from their own relay satellites, isolating each signal and decrypting it. Already a lot of internet traffic goes through satellites, not to mention, telephone communication, military communication, financial data etc.
All the aliens need is sensitive enough radio antennas, excellent processing power and massive amounts of storage. They'll get all the latest shows from Netflix, kids doing homework from Wikipedia right through to encrypted government communications.
[Answer]
I am not sure I quite understand the focus of the question. It seems to me the answer is elementary, my dear Watson. And pretty much the same level of technology also, my dear Sherlock. Well, maybe not that long ago, but a century and a half ago. Sherlock and Watson were, after all, apparently around in 1887, right at the beginning of the required technology.
My eight year old grandchild can access the Internet, use email, search google, yet knows absolutely nothing about Internet protocols, TCP/IP, encryption, or, really, even what the Internet is. All of this is done by the interface, and the device. Cell phones, tablets, watches, cameras, cars, even light bulbs can access the Internet. For the end user, everything about the Internet is nothing but a black box.
So the question is, how do they get access to any one of a number of devices that already connect to the Internet, remotely, without worry about the time lag, using very simple technology to do so? That is, they do not need to know anything about the Internet, if they can gain access to a device that does all of this for them, remotely, from Mars, using simple radio wave technology, and better still, a code as simple as Morse Code, and Morse Code-type handshaking.
Very often, we tend to over-think the problem, and try to figure it out from a high level high tech perspective. Sometimes, the answer is in very old technology. Remember ham radio? The short wave band, which used to be very popular with hackers? The dot-dash of Morse code? The basis for the originator of ASCII code and binary transmission? The one that was the go-to option for technoadventurers before computers and the cell phone? The system that just needs some basic equioment, made in the basement with a soldering iron, and huge antennas in the back yard? Things that could be buit from odds and sods available in 1912? If a culture can make it to Mars from some remote place in the galaxy, they can figute out how to make a basic ham amateur radio rig.
Well, it so happens that these rigs can be and are interfaced to the Internet. That's right, ham radio was not killed by the Internet, it was just made easier. Ham has transitioned to the Internet, interfaced with ham radio transceivers through publicly accessible Internet gateways. See [this](https://www.dxzone.com/catalog/Internet_and_Radio/Radio_Gateways/), for instance.
A simple communications rig, on Mars, connects through short wave to any of a number of existing Earth gateway base stations, run by HAM radio amateurs holed up in their basements, connected to the Internet, all protocols taken care of by the ham equipment.
Since ham radio broadcasts are easy to pick up, and there is constant chatter over ham radio frequencies, and these amateur radio gateways are far from a classified secret, it would be no problem for an advanced civilization to learn how to tap into the existing widespread amateur radio/Internet gateway community just by listening to non-encrypted public access short wave radio chatter. All they need is an antenna and a basic radio rig.
So this colony on Mars uses short wave radio to contact any one of these earth-based gateways, and they are into the Internet, no knowledge of protocols necessary. At least, none that they can not pick up just by listening to unencrypted ham radio traffic. They use plain old ham amateur broadcasts to send their communication to a gateway, the gateway hardware and software takes care of all of the translation/interface/handshaking/protocols to shft the communications on to the Internet, the Internet responds back to the gateway, which beams the response back to Mars using normal, rudimentary short wave.
] |
[Question]
[
This is one of a series of questions centered around how an isolated group of people would survive. Each question focuses on a single aspect of survival. Details about the peoples' situation are below:
>
> In a novel I am developing, a village's worth of people is living on a
> peninsula. The isthmus connecting the peninsula to the mainland is
> very narrow, and spanned by a wall, which prevents the people from
> leaving (there are deterrents preventing them from climbing the wall
> or otherwise circumventing it). They also cannot swim around the wall. This also means that no land-based
> animals can cross onto the peninsual from the mainland. The
> inhabitants have to live with what they have. For the sake of details,
> assume the peninusla is roughly the size, shape, and location of [Mahia
> Peninsula](https://en.wikipedia.org/wiki/Mahia_Peninsula).
>
>
>
This particular question deals with water being an escape route. For the moment, assume that there is no way for the inhabitants of the peninsula to approach or get across/around/under the wall. The wall is not an option. Flight has not yet been dreamed of (think 13th century). The only remaining option is the sea.
It is very important that the inhabitants have *no way off the peninsula*. This is vital to the novel. The sea cannot be an option for escape, and there can be no doubt about this. What can I do to make sure escape via water is completely out of the question?
For technology purposes, assume the inhabitants of the village are peasants of the medieval era, perfectly adept at building.
---
I've marked the answer by Lu22 because I feels it provides the most air-tight deterrent. Everything else, while great, still has the problem that given enough attempts, someone is *bound* to succeed in the end (granted no one will know that he succeeded, but still).
I would like to mention that the [answer here](https://worldbuilding.stackexchange.com/a/61661/6620) has a convenient index of sorts of everything listed. The [answer provided by Strongo](https://worldbuilding.stackexchange.com/a/61658/6620) was also a very helpful one, and combined with sea monsters I think would be an awesome combination.
[Answer]
There's a whole other route you can go.
**Dependency**
Whoever built the wall did so in order to keep the people in. So how about as an extra measure they had the entire village addicted to a substance only found on the peninsula?
For example a fungus or plant that only grows there under strict conditions, or even a unique tree's (that cannot be propagated) sap.
If not consumed daily the villager suffers extreme withdrawal symptoms or even death. The addiction could be passed from mother to child via breastfeeding, so the villagers can't phase it out.
Alternately it could be a disease affecting everyone (such as HIV), with the substance delaying its potency and allowing a normal life if consumed regularly.
In order to keep the people from hoarding it and being able to travel, the substance would need a very short shelf life.
This would keep the people in the peninsula even without the wall.
[Answer]
## Give them nothing to build a boat out of matched to the nastiest coastline you ever did see.
No wood, no reeds, no beach, just jagged cliffs facing onto the Southern Ocean. Much like Zavodovski Island.
[](https://i.stack.imgur.com/6Pp9F.jpg)
House building is able to cope with this restriction, it just makes it a bit harder and more expensive to build, as long as they have the stone, but far from impossible. However by taking this option you're effectively limiting the people to stone age technology unless they already have active mining and iron working before the wall was built.
---
The problem here is the breadth of stuff you can use to build a seagoing boat.
* Reeds
* Timber
* Light wood and Hides
Which means that to keep the people on the peninsula you need to prevent them from having any wood, any large animals, any large rivers or accessible shoreline. People will build boats, all they need is half a chance. If you make them desperate enough they'll probably work out how to build a boat out of the skin and bones of their dead relatives.
[Answer]
Strong currents moving in wrong direction, extensive coral barrier, wind blows constantly the wrong way, permanent mist, constant heavy surf, etc. There are many shores in the world which are utterly unsuitable for navigation. See for example the Skeleton Coast, <https://en.wikipedia.org/wiki/Skeleton_Coast>. Then question remains why don't they simply go *around* the wall...
I guess that it must be important for the plot that the people are on a *peninsula*, probably because at a certain point some enemy comes over the wall, or one or more characters find a way to cross it. Otherwise you could place them on an island or oasis.
[Answer]
I have yet to see this, so I'll add it as a suggestion: make the sea itself inhospitable to organic materials (including humans).
As in, make it so that the water has some weird chemical composition or there is a microbe/small creature in the water that will eat away and dissolve any organic material in a matter of hours - think barnacles on steroids - far too soon to reach anything beyond the sea and far too late to swim back to shore and tell anybody about the problem.
Now, I don't think you want to kill people who just went for a quick swim, so you could have this toxic element start in the deeper ocean. Basically, you make the area near the shore safe-ish and not have this problem, but if you sail a day or so out then your boat will sink and you will certainly drown or get dissolved by the same effect that destroyed the boat.
13th-century technology is no way capable of making a blue-water vessel out of non-organic materials or of creating a coating which can resist the water's corrosive abilities, so this barrier will completely prevent navigation by water.
You'll just have to make the wall extend 25 miles out to the side from the peninsula, and you'll be good to go.
[Answer]
Note that you don't need specific or modern materials to make very good boats.
"... the traditional umiak was made from a driftwood or whalebone frame pegged and lashed together, sometimes with antlers or ivory, over which walrus or Bearded seal skins are stretched. Oil, usually from seals would be used to coat and waterproof the seams." - <https://en.wikipedia.org/wiki/Umiak>
Polynesians travelled thousands of miles across open ocean without access to modern navigation techniques, using dugout outrigger canoes with no metal parts (<https://en.wikipedia.org/wiki/Polynesian_navigation>).
So from the frozen north to the tropics in all sea conditions, people are very good at seafaring, but this skill develops over many generations. If the people had been recently deported there from a landlocked place with no navigable rivers then they wouldn't have the knowledge or understanding of boats for some time.
[Answer]
Building up on [Lu22's answer](https://worldbuilding.stackexchange.com/a/61636/29320)...
### Unavailability of non-perishable food
The scenario does not require that people are not able to build boats, it just requires that people are not able to *get to any other place* via sea. So, we just need to make sure that the amount of supplies needed to get to any other place is greater than the amount of supplies that can be collected and *stored properly* in a boat.
This means no preservatives (no salt mines, no salt plains, no desalination technology), no milk-based products, no smoking meats, no nut trees, no edible animals on board, no fishing.
It is not needed that the amount of perishable food is exactly zero. We can assume that the available amount of supplies that can be stored for a long time is *small enough* that sea travel is only viable for a very small amount of man-days.
e.g. the islanders spent a few years storing supplies for twenty man-days, and a lone explorer was sent away, but came back after three weeks, starving.
### Quick-onset scurvy
We all know about [scurvy](https://en.wikipedia.org/wiki/Scurvy), right? The disease that plagued pirates because they didn't eat enough C-vitamin?
The problem with scurvy is that it takes several months for sailors to display symptoms.
Simply create a scurvy-like disease, but with an onset of days instead of months. The disease is easily cured by eating something perishable (the islanders cannot store more than a few days worth of it in a boat), or by being in a completely dry and warm environment.
e.g. the islanders sent lone explorers out to the sea, but they came back after a few days, disoriented and very sick.
### Lack of navigational tools
Get rid of compass technologies (no deposits of magnetite or similar minerals), and prevent star-based navigation (due to weird climate patterns, there's heavy fog at night out in the sea).
Without compasses or [Iceland spar](https://en.wikipedia.org/wiki/Sunstone_(medieval)), it's pretty much impossible to navigate the sea in a straight line. Watch the few first episodes of [Vikings](https://en.wikipedia.org/wiki/Vikings_(TV_series)) if you need a bit of background on that.
Islanders would still be able to sail around the island, as long as they have a clear view to the landmass. But sail more than 30km away from land, and sailors get lost *fast*.
---
Obviously I'm not addressing the issue of sailing around the isthmus wall, but the OP is explicitly handwaving that issue for this question.
[Answer]
Setting aside that thing about the wall, and taking into account the number of people and the era, you might preventing escape by a combination of a huge predator and a lot of superstition.
Over time, someone will ty to escape. That's only human, so assuming they would not seems to be out of the question.
If you have a large reef around your peninsula, this would provide plenty of food for your village, making life easier, and reduce the pressure to migrate. But the same would be true for large predators.
It would also prevent large vessels from escaping.
Sooner or later someone will fall victim to a large predator. If we are talking about sharks, who normally don't feed on people but just attack because they mistook them for something else, you will have badly mainmed boats and corpses on your sore after an unsuccessful attempt of escaping.
Perils tend to become bigger and more dramatic the more they are reported at night around a campfire. After the second or third attempt, your villagers will have interestin stories of enormous monsters lurking in the sea, hunting humans, tearing them apart, and whatnot.
Also, they will be green, tentacled and fanged, of course.
as a result, joined efforts of leaving will be strongly discouraged. And while from time to time a young hotspur will try to escape, mostly failing very painfully, the only attempts that actually stood a chance would never happen.
What is more, even if our young hero managed to escape, the villagers would never know, and would most likely assume that the monster ate him whole.
So, while it is hard to conceive a way of preventing escape by geographical means, human nature might do the trick of locking them in.
[Answer]
What is on the other side of the wall? If there are hostile people or dangerous animals there, then someone who swims or builds a boat to go around the wall would have no safe place to go.
The water could be full of sharks or other dangerous sea creatures to prevent people from swimming.
People could have the engineering skill to build houses and tools but have no idea how to build a boat. But this gets weak if we're talking about simply getting around a wall across an isthmus. I could easily believe that people can't leave an island because they don't know how to build boats capable of travelling hundreds or thousands of miles. Tougher to believe they can't figure out how to build a simple raft that would take them past a wall. How thick can this wall be? A few feet? Strapping a few logs together so you can sail ten feet doesn't seem all that tough, you'd think someone would think of it sooner or later.
How about something cultural? These people have just never thought of the idea of travelling by water. Or they have a superstition about water, they think ghosts inhabit it or something. Seems to me that sooner or later someone would test such beliefs, but it might be plausible.
Can there be people actively patrolling the waters around the peninsula? Powerful warships quickly sink any boat these people can build and massacre the survivors?
Oh, or how about: the shoreline is steep cliffs. Sure, they could build a boat. But then they'd have to lower it 100 feet to the water and climb down. Then they sail around the wall but to get ashore, they would somehow have to climb from the boat up a 100 foot cliff. It would be possible, of course, but very difficult, the few who try it fail and everyone else just accepts it as impossible.
[Answer]
Other answers cover a point I was going to make - if you remove any reliable source of wood from the inhabitants, they have nothing with which to construct a viable ship, and so wouldn't be able to go much of anywhere.
You have said in your question that there is no way *around* the wall, but then gone on to specify the sea as their remaining escape route, so the following works on the assumption that your restriction on their ability to bypass the wall is geared towards land-based methods.
With this in mind, there does remain the possibility that they may be able to cobble together some short-range rafts though to bypass the wall by following the coast to the mainland.
My suggestion to avoid their doing this would be to replace the wall with a mountain range.
Doing so would be able to give rise to incredibly violent storms resulting in any navigation following the coastline to effectively be scuppered by a wall of it's own, in the form of treacherous currents, unpredictable storms, and consistently violent winds.
This could also lead to reefs being present in the area, in the form of the mountain range extending out past the land to either side of the peninsula along the seafloor.
This would provide the dual advantage of further destabilising currents and adding the risk of the sharp rocks in to the equation for someone attempting to traverse the waters in anything from a rickety raft to a full-drafted ship.
[Answer]
I would do either:
* A predator in the sea that will devour anyone that crosses its path.
* Sharp underwater reefs
* Maelstrom's
* Currents pulling a ship against the cliffs
* Alot of fog so nobody can navigate anywhere.
* Lots of rogue waves
* Vulcanic or seismic activity underwater which creates alot of waves. (Tsunami)
* Thunderstorms and bad weather which would be visible from the shore.
The last one is my favorite since it stops people from even thinking of leaving the island.
You could ofcourse combine some ideas to make for a very interesting and dangerous enviroment.
I hope this helped please ask questions or give constructive criticism if you would like to know more or if I missed something.
[Answer]
Why not get psychological? You may have heard of the supposed '5 Monkeys and a Ladder' social experiment. Basically, the original group are punished whenever one attempts something- thus it becomes taboo to do that thing. Finally you end up, a few generations later, with a group that will not do something despite not knowing why. See also: The Village
How to apply this? Your original group of settler, prisoner, whatever, were closely observed. If any tried swimming away then their settlement was raided or someone 'disappeared'. Naturally over time they realised that trying to swim away had a consequence. And the elders, or ruling group now actively prohibit it.
Of course it's not water-tight (ha). But for a bonus there could *actually be something in the water* as others have suggested- but this isn't ever outright said, just hinted at.
[Answer]
Add a continuous fog bank on the mainland that lifts on very rare occasions.
When visible make the land behind the wall all the way up both coastlines appear lethal with lava, scorpions, suffocating smoke, triffids.
Let the local folklore explain the wall as a safety measure rather than imprisonment. Have the dangers forever creeping around and over the wall requiring vigilance and pruning. Have some of these dangers artificially generated if required.
Add jelly fish, electric eels, piranhas, Candiru :-) , sharks etc to make attempts less tempting, maelstroms, foaming or burning methane.
Also make the shore landing treacherous with venomous sea urchins, jagged sharp cliffs and cannibal tribes.
Let your imagination soar, all you can do is make it hard, the outcast will always find a way. As mentioned in a comment the book Destiny's Road by Larry Niven has a lot of interesting thoughts on this problem. There is also a diet dependency for the population thought the trace element actually comes from the mainland and is traded with the peninsular inhabitants so they are hostages. I recommend this book as a good reference scenario to try and improve on.
[Answer]
Acid leeches.
They live just offshore, feeding on driftwood, beached whales, and the carcasses of fallen sea birds. Nothing else swims in those coastal waters - not for long, anyhow. The leeches' highly developed sense of smell allows them to detect any organic matter - they can eat more or less anything. When they smell something tasty, they'll swarm over it, latch on, and inject a toxic acid from a spine inside their acid-proof suction-cup mouths. The wood - or if they're lucky, meat - dissolves quickly, and they drink it up, swelling up to twenty times their original size - up to the size of a loaf of bread. Afterward, they'll swim along the shoreline, dispersing their eggs over a wide area. There, the adolescents will hatch, fully formed, and sit dormant, for months if need be, until they scent food. They exist along the whole shallow coastline, for miles out, at a density of up to ten per square meter.
One bite is enough to kill a child, or seriously weaken a strong adult. Besides having a tendency to bog down and rapidly consume any wooden boats, the leeches also have the unsettling ability to climb and crawl, like huge, horrifyingly fast alien slugs. Once they've caught the scent, they'll squirm with all their might in pursuit of delicious humans, mindlessly willing to die for the cause. Therefore in addition to dealing with a heavily encumbered, progressively disintegrating ship, any hypothetical sailors would be engaged in a ceaseless battle of whack-a-mole in which one missed strike could result in their death.
[Answer]
if all the mainland coast for many miles is high cliff, they would just need patrolling to keep people on the island. just make sure no one who makes it to the mainland lives long enough to makes it back to the island.
the big thing is it may not need to be perfect, just nearly impossible for a few generations, once they believe there is no way off the island they will keep themselves on the island, you don't need to make impossible just too difficult to seem possible.
[Answer]
A small community with humble technology could be thwarted from escape by a combination of factors without having to resort to depriving them of wood.
Imagine strong surf breaking against a rocky cliff of a shore line, making leaving nearly impossible. If our intrepid explorer gets past the surf, the rocks and shoals, then he or she would be swept out to sea. Since they can't see anything but water (which can be accomplished by having no no land or other feature for about 50 miles. The highest point on Mahia is 1302 feet high. A six foot tall person on top of the hill could see a little [over 44 miles](http://www.ringbell.co.uk/info/hdist.htm) on a clear day.) there is no obvious destination.
Add to this a dead zone around the peninsula due to Phosphorous(see [Dead zones](http://nationalgeographic.org/encyclopedia/dead-zone/)), and any explorer swept out to sea would never make it back alive. In addition, no fish in the water would take away fishing as a motivator for building boats.
There is a reason the wall was built. Whether to keep them in or keep them out, lore would build up around the wall telling of the horrible creatures waiting on the other side.
[Answer]
These are some of your options to make the inhabitants captive of the peninsula:
**Fast water currents, as suggested by AlexP**
No detail on this, as it has been already covered by AlexP.
**Sea Monsters**
If your world has magic available, then we are talking about true horrors like [krakens](https://en.wikipedia.org/wiki/Kraken), [gorgons](https://en.wikipedia.org/wiki/Gorgon) or prehistoric sea monsters such as [pliosaurs](https://en.wikipedia.org/wiki/Pliosaurus), [megalodons](https://en.wikipedia.org/wiki/Megalodon) and [tylosaurs](https://en.wikipedia.org/wiki/Tylosaurus).
The very sight of these sea monsters in deep waters would keep the people from any thought of getting into deep waters, although they would be free to go fishing in the shallow shore waters (upto the depths of 50 feet or so).
**Lack of required materials for shipbuilding**
Building a ship requires metal. If you don't have any metallic ores on the peninsula, your people would not be able to build any ship in the first place. While they would still be able to hollow out canoes, these would not be large enough to stock a weeks' long reserve of food and water, making long sea journeys impossible.
[Answer]
Ok, best I can come up with would be for the peninsula to have 1) a fairly steep shore/cliffs with the livable land say 20-250 meters above the sea level and 2) be in a crater sea with 3) the isthmus surrounded by that crater sea then by a crater wall 10~20 meters tall with 4) it's connection to the mainland being a (150-200 meters) steep ridge. We could say the unique geography was created by a combination of meteor impact and volcanism. 5) In the crater sea there are many large blue holes letting ocean water easily flow in and out of the crater sea allowing us to have some life in the water. 6) While there are no longer any obvious signs of volcanic activity, CO2 is seeping up and filling the bowl of the crater from the surface of the sea up to say at least 10 meters but below hospitable zone for the peninsula.
This should leave the steep ridge of the isthmus as the only survivable passage to and from the island and give your wall the intended meaning.
] |
[Question]
[
The world is covered in mana, the life force that flows through all things. In certain places, this mana saturates to high levels. This affects the animals living in those areas, who absorb the high concentrations. Over many, many generations, these animals mutate away from their parent species, giving rise to unnatural creatures that are larger and more powerful. Ex: snakes evolve into hydras, lizards become great wyrms, horses become unicorns, etc. Their changes get passed down to their offspring, which may continue to evolve in surprising ways.
The high concentration of mana in their genes have a number of various effects that give them advantages over other members of their parent species. Although they are not sapient like humans, they are more intelligent than average creatures. This makes them more efficient predators or prey animals.
Given how evolution works, these creatures would eventually out compete their cousins and drive them to extinction. This would eventually lead to the world being dominated by magical beasts, eliminating all other kinds of "regular" animals.
I want these places of highly concentrated mana to be rare but can occur anywhere, allowing these super charged creatures to interact with their less evolved brethren. At the same time, I don't want regular animals to be made extinct. How can I make this happen?
[Answer]
Something many people seem to struggle with is that evolution is about survival of the *fittest*, not the strongest or the biggest.
The fittest individual gets to live long enough to get enough offspring that have a higher chance than their brethren to get their own offspring.
Your hydras and unicorns would require more energy than their "lesser" counterparts. They partially counter this through higher intelligence allowing them to hunt prey better, but during times of scarcity it will be the hydras, unicorns and their children that will perish first.
Also as a strategy many creatures that are larger will have fewer children per birth. This allows the "lesser" variants to compete with numbers, as they'll take up most of the food and during scarcity have more individuals that might survive.
[Answer]
## Hydras would not compete with snakes
Most snakes eat rodents, or other small animals. Even large constrictors don't generally eat adult-human-sized prey. Assuming that hydras would be interested in human-sized or larger prey, they are no longer in competition with their mundane snake forebears. The same holds true for lizards (often eating bugs) and great wyrms.
Now, the hydras and great wyrms might threaten to wipe out your horses, but that's another question.
Horses and unicorns could coexist, the same way elk and moose, or elephants and zebras, etc, coexist. As long as you've got a rich and varied ecosystem.
[Answer]
Make the super animals depend on mana to live, and move the mana around. As it passes through any given area it moves slowly enough that the animals change, but fast enough that the super animals don't have time to eradicate the normal animals.
This will cause the super animals to either migrate permanently to follow the mana (assuming they can adapt to new biomes), or die out. It's no problem if the supers die out because more will arise when mana passes through the same area again.
One way to move mana around is to make it depend on some pseudoscientific thing like astrology, so the ley lines are defined by where the projected paths of the planets on the surface of the Earth get closest. Maybe the mana spots cycle through the Earth's chackras (seriously, google it up, I couldn't come up with that on my own), but with the addition that the chackras move. Or maybe they form where mana flares from the sun strike the surface, because mana flares are invisible and not deflected by the planet's magnetic field.
Or, who knows? The gods do play dice with the universe. The world is a grid and mana spots are random events.
[Answer]
>
> Given how evolution works, these creatures would eventually out compete their cousins and drive them to extinction. This would eventually lead to the world being dominated by magical beasts, eliminating all other kinds of "regular" animals.
>
>
>
Actually, that is not how evolution works. The basic principle is indeed "survival of the fittest", but in practice it does not come down to "biggest baddest animal wins". If you carefully consider the mathematical implications of Darwinism, and set your assumptions reasonably, you realize that in fact it's a vastly more complicated story - which is how we get our diverse biosphere on Earth. I won't go into the details of this because it's a topic that could (does!) fill whole textbooks. You'll have to take me at my word.
How can it be, you ask. How can the magnificient unicorn not dominate the horse? Well, that's all in the textbooks. But basically:
* Fitness is relative to the environment and the magical animals may be fit for the mana hot spots, but they may have very poor fitness outside. A classic fantasy staple is that magical creatures begin to weaken when not around magic. See "waning" of the Elves in Tolkien, among others -- elves are like magical, better humans, right?
* An animal maybe more bad ass, but it may need to also eat more. That's why there's more rats in the world than tigers. Fitness is not about being the most badass, but most efficient. Whoever gets the most bang for their buck proliferates the most. Buck here being food or energy, bang being, well... [You know](https://en.wiktionary.org/wiki/bang). Wizards becoming extremely hungry after casting big spells, and having to eat ridiculous amounts of calories, is another fantasy staple. It even has an analog in reality, if you look at programmers, mathematicians or students in tough exams. In fact, high caloric intake is suspected to reduce lifespan, so you could also go with that idea. So maybe unicorns can't find enough food and starve, or maybe they can but they waste so many calories on magic they rarely use that they end up dying young from heart attacks or cancer.
* This is the same as fitness being relative to the environment, but it is not a given that a magical animal will feel the same exact pressures as its mundane analog. People don't hunt horses that much, but unicorns are *really cool*. People might hunt them to extinction. See dodos, buffalo, and others. Same might apply to other predators, maybe wolves find unicorns *really* delicious.
* When you mention that "their genes are mana infused" you kind of break with any real world biology, so anything is possible. But I'm assuming this means literally that their DNA is not merely mundane nucleic acids, but has some magic in it, similar to how a magic sword is metal infused with magic. So then, if an animal eats the magic unicorn, those same molecules will be incorporated into the eater's cells, and they will likewise be just as magic.
* Predators, parasites, diseases and so on maybe somehow inhibited or killed by mana. So the unicorns do really well in the mana hot spot, but as soon as they stray too far they get exposed to all sorts of new threats they haven't adapted to. You could even play this for laughs, and make them all die from the common cold (which for some reason is cured by mana hot spots).
* In real world biology, all adaptation has a cost. Increasing your fitness with respect to one environment almost always decreases your fitness to another environment. Trivially, you cannot be both large and small. But also, it's just how physics and chemistry works - it turns out that "free lunches" are very rare in biochemistry (this may be because we're already starting with a very optimal organism) and extreme generalist, "Swiss army knife" species (eg. us) tend to not be very good at any particular thing. For example, when bacteria become resistant to an antibiotic, it usually also makes them grow slower when not exposed to that antibiotic. So your magical creatures are unlikely to be much better than their mundane cousins, and outside their original environment, might do very poorly. This is again a consequence of "fitness is relative to environment".
* Just because species A has higher fitness doesn't necessarily mean it will become the only species. When it does, that's called a selective sweep. But selective sweeps do not always happen for all sorts of reasons. The result would be a mix of the competing species in equilibrium, especially for small fitness advantages. Populations often retain a small pool of "unfit" individuals as backup for sudden environmental changes.
However, I think the main fallacy is that you assume that mundane animals are "not evolved enough", and that there could be better, "more evolved" creatures. In fact, all creatures are equally well-evolved - they have all been evolving for the exact same amount of time; which is the time since the creation of the first ever organism from which they all descend. As I noted earlier, evolution is about adaptation, not being the most badass. Therefore, in "steady-state" all species tend to be almost perfectly adapted to their environment. If you think of evolution as searching for the local minimum [of energy expenditure per offspring] of a mathematical function, most species are already in the local minimum. There's nowhere else to go.
Another way to put it is that mutation rate is not the limiting factor. It's not like these animals could explore crazy new evolutionary possibilities, if only they didn't have to sit around waiting for the odd once in a million year mutation. They are already mutating way more than enough. In fact for most things, the name of the game is to cut down on that mutation rate, both to avoid losing their "optimal" state, and also to avoid getting cancer (I think "magic gives you cancer" is a very underappreciated theme in fantasy, personally). Don't believe me? Look at Chernobyl. While there's supposedly some weird new mutants that were found there, it hasn't really created any super-animals.
So the thing you are suspecting cannot happen. Even if magic accelerates evolution, it wouldn't matter, because evolution is already fast enough and most species *are already at the finish line*. If magic also gives supernatural powers, that's a different story -- you have to ask why would any animal give up such awesome power, why wouldn't every animal evolve to become magical? The simplest solution is to make magical powers not work without mana, or make magical powers come with a cost.
It is true that evolution is not instant. So any a change in the environment can be too rapid for an organism to adapt. For example, even though there are bacteria that can live in scalding water, if you put an average E. Coli in a boiling pot, it will just die. You would need to raise the temperature a tiny bit in every generation. Similarly although bacteria can become resistant to antibiotics, a naive bug will not instantly resist a brand new antibiotic if it gets administered at 10x the lethal dose. You have to give it increasing, sublethal concentrations for a while. This is where mutation rate comes into play, as it can possibly accelerate the process, but not by much. This is because getting multiple mutation steps without selection acting in between is very unlikely due to the large number of probabilities involved. So if magic increases mutation rate, then it will only affect adaptation/evolution if the animals experience a sudden shift in environment, and it will only affect it briefly (until the mundane species catch up), and it will only affect it slightly.
[Answer]
**Competition:** The majority of evolutionary competition affecting predators is between the predator and its prey, not between competing predators. For example, there is an evolutionary pressure on cheetahs to run faster in order to catch their prey and a similar pressure on the prey to run faster in order to escape. A super-cheetah may find it easier to catch prey but won't compete directly with a standard cheetah so long as they don't deplete the prey animal too much. So both cheetah and super-cheetah could coexist in a similar manner to how two different predators with different hunting efficiencies often do exist in the same region.
As an alternative, perhaps super-predators naturally hunt super herbivores as they are larger (and tastier?). So normal prey animals are left for the normal predators.
**Intelligence:** If the super predators are smarter, they may voluntarily limit their populations to avoid killing all their normal prey - therefore there will be prey left over for normals (even if the normals find it a little harder to get a feed).
**Fecundity:** As an alternative, the mana might mess with ability to reproduce - or greatly increase time to reach maturity - in that case the supers population would always be small enough that they wouldn't compete for resources.
**Competitive animals:** There are some species that naturally compete amongst themselves, for mating privileges, leadership etc. Presumably supers would breed amongst themselves so there wouldn't be direct conflict with normals. Similarly, a super wont see a normal as a fitting opponent so wont bother fighting them for leadership - as a lion wouldn't bother fighting a cat.
In practice though, you might lose some normal species regardless of what rules you enforce. A super lion might find a normal elephant a better meal than an antelope or zebra, and they will be much easier to catch as elephants have not evolved with any defense from an extra-powerful predator. Consequences like that are the usual outcome when you add any new species to an ecosystem, and the supers are effectively equivalent to new species even in their normal environment.
[Answer]
If it takes multiple generations for the mutations to take hold and change the animals into a new species, the local ecosystems have time to adjust. As others have pointed out, a new species can certainly change the prey/predator balance and result in problems in obtaining food or other resources, but it isn't necessarily the new species that came from one animal competing with (and winning over) that animal.
Intelligent animals can also work to increase available food, which helps other species as well. Behaviors that do this can come from evolution itself (like how ants can herd aphids) or can be from increased intelligence (primitive agriculture or creating habitats for food animals). Depending on how intelligent these new species are. You can build this skill into your evolutions if you choose.
Any animal that doesn't have enough food, water, or safe places to create and raise their young will migrate. If the new species are happy staying put, their cousins will find better pastures, as it were.
Even if one species reduces in population due to changes from the new species, there will be other communities elsewhere. So they won't go extinct.
[Answer]
First, a subdued rant against such terms as "hyper evolved", "more evolved", higher life form", etc.. These suggest the "ladder of life" view which is almost a defining characteristic of people who do not understand evolution.
As for your question, you seem to have almost answered it yourself. If mana is not uniformly distributed then there will be high mana areas where mana-using animals will dominate, and low mana areas where conventional animals will. In between there will be areas where they compete but because each has a safe refuge it will not be driven to extinction.
Keep in mind that mana-using organisms are not "higher" but "different". They have different needs and probably will not be competing directly with their non-mana-using progenitors.
[Answer]
You could just make the "magicisation" process work both ways.
After several generations of snakes/horses/lizards in a mana-rich area you get Hydras/unicorns/dragons, but after several generations hydras/unicorns in a mana-poor area you get back to snakes and horses (or perhaps some other mundane animals that lack magic but are not quite the same as the base animals were originally).
So as you move away from the mana-rich zones the abundance of magic creatures would fall, even if they are just better at everything than their non-magic relatives.
(A somewhat Tolkenesque weakening of the blood over time.)
[Answer]
A mana-based lifecycle.
Creatures don't consume this mana to live, but they do need it to live and they need it to produce offspring (imbuing the offspring with the mana to be magical).
Mana flows from prey to preditor, and from animal to plants when the animals die.
So unicorns have to eat grass to live, but to produce new unicorns they need to eat mana-rich plants. Similarly, Hydras have to hunt mana-saturated animals in order to reproduce.
Mana-saturated animals would learn to *taste* mana, *smell* mana, and would prefer eating from mana-saturated food stuff. They would eat *some* other foods, but a hydra that goes around eating horses gets fat and dies of old age and doesn't reproduce.
Mundane creatures that avoid becoming mana-saturated are low-tier food for mana-preditors. They aren't *tasty*.
Depending on the amount of bioavailable mana in an ecosystem would then determine the amount of magical plants, prey and preditors. The usual mass ratio would apply; plants would far outweigh prey, and prey would far outweigh preditors, as each has to work to consume the other, and if their food is rare their numbers decrease.
[Answer]
We are not Pokemon! Evolution does not favor superior skills, but the ability to survive. Sharks have remained relatively unchanged since well before the dinosaurs and surviving Dinosaurs evolved into Birds (Or Crocodiles/Alligators, which are surprisingly close in relations when compared to birds and any other reptile). It's entirely possible that a hydra and it's genetic relative snake can exist in the same environment because competition edged both to survive in unique ways. Proto-Snake could retain snake like advantages because he was better at surviving with those advantages than proto-hydra snake, which faced the choice to either evolve to be better at something else or go extinct. In this case, a mana using Apex Predator role was not being fulfilled by anything better than Proto-Hydra and thus, the reproducing adults were able to pass on those advantages... but snakes remained the dominate filler of the role proto-hydra and proto-snake were competing for... though some of modern snake's advantages over Proto-Snake would occur to survive against the Hydra.
It's not that Hydra is better than snake, but Hydra is better at things the Hydra does because Proto-Hydra could not beat Proto-Snake at snake's niche, but it could beat it at another niche.
We can see this also with Birds. It's been common knowledge that Birds are the living descendants of Therapods aka Dinosaurs. Specifically certain subclasses of Dinosaurs that are mostly characterized by small bipedal builds. When the KT extinction event occurred, the sudden die off meant that for the large herbivores dinosaurs to find plant life as it wasn't growing in supplies large enough to graze upon... and the large predators had trouble finding large herbivores because, it was hard to find large sources of meat... there wasn't enough prey to sustain a large predator, smaller dinosaurs were to agile for larger predators and didn't have enough meat to offset the fuel it took to catch them, and carcasses of either were quick to rot and fester, meaning they would get sick and likely die. Being light, nimbile, and agile was an advatage in this world... one that the first mammals and proto-bird dinosaurs were better suited for than T-Rex and Triceratops... If I have a Hummer and I have a Mini, in a Mad Max style fight to the death to the nearest gas station with only enough fuel to one car to full and one car to half a tank, well the advantage is the Hummer if he can knock the Mini off the road first... but the mini is smaller and thus harder to target for the Hummer... and this also consumes more fuel for the brute with each successive attempt. The Mini is more likely to get to the gas station before the hummer... the distance over the hummer and the ever shrinking limited range before it can go no more will eventually kill the hummer in the long run... unless the hummer drive lightens the load in some fashion... or fit a more efficient method of consumption of fuel... or even finding a new mode of power... When fuel was aplety, the Hummer and the Mini could coexsist... but now that it's scarce, the Hummer needs to change how it plays the game and the next time the driver looks for a car, he's likely to take these rule in mind... or he's out of the game for good.
Evolution is all about living long enough to pass your genes along to the next generation, by any means possible. And as we know, if you want to pass your genes on, size doesn't matter, it's how you use it that counts.
[Answer]
## High mana concentration is necessary for raising a healthy offspring.
While your magical creatures can normally roam around even in areas with low levels of mana, they need to come back to mana sources for breeding. If they don't do that, there is much higher risk that their offspring will be born dead or with some defects (like unicorn lacking a horn).
With mana sources being rare, they will become crowded with magical animals. And hydras will mostly hunt unicorns, not regular horses, to feed heir babies, because that's the type of prey that will be available close to their nests.
[Answer]
Mana rich environments are populated by the creatures that have evolved to exploit this resource. However, in mana-poor areas they cannot out-compete their base forms. (It's really expensive to keep a Mana metabolism around if it's not being used.)
Think about conifers versus deciduous trees. At one time the planet was covered with conifers. Then deciduous trees evolved and out-competed the conifers in the richer environments. However, we still have plenty of conifers and other tree-like plants in more inhospitable areas, pines in mountains, palms and Joshua Trees in the desert, stunted bristlecone pines in really windy areas, etc.
Perhaps a clearer example: reptiles and mammals. Almost every biome on Earth that has one, has both. Yeah, the reptiles can't out-compete their descendants, the mammals, in most ways, but they are still here.
You're going to have three types of species:
1. Can only thrive in Mana rich areas
2. Can only compete in the absence of mana-powered competition
3. Can exploit Mana when available and can do tolerably well without it. These will not do *best* anywhere, but will prove far more adaptable, especially if mana-rich areas move over time.
[Answer]
Have the mana "settle" in isolated locations such as an inaccessible valley or island. Something which genetic exchange is either difficult or impossible.The species in this valley would then evolve isolated from the rest of its cousin species.
[Answer]
# Mana Affinity
There are different "flavors" of mana. The organisms capable of using mana are best at using the mana generated by others similar to them, so when they start to displace the mundanes, their supply of mana falls off accordingly. This places an upper limit on the portion of any given type of organism that can use mana, and assures there must always be some of the mundanes producing it for them to consume.
[Answer]
You said the magical versions of the animals have increased intelligence. Let them recognize that their survival is somehow dependent on their base form. I would suggest that the base form produces mana which is more beneficial to the higher form than other producing forms. Mana is mana, but the ones that share a heritage with the higher form are more beneficial in some way.
The higher forms could be aggressive to all other higher forms, much like in the tv show highlander where the immortals are perfectly happy to kill each other usually, but usually leave the humans alone.
The higher forms could be social with their same kind but hostile to others unless there is a beneficial relationship, like those birds that clean the teeth of predators. So grey squirrels all get along, but hate black and red ones.
[Answer]
So... mana helps evolve man from apes. Apes lose? Destined for extinction? Same reasons we coexist, other species can coexist. Monkeys are not disappearing any faster than other species.
] |
[Question]
[
To avoid being too broad, I'd like to use the portals for purely altruistic purposes (health, environment, safety), and not for scientific or military acheivement (e.g. - not an instant space elevator, which would be to save money and a bit of the 'ol environment).
My fairly well-to-do scientist is today working in the lab, when an alien race delivered two 3m radii portals: A connects to B. Place a person or object through A and they come out of B. It is an amazing thing for her to be given. They only weigh about 10kg too, so they can be handled more easily than a fictional 'stargate'.
The aliens have said rather condescendingly that humans won't be able to deconstruct it to make more of them, but more positively that it could only be used if she, herself, completely supported its use.
She has made her living, ready for a peaceful retirement in Portland's west hills, so she doesn't need money. **She wants to use it for an altruistic purpose**, which would only include increasing the health, safety, or environment. It requires no energy input that we know of, and can presumably last for a very long time and be transported easily. Technology is today (plus two new toys).
PS - this is for a short story.
EDIT1: This is an attempt, as stated: to formulate the best altruistic use of this alien gift today would be used for side part of a short story. I have used the [dialogue and comments on this question](https://worldbuilding.stackexchange.com/questions/26884/rynns-jewelry-box-best-way-to-use-a-unique-small-scale-replicator) for guidance to avoid being too broad or too opinion-based; although they are very different devices and intentions haha.
[](https://i.stack.imgur.com/ft8wN.png)
[Answer]
# Congratulations! You've solved the energy crisis!
Place Portal B some distance above Portal A. Now place a turbine blade in between the two of them. Slowly insert a steady stream of water, stopping when you reach a certain amount.
As the water travels through Portal A, it goes to Portal B. It then turns the blade of the turbine (producing electricity), and goes back through Portal A. It's a perpetual motion machine.
**Why this works**
The portals take an object at a lower potential and move it to a higher potential. Thus, the object is given a higher potential energy. That energy can then be harnessed.
**A problem . . . and a solution**
Admittedly, you've got an opening of less than 30 square feet, which is tiny, but you should still be able to generate a substantial amount of energy from this. Simply move the portals further apart (i.e. move Portal B higher) and you've increased the energy change, thus making it possible to capture more energy. You can insert more turbine blades.
---
It turns out that this thing generates a lot of energy really quickly. See [Cort Ammon's answer](https://worldbuilding.stackexchange.com/a/32531/627).
[Answer]
This is a follow on to HDE's answer, exploring just how much energy you can get out of the thing. The 3m radius yields roughly a 30m^2 area to drop things through. Do the Portal thing: put one portal above the other, and start dropping!
Now let's consider dropping slugs of material through this thing and seeing how much energy we can develop in them. From our physics classes, we can get a potential energy calculation from the mass of the object, the gravity, and the height of the object. $E=mgh$. Each object that goes through and falls to the bottom, which is some $\Delta h$ below. Now we're going to be interested in power in the end, which is energy per unit time. We're shoving mass through at a rate, $\dot{m}$ (the dot is a fancy way to say a mass rate per time). Putting all of these together, we get the formula $P=\dot{m}g\Delta h$. Power is equal to the mass flow rate times the acceleration of gravity, times the height between the portals.
Now we need to bring in the velocity of the mass. If we're throwing slugs at this system, the faster the slugs are traveling, the more of them we see passing through the portal. Let's simplify and assume we can just continuously throw slugs of material through the portal, that happen to consume the whole area. This means the mass flow rate is proportional to: the density of the material, the area of the portal, and the velocity. $\dot{m} = av\rho$, where $a$ is the area, $v$ is the velocity, and $\rho$ is the density. We know the area (its roughly $30m^2$). Lets throw something really dense through: Uranium ($\rho=19050 kg/m^3$). Put these together and we find $\dot{m}= 571500v (kg/s)$
Now we put all of this together, to get $P=571500v\cdot9.8\cdot\Delta h = 5600700v\Delta h (W)$ Note that I took care of all the ugly unit conversions for us. We have Watts. Of course, we're talking about powering nations, which is typically phrased in larger units, like terawatts. Let's convert to a bigger unit. Megawatt's happens to be a convenient unit, so I'll pick up that for all calculations here on out: $P=5.600700v\Delta h (MW)$
The power consumption of the entire world is 16 terrawatts, thanks to [my favorite set of Wikipedia pages of all time](https://en.wikipedia.org/wiki/Orders_of_magnitude_%28power%29#gigawatt_.28109_watts.29). To put that in similar units, 16 TW is equal to 16,000,000MW. That's the number we're going to try to hit with these portals.
Now, if we drop these slugs in a vacuum tube (which is fair game, given we're talking about powering the entire world), we can go arbitrarially fast. But let's be nice and not do that. Let's take the orbital velocity of Earth at LEO: 7.8km/s, or 7800m/s. Solving for $\Delta h$ we get $\Delta h=366 (m)$
Think about what that means. If we built a vacuum tube 400 meters high, at the level of vacuum equivalent to low earth orbit (which we do on a regular basis for testing), put our portals at the top and bottom, and started putting uranium pellets in, we could generate as much power as the entire power consumption of the world.
Now, realistically speaking, that's a high power density. If we pulled power out of this using magnetics, just like a modern generator does, we'd actually have to worry about how to get all of the heat away from the magentic coils. There might be some games to play with superconduction, but I'll leave that for later. Engineers are good at solving heating issues. At worst, you can always do something like drop things from a taller height, and have them moving at a lower velocity. That would let you physically space the coils out along a larger vertical length.
Note, this also shows just how mindblowingly *fast* things are in space! LEO velocities are fast!
[Answer]
## International Rescue/Superhero!
This one requires some charitable donations, but I'm sure the UN could help out here. At the same time you will need to jeep check on your ego in case it gets too large so a degree of anonymity may be required (probably not a suit where you look like a bat or spandex based however).
You have pretty much the ultimate logisitical tool. Instantly able to transport matter from point a, to point b. Anywhere.
You start off by announcing to the world at a press conference you have this technology and this is how you prepare to use it, so everyone knows about it, and makes it harder for anyone else to try steal it or coerce you into a different train of action. Include a demonstration plus details of your charitable donation and how people/organisations/business can help.
Next. Portal transport, using your stockpile of charitable donations you buy yourselfs a quick and handy transport option. Something like a transport place which can take a helicopter and/or you can skydive out of (face it you're going to want to make an entrace where you can!). (Somewhat like Thunderbird 2 I suppose.)
Second thing. Hire a team to monitor the world (space station optional), they keep track of all news stories around the globe allowing you to respond.
Third thing. Base of operations, you'll probably want to stockpile resources for distribution and a place to service and fuel your transport.
Finally save the world!
* Drought in Africa. Fly one portal under the Niagra falls, the other to Africa, water quickly appears, use it to top up a reservoir (somewhat ambitious) or attach to the back of your transport vessel and water the ground below.
* Volcano in the pacific. Use it to evacuate people away from the danger, where they instantly walk from the impending lava straight into a camp with fresh linen and running water.
* Food crisis in Sweden. You set up one portal at your base of operations (or place managing aid), and the other where the food crisis is. Instant delivery of supplies without the logistical worry (think how long it takes to load and send a plane, plus logisitcal cost of crew, fuel, maintenence etc).
* Disease outbreak in Australia. Why worry about multiple plane/ship journeys taking people and medical supplies when you can just send them through the portal.
+ Miners stuck down a deep mine in Greenland. Ok you still have the trouble of getting down there and back yourself, but whats one trip compared to multiple especially if theres a lack of supplies.
There are so many endless possibilities of how you could save the world, cutting down on cost and environmental impact (your own plane journey compared to multiple hercules). You're not being paid for it, rely on charitable donations and will try to help anyone anywhere wherever you can, however the multiple inspiring real world heroes you hear on the news become one (hence keeping your ego in check).
**And I leave you with this. Where there's heroes. There's always villians. People will try obtain this technology from you for their own evil gains.**
[Answer]
You shouldn't really discount that "instant space elevator" thing - it's a major thing on our step to a higher level as a civilisation.
Suddenly, a lot of things become almost trivial in cost - solar satellites in Earth orbit, for example, are much more efficient than ground-level solar panels. With "free" orbital insertion, the satellites themselves would be extremely cheap, probably being able to compete with ground-based power generation handily. A lot of the complications with the technology disappear - it'd still take time to exploit fully (e.g. transmitting the power - we know how to do it with microwaves, but it'd still take a lot of engineering to perfect), but it's got a much better potential than anything we can do now, economically.
So now you have solar satellites beaming power down to any place on Earth. Suddenly, you have great opportunities of using that energy - the amount of useable land greatly increases, you can provide cheap fresh water to everyone on the planet, and you can get rid of lots of those ugly coal-powered power plants. And since your energy costs have dropped so low, you could even possibly move on to making petrol from thin air, solving both a potential energy crisis and closing the carbon cycle with one swing. Again, it'd still take a long time to develop, but if energy prices drop low enough, it's going to become a thing.
Not ambitious enough? Why stop at Earth's orbit? Move one end of the portal to the asteroid belt or Jupiter, and use it to build up mining infrastructure. Once you get the (robo-)colonies going, they can use mass drivers to send materials back to Earth. This is going to have some trouble competing with Earth-based installations for some time, but it should become very profitable relatively soon, increasing the living standards all over the world. And of course, it would give us an opportunity to disperse over the Solar system at least - in a hundred years or two, the next Planet Killer that hits Earth might not mean the death of our whole species anymore.
Don't want to send your only portal on such a long journey? You can still save yourself a huge amount of work if you use the portals in Earth orbit to accelerate interplanetary spaceships - allowing them to save up quite a bit on fuel needs for the trip (you only need to keep enough fuel to accelerate in your destination - that's to the brutal rocket equation and various engineering hurdles, this means saving *much* more than half the cost).
All in all, your portals are a bit too much of a god device for a good story, I think. Unless of course you focus the crux of the story on some issue the portals *can't* fix, or some issues *caused* by the portal :P
A great example might be some of the suggestions here and in the other answers - look at a suggestion and think *hard* (or, in some cases, just thinking at all is quite enough) about what could go wrong. Used the portal to transport water to water-starved regions? Ooops, we accidentally opened a line between two places with vastly different atmospheric pressures and compositions. Used it to generate infinite power? Ooops, the portals got a bit misaligned and the near-the-speed-of-light pellets got out of the loop (although be very careful about that - I have a feeling it might be a planet killer :)).
Or you can just look at all those social changes that come from your little device - the story can very easily be about a factory worker who lost job one day due to that sodding piece of stupid technology replacing him!
[Answer]
## Contratulations! You saved our Universe!
If a portal is always able to transport matter, once one of them reaches a vacuum (e.g. outer space), matter will move towards that vacuum, creating a similar effect to what is known about [black holes](https://en.wikipedia.org/wiki/Black_hole).
Besides the obvious destruction power one could harness from transporting only one portal to outer space, this effect would be extremely useful for **closing existing black holes**: by releasing each portal from opposite directions into a black hole's gravity pull, when both portals superimpose, that same black hole would pull itself into extinction.
This allow us to close the universe by extinguishing all [gravitational singularities](https://en.wikipedia.org/wiki/Gravitational_singularity), thus guaranteeing that the [Big Crunch](https://en.wikipedia.org/wiki/Big_Crunch) will never happen.
Answering the question, humans granting immortality to our universe would perhaps be the most universal "altruistic purpose".
[Answer]
Use the 2 portals to control the distribution of water. This could be useful in several ways:
1. When an area of the world is undergoing drought, bring in water from another place to fill up local dams, rivers, or other water storage systems.
2. When an area of the world is undergoing flooding, take out water to another place that can handle the additional water. Bonus if this and #1 could be done at the same time.
3. When global warming raises the global water levels, move water from the earth's ocean to some other place where it won't cause problems - maybe outer space or the moon.
[Answer]
It may be tempting to use this for "unlimited energy" but this is wildly impractical. Transmitting power is difficult because there are always losses (either losses in the transmission line or in the storage for physical transport). It would only be feasible for nearby uses but definitely not even the entire US, let alone the world.
Because these have to be physically moved and they cannot fit through themselves, they have limited practicality for things on a world scale except for hotspots or for scientific advancement.
The two biggest uses I can see are (1) military transport to war zones and (2) getting into orbit.
The former is still somewhat limited in its usefulness, especially with the probability of it falling into enemy hands.
The latter is significant, especially since it would become trivial to construct a larger space station, which would significantly improve both scientific research and microgravity-based medicine. It would also make intercontinental travel easier, at least from a single location, as you can construct recently vehicles in orbit, load them, then drop them off.
This, IMHO, would be single most important use of this technology in the world because it can directly help the entire world practically.
If, however, you must refrain from military and scientific purposes, there are some other alternatives, most notably in the form of transportation.
There are some extraordinarily expensive medicinal machines and it would be great if we didn't have to build so many. If two hospitals were linked (say one in central US and one in London), they could share resources between entire continents so each hospital only needs half the equipment it would ordinarily need. They would also have faster transportation to hospitals near the other hospital, further decreasing equipment requirements. This may be one of the more significant uses of a point-to-point static link.
**Math behind transmission line losses:**
To show you the kinds of things I'm talking about with transmitting that energy, let's say you have this awesome generator in New York City and wish to replace the Palo Verde Nuclear Generating Station in Arizona. Yes, this is a contrived example because you'd realistically put the generator in a better location, but this is just looking at a single replacement of a single generator; doing this on a nationwide or worldwide scale would be enormous, so let's just look at *one* transmission line.
If your cables were as thick as the cable bundles on the Golden Gate Bridge but were solid copper and your transmission line was at `765kV` (the highest I could find), your cable incurs `4.675MW` of losses, which is small compared to the `3937MW` generated by the station you are replacing. If the cables were half that thick, it would waste `18.7MW`, which is still small. If you somehow had a dialetric that could handle `2000kV` lines, your losses are `0.683998MW` and `2.736MW` respectively, both manageable.
*Except that your small cable (`2.031e10kg`) just consumed more than the 2014 worldwide production of copper (`1.87e10kg`)*. **Congratulations**. If you think drilling for oil is hurting the environment, just wait until you have to produce that much copper.
Sure, this line could be thinner because it can handle the losses (basically trading wastefulness in mining with wastefulness in heat generation) but this is just ONE line. A number I found shows that the US, in 2011, had an overall summer production of `1000GW` of power - three orders of magnitude higher. Incidentally, if half of that were transmitted by the thicker line (and at least half will have to in the US), your line losses are `11GW` and it weighs `8.122e10kg`.
Ok, so we get this from other planets... Except that the space shuttle with its boosters at launch weighed `1.99e6kg` and that was HUGE. We don't have the ability to support an extraterrestrial mining operation, let along get all that copper back here. So that's right out.
And this was just for the US.
You could theoretically instead use this to power a plant to store energy by either generating hydrogen from the oceans or creating hydrocarbons, but these produce a lot of heat in the re-generation of electrical energy later, not to mention the volatility of hydrogen or the gaseous emissions of the hydrocarbons.
You could absolutely use this for free energy, but the bottom line is using the energy would be significantly more destructive than keeping our distributed power supply system.
[Answer]
It could be a good tool for disposing of hazardous materials. The destination portal could be someplace extremely safe, secure, or distant, and presumably you could go about with the entry portal scooping up radioactive waste or whatever, without having to transport it through places where you don't want to risk spills and take great effort to avoid them.
It might be worth experimenting to discover what this exactly means: "it could only be used if she, herself, completely supported its use." How is the support detected, and what happens if her support isn't completely there? Like, it doesn't somehow strip people of disease as they walk through, if she thinks how she'd like the subject to be able to walk through, but "doesn't completely support" his plague virus going with him". If it *does* work that way, then it could function as a magic disease-curing device, for example. Maybe you could get the garbage out of a dolphin's stomach by having it swim through.
You could also see if the aliens have some other good altruistic advice to give us, and use the portal as a demonstration that these guys might have some good info we should pay attention to. After all, humans are pretty backwards and argue with each other a lot, and might benefit from being told some stuff by a third party with demonstrated intelligence.
[Answer]
These portals are time bombs. It only takes one idiot to wonder "What would happen if..." to put the portals in a position to drastically reshape life on Earth, and not in a good way. Transporting people and objects is great, but the laws of physics broken by these portals can have terrible outcomes.
The best thing to do with these portals is to destroy them, if possible; otherwise, return them to the aliens. This is *humanity* we're talking about. As a species, we're still in the "licking electrical devices to see if they're still on" phase, and only managed to arrive there by licking other things first. We're just not ready for physics-breaking devices.
## Power Generation
Since you only have the single set of portals, you can only create power in one location. That means that a percentage of all power transmitted will be lost due to resistance in the transmitting wires. While today's wires already lose power over distance, there are a few reasons why the portal generator is much, much worse:
* Resources! The power transmission lines would need to be huge to limit power loss, and enormous ultra-high-voltage transmission lines would need to be built, connecting every major, minor, and otherwise-insignificant city to the main power trunk, as well as redundant connections and some serious power network monitoring and switching. Need for new copper, steel, rubber, and other raw materials would skyrocket. The free energy would make it worth it (at least in that regard), but only after significant investment. Maintenance to the power lines may actually be more expensive than building power plants.
* Physical limits! Power loss is equal to the square of the current times the resistance of the wire (which is, in turn, based on the diameter of the wire). While raising the voltage has a significant impact, it can only be raised to around 2000kV. At that point, power is lost to the air through [corona discharge](https://en.wikipedia.org/wiki/Corona_discharge). Larger wires help, but again, there are a physical limits - eventually, the world runs out of copper!
* Heat!! Let's say you generate enough power to supply the entire world, plus transmission losses. The US, on average, saw about [6% power loss](http://www.eia.gov/tools/faqs/faq.cfm?id=105&t=3). Assuming those losses are roughly equal to the power lost over our entire system, which is producing about 16 TW (the total average power in use according to Cort Ammon's [favorite Wikipedia page](https://en.wikipedia.org/wiki/Orders_of_magnitude_%28power%29#gigawatt_.28109_watts.29)), we should see about 960 GW of heat loss. The sun adds roughly 300 TW of heat energy to the Earth (according to [this page](http://www.easterbrook.ca/steve/2012/01/how-much-extra-energy-are-we-adding-to-the-earth-system/), anyway). That means energy loss from the system is roughly 0.32% of the energy from the sun. But that's with today's energy usage; free energy will mean a lot of growth, which means a lot more energy. If the world's power demand increases by a factor of 10 (a conservative estimate; currently, 1/4 of the population of the world lacks electricity), so will the heat due to power loss - 9.6 TW, or 3.2% of the power delivered by the sun. That amount of heat energy will have a *significant* impact on the heat of the planet.
## Material Transport
What about moving supplies? It's possible, of course, but you'll need to have a pressure-adjusted room available. If one portal is in a location with a higher atmospheric pressure - say, a few feet higher above sea level - the ambient air pressure will push air through. A little pressure difference is fine, but if there is enough of a difference, the wind blowing through the portal will be gale force - which means pushing materials through will be really hard, or really easy. And I'm quite sure delivering a pallet of tools at tornado-wind-speed is a bad idea.
Assuming one portal is in a room where it is possible to stabilize pressure, and the other is used to transport materials, it shouldn't be too much trouble... except that there are only two portals. Which means that they will only be able to move to one location at a time... much like a standard airplane. That's fine if you need to move a lot of stuff, but with a round opening of only 6 meters at the widest, you won't be able to move a lot of really big stuff. Only things that already fit in airplanes or shipping boats. In reality, that's not going to get you much of anywhere.
## Accidents and Not-So-Accidents
All technology has downsides; nuclear power, for instance, can leave a smoking radioactive crater if used improperly. That's bad. Misusing these portals? That's much, *much*, **much** worse. Here are a few examples of What Not To Do, with the best case in every example being "the portals are destroyed and stop working":
* Drop one portal into the ocean. The tremendous pressure will cause water to blast out of the other portal. Current technology would be unlikely to be able to fetch the other portal, either; not only would the pressure be too strong, but anything that got close enough to grab it would get sucked through. If the portal is transported across an ocean, there is a chance on every trip that it will end up in the drink.
* Drop one portal into an active volcano, or other unfortunate location. Best case, a bunch of lava ruins someone's day; worst case, the sudden cooling causes the volcano to erupt, and a bunch of lava ruins a lot of people's days.
* Allow it to be stolen. Between terrorists, governments, and corporations, there should be some serious security for both portals. Because if it's stolen, then it will be stolen again, and end up with whatever group has the biggest guns. And, of course, those guns will get stuck through the portal in short order.
* Associate it entirely with one government. A lot of other countries will be jealous of this one-of-a-kind toy set, and want their own, which will probably include "liberating" both portals. See above.
* Put them too near each other. If one portal is placed above the other, any number of objects will be able to fall through, constantly accelerated by gravity. If the two portals are placed face-to-face, even the tiniest particle will eventually accelerate to near-light speed. A few square millimeters of wind moving at near-light speed will leave quite the dent in the planet.
## Other Considerations
All this assumes the portals only transmit matter and certain forms of energy; if magnetic fields or gravity are also transmitted, even worse outcomes are available. Does pointing a portal at the ground negate gravity above it? I'm not sure I want to find out...
[Answer]
Another follow-up to HDE's answer. I suggest that the power generation facility will need to be a bit more complicated than heretofore described.
The difficulty arises from the fact that the momentum of the particles transiting the portals is apparently unchanged. In effect, the particle stream is inertially floating, while the earth changes orientation. Think of a Foucalt Pendulum. On steroids.
Worst case, of course, occurs when the facility is located on the equator. Then the orientation of the particle stream varies by 15 degrees per hour. If the portal/generator assembly is not gimbal mounted, the particle stream will almost instantaneously begin to impact the edge of Portal A. In the case of a 6-meter diameter system with a 366-meter separation, the angle from one edge of Portal B to the opposite edge of Portal A is $$\theta = tan^{-1}\frac{6}{366} = .94 \text{ degrees} $$ With a rotation rate of 15 degrees/hour, all of the column will have impacted Portal B in 3.75 minutes.
Assuming that the generators are working to the last (so the remaining particle column is not experiencing a net acceleration), the total energy transferred to the portal frames is just the kinetic energy of the uninterrupted column, or $$E =\frac{mv^2}{2}$$ and for Cort Ammon's uranium/escape velocity version $$m=Ah\rho = 30\times366\times19050= 2.1\times 10^8 \text{ kg}$$ Then $$E = \frac{2.1\times 10^8 \times (1.1 \times 10^4)^2}{2} = 1.3\times10^{16}\text{ J}$$ Which is nearly nine megatons TNT equivalent. Unless the aliens are really hot stuff in the damage-resistance field, this suggests that Portal A will fail, and the entire 9 megatons of energy will be dissipated in less than a millisecond on the foundations of the power plant. It should be quite a show.
True, this is worst case, but it does suggest that the system should probably be installed at one of the Earth's poles. A North Pole installation would need to be built on the seabed, which is a complication, but it would be nearer the current majority of users. This would also have the advantage of providing a ready source of cooling water.
Assuming a pole installation, the major worry is precession of the poles, and the effect this phenomenon is left as an exercise for the reader.
This suggests, of course, that Something Must Be Done if the installation is to be placed somewhere a bit more convenient. The most obvious way to handle this is to install a magnetic field generator to slightly change the velocity vector of the particles to compensate for the Earth's rotation, but there are a few implications to be considered. First, magnetic deflection probably rules out uranium as a working fluid, unless the entire column is electrically charged. This actually isn't a horrible idea, since the entire mass has to be held in a vacuum. Assuming this isn't feasible, something magnetic like iron would have to used, and the lower density limits power production for a given velocity. Another factor is the need to reduce the diameter of the column, to allow for detection of variations in the column vector. Like the reduction in density, this will lower power output for a given velocity. Finally (and probably worst) is the need for an absolutely uniform magnetic field over a 5 meter area, since any non-uniformities will cause beam spread in the column, and we CAN'T have that.
EDIT - Another difficulty with placing the facility on the equator is that it will cease producing power, at least in a time frame greater than 24 hours. Because the flow vector will rotate 360 degrees in a day, for half the day the mass column will be trying to fall up, rather than down, and the mass will be decelerated rather than accelerated. One of the poles is definitely the way to go.
[Answer]
Chunnel anyone? A 3m "moveable hole" would be able to create a tunnel very quickly, just dump the "output" somewhere out of the way and voila, instant tunnel. All that would be left to do would be to insert some reinforcment so it doesn't collapse.
[Answer]
OP said "She wants to use it for an altruistic purpose"; combining this with @Dronz' idea gives me the following:
- drop the "Receive" portal into an active volcano;
- take the "Send" portal to your local parliament/congress/majlis/whatever;
- persuade the members to walk through it.
[Answer]
Normally, using the portals as an energy generator wouldn't work. The reason is because you need energy to keep the portals open (otherwise the story becomes impossible), and even if the system was 100% efficient in generating the energy, it would only produce exactly enough energy to keep the portals open. Attempting to use the energy for anything else other than that would quickly cause the portals to collapse. This is because energy can't be created. This means you're not using portals and gravity to generate electricity, you're transforming the energy used to keep the portals open into electricity.
However, if the portals harvest the energy required to stay open by themselves, and their energy source is of a kind that we don't understand or are unable to use, it would be a good idea to create this generator, since the electricity generated would be able to be used to power pretty much everything we use today.
] |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.