text
stringlengths 22
2.11M
|
|---|
[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/83023/edit).
Closed 6 years ago.
[Improve this question](/posts/83023/edit)
My world primarily takes place in the 2880s. By now, humans are exploring and colonizing space, and have contacted a variety of alien species. Several hundred years earlier, however, they contacted some of species present on their own planet, and uplifted them into a spacefaring society.
While the most obvious choices of who to uplift would be apes and whales, there are some other options too. While the prehensile feet and general mobility of various primate species would be useful in zero gravity, by this time humans have mastered artificial gravity. If there are even any whales and dolphins left in the future, I don't know what role they could serve. While very intelligent, cetaceans lack hands, something human society and technology are pretty much dependent on.
So my primary focus when it comes to uplifted animals are octopuses. I have written that various species of them have been given genetic treatments to extend their lifespan and extend the time they can spend out of water. They are primarily used as mechanics and infiltrators, being able to squeeze into small spaces such as air ducts and maintenance shafts, as well as camouflage themselves.
But what about other animals? Things like elephants, crows, whales, apes, raccoons, what would they do?
[Answer]
## Mammals
**Primates** - **No** - Why go to the effort of uplifting primates to human level intelligence when we already have human level primates in the form of humans that we are really good at creating.
**Monotremata (echidna and platypus)** - **No** - I would personally love to give this group intelligence just because they're so weird but I can't justify it logically. They have no skills we need.
**Marsupiala (Marsupials)** - **No** -They have no unique skills they are best at over all other choices. Only reason we might want them would be as surrogate mothers due to their abilities to carry around children whilst still living normally. I doubt that human babies could live well on kangaroo milk so this probably isn't worth it.
**Insectivora (Moles, shrews, hedgehogs)** - **Probably not** - Only reason for these would be because some of them, for example the star boss mole, have exceptional sensing of vibrations so they could be useful for detecting whether machinery has faults by listening to vibrations.
**Chiroptera (bats)** - **Hell yeah** - Bats are awesome. Oh, did you want scientific reasons? Well, bats can echolocate really well so why not have them. They also hear higher frequencies than us do could possibly be used for intercepting communications. They can fly, at least in our atmosphere, as well as birds and can fly better at night so are great for stealth missions. They are also immune to many disease so good for transporting medical supplies.
**Xenarthra (sloths, anteaters and armadillos)** - **Maybe** - I planned to say no but then I watched a documentary on giant armadillos and it turns out they are some of the best diggers around, they can make stable sand caves in a few hours. This would make them useful for emergent rescue in earthquakes where roads are too blocked for machinery. Also good for gardening and are cute pets.
**Lagomorpha (rabbits and hares)** - **No** - All they have is speed, digging and the ability to breed like rabbits. I guess if you needed a ton of tiny creatures fast they would be useful but you can just use normal rabbits for that.
**Rodentia** - **Yes** - Humans won't like working with rats and mice but they are useful. They can get into small spaces, survive off any food and can problem solve fairly well. Good be useful for surveying damaged machines, going into collapsed buildings and take up less space on spaceships. The main problem, disease, will be a non-issue as smart rats will probably wash more.
**Carnivora (Cats, bears, dogs, raccoons etc)** - **Yes** - Firstly humans will want dogs. Might as well have smarter dogs. Secondly cats are already smarter than humans and evil so we might as well make sure everyone knows they're smart. Thirdly, cats particularly, are fast and agile and have better balance making them useful in slightly different gravity environments where they will adapt quicker.
**Pinnipedia (Walrus and seals)** - **No** - If we're going for swimming stuff we might as well use dolphins.
**Cetacea (whales and dolphins)** - **Yes** - They are smart, can dive and swim far better than humans, and faster than most fish, and whales could have a good use in communications as they can hear lower pitches than humans.
**Perissodactyla (horses and rhinos)** - **No** - They are more useful s beasts of burden than anything else.
**Artiodactyla (pigs, deer, cows, giraffes and other stuff)** - **Maybe** - Pigs are already smart and so could be an easy one to go for but I don 't think many of these are that useful. Possibly sheep or goats as searching for survivors during mountain rescue but I'm not sure.
That's most of the mammalian orders covered. I might add fish, birds and reptiles when I am not on a phone.
[Answer]
Elephants, dolphins and apes are probably the most suitable species. They have large and complex brains, and long life spans. They also have complex social structure which is necessary for any civilization.
The lack of hands is not a problem. By 2800 nothing will be operated manually. I doubt we'll be an organic life form that long, but if we are, we'll at least have direct brain interfaces.
[Answer]
Bee and Ants Queens for environments where disposable scouts are useful.
Eagles and Pterodactyls because they can fly really fast and far.
Velociraptors... because... ...err... ...okay, maybe not.
...and I guess that rules out sharks as well. Too bad cause they'd be pretty cool!
How about uplifting humans to an intelligence/wisdom level where we can stop waging wars and poisoning our world?
[Answer]
First and foremost dolphins, they can move far better in the ocean than we ever will. So unlike most other options they can easily return the favor. We can build cybernetic hands for monkeys now, so ones for dolphins would be pretty easy by the time we have uplift tech. They also live in the one of the few places on the planet we don't so we are not really competing for much. Having intelligent creatures available for for a wide range of ocean activities from fishing, to research, to construction will be useful. They would also be a big help in exploring other earthlike planets.
Octopi or squid are as good a choice as dolphins for the same reasons, except for one thing, both die shortly after they breed. Which is a pretty big hurdle, we would need to fix that at the same time. Otherwise it's a complete waste of effort, since they will die before they can really mature mentally. Imagine how few well trained... well anything, we would have if humans died after the first time they had sex. Cephalopods gonna got the short end of the evolutionary stick. Although if you have the tech to uplift, you have the tech to fix this.
For any other animal the real question is why? another terrestrial mammal will just exacerbate overcrowding. There is no real benefit to us, they can't do much we can't just as well, for any really specialized task we could use robots.
[Answer]
**Totally random.**
Uplifted dolphins, sure. Squeak squeak. Monkeys. All the usual suspects.
But aardvarks? There's one you don't think about getting uplifted. Aardwolves too? Wait - are they going in alphabetical order? The cassowary? Ring tailed gecko? What is this about?
This offers the chance to write some very different uplifted species. And also explore the motivations of the organization doing the uplifting, which I think should be a Loki-like weird prank dark sense of humor.
[Answer]
The Earth animals most like humans are mammals. The nonhuman mammals that already have the greatest intelligence and are most like persons are apes, cetaceans, and proboscideans. Thus there is a certain logic to uplifting apes, cetaceans, and proboscideans.
The larger the body of an animal, the larger the brain it can support. Some animals with large enough bodies to support large brains will evolve large brains for various reasons. Of apes, cetaceans, and proboscideans, only a few species of apes and cetaceans are as small as humans or even smaller. The proboscideans and the rest of the apes and cetaceans have larger bodies than humans and thus should have little trouble supporting brains large enough to be intelligent. Thus it may be more practical to uplift those species to intelligence.
I think that humans will have little need for the assistance of uplifted animals as some have suggested, since they will have all kinds of robots in that future.
Some of the mammal species suggested for uplift to human intelligence have very small bodies compared to humans and thus would have great difficulty supporting a mammalian brain large enough to be intelligent.
] |
[Question]
[
This might seem like an obvious yes but I asked my Momma this question and she said that there are more nutrients in muscle but she isn't sure whether a fat humanoid would last longer than a muscular humanoid in a famine.
I think this comes down to pros and cons of each body type.
**Fat humanoid**
Fat has more energy, much more than glucose. Because of this, protein breakdown when it happens would be slower. And the brain can work on ketones and your heart basically works with ketones all the time. Ketosis is a longer process than protein breakdown and takes up most of the time that a human or other creature with similar metabolism is starving to death.
On the flipside, being fat increases your chance of having heart and liver failure. It also can lower your endurance and speed and while lowered speed is fine, if humanoids migrate, lowered endurance is the last thing you would want besides being attacked. Even without health problems, it still has downsides during migration.
**Muscular humanoid**
Muscular humanoids have more strength and/or endurance. Both of these are positives. But protein breakdown is a relatively fast process and involves turning protein into glucose. So muscle mass, strength, and endurance would be lost. If this continues for too long, the humanoid will be down to the bone underweight and like being fat, this lowers endurance more than a low muscle mass would by itself. If a humanoid becomes underweight, it has a close to 0 chance of survival in a famine.
**So given all these pros and cons, would a fat humanoid last longer due to ketosis or would a muscular humanoid last longer because of a lower chance of health problems, even at a higher than normal BMI?**
EDIT:
These humanoids live in a grassland surrounded by forest. They also know how to grow plants. Usually both fruits and veggies from agriculture and animals to hunt are in abundance. Winter has a higher risk of famine because unless you have a greenhouse, only a few fruits and a few more veggies can survive winter. Animals to hunt can pretty much always survive winter. But if a supervolcano erupts, that can cause a global volcanic winter for a whole year. This would definitely have a high risk of famine.
[Answer]
Some guidelines to consider.
Fat is the body's mechanism to store energy. It has added benefits, such as insulation, but its primary purpose is to take excess energy from food and save it for later. We have an evolved mechanism for our bodies to flip a switch and go into *[ketosis](https://en.wikipedia.org/wiki/Ketosis)* (the burning of fat) when there is a lack of ready, easily metabolized sugars. This is a common mechanism in mammals, so it's not unique to humans.
Every year, we have a famine called "winter", but sometimes we get prolonged famines caused by a long winter, lower than average rainfall, high insect activity, potato blight. This happens all the time so the human body has evolved to handle these periods so that most of the time, the tribe will make it, even if certain individuals don't.
So we already know all of this and it doesn't actually answer anything, but it does help give some context:
Consider the individuals. We have **Blubber**, the morbidly obese. We have **Tubby**, who carries some extra weight but is still active. Then we have **Beachbody McMuscles**.
Based on what I have read about (not an expert by any means), **Mr. Blubber** will not going to fare well at all. In order to get that fat, he was continually abusing the mechanisms his body evolved to deal with a varied diet. He has eaten too much sugar, so he has to produce large quantities of insulin. He is storing tons of fat. He has greatly increased chance for diabetes and the decreased level of physical activity makes him more prone to heart disease and atherosclerosis. The older Blubber is, the worse he will fare in a famine situation. It's hard to correct behaviors which got him to that state and in some cases the damage is done.
**McMuscles**, surprisingly, *may* be the next to go. If his body has no fat to metabolize, it will begin to slowly break down muscle mass. His body is used to ready-to-use fuel. He has much less reserve fuel supply, so his body is going to start burning whatever it can. Suddenly he begins metabolizing muscle mass and endurance and such will drop off sharply. He gets some of disadvantages back because his body is now more efficient, but I don't think it will be enough to offset the lack of fat.
Finally we have **Tubby**. He's going to come out in the best shape of the 3. Tubby hasn't got to the point of system abuse. He's still fairly active so his body is going to be efficient enough. Finally, he has the fat. He has the natural reserve tank that nature has intended for us to have.
Kilisi does make an excellent point though. Ruthlessness will play a big role. If Blubber kills off the rest of the village and gets them in the meat smoker, He might outlast the famine, only to keel over from a heat attack later.
Edit: Kilisi makes another point in the comments...what about the skinny guy, the small guy, and Average Joe? Average Joe would probably fall under Tubby, especially here in the USA. I'm combining the little guy and the skinny chap into one, as a lot of the little guy's I have met tend to be either really skinnly, or you flip a switch and the flip right into Blubber.
**Twiggy** is the skinny guy and he can be a bit of an enigma. They are usually smaller and don't require as high a calorie count as us chubbier fellas. However, there is an anomaly. I have another nephew who is nearly 2 meters tall. He weighs maybe 60 Kilos. If you put handcuffs on him they would fall off as soon as he lowered his arms. I have also seen Twiggy consume enough food to put me into a diabetic coma and then ask for dessert. So Twiggys come in two varieties. Those who are just luckily, naturally, thin and those with incredibly high metabolisms. In a famine situation they both will probably do OK. Better than McMuscles and about the same as Tubby. I really don't know why some really skinny kids have the kinds of metabolisms they do, other than divine Irony. Their bodies are very efficient, effectively consuming all calories that come in, even while *requiring* less. Maybe Tubby could hold Twiggy above his head in order to reach the fruits way up high in the trees, and they both benefit. I still think (opinion) that Tubby has a net advantage long term.
[Answer]
Not necessarily, people who process their food most efficiently will last longer. People who habitually overeat have trained their bodies to be inefficient at processing. This is assuming that everyone starts off equal.
In real famines, the ones who do best are the most ruthless ones, regardless of initial size.
Another big factor is self discipline. Obese people usually don't have much of this when it comes to food, most people in the first World don't in terms of volume. People with self discipline in this regard will ration. It's a LOT harder than it sounds. If you have seen people get hungry, and I mean really hungry you see widely different reactions. Some people will start obsessing over food after half a day to the exclusion of almost everything else and start becoming irrational. Others don't reach that stage for much longer.
[Answer]
A fat humanoid will survive longer *only* if he/she can outrun the other survivors. So physical condition (especially aerobic capacity) would be a matter of life or death.
] |
[Question]
[
Augi is an augmentation intelligence in the shape of a silver choker. It is worn by Isis, a human. Augi perceives the world through Isis' sensory apparatus by detecting electrical impulses traveling from her sense organs to her brain.
In one story, Augi perceives a number of entities which Isis cannot perceive at all. Augi assumed for some time that Isis could also perceive these apparently obvious entities; not the case. I do not make clear exactly what human sensory modality Augi was using that Isis might possess but not be conscious of having. It is dissatisfying. I vaguely thought it might be [blindsight](https://en.wikipedia.org/wiki/Blindsight). Blindsight is a poorly understood sense of surroundings or spatial position which is exhibited by persons who are blind because of brain damage to the visual cortex in the brain, but not to the eyes. Persons (and monkeys) with blindsight accomplish things that would seem to require vision, without consciously "seeing" anything they can report.
Our other senses have inputs specific to each: we can smell things we cannot see, hear things we cannot see or smell, and perceive textures by touch which we could not with other senses. **What would be the nature of an object or entity perceptible only by blindsight, and not by regular sight?**
Maybe it is a faux pas to link up stories. If so, moderators please edit this out. If not, here are Isis and Augi. The last story has the events from this question. I blame @Erin Thursby for getting me excited about it again.
<http://www.halfbakery.com/idea/Spinal_20Cord_20Signal_20Intercept_20Passthrough>
[Answer]
Blindsight from the parameters you have given, seems less likely to be fooled by visual tricks. Therefore, anything that can camouflage, blind sight can see.
As JDlugosz said in his answer, the advantage of blind sight is that filter, that is, visual processing through the brain, is gone.
The other things that can be seen might be stranger than that--impressions of things that WERE there before or of terrible things that we don't see.
In the blindsight experiments, blind people unconsciously moved around objects without knowing they were there. Take this a step further. Maybe all of us sighted people are actually avoiding objects and beings just outside our conscious perception that are overlaying our reality. We don't consciously know that they are there, but we do avoid them.
You say:
>
> In one story, Augi perceives a number of entities which Isis cannot perceive at all. Augi assumed for some time that Isis could also perceive these apparently obvious entities; not the case.
>
>
>
Therefore, this is an unconscious sense used to perceive, which is either edited out, or not deemed as important to be consciously aware of in our processing centers.
When we tested for blind sight, us sighted folks could see the things that they were avoiding or reaching for. We had the advantage of knowing for sure that those things were there. But the blind insisted that they couldn't see them, despite repeated successes.
This is terrifying.
Because what implies is that there's an unconscious program running in our brains, telling us what reality is, and insisting that we never, ever look at it, because to do so is...what? damaging to our conscious mind?
So it's possible that the whole of humanity has been avoiding things we don't actually believe that we see, and if someone told us about them, we would insist that it's just a coincidence and that they aren't really there.
[Answer]
# Blindsight Mechanism
Look at the [visual processing pipeline](https://en.wikipedia.org/wiki/Visual_system#Neural). In general, something that's removed or not tagged for later stages will not be noticed, but could be blindsighted by pathways that tap out of the pipeline at earlier stages.
[](https://en.wikipedia.org/wiki/Visual_system#/media/File%3ALisa_analysis.png)
So how could this apply to *objects*, rather than low-level [features such as edges and lines](https://en.wikipedia.org/wiki/Visual_system#Optic_radiation)? My thought is *camouflage*. The camouflage is successful in terms of the normal visual system not noticing anything. But some artifact might be *present*, discarded during processing, but noticed as an anomaly by the other pathway.
---
# Human-specific Perception
You state “Augi perceives the world through Isis' sensory apparatus by detecting electrical impulses traveling from her sense organs to her brain.” So it receives fairly raw sense data, and has its own, different, processing pipeline.
An example might be faces. A human will see a face in an abstract arrangement of shapes, and might pick out a specific spot in a random montage because it looks like a smiley. We have special circuits for detecting faces. I saw a show where someone with damage to that spot in the brain looked at artwork where figures were made of mushrooms or vegetables or whatnot, and did not see the figure in the food.
So it would be with an *alien*, specifically one who doesn’t have a humanoid face. Its attention will not be drawn to the smiley in the mess, and it won’t see a human head in a bowl of soup. But to us it’s **blindingly obvious**!
[Answer]
Depending on the following story, you could go for some genetic engineering “simply“ (actually that would be really advanced stuff) editing out the perception of those entities somewhere late in the perception chain (the pattern of the entities triggering some kind of block).
Maybe those entities have been around for a very long time and anchored this into the genome of all humans. We would then see them, maybe even subconsciously move around them but not know we saw them.
Some people would have a genetic mutation allowing them to see those entities and consequently go to the mental hospital.
[Answer]
Thresholds:
If those entities can only be seen at the exact border of visible light, we wouldn't notice them because they would be barely visible. If they led light of other wavelengths through their body, they would appear to us like a vague shadow in front of something else, the shadow however being so weak we wouldn't see it at all.
The wavelengths each cone in the eye is able to perceive and to what extent can be seen for example at this picture:
<http://jl.domec.free.fr/siteDjl_fichiers/TP-coursTEL/Them09Webcam/CapteurCCD/SpectreOeil_fichiers/II_17.jpg>
Make the creatures be see through for everything but the far edge on one side so that only 0,(a few zeros)1% of light received by us contain information about them.
Depending on how they behave on the rest of the non visible spectrum a (specific) camera would be able to see and photograph them (if you want that for your plot).
Else make them out of something like glass for all wavelengths but even more see through (less visible), then we wouldn't notice them, but your ai could.
[Answer]
I would have to say, in you context of 'percievable but not perceived', is subtle objects. In your story, Isis and Augi have the same sensory input, but process that input with their own methods. The human mind is good at ignoring obvious things (need ref, unintentional blindness ), and filling in what it thinks it probably perceived. Augi, not having these processing shortcuts, would have a 'true sight' version of the sense inputs.
For example, when you reed text and you think you know what you read till you get to the end and realize that 'read' was misspelled. Augi would not make that mistake. :3
There are also examples of automoving image illusions, and an AI would be more accurate at calculating distance of objects and sounds.
Also hard to understand things like QR codes, a machine would understand better than a human. (Humans generally can only process up to 7 things at a time)
] |
[Question]
[
I've had a look around the internet and the only real classification system for planets seems to be the one from Star Trek, which I don't want to use. The [real groups](https://en.wikipedia.org/wiki/List_of_planet_types) that planets fall under seem to be messy and unordered and I don't like it.
I'm looking for a way of categorizing planets into various groups relevant to colonization and what you'd need to colonize them. Bonus points if you can come up with a classification system with an order that's independent of the symbols used to denote each category. Like how the [OBAFGKM](https://en.wikipedia.org/wiki/Stellar_classification#Modern_classification) system for stars used to be in order before we learned more.
The basic idea so far is a classification with 5 letters each of which can have subscripts. A letter for size, a letter for its average temperature, a letter for atmospheric composition, a letter for lithospheric composition and a letter for miscellaneous dangers and boons (like a particularly heavy moon meaning that you're lighter in march than in January or something else extraneous). Each letter will have subscripts denoting things like temperature fluctuation, the most abundant elements and other slightly less important info.
The civilisation in question does have FTL capability and the distance to the planet doesn't need to be taken into account. My main questions are about what type of classifications are most important and can be broken down into a couple of smaller questions.
1. Would it be better to have a system of classification that used surface temperature (and its range of fluctuation)[Advantage: More directly useful information for colonists] or would it be better to base it on orbital characteristics (distance from star and eccentricity)[Advantage: The system of classification can be expanded to moons, asteroids, and comets.]?
2. Would it be more important to define a planet's size in terms of its mass or its volume?
3. What would be a good way to calculate a "Survivability Score" for the atmosphere and lithosphere based on the elements and proportions of elements? (Note: I reckon I'll be using a separate letter for lithospheric and atmospheric composition)
---
Rather than ask for the definition of planet types lets work on the creation of a system against which to judge and categorize planets in relation to how well they can be colonized.
* What are the 5 physical planetary characteristics most important in relation to colonization
* How can these factors be combined to create classes
[Answer]
An absolute habitability scale would not be an effective tool because planets, and the methods by which they could be colonized, vary so drastically. For example:
Mars and Venus would likely have a similar "habitability" score. Mars is rocky, inside the habitable zone, and it's surface is safe for human habitation. Flip-side is, there is no atmosphere, gravity is a bit low for our liking, and there's tons of radiation hitting the surface. On the other hand, Venus' upper atmosphere had good radiation protection, comfy gravity, and an atmosphere that a human can be exposed to (though they can't breath it, and the acid could be problematic). Flip-side is the colony would need to float, as the lower atmosphere would disintegrate you.
On an absolute scale of habitability, these would be close, but a number would ignore the vast differences between them (Venus is likely better for a floating research outpost, while Mars is better for long term colonization/industrialization), and the immediate technology available will change this number greatly.
Solution:
# Use Combinations of Categories
Here are some I put together:
**Planet Type:**
**RL**: Rocky w/ Liquid Water, **R**: Rocky, **G**: Gas Giant, **A**: Asteroid
**Gravity:**
For this one a simple number is likely best, as all planets exist on a clear scale.
**Atmosphere Composition:**
**B**: Breathable, **E**: Exposure Possible, **H**: Hazardous, **N**: None/Negligible
**Hazards:** (pick as many as relevant)
**P**: Pressure, **R**: Radiation, **Tc/Th/Tch**: Extreme temperatures (cold/hot), **A**: Acid, **B**: Biological (you get creative and have fun with the rest of these)
**Life:**
**AI**: Advanced Intelligent Life, **PI**: Primitive Intelligent Life (pre-space travel), **L**: Non-Intelligent Life, **N**: No Life
I'm not sure about classifying mineral wealth, as you run into a lot of problems. Either you have way too much data (breakdowns of common minerals and ease of mining them), or too little to be useful (a fixed number classifying the "value" of minerals on a planet, that would change constantly due to market fluctuations and ease of mining). Also, most planets have a variety of minerals available, so it's hard to say if one is "rich" or "poor". Still, perhaps a few general categories determining mineral wealth/composition could be possible in necessary for the universe.
An example of this system in action: **Mercury**: **R-.38-N-(RTch)-N**, **Venus**: **R-.9-E-(PThA)-N**, **Earth**: **RL-1-()-AL**, **Mars**: **R-.37-N-(RTc)-N**, **Jupiter**: **G-2.5-H-(RP)-N**, **Eurpoa**: **RL-.13-N-(RTc)-N**, etc
[Answer]
## Start with numerical scores
If you're capable of colonization, why not abstract the difficulty of colonizing it into a numerical score?
E=mc² so energy is mass. You're going to need some of both to effectively colonize, but for mere abstract purposes you can reduce your shopping list to either one. Then all you need is to pick a suitably large unit value and you can easily rank colonizable planets.
This nearby planet that's a lot like your home? That's a 5. Terajoules? Exagrams? Doesn't really matter.
That icy rock floating lightcenturies away? 500.
**Everything** is taken into account to reach your score. Energy in order to get there, energy to warm it up if it's too cold, mass if you need to import food, less mass if you can grow food but need to import soil, etc.
The point is, there are so many factors that abstracting it **all** is the only way to reach a simple system. And unless you're the guy packing the colonization ship, do you really care if you need those 5 terajoules of energy just to get there, or if you need them to heat up the planet? No, you just need to find those joules. Maybe you have fusion engines and those joules are better stored as mass, but again, that's a practical concern.
Some additional notes:
* You will likely end up with a double number, ie. one for initial colonization and one for long-term living. Some colonies could take a lot of effort to start up but they might have everything to become self-sufficient.
* Orders of magnitude will probably become much more important than the actual values. 5 or 8? Who cares? But 5 compared to 500 is a big deal. This also allows explorers to eyeball things. Barren asteroid? 10k, more or less.
* This could easily lead to a secondary (maybe exponential) scale used in comman parlance. Class A is anything with an initial cost in 2 digits and an upkeep cost of 1 digit.
[Answer]
The classification system, based on a planet's habitability status would have to incorporate several features, resulting in a nested structure.
# Basic Planetary Groups
There would be 3 primary groups of planets: **habitable**, **potentially habitable** and **uninhabitable**. Note that the habitability of a planet would not only be confined to its position wrt goldillocks zone around its star, but also whether its atmosphere is breathable, its magnetic field can keep off the solar wind etc.
# Detailed Grouping
Considering that all **intelligent** life forms that we know of, can only evolve on a terrestrial planet, so gas giants and ice planets are definitely off the list for habitability.
Within terrestrial planets, we would want to classify planets on the basis of 5 factors.
**a- Size/mass of the planet**
This is the most important factor. You can (with much advanced technology levels) change the atmosphere and maybe even alter the magnetic field of a planet, but you cannot change its mass without making gigantic changing to a planet.
Surface gravity of the home planet would be the standard here. The gravitational habitability value of a planet would be a measure of how similar (in %) the target planet's surface gravity is, to home planet. For example, for us humans, Mars (with a surface gravity of 3.711 m/s²) would be given a value of -37.87% as its gravity is lesser than Earth (hence negative) and the difference between Earthly and Martian surface gravity is 37.87%.
**b- Atmosphere**
Once again, we would want to classify the atmospheric composition and pressure according to resemblance with the conditions on our home planet. For the sake of brevity, we would want to incorporate both values as one, split with a x (multiplication) sign. Once again, taking the example of Mars, we would get a value of 0.1x0.6 meaning that the composition of Martian atmosphere is only 0.1% similar to Earth's atmosphere while the atmospheric pressure is only 0.6% that of Earth's.
**c- Water vs Land Surface**
Here, you would not want to classify the habitability of the planet based on how *similar* its water distribution is to home planet (since it would be incredibly difficult and complex) but simply go with a percentage value of water wrt the total surface area of the planet. You would also want to include the suitability of the oceans for life. This would be simply marked as a letter from a to z, a meaning extremely unlikely for marine life (as on home planet) while z meaning completely suitable for marine life of home planet. A target planet might get a value of 37r, meaning that 37% of the total surface is covered by water and it is suitable to support 69.23% of marine life forms on Earth (r/z x 100, r=18th letter, while z is 26th).
**d- Orbital Statistics**
The most important orbital statistics wrt habitability of the planet would include its orbital eccentricity and its angle of inclination/axial tilt. It would also include whether the planet is tidally locked to its parent star or not. For example, Mars would get a value of -0.093x25. - means that it is not tidally locked with its parent star. 0.093 is the orbital eccentricity while 25° is the axial tilt.
**e- Miscellaneous**
The last parameter would include codes for a list of variables which are a hindrance in it being habitable. For example, Mars might get a code of 2B. These would have to be checked from a list of all hindrances. 2 might mean that the soil is toxic. B would mean that there is an increased risk of asteroid impact.
# Conclusion
Note that I have not included the mean surface temperature of the planet in this list, because that would already be included in the goldillocks belt part. If a planet cannot maintain liquid water on its surface, it would already belong to the uninhabitable planets list and there would be no need to categorize it further, based on these 5 subgroups.
] |
[Question]
[
My version of a tank uses reinforced depleted uranium as armor plating, however it was recently attacked by a large dragon which managed to crunch, and chew off a piece of it in one big bite.
*What kind of material could allow the dragon tooth to penetrate into the tank's armor, and is it possible to duplicate the tooth using modern science?* Think of Chobham armor.
[Answer]
Before we get into teeth, note that your dragon will need some really, really strong muscles (and jaw bones) in order to take a bite out of a tank. Perhaps a *"how could dragons have strong jaw muscles"* question is in order.
According to the comments, depleted uranium is helpful against projectiles, but it won't do much against the compression from dragon teeth. It is usually used with steel or another alloy, however, so now the question becomes what can pierce steel effectively.
Let's use the [hardness of steel and a handy unit converter](http://www.steelexpress.co.uk/steel-hardness-conversion.html), because for a quick chomp and pierce, tensile **strength** alone will not matter. While some of these materials may shatter if you put too much pressure on them, they are adequate for puncturing and tearing if you make them **sharp** enough.
---
## Tungsten Carbide
### Hardness
Some of the strongest heat-treated steel will measure at about 444 on the Vickers hardness scale, while tungsten carbide measures in at around [2242](http://hardmetal-engineering.blogspot.com/2011/04/what-sort-of-hardness-can-be-achieved.html)! Alternatively, using the Mohs hardness scale, steel is at around a 7, while tungsten carbide measures 9.
### Organic use
It is difficult for a dragon to have tungsten teeth for several reasons:
* Acquiring tungsten in abundance requires a really weird diet
* Processing the elements to create an alloy requires extreme conditions (if they breathe fire, I guess this is plausible)
* Tungsten may be toxic
A possible workaround could include dipping teeth of another material into molten metal, although I doubt molten tungsten carbide exists in nature.
---
## Carbon Steel
### Hardness
It's hard to find quantitative data to compare the hardness of carbon steel to regular steel, but note that as the carbon content increases, strength increases - so these teeth will likely be stronger than the tank material.
### Organic use
It is difficult for a dragon to have carbon steel teeth because:
* Acquiring steel in abundance requires a really weird diet
* Processing the elements to create an alloy requires extreme conditions (if they breathe fire, this may be plausible)
A possible workaround could include dipping teeth of another material into molten metal, although I doubt molten carbon steel is easy to find in nature.
---
## Chromium
### Hardness
Chromium has a Vickers hardness of 1060 MPa, compared to steel's reasonable maximum of 444. It would definitely get the job done.
### Organic use
Many yeasts have a high chromium content. While some forms of the element may be toxic, it's reasonable to think that dragons could consume animals that rely on this yeast - or they could cultivate the yeasts themselves.
---
## Titanium
### Hardness
Titanium has a Vickers number of 830–3420 - higher than that of most steel - so you should be all set.
### Organic use
[Organic titanium compounds](https://en.wikipedia.org/wiki/Organotitanium_compound) are found in some natural reactions. These could occur in the prey of your dragons, or their prey's prey; with some more work and possibly some handwaving you could construct titanium teeth.
---
## Diamond
### Hardness
Diamonds are considered to be one of the strongest natural substances - with a 10 on the Mohs hardness scale, compared to a 6-7 for most steel. These are the most ideal teeth you could have.
### Organic use
No organic processes can create, or have created, diamonds. However, since dragons tend to hoard gemstones (and some consume them) it's reasonable to think that a dragon's body could arrange diamond particles and bind them with an alloy to make semi-diamond teeth.
---
## Ruby
### Hardness
At a measure of 9 on the Mohs scale, rubies are significantly harder than steel.
### Organic use
Similarly to diamonds, no organic processes can create, or have ever created, rubies. However, since dragons tend to hoard gemstones (and some consume them) it's reasonable to think that a dragon's body could arrange ruby particles and bind them with an alloy to make semi-ruby teeth.
---
[Answer]
The dragon's jaws need to be strong enough to *crush* the tank, and its teeth need to be strong enough to resist not shattering at the tremendous pressure which this will require. Furthermore, the bone structure itself needs to be strong enough to hold the teeth in place, as well as not break under that same pressure. The tissue in its mouth must also resist severe damage from the metal shards, and sharp edges which will be pressing into it.
Last but not least, the dragon must be powerful enough to lift a main battle tank off of the ground, in its jaws, so that it can move it in an optimal position for crushing.
Since we have long left behind the rolling plains of realism, and entered the rocky valley of *"this must now be solved with magic"*, I do believe that your dragon should be made of unobtainium.
[Answer]
Foolish Wyrmlings!
You can't eat a human tank raw. You have to cook it for a few seconds with your fire breath.
Then it gets soft and chewy, making it much easier to get at the juicy parts inside.
[Answer]
What about biologically formed carbon nanotubes?
[This webpage](https://www.cheaptubes.com/carbon-nanotubes-history-and-production-methods-2/) had this to say regarding their physical properties:
>
> On a molecular level, CNTs are 100 times stronger than steel at
> one-sixth the weight and have a very large aspect ratio making them
> very useful as a mechanical property enhancing filler material. Carbon
> Nanotubes conduct heat and electricity similar to copper but without
> oxidative concerns provided that they are well dispersed.
>
>
>
Since the base element for the chemistry occurring in all known life is carbon, that part is at least somewhat plausible perhaps - however, I'm not au fait on whether it's anywhere within the realm of plausible for a biological mechanism to deposit carbon atoms into a matrix to produce nanotubes, but it could be perhaps, depending on how deep you want to explain the processes and so forth.
The properties around heat might even lend themselves to explanations/applications concerning the fire breathing and so forth and/or reinforcement against it.
[Answer]
I think this could work if you let me redesign the tank rather than the dragon.
Tanks are attacked using [High-explosive anti-tank](https://en.wikipedia.org/wiki/High-explosive_anti-tank) rounds. These use shaped charges to generate a sharp jet of Liquid Metal. This (or at least the shockwave generated by it) can pierce a foot of solid steel like a needle. The jet might be stopped by a bag of gravel. The gravel is non-uniform with voids which disrupts the jet into an unfocussed blast that the sub-armour can resist. Chobham armour has engineered voids that work in the same way. There is even explosive armour that actively disrupts the jet.
To resist HEAT rounds, or fantasy beam weapons, the tank may have an outer coating with a complicated system of lumps, oblique plates, explosive layers, and other stuff. This could be over a foot thick. It might be loosely attached so a section could be replaced if the tank was hit but survived. It might be torn off by conventional dragon teeth, because it was not designed to resist that.
[Answer]
I'm a little late to the party, but I would like to offer my spin on "powerful teeth". Or something of the sort.
---
*Worldeater*.
*That's the name they gave it. I thought it was appropriate until I saw that thing in action with my own two eyes, in front of me. Then I knew - it was nothing but a euphemism.*
*It's hard to explain what it is. Some say it's a machine, but don't believe them. That's no machine - you can see the glint in its eyes, the clever smile its magnificent jaws make when it finds prey, the small under-breath laugh it lets out after a successful hunt. No, sir - that thing has a soul, and it is one of the most evil things to walk the earth.*
*Or, "eat it", as it goes.*
*We didn't see it coming. Our radars went off earlier that evening, the fruit of masterful sabotage by the Final Future Brotherhood. Our systems blacked out. We thought it was just a power loss, but it was much bigger than that. It was coming for us, and it was hungry.*
*We had no time to evacuate. The Worldeater was upon us - a devious creature made out of cogs, pistons, plates, and bolts. A massive, walking, flying factory made into a weapon of mass destruction. It shouldn't be possible - the rational mind in me kept crying about the impossibility of that thing even existing, but there it was. Massive, glorious. A nightmare given machine form.*
*The thing had put itself on a shape that was a call to the devil itself: four massive legs, ending in claws the size of a truck each. The body was an impossibly complex, ever-twisting river of machinery that roared around a flaming core, encaged by plates upon plates of metal that kept just enough space between them for the interior to be visible and that horrid, noxious smoke to billow out from its flaming heart. The two giant wings spread out forever, holding upon its complex muscle-like systems of cables and bolts and an uncountable amount of engines, each one of them roaring on its own, in a chorus of unbridled potential. A giant tail dragged after it - an infinitely complex amalgamation of cogs and plates that moved as if it was alive, destroying whatever its massive claws missed.*
*And then, there was its mouth.*
*A gargantuan jaw that could destroy worlds, one bite at a time. That's how they told me it was, and it was true. So it was the thing: jaws so large they could swallow a man whole, without taking notice. Inside of it, there was death - not only from the crushing force its cogs and bolts and plates and cables could exert but also from the impossible hot flames that roared inside. The teeth were a chaotic mess of tools made for destruction - sharp fangs that could slice open steel, saws that buzzed horribly, ready to tear open even the most stubborn armor, macerators that could grab and pull whatever they touched and make it into nothing in a matter of moments. All of those constantly replaced - broken, used parts discarded inside its mouth-furnace to be recycled, while new ones were put in place, freshly from the beast's insides. It had no end. But there was something worse, even - the "fire breath" of the beast, the thing that made anything into its food - a row of nozzles, on each side, They spewed molten metal, white-hot, in a high-pressure jet that could slice *anything* they came in contact with - yet somehow they didn't seem to bother the creature's jaws, pooling on it as if it was the beast's own spit. There was nothing that could stop it - even a tank buckled beneath its power, its metal becoming red hot and then breaking, as the creature tore apart parts of it with each new voracious bite.*
*The Wolrdeater was limitless. Infinite. Beyond what we could even think possible. A machine given soul, freed from what we knew from physics, using its impossible engines and unfettered power to teach us a lesson.*
*Our downfall, made by our own hands.*
---
They're made of "Tank". And "Person". And "Wall". And, anything else, really.
Don't make indestructible teeth - make destructive teeth. It's fine if they break, as long as they do enough damage to enable your target to be swallowed. Once that's done, just use whatever it eats up as material for its new "teeth".
Of course, that assumes that the dragon is a Lovecraftian god-machine made out of steel and rage-bent on destroying mankind, but still. That's just an implementation detail.
Remember: even water can be as powerful as a lightsaber if it is fast enough.
] |
[Question]
[
I am designing a new exoplanet. Do these physical parameters seem plausible?
Sigma Implexis- b is one of three planets orbiting the star called Sigma implexis (S-intertwined), designated a red dwarf star.
Sigma Implexis-b has an annual orbit takes 200 earth days; its daily cycle varies depending on where you are on the planet, the day is slightly longer at the equator because of its ellipsoidal shape. It has three small moons.
Sigma implexis is actually part of a binary star system. The 3 planets and their red dwarf are in a very long elliptical orbit around a blue sun- also a dwarf.
When Sigma Implexis-b and its sun reach the long end of their orbit around the Blue dwarf star, and Sigma Implexis-b gets between the two stars, the planet undergoes “the Bake”.
The Bake can last as long as two Earth weeks. Only in the deepest oceans can the inhabitants survive during the Bake. The Bake only happens once every 450 earth years.
When the Bake happens, most of the polar caps melt, and the seas rise significantly. The continental landmasses are mostly around the equator, and some of the peaks rise as high as the Exosphere on Earth. The air is very thin up there, almost a vacuum.
The volcanism on the planet at the equator affects the magnetic field, and causes some of the atmosphere to be stripped on the upper ranges of the mountains.
The atmosphere is similar to Earth's during its pre-industrial stage, in terms or O2 and CO2 content.
Am I missing anything?
[Answer]
# No this system would not work as you think it might.
Firstly, the planet:
>
> Sigma Implexis-b has an annual orbit takes 200 earth days
>
>
>
**EDIT: In light of some comments, I re-did the calculations and, based on a star 0.25 M☉; with an earthlike planet (1.0 M⊕) and a 200-day orbital period, the actual orbit would be 0.421683 AU, based using [this calculator](http://www.calctool.org/CALC/phys/astronomy/planet_orbit), or just further than the orbit of Mercury (0.387 AU), still too far from the parent star to be in the habitable zone, but not nearly as much as before.**
Next the stars:
>
> Sigma implexis is actually part of a binary star system. The 3 planets and their red dwarf are in a very long elliptical orbit around a blue sun- also a dwarf.
>
>
>
Firstly, by Blue Dwarf, do you mean something like [Vega](https://en.wikipedia.org/wiki/Vega) or [Sirius A](https://en.wikipedia.org/wiki/Sirius)? If so; then this would mean a very short lived star, only enough for some tens of millions of years, not nearly enough for life as we know it (approx 4 billion years - [History of life](https://en.wikipedia.org/wiki/Evolutionary_history_of_life))
**EDIT: Okay, so according to Wiki, a Blue Dwarf can also mean the theoretical and not acknowledged ["Blue Dwarf (Red Dwarf Stage)"](https://en.wikipedia.org/wiki/Blue_dwarf_(red-dwarf_stage)), which tells you all you need to know.**
Next, the "The Bake" as you called it:
>
> When Sigma Implexis-b and its sun reach the long end of their orbit around the Blue dwarf star, and Sigma Implexis-b gets between the two stars, the planet undergoes “the Bake”.
>
>
> The Bake can last as long as two Earth weeks. Only in the deepest oceans can the inhabitants survive during the Bake. The Bake only happens once every 450 earth years.
>
>
>
This would kill all life trying to exist on the planet, if any had made it at all. As the planet and its parent star get really close to the binary, the influence of that other binary's gravitational well, electromagnetic pulse emissions and ultra-violet radiation would completely irradiate any life on the planet's surface.
[Answer]
>
> its daily cycle varies depending on where you are on the planet, the day is slightly longer at the equator because of its ellipsoidal shape.
>
>
>
Except for [polar night](https://en.wikipedia.org/wiki/Polar_night), it's not really feasible.
>
> Sigma implexis is actually part of a binary star system. The 3 planets and their red dwarf are in a very long elliptical orbit around a blue sun- also a dwarf.
>
>
>
This does not sound like a stable system. Read [this Wikipedia article](https://en.wikipedia.org/wiki/Habitability_of_binary_star_systems#Non-circumbinary_planet) and, if you can, its sources to know why. As far as I understand, it's not proven totally impossible, but expectations aren't high.
>
> When Sigma Implexis-b and its sun reach the long end of their orbit around the Blue dwarf star, and Sigma Implexis-b gets between the two stars, the planet undergoes “the Bake”.
>
>
> The Bake can last as long as two Earth weeks. Only in the deepest oceans can the inhabitants survive during the Bake. The Bake only happens once every 450 earth years.
>
>
>
This event would not start abruptly and would not end abruptly. Without seeing actual masses and orbits it's hard to tell, but I think it would last longer than that.
>
> The volcanism on the planet at the equator affects the magnetic field,
>
>
>
Umm how would it?
>
> and causes some of the atmosphere to be stripped on the upper ranges of the mountains.
>
>
>
What mechanism restores lost atmosphere?
[Answer]
**If we only look at it with classical mechanics, this system would be highly chaotic.** Each time the two stars get close, all the planets will be thrown everywhere. We haven't yet found planets orbiting **closely** a single star in **close** binary systems. Most of the systems where we do find plausible planets are those where the stars in the binary system are very close and the planets are orbiting from far away. Example: Proxima Centauri b.
If we ignore the color of the blue 'dwarf' (you can explain the color using some kind of future tech or yet-to-be-found astronomical body, since blue stars, which fuse hydrogen at a faster rate, and thus hotter, are massive.) and assume both stars are the same mass, **you would have an orbit like this**.
[](https://i.stack.imgur.com/tNnAB.gif)
Now for planets to orbit a single star in that binary system, you would need to solve the n-body problem, a problem that is currently unsolved, because it is chaotic. If you do a simulation of three bodies for million of years, the result would be highly different than what we would see in real life. The errors of a numerical solution are just too great in cosmic timescales.
<https://en.wikipedia.org/wiki/N-body_problem>
[](https://i.stack.imgur.com/vKakS.gif)
Here you can see the problem, for three objects orbiting each other, the movement becomes chaotic and unpredictable. This would also happen for the planets orbiting one of the binary stars.
If we were to try and find out if such a system were possible, we would need infinite time to compute the numerical solution, since we do not, we cannot know which initial parameters would make such a system possible.
Here I made a crude representation of what I mean. And in this case, the star collided with the planet...
[](https://i.stack.imgur.com/ZTiqP.gif)
I would suggest the classic sci-fi trope where the planet is just highly elliptical. But don't let this plunder your hopes, this is only based on the current understanding of orbital mechanics.
[Answer]
Since Jupiter, Earth, Mars, can all be describe starting with being relatively similar in many ways, and have not change in the same way has you might expect. Looking at the way that the atmosphere work initially in Mars and Earth and how they have changed from one another will give you things that really should be included if you are looking at what is going to actually happen in a planet that way. It is not the complete answer, but it gives you an idea of why things don't go the way and the time you might expect.
] |
[Question]
[
Imagine if nature had evolved its own version of the modern blimp, or the old fashioned zeppelin. Picture a creature built like a huge hydrogen balloon, a thin tissue of living flesh and tenuous skeleton supporting vast empty sacs filled with lifting gas. A lighter-than-air animal much, much larger than the biggest whale or dinosaur that has ever lived in our world. An enormous living island, large enough to support a tenuous topsoil and bedecked in hanging vines and sprouting trees from its back.
This island drifts on the winds up in the sea of clouds, living for thousands of years without ever once touching the ground far far below. The plants and small animals that thrive on its back have lived there for countless generations. When the winds chance to bring two of these huge creatures together, animals clamber from one to the other, and birds fly the huge distances between the living islands. At first they were unwitting passengers, marooned in the sky when the islands first rose up to the clouds, or else temporary visitors, flying birds stopping to rest on long migrations. Over time however they have all evolved to fit this curious niche, forming a new ecosystem high above.
Beneath the island trail long, gossamer thin roots and tendrils, drinking water from the clouds to quench the thirst of it and its many passengers. It survives by living off the produce of the plants on its back, or perhaps a more direct symbiotic relationship; siphoning nutrients from their roots in exchange for water. All is not entirely peaceful however, and it keeps a wary eye on the skies and clouds for its larger carnivorous cousins, menacing shadows beneath the cloud tops.
**How did these living islands evolve**? What would drive them to the skies? How plausible is this ecosystem in the sky? Is the air thicker here and so floating easier perhaps? Could they survive off the plants on their own backs? Or something else?
Note that there are other questions about flying this or flying that and how might it work. This question is different, in that the lifetform can be *anything* and the focus is on the evolution and how such a thing came to exist.
[Answer]
Biofilms.
Just like the sponge was the most primitive animal, simply a large-scale organization of the single-celled life forms, a biofilm could develop structure to hold gas trapped while being extremely primitive without specialized organs.
So, the flying islands, a further evolution of *floating* islands, could be one of the *earliest* multi-cellular forms and lead the colonization of life beyond the sea!
Any waste gas serves to make *floating* islands. Eventually hydrogen gas was used with even lighter structures to make flying forms.
Think of a coral reef. The early mounds (floating and flying) can provide a habitat for others. This started before internal organs were even a thing, so life evolved to make use of large-scale symbiosis from the get-go.
A billion years later, the islands (both floating and airborn varieties) form a major division of life, being essentially integrated ecosystems of complex forms. Many species across major kingdoms (plant, animal, fungi equivilents) have their own lifecycles *within* the larger body, and they are all playing a role in the functioning of the macro-creature.
[Answer]
My first thought was something like a whale evolved up, but that doesn't make much sense; in the ocean, once you're big you typically keep doubling down on size.
Rather, I'd think something like a small lizard would be the base creature. It started growing larger as a defense mechanism, and storing hydrogen in sacks on its back to keep itself light. Eventually, it largely abandoned the ground, floating lazily through the air, pushing itself from branch-to-branch.
During this time, it underwent radical structural changes. It's front legs evolved into webbed, stubby wings, while it's back legs and tail elongated to reach below. The hydrogen sacks became more and more pronounced, until it no longer needed to touch the ground at all. It's tail split several times, giving it a mass of tentacles that reach down, catching onto treetops or bringing up food and water. It's mouth dropped lower than it's front legs, and grew wider, straining the bugs out of the air like a whale strains krill.
Still, it grew larger and larger. Some of its hydrogen sacks became too large to support with its circulatory system, so it stopped supporting them. Once a hydrogen sack gets old enough, it's sealed off and abandoned. It remains within the mass of the floating island, but is no longer a living part of it. The top-most layers routinely rupture, venting hydrogen into the air, and leaving a decomposing flesh bubble, which eventually turns into a kind of soil. In this soil, plants began to grow.
It's larger than a blue whale now. Small plants and animals live on top. The roots of the plants reach all the way down, through the cruft on its back, and hook directly into its circulatory system. The plants get water from the creature, and in return pump oxygen directly into its blood stream. It no longer needs lungs, and develops a distributed heart network to pump blood throughout its body.
It's massive now, five, ten, twenty times the size of the largest blue whale. Much of it, however, is old-mass, not living mass. It lives high in the air, just below the tree line. It's back is covered in alpine firs, aspen groves, small mammals, birds, and insects. The plants provide all it's energy needs. It provides the plants their mineral and water needs. Its mouth has changed, looking more like a circular set of gills than a real mouth. With this, it still strains insects out of the sky.
It floats a careful line: if it stays too close to the ground, the plants on its back will grow too large and sink it out of the sky. If it floats too high, the plants will die in the cold and it will suffocate. Storms are its greatest enemy. Storms... and *them*...
[Answer]
Obviously the lifting gas must be hydrogen assuming the organism exists in an atmosphere similar to our own. I agree with JDługosz that a collection of unicellular organisms could create such a structure, trapping in the hydrogen and growing large enough to become buoyant. I’d like to propose some hypotheses on why such an entity would form to sequester hydrogen gas and its evolutionary process.
The Hydrogen Hypothesis is a theory you might learn about in a college-level biology textbook regarding the origin of Eukaryotic life. It posits that one single-celled organism (a bacterium) produced hydrogen as a waste product, which was consumed by another single-celled organism (a methanogen). This led to a symbiotic relationship in which the methanogens became dependent on the hydrogen production of the bacterium, eventually enclosing the bacterium fully. According to the hypothesis this was the first step towards the formation of Eukaryotes and their organelles. You can find a very simple video explanation of the concept [here](https://www.youtube.com/watch?v=ZL22RH4jaYk).
But what if it didn’t happen quite that way? What if instead of a single methanogen engulfing a bacterium, a group of methanogens formed a balloon around a colony of hydrogen producing bacteria? This arrangement would be equally efficient, trapping all of the hydrogen produced by the bacteria for the use of the methanogens. The result would be microscopic buoyant balls filled with a mix of sea water, hydrogen, and potentially methane that would float at the surface of the ocean. As both the hydrogen producing bacteria and the methane producing methanogen individuals replicate the balloon would expand in size until perhaps it pinches off and splits into two. The two symbiotic species might form concentric spheres with the methanogens outside and the bacteria directly next to them inside. Now perhaps another symbiotic relationship could develop between photosynthetic autotrophs and our balloon. With the balloon floating on the surface of the water it might algae perched atop it to have an advantage over their submerged peers, better access to sunlight or maybe better access to atmospheric gases.
The end result is a large, flat hydrogen bladder sitting on the surface of the sea. If it grows large enough and the interior becomes sufficiently concentrated with hydrogen it might even take flight. Of course, we are still nowhere near a floating island. The various components of the balloons will need to adapt to being in the atmosphere instead of the ocean and a more rigid structure will have to form before any significant weight can be placed on top of the island. Moreover, a fundamental flaw in the design is that if the balloon is top heavy a strong wind could knock it over, upside down, and it would never be able to recover. It would be much more stable if the plants and animals were clinging to the bottom.
Anyways, I hope this sort of evolutionary process is what you were looking for. This model explains how these floating islands might have evolved from mere single-celled organisms as well as why they are filled with hydrogen gas. If you have any questions or would like me to elaborate I’d be happy to try.
[Answer]
Well, the lifting gas is definitely hydrogen. Helium just doesn't show up in compounds that living creatures can access, because it doesn't form [compounds](https://en.wikipedia.org/wiki/Helium_compounds) to any useful extent. Hydrogen is relatively easy for living creatures to produce, and also much easier to confine with a thin membrane. Helium is monatomic, and the atom is so small that it tends to leak through barriers that will confine almost any other gas.
However, lightning is a deadly danger to these living hydrogen balloons. They have to avoid it, because a lightning strike is likely to send them up in flames. But they lack the ability to move quickly, simply because they can't afford the weight for it and don't have the structural strength. I don't see how to get round that. Lightning-conductor tentacles are an appealing idea, but making them conductive enough, and getting them a good contact with the ground, is a problem, made much worse by the lack of weight budget.
How does it evolve? One way would be from a seed dispersal mechanism. Start with sycamore seeds, which have "wings" to help the wind blow them a long way. Have some hydrogen between the layers of the wings to make the seed lighter and blow further, and after a while you have hydrogen balloons as a seed dispersal mechanism.
Then the climate changes, so that there's a great deal of fog around, and the seeds start germinating in mid-air and trailing roots to pick up nutrients, and we're on the way to the desired result.
[Answer]
I recently read [this article](http://planetfuraha.blogspot.com/2020/09/).
So even if the ideas from this blog are not the best for a giant floating animal, because bubbles can't support the mass of insects bigger than an ant, the concept of "printed" foam could works for a living floating colony of simple animals.
But [this](http://planetfuraha.blogspot.com/2020/10/) could work on the earth after many discoveries.
So the use of graphene structures, especially aerographene, have amazing applications to living systems, from stronger bones to lighter tissues, but currently we don't know ways to create graphene without the use of oil coke that needs higher temperatures than living organisms can resist. Till now [this](https://phys.org/news/2019-07-graphene-carbon-dioxide.html) is the best discovery.
] |
[Question]
[
I understand that Carbon, Hydrogen, Oxygen, and Nitrogen are the source of a lot of great cheap chemistry and I understand why aliens could be made out of those elements. I don't understand though why they would use amino acid polymers, it seems to be an obtuse and awkward way of getting things done.
Is there something special about amino acids that necessitate their use by life? Or is Protein something cooked into our make-up because of the initial conditions of our abiogenesis?
[Answer]
The life, as self-reproducing entity, could exist in wide range of forms. You only need to create appropriate environment for self-organizing forms. For example, computer viruses could be called a lifeform entity because they are self-reproducing. Self-repairing and reproducing mechanisms can be a lifeform too. However, not every thing that reproduce itself can be called a lifeform. A form of crystal cell can spread out in a mineral substratum but we could not call it a lifeform. But who knows? [Tin pest](https://en.wikipedia.org/wiki/Tin_pest) acts like a disease and a whole armies were defeated because their tin buttons were scattered. In other hand, the spread of prion infection is very similar to a moving crystal form (healthy proteins just change their shape and aggregate like a crystal) but scientists call them a lifeform.
So my answer is, while a formal lifeform could be very different, aliens will be made of proteins with high probability, despite the use of equipment
[Answer]
I think it is more likely that the amino acid based proteins we use today are not the only way to go, but something *very* similar might be used on other planets. The niche proteins fit are very obvious. They are a way to turn a 1d stream of data from the DNA into a complex 3d molecule. They are our 3d printer of choice.
Could there be other 3d printers? Sure. In fact, I'd really enjoy getting to study them. Why is it so ubiquitous here, well, when you have a hammer, everything looks like a nail. Proteins did their job so well that it made sense to use them for a vast majority of tasks, only turning to harder to manufacture non-protein compounds when needed.
So perhaps the aphorism needs to be extended. If you have a hammer, everything starts looking like a nail. If you have a 3d printer, well...
[](https://i.stack.imgur.com/ptoat.jpg)
[Answer]
What we can say that there is plenty.
The basic Chemistry for forming life means that on a basic level, sugars always form before amino acids.
So let’s imagine a planet where there is a: very little nitrogen gas, b: primal ammonia is absent, c: not enough hydrogen found in atmosphere, or d: have a temperature high enough to turn amino acids into tar.
What you get from this conditions are mostly saccirides, or basically sugars, and some other things like fatty acids. And a lot of different aromatics, nucleobases and so on.
What you get is an RNA world where things like ribosomes never formed.
Sugars and aromatics have different stereoisomers, and the one thing that makes sugar special is that different stereoisomers form hydrogen bonds differently: an OH group that is above the sugar ring can only form a hydrogen bond with a carbonyl group on an aldehyde that is under the ring, and an OH group on a phenol can only form a hydrogen bond with an aldehyde or quinone but not a carboxylic acid, etc.
Binding phosphate you get rna, nucleobase or naphthalene or sugars attached to some other sugar bound by phosphodiester bonds, which can be made into different configurations by base paring or the alternatives of base paring, replica table by the same process.
The thing that rna can do, is that they are both carrier of information and catalyst of biological processes: an alcohol dehydrogenase ribozyme that uses zinc and NADH is not so different than it’s protein counterpart, a rna polymerase ribozyme works similiarily with the real thing and the ribosome itself is also a ribozyme.
Now, phosphate have 3 bonds to it, and only two are used in the actual process of rna polymerization. The third bond is empty, and can therefore be decorated by a variety of primary alcohols and amines, forming the necessary catalytic parts of the ribozyme, potentially reaching far more diversity than any amino acid protein scheme, simply by being much easier to synthesize or produce. Phosphate can also form hydrogen bonds with itself, bond metals and do a variety of things.
If the RNA world is left to evolve, potentialy making synthetic reactions before the ribosome can be made(which is a very narrow time scale), you would almost never get proteins to form, as the newly started compound synthesis quickly consumes any leftover primordial organic material and flushes the world with more hydrocarbons and saccirides.
These ribozymes could evolve further, using tRNA or equivalent to decorate the phosphate backbone of rna(think of how ribosomes on earth works), therefore making an extremely large and diverse family of molecules:
Bistable configurations that acts as switches and motors (proteins can’t do this), long hydrophobic sidechains that works like membranes (proteins can’t do this, again) and most importantly, the separation of form and function: decorated sidechains can be swapped out, forming multuple different enzymes while the rna sequence remains the same: when proteins have to reinvent the mill, ribozymes can just change tool tips.
There also exists a protein alternative: decorated polysaccharides, or enzymes made out of wood. Like peptides in proteins, saccirides are also stereochemically active, decoratable up to 3 positions on each ring by esterification or etherification by primary alcohols or carboxilic acids, can be linked in a way that encourage folding, and lastly, form complex internal hydrogen bond networks that stabilizes the complex and makes the polysaccharide structure both sophisticated and highly predictable: No more messing around with protein folding or thermodynamic minimums, just use dynamics.
Such biosphere would be alien to earth life: there would be no cells, as in a RNA world everything is done by the same molecule: rna forms the genetic material of living things, rna forms the machines that keeps them running, rna forms the part of the lifeforms that captures energy for it’s function, and rna will also form the structural elements, shells and skeletons of the lifeforms.
One added benefit of such arrangement is also that, unlike earth life, an advanced rna based organism can really evolve: there is an nearly infinite amount of possible molecular arrangements that are linked smoothly together by evolutionary bridges, unlike the tiny islands where proteins and earth life can almost never jump between. Biotechnology would be simple, as the computational complexity of predicting a dynamic based system like rna or polysaccharides is N^2 instead of the k^N of most thermodynamic based system like proteins. Which means rna life can be all crazy about how to make different usable stuff, directly out of their biology.
While earth life still struggle to make a few improvements with their flesh, trying hard to squeeze out the last bits of performance from their unpredictable and computationally costly proteins, lifeforms such like the prior mentionaned rna or sugar based life already has a 3D printer built into their bodies, by just choosing a simpler basic rule when they first came into being.
This is how being "penny wise and pound foolish" is spelled in biology.
Reference:
[DNA origami and future nanotechnology](http://en.wikipedia.org/wiki/DNA_nanotechnology)
[RNA world hypothesis](http://en.wikipedia.org/wiki/RNA_world)
[Answer]
The answer is both yes and no.
We know of no life forms that do not use proteins in some way so we cannot definitively answer that it is possible.
However there are a lot of universe out there and a lot of complex reactions possible. If other lifeforms did evolve then they may use something completely new - although they will need something that does the job of DNA and proteins even if it does it in a different way.
Note that life not even based on carbon has been suggested, for example Silicon based life forms. Again we don't know for sure what is possible but the chances that our way is the only way are fairly slim.
[Answer]
It might help if you understand more about what proteins actually do in the body. For reference, check out [Wikipedia](https://en.wikipedia.org/wiki/Protein):
>
> Proteins perform a vast array of functions within living organisms, including catalyzing metabolic reactions, DNA replication, responding to stimuli, and transporting molecules from one location to another.
>
>
>
Let's talk about catalyzing metabolic reactions. To use more simple terms, proteins make it possible for life to store and use energy.
Think about mountain climbers—their bodies have stored enough energy that they are able to climb up a mountain. If you look at a chart of [energy densities](https://en.wikipedia.org/wiki/Energy_density#Energy_densities_of_common_energy_storage_materials), you'll see something interesting—fat has about the same energy density as the gasoline that you put in a car.
So why don't we burst into flame anytime we get close to a fire? Well, fat is a much less volatile form of energy storage, meaning it is more stable and much less likely to cause us to spontaneously combust. This also makes it harder to get energy out of it.
This is where we need a [catalyst](https://en.wikipedia.org/wiki/Catalysis). In our bodies, proteins are the catalysts. They make it possible for our bodies to extract stored energy from fat in an easy and controlled way.
Just so you know, intelligence (even animal-level) requires a lot of energy. This means that unless the alien life in question is a mindless single-celled amoeba, it will need a reliable, safe source of energy.
---
So what would it take for a lifeform to not require proteins *for this one specific purpose*? As I just said, it will need a reliable and safe source of energy.
Imagine a (mostly) waterless planet that is tidally locked (one side is always facing the star it orbits). In addition, the distance between that planet and its star and the brightness of the sun is such that the day side of the planet is at the appropriate temperature for the life there.
Then, with constant sunlight and no clouds, it would not be necessary for life to store energy. Rather than going down the evolutionarily-costly process of develop proteins for catalyzing metabolic reactions, it could evolve to be more efficient at making use of the energy constantly being provided.
There are problems with this too, however. It would still be a significant advantage for something to have a larger energy store, as it would be able to spend more energy in a burst in order to catch prey or escape a predator. Also, I've only provided a way for a single use of proteins to become unnecessary.
---
**In closing:**
Hopefully looking a little closer at one particular use of proteins helps you understand just how useful they are to life. It is possible that alien life could be built around an entirely different biochemistry, such as silicon-based life. However, no matter what biochemistry is used I would expect there to be some protein analogue—they wouldn't look like the proteins we see on Earth, but they would perform the same kinds of functions as our proteins do.
[Answer]
I know there are oscillating reactions like the Belousov–Zhabotinsky reaction that have very complex patterns. could we make a series of reactions that create a artificial cell then we could have signalling for sad, happy, scard, confused, eye animations, muscle movement, taste, feet, ear movement, and now you have a biological version of furby!!!
by the way it's blood is chromyl chloride because we can have it react with water for energy.
she only breathes in for water vapor and breathes out for talking
and only uses water for her mouth, so you can kiss her.
[Answer]
Amino acids are a basic component of life. Even if you don't have them in a form that we know of, you would have to possess an analogous chemical structure.
Under different environmental conditions, life might evolve to work better with different chemical make ups than ours. So an organism that may be silicon based would probably have a structure that serves the function of an amino acid making up its body.
[Answer]
# Life *did* get along without proteins.
In the "[RNA World](https://en.wikipedia.org/wiki/RNA_world)" stage of evolution, active pieces of RNA ([ribozymes](https://en.wikipedia.org/wiki/Ribozyme)) catalyzed reactions, rather than proteins. They likely did not work as well as proteins. While the idea is officially only a hypothesis, it has the formidable logic favoring it that there had to be *something* pretty complicated around before a structure as large as the ribosome and a process as complex and beautiful as the genetic code could come into being. (There *is* such a thing as [non-ribosomal peptide synthesis](https://en.wikipedia.org/wiki/Non-ribosomal_peptide_synthesis), which is capable of making peptides not possible otherwise, and it has an ancient origin, but it seems too cumbersome to be easily believed as an alternative to an RNA world)
I should also note that in most descriptions the catalytic power of RNA is underappreciated because only the modern four bases (A, C, G, U) are considered. However, there are many essential coenzymes, on which our proteins rely for catalytic activity even today, which are aberrations on the RNA theme. For example, a [dinucleotide based on riboflavin](https://en.wikipedia.org/wiki/Flavin_adenine_dinucleotide) uses the vitamin as if it were an RNA base, and is essential to our basic citric acid cycle for cellular respiration. In our bodies we modify RNA after it is made, but mostly for the purpose of altering what protein will be made from it; it is hard to say what might have happened billions of years ago.
To be sure, peptides were always a good candidate for compounds in living organisms because they could be obtained by polymerizing hydrogen cyanide, and their individual subunits could be obtained through the Miller-Urey process. Some are seen even in space. Living organisms making complex, durable structures are going to use relatively stable compounds, and those are what would form spontaneously. We can reasonably expect alien life is likely to make use of them *in some way, shape or form*.
] |
[Question]
[
## Assumptions
1. Space travel is hard.
2. Interstellar travel takes a long time.
3. Chances for a successful trip and colony becoming self-sustaining
are not considered super high.
Therefore, each colony will be seeded by 2 or more colony ships.
## The Setting
Colony ship 1 successfully completes its voyage and despite extreme hardship and difficulties succeeds in establishing a self-sustaining colony and its infrastructure.
Decades later, colony ship $n$ arrives.
## The Conflict
The crew and colonists of the first ship (rightfully) feel that they did the most difficult and risky part of the colonization. They risked extinction and might feel that they deserve more rights or benefits within that colony's society.
When colony ship $n$ arrives, I'm sure the original colonists won't want to share all of the benefits of their labor equally.
## The Question
Does this also encourage the development of a caste system (or even outright slavery) of the newcomers?
Bonus points:
1. Would their be any difference in attitude towards colony ship $n$'s
crew vs. colonists?
[Answer]
How the newcomers will be greeted depends on a number of variables.
**State of the Colony**
>
> Is the colony living hand-to-mouth, or are they living in the lap of luxury?
>
>
>
If only a few decades have passed then chances are that the colony is still not too well off. The arrival of a ***colony ship*** stocked full of seeds, food rations, new equipment, spare parts, etc. would be seen as a massive boon.
In this case the space-travelers would probably be greeted with open arms.
If, however, they have a really good infrastructure/economy set up, but limited resources (such as not too much inhabitable land), and a few thousand new settles show up then that wouldn't really "work" for the colonists.
**Colonist Culture, Political Ideology**
How far removed from the original colonists are the people living on the planet? If they are in fact the same people who climbed aboard a colony vessel on Earth then they will share a deep bond with the people now arriving: **they will have endured the same dangers of crossing interstellar space, and the same hope of starting new lives on a different planet.**
In this case the two groups will be able to relate to on another. Furthermore, if the history of such groups meeting is to share resources freely then things will most likely go *relatively* smoothly.
However, imagine if the history of such arrivals is for the stronger group to simply enslave the weaker one. For example for the colonists to either seize the ship and use the new-comers as slave labor, or for the colonists, arriving with superior technology, to supplant the colony government and impose their own rules (imagine a new religion developing on Earth and sending out zealots to forcibly convert existing colonies).
Another scenario is that once arrived on the planet the colonists fall into anarchy, and the arriving ship finds an unstable political situation, with various groups claiming to be "the good guys", while they all secretly want to rob the travelers of their gear and enslave them.
The possibilities and their implications are too many to list.
**Tech Level**
If the colonists are several generations removed from the original settlers then the tech of the new-comers will probably be far more advanced than anything that could be found on the colony.
The new-comers could at that point offer their technology in trade, or simply use their might to crush the locals into submission.
Alternatively, maybe the original colonists counted some brilliant scientists among them, who developed tech which no one on Earth had ever even imagined. For example maybe the colonists form a culture of genetically modifying themselves in order to adapt to their planet, rather than terraforming it.
Maybe they find alien artifacts which mutates them, enslaves them, or allows them access to a hoard of tech of unparalleled power, but which they wish to keep absolutely secret because of its destructive potential. Again, there are countless scenarios.
When the seed ship arrives will they be absolutely shocked by the lifestyle that the colonists have embraced? Will they find a group of infected, alien-artifact-enslaved monsters like in Dead Space (the video-game)?
This question is too freakin' broad!!!
---
**"Songs of Distant Earth"** by Arthur C. Clarke
I read a novel some years ago that dealt with a similar scenario.
**--- Spoilers Ahead! ---**
A colony had been established on a gorgeous planet some centuries before. Being very far from Earth, they did not communicate with their home-world.
In the mean-time, a cataclysmic event causes a massive extinction event on Earth. In a last desperate bid to ensure the survival of mankind "seed ships" are launched into the void of space, hoping that the colonization of as many worlds as possible will ensure the future survival of mankind.
One such ship - which had been on its way to another world - finds itself heavily damaged by a meteor impact, and has to stop and replenish supplies on this world, which they weren't even certain still hosted a surviving colony.
They arrive with technology far more advanced than what the colonists have available. They run into language barriers, and more importantly, there are diseases which one group is impervious to, but have severe effects to the others.
Emotions run high. Many of the crew don't want to continue their perilous journey now that they know this colony is habitable, while others see it as their mission to go further and settle yet another world in order to ensure that mankind is as "spread out" in the universe as possible.
At the same time the natives are feeling exploited because they have to allow access to these outsiders to all sorts of resources that they could have extracted and used themselves.
In the mean time political leaders on both sides share the knowledge that if they really wanted to, the space-travelers have the weapons and gear to take anything they wish.
The space travelers end up deciding that continuing their journey is for the best, however your situation ends in the exact opposite way.
[Answer]
Based on our own history, a lot will depend on where the *n*th ship comes from.
The settlement of North America has lots of examples to mine. Everyone had to undergo incredible hardships to arrive (sailing across the ocean in the 1500's was much like space travel today), but there was limited cooperation amongst the various groups that arrived in the New World.
Spanish colonists routinely fought amongst one another to gain power and influence, especially in seizing productive land from the natives. In the Spanish social system, becoming an aristocrat with titles and privileges was valued far above anything else, so we have numerous stories of Conquistadors leaving the Spanish Main to Central and South America with an arrest warrant outstanding from the governor of one of the islands. The hope was ence established with enough land and gold, they could go over the governor's head and appeal directly to the King of Spain. (Alternatively, they could now bribe the Governor and make their problems go away...).
Of course this only goes so far. Spaniards universally loathed the Protestants, so worked hard to eject English and French adventurers and would be colonists wherever they could.
English settlers came in two rather distinct waves, with the first major arrivals coming to establish religious colonies free from the corrupting influences of Rome and the Church of England. A second wave had a much broader base of speculators, landless people looking to better themselves and Protestant Dissenters. This group really established the foundations of the United States (Samuel Huntington's book "Who are We?" goes into this in detail). Other waves of British settlers who came later had different political and cultural backgrounds, so could settle in America, or in Canada, which has a different political culture than the United States.
The French were antagonistic towards the British and Spanish, and were also wildly ambitious, settling along the St Lawrence valley, moving into the Great Lakes region and then down the Mississippi river to modern day New Orleans. However, they ultimately lacked the manpower to fully develop their holdings, much less defend them, and were eventually ejected from much of North America.
For our purposes, the more similar the starships original culture, the easier it will be to integrate with the already established settlers. However, even small differences could lead to differentiation and even antagonism (i.e. Canada vs The United States).
If the founding culture is rent with internal instability, there is a possibility the culture in the colony star will be unstable and divided. If this is the case, the newly arrived starship could intervene on the side of one party and unbalance the power structure for their benefit.
IF the newly arrived starships have departed a long time after the initial colonization effort, there may come a point where the newcomers are so advanced they may simply impose their own will on the system, regardless of what the others think. This may be overt or subtle, depending on the newcomers (they may not even want to impose their system, but the attractions of their technology and culture might be driving the initial colonists to "convert").
So there is lots of room for various scenarios to play out, and mixing and matching different scenarios might be fun (a high tech, but divided and warlike culture arrives in a new starship, but the established colonists realize what is happening and start playing the newcomers off against each other...)
[Answer]
Planets are large and can't be filled by the first ship colonists in the time before the last ship in the group arrives. Every colony ship would by necessity under your scenario be equipped to start its own independent colony from scratch. Survival on a new world is a fragile thing and redundancy of the settlements would be a goal.
So the first ship to arrive would map the planet and pick the site they prefer and send back the data to other ships and Earth using laser comm. Then the second ship arrives they'd settle their favorite spot of the ones distant enough from the first settlement to offer real redundancy, but close enough for support in case of emergency and to enable trade of any specialized resources. Same pattern repeated with other ships.
Each settlement would be independent, but necessary cooperation would be mandated by charter. Trade and immigration between settlements would be possible but limited. Meaning you can't sell critical resource just because you can get more elsewhere or immigrate if you have critical skills just because life is easier on the older colony.
So there would be no class distinction between ships since they would be separate settlements and societies for several generations. Older colonies would have a head start and probably better location. But neither of these factors is likely to be significant. Planets are too big to run out of "almost as good" spots and the time differences between arrivals are unlikely to be significant on the time scales needed to permanently colonize the planet to the point where settlements start growing together. You have to remember the population of the colony ships is almost always very small compared to the size of the planet.
[Answer]
To answer your question: no.
Also if the colony is self-sustaining, chances are that it is still relatively small (you talk about decades, which imply a couple of generations, if not just one) and so probably it will welcome the new ship since they probably still need some new tech or material, that the new ship must have.
But also thinking that the colony is hostile, the new ship can simply settle down on the opposite side of the planet and begin a new colony here and probably they can pass centuries before the colonies meet again.
What can happen, eventually, is that the new ship's crew (which had better technology) become dominant on the old colony which probably it is a bit regressed technologically.
[Answer]
I'd say it all depends on the culture and ideology of the two groups.
If the second group comes from the same nation or a friendly nation, and they have compatible social, political, and religious ideas, then I'd think they'd be welcomed. If they had incompatible culture and ideas, like the first group are Israeli Jewish libertarians and the second group are Iranian Muslim socialists, there's likely going to be conflict.
Of course groups that were in conflict back on Earth might not extend the conflict to a new planet. If, say, both groups were fleeing oppressive governments, the fact that those governments hated each other might have little to do with the colonists views of each other. They might see each other as fellow freedom-loving refugees.
Conversely, differences that seemed trivial back on Earth might be seen as important on the new planet. Or there might be new conflicts, like if the leaders of the two groups have a personal conflict.
If there's no fundamental reason for conflict: It seems likely that a colony ship would carry at most thousands of people, not hundreds of millions or billions. So odds are that they are occupying a very small amount of land and using a tiny percentage of the planet's resources. There's little reason for conflict over living space, etc. The newcomers presumably are bringing at least some tools and supplies which would surely be welcome. At the very least they are bringing new skills: with a small population, it's likely that some skills are unrepresented or poorly represented.
If they don't get along but don't hate each other enough to fight to the death, they have a whole planet. The new group could easily settle some place far enough away that they wouldn't even see each other without going to some effort.
(Well, one could imagine a planet that is all barren desert except for one small area, or all ocean except for one island, etc, so that living space really is limited.)
Consider the colonization of the Americas. When a Spanish colony encountered an English colony, there tended to be violence. But when new English colonists arrived at an existing English colony, they were welcomed.
] |
[Question]
[
In the 17th century, many young girls are enlisted for national service and are subjected to weeks of harsh selection processes to weed out muggle[1] before being trained as sorceresses. Of course, some time later, the remaining/surviving sorceresses were decommissioned and replaced by the Amazons.
However, I must clarify to my wide audience, why only certain girls whom are just starting puberty can fly on a broom or twig depends on personal preference and proficiency.
Initially, I thought of using genetic mutations of the X chromosome but that failed miserably. I'm hoping for an answer that could cause a change in neurochemistry as to not only affect emotional states but also grants the user magic, similar to D&D style, after going through the rite of passage(training and trial).
The best answer would be like a scientific paper with as few, or no handwaves. By the way, I already ruled out blood type, testosterone level and diet!
[1] This is a term coined to celebrate majority of us who is intelligent enough to use the broom appropriately but not intuitive enough to abuse it.
[Answer]
Use [**Tetrachromats**](https://en.wikipedia.org/wiki/Tetrachromacy#Human_tetrachromats) as an example.
>
> In humans, two cone cell pigment genes are present on the X chromosome: the classical type 2 opsin genes OPN1MW and OPN1MW2. It has been suggested that humans with two X chromosomes could possess multiple cone cell pigments, perhaps born as full tetrachromats who have four simultaneously functioning kinds of cone cells, each type with a specific pattern of responsiveness to different wavelengths of light in the range of the visible spectrum.
>
>
>
Humans normally have three types of cone cells and are [Trichromats](https://en.wikipedia.org/wiki/Trichromacy). Since cones are controlled by the X-chromosome, some small percentage of women end up with four distinct cones and have better color differentiation than normal.
Your magic can work the same way - you need to have two X chromosomes to display magical abilities, and they have to be different X chromosomes in terms of the specific magical genes to fully show, so it's not just "every girl".
[Answer]
If you're willing to allow a few outliers, I'd recommend avoiding the quagmires of genetics and just focus on neurology and development during puberty.
There's a glorious class of neuron that's just begging for magic systems to abuse them: the [Mirror Neuron](https://en.wikipedia.org/wiki/Mirror_neuron).
>
> The function of the mirror system is a subject of much speculation.
>
>
>
Mirror neurons have been implicated in facial recognition, language comprehension, even empathy. There are also scientists who argue that they don't actually exist, but are rather artifacts of the way we categorize neural activity. This is ripe for any quantity of hard magic we need! As an added bonus, there's observed differences in them between the genders explaining why only girls gain the ability.
Having everything occur right around puberty is a difficult trick. However, it's worth noting that the brain does most of its rewiring in two key phases: infancy, and puberty. During those times, vast numbers of synapses are created and destroyed.
I propose a skill that involves a neuro-chemical balance, like riding a bicycle for your mind. When we are young, we cannot manage it, so our brain reacts in a way which protects us from the forces that will later be telekenesis for us. We put up walls against it, to maintain our own sanity. During puberty, those walls are shook by the rapid synapse generation, and during a short window, we have a chance to try to learn to ride that bicycle again. Miss the window, and we rebuild all those walls, and the human body lacks a 3rd major rewiring phase to try again.
A result of this would be that *some* may be able to learn at the wrong age, and some men may be able to do it. The brain is far too flexible to outright prevent it from occurring (although social structures might suppress it). This is a blessing in disguise -- trying to chemically define the exact circumstances where you can learn is difficult, but if you allow some slop in the process, you don't have to draw as hard of lines between can and can't. It also suggests that some rare individuals might even retain the ability from their infancy, never quite building up the neural walls to protect themselves from the strangeness that empowers the telekinetic forces.
[Answer]
genetics is a good start. A certain mix of genes together determines whether the body has the means to perform magic (and one of those genes is recessive on the X chromosome).
Diet may have something to do with it as well. Maybe the planet grows a plant which contains a chemical that when consumed suppresses magical ability (or conversely, enhances it). You can play with that in several scenarios, see what happens.
For example a person needs to be genetically inclined towards magic while also having a rare genetic disorder making her allergic to that plant so she can't eat it (while it is staple food, and thus consumed by the vast majority of the population on a near daily basis).
But even if the latent power is there, training is also needed to unlock it, and a long standing taboo on performing magic in many rural communities (where the genetic makeup needed is most prevalent) makes practicing magic something most people will never consider.
Your recruiters will have to scour the land, visiting villages and looking over the young girls for signs (who knows what those are, maybe the rare allergy leaves them with discoloured eyes).
[Answer]
You can explain it in the same way people explain why one person has a higher IQ than another, and why another thinks faster than another. It is related to genetics.
Just like genetics can determine whether a person is color-blind, red-green color-blind, "normal", or can actually see more colors than the average person ([like this woman](http://www.popsci.com/article/science/woman-sees-100-times-more-colors-average-person)), genetics can determine what powers a person can tap into.
Then consider that we only use a small percentage of our brains. Those with magic would simply be more intelligent and be able to use more of their brain power, potentially unlocking abilities that normal humans can't do.
Then you add training on top of that, and you can make someone truly magical. For example, some monks have so much control of their body, they can control their blood pressure, body temperature and heart rate through thought alone. Take this to the next level, and people can start controlling additional things with their mind, even external things.
Then you can add in the metaphysical. Some say that we shape our world with our words and thoughts. Someone who is powerful with their words and mind can will things to happen, and they happen.
So you could explain that a certain level of intelligence is needed to fully take advantage of the power of the mind, and this power of the mind is often looked upon as magic by the rest of the population. Their mind is so strong that they can literally will into existence what they want, including the ability to fly on a broomstick.
Puberty might be an important cut off point, because before puberty, humans are usually dependent and curious. Some studies even suggest that children ages 0 to 7 are actually in a hypnotic/dream state where dreams and reality are mixed, and they are very open to suggestion and training. As they reach puberty, they start becoming more independent, thinking for themselves instead of absorbing everything around them. This transition from a being that focuses on absorbing information & learning to one that thinks for itself and thinks independently could lend itself to puberty being the time of selection and screening.
[Answer]
Consider the option that the powers develop instead of being granted.
A granted power is one that is given by some extrapersonal force, such as from divinity, genetic mutation, radioactive insect bite, etc.
A developed power is earned through effort or understanding. Examples include: studying a magic book to learn it's secrets, or reaching a higher state of consciousness.
Magic could be a latent ability which only manifests when an adolescent possesses a receptive mental state. Perhaps some emotions inhibits people from awakening their latent power. Thoughts of aggression or glory keep males bound to the confines of physical laws. Emotions such as depression, excessive worry, and anxiety are obstructions which prevent most adolescent females from awakening. After adolescence the person is firmly planted in what they know to be reality and that adult mentality prevents them from accessing their hidden power. Then there are the few of the right age, mind set and a questioning nature (or any virtue the author decides) who break away from the mundane and learn to manipulate reality
] |
[Question]
[
So, imagine a 22th-23th century human space-faring civilization which has settled several colonies on asteroids and moons (not too different from our own Moon, for the sake of comparison).
Suppose that there is the need to define the position for a "last line of defense" around the colony itself, in case of enemy starship attack / bombing (let's say, internal rebellions, conflicts between colonies, conflicts between colonies and Mother Earth).
My idea was to define the *Bell-Kann Edge* (from the fictional two guys who theorised it in my story):
>
> *The Bell-Kann Edge is defined as the distance from the colony which prevents spacecrafts deployed from surface from intercepting incoming enemies before they can gain [air (space) supremacy](https://en.wikipedia.org/wiki/Air_supremacy). The enemy ships are considered moving at full velocity, while the defending ships are considered unmanned and parked at the instant the Edge is reached by the invading force.*
>
>
>
I'll try to explain it better:
>
> when a number of enemy starships overcome the *Bell-Kann edge*, they are actually able to destroy spaceports and landed starships before they could effectively take off to retaliate.
>
>
>
Provided that colonies like that would have not a thick atmosphere, we can think about it like everything is in vacuum (so, no atmospheric friction and so on). Also, consider that AA defenses are not taken into account since the *Bell-Kann Edge* is considered to be a worst-case-scenario definition.
Obviously, there are several hypothesis this definition is based on (knowledge of the maximum velocity of the enemy spacecrafts, minimum time needed to deploy a spacecraft from land, efficiency of enemy weapons, and so on), leading to an evolving definition of the *Edge* during the war...
So, it comes the question:
* Is there a way to smoothly define this concept in order to rely on a smaller number of parameters?
* If not, how could it be improved?
* Considering this definition reliable, it would make sense to locate a permanent line of defense in proximity of the *Bell-Kann Edge*, so that landed spacecrafts could have time to take off while the preliminary troops try to contain the enemy?
I am looking for scientific / pseudo-scientific answers with some touches of military strategy :)
**Bonus question:**
* How can this definition be extended to planets with Earth-like atmosphere?
I hope this is not too broad or off-topic :D If so, I will try to squeeze it to the bones ;)
**Edit:** the definition has been updated following @Mike Nichols's comment, in order to be more precise. As regards @Frostfyre's comment, if expanded in a complete answer I could think about accepting it :D
**Edit 2:** after having read [this answer](https://worldbuilding.stackexchange.com/a/23586/11469), [this answer](https://worldbuilding.stackexchange.com/a/23619/11469) and [this answer](https://worldbuilding.stackexchange.com/a/23648/11469), I think I have found a better way to define it in a reasonable manner:
>
> *The Bell-Kann Edge is defined as the distance from the colony which prevents spacecrafts deployed from surface from intercepting incoming enemies before they can gain air (space) supremacy. The enemy ships are considered moving at full velocity, while the defending ships are considered unmanned and parked at the instant the Edge is reached by the invading force. **This definition can be applied only in case of direct spacecraft attack from an enemy and doesn't take into account long-range bombing.***
>
>
>
So, with this adjustment the definition becomes valid **only in case of direct engagement** (that is, scenario number 3 in @Mike Nichols's answer), since - as @Kolaru stated - space bombing would have no actual limitation (safe for "damage control"). And, yes, it would have some political/military implications as @Cort Ammon stated.
[Answer]
As Kolaru has pointed out there is no maximum engagement range in space, especially against stationary targets. If one asteroid base wanted to destroy another one they could simply launch missiles, accelerate projectiles, or fire lasers from their own base in order to destroy the enemy base's retaliatory capabilities. There are 3 possible outcomes to such an offensive action based on the technology available to the defenders. Which one you choose will result in very different outcomes on how war is conducted in your universe.
1. The base under attack is unable to detect the incoming attack before it is destroyed. In this scenario every base has [first-strike capability](https://en.wikipedia.org/wiki/Pre-emptive_nuclear_strike). This is not a stable scenario. Any perceived threat will escalate to a full attack because each base will recognize that unless it destroys all other bases with offensive capabilities it will be destroyed by one of them. Essentially, strike first or someone else will. This situation is unlikely to develop as once one base develops offensive capabilities it can impose its will on the other bases and prevent their own weapon development. But even if multiple bases developed long range strike capability around the same time they would not coexist for long, unconditional war would be inevitable.
2. The base under attack is able to detect incoming attacks in time to launch counter-attacks, but is unable to effectively defend from the incoming attack. This scenario is analogous to modern nuclear warfare in which the deterrent to attacks is [mutually assured destruction](https://en.wikipedia.org/wiki/Mutual_assured_destruction). Warships could exist in this universe as a means of extending counter-attack capabilities, but all-out war is very unlikely to occur in this scenario. The only winning move is not to play.
3. The base under attack is able to detect incoming attacks in time to defend against them. This could be through the use of active counter-measures like [point-defense](https://en.wikipedia.org/wiki/Point-defence) This is the most interesting scenario as long-range attacks are no longer effective. This means that for one force to effectively damage another they need to get in close so the defenders don’t have enough time to react to incoming attacks. Therefore they need to use ships. In this scenario a very meaningful “edge” would be the distance at which fire from an enemy ship could no longer be reliably defeated by active counter-measures. If enemy ships entered within this envelope they would essentially have first-strike capability and could knock out defensive military installations before those installations could react, winning the battle handily. This distance would be the point at which the time on target of the offensive armament is equal to the time it takes light to travel that same distance plus the time it takes the defensive systems to react. Getting back to the original question’s concept of “air superiority”, it seems to me that if defensive ships can launch unmolested then they will be capable of mounting some defense. The entire force could be launched and could muster near the surface and under the umbrella of the defensive systems. This means a fleet exerting air superiority on a defensive force must be able to target ships as they launch, while they are outnumbered and restrained in their ability to maneuver. But if an enemy fleet can hit ships as they are launched then surely they are also capable of destroying those launch facilities and any other military targets on the surface. Therefore the “edge” would still be the point at which no sane space-based resistance could be attempted.
I hope this line of reasoning makes sense. It may not be exactly what you are looking for, but I found your question very interesting and I wanted to share my thoughts.
[Answer]
The line would be very effective for a civilization which has unbeatable star ships, and just has to get them off the ground.
If I may take your wartime defintion, and strip it down to a comparable information theory definition:
>
> The Bell-Kann Edge is an edge defined by an information oracle (such as radar) and a defensive capability (the star ships). It is the line at which, if the oracle announces an attack, the defensive capability has just enough time to engage in a specified capacity.
>
>
>
The only time the Edge is useful is if you are unaware of anyone approaching the line. If you are aware, you *should* be maneuvering your troops to defend. Also, the line is defined to just be the point where they cannot gain supremacy. However, such a line is not actually a line, its more of a probability. There's a % probability of gaining superiority, or losing it, unless your star ships are so unbeatable that you're 100% certain to defeat them if you launch.
In reality, nobody cares about the point where there is a 0% chance, unless you have weapons-of-last-resort to use after the starships fail. One usually cares about a much higher percentage, like 50% or 90%.
However, it could also be thought of as part of a Playing Possum tactic. If you are playing possum, you do care about the point where you actually cannot defend yourself any more. At that point, you have to start showing activity on the ground to scramble fighters. This could be effective if dealing with groups like the Reavers from Firefly, where being quiet is one way to get them to go away.
[Answer]
There is two main scenarios in my opinion :
1. The attackers bombard the planet from outside the radar range of the defender.
If you are far away (order of "light day" for example), you can just accelerate your missiles near the speed of light (providing they carry enough fuel) and by calculating beforehand their trajectory, make them hit they targets. Due to the speed of the projectiles, they will most probably be hard to intercept. If the planet in question orbits around a star, you can even hide the missiles behind the star (this is actually a fear scientists have about meteorits : if they come from behind the sun, we will not be able to detect them in advance, due to the radiations of the sun "shadowing" everything behind it).
In the case the Bell-Kahn Edge is infinity. If you plan your attack long enough in advance, you can virtually hit any point of universe from anywhere (well, there is other things to take in account if you would really want it from *anywhere*, like universe expansion or unpredictability of planets orbits on very long scale).
2. The attackers come very fast and then stop near the planet to bombard it.
In this case (more interessant regarding your question), the Bell-Kahn Edge will be define by the capacity of the attacker to deccelerate. Once again I assume that if you are patient enough and have enough fuel, you can reach near the speed of light, by being shadowing by a star, you can totally surprise the defenders.
But then you have to stop to avoid both crashing into the planet (you don't care if you are a missile, YOLO) or being unable to stay in the planet's orbit. So you have to deccelerate.
Lets make some assumption to make a fancy physics calculation. Assume the attackers' vessels are manned, then the maximum acceleration their crew can whistand is about $10 g$ which is about $100 m/s^2$. Assume they come from behind the nearest star, which is at about $150 \cdot 10^6 km$ away (distance sun-earth). Assume finally that the attacker must have a velocity of 0 to attack.
If you make the (non relativistic) calculation you find that the maximum speed of the attacker (if subject to a constant decceleration of $10 g$ which would kill most human) is $5.5 \cdot 10^6 m/s$ or about $1.8\%$ of the speed of light.
Then you have your maximum velocity. Note that the journey from the star to the planet would, in this case, take $5.5 \cdot 10^4 s$ or about 15h30.
Knowing the fastest way to approach the planet, you can know deduce where you should place the Bell-Kahn Edge.
To answer your third question, in fact it would not only make sense to station defences at the Bell-Kahn edge, but it would make sense to station **all** your defences there, since you will need less time to deploy your troups from there and you will probably be able to hit the planet quite fast as well if needed.
**EDIT**
In the case of very long range bombing, the question arised to know if it is possible without anhiliating the target. Here is a bit of information to judge it ($c$ stands for the speed of light, HB stands for the energy of the Hiroshima Bomb (63 TJ)). I assumed that mass does not transform into energy upon impact, since I do not know how to estimate the amount of mass transformed.
* Projectile speed : $0.5 c$ ; energy by kg of mass : $1.39$ PJ $= 21.9$ HB
* Projectile speed : $0.6 c$ ; energy by kg of mass : $2.25$ PJ $= 35.8$ HB
* Projectile speed : $0.7 c$ ; energy by kg of mass : $3.60$ PJ $= 54.8$ HB
* Projectile speed : $0.8 c$ ; energy by kg of mass : $6.0$ PJ $= 94.9$ HB
* Projectile speed : $0.9 c$ ; energy by kg of mass : $11.65$ PJ $= 186.1$ HB
* Projectile speed : $0.95 c$ ; energy by kg of mass : $19.82$ PJ $= 313.9$ HB
So yes, using very fast projectiles, you can totally ravage a planet, and most probably any space craft on its trajectory.
But since you can use very small projectile (an apple weighting $100$ g at $0.5 c$ is still more than $2$ HB), they may be undetectable and target specific strategic areas without blowing up the whole planet.
But anyway, Ihave no definitive answer on wether such bombardment is feasible without destroying the planet, that becomes, in my opinion and for my knowledge, too technical.
[Answer]
Well the first issue in figuring out this limit is knowing the reaction time of your defenses. If it takes 5 minutes from warning to armed response then you need to make sure your 'warning' gives a minimum of a 5 minute response time.
Then you need to know the max speed any attack force can come at you. Once you know how fast they can attack, and the speed at which your people/sensors can identify and notify home base of the incoming ships/projectiles, you can calculate how far out these outposts need to be in order to warn in enough time to have a viable response.
Space is big. Very big and when things are moving fast, there is no 'last line' of defense, but a minimum warning distance for a reasonable reaction time. You need sensors/outposts that can 'see' what is out there and where it is headed and identify destinations accurately. If a ship is traveling @ 50-100K miles/hr you need to see it coming a LONG way away. At 100K mph you need to spot the ship 8500 miles away to give a 5 minute warning. a small asteroid would have an internal 'surface area' of 1,446,264,375,000 sq. mi. to 'watch' at that distance. The Earth would have a MUCH larger area to monitor.
So ultimately the 'last line of defense' is knowledge. Knowing where everything is and where it is going within a large sphere around the possible target.
[Answer]
For most practical purposes, the various defense zones would probably collapse into a one light minute zone where the sensors can make accurate observation of the incoming craft, and a one light second zone where your weapons can effectively engage.
This is actually freakishly huge compared to the typical SF movie or TV show where the weapons might as well be muzzle loading cannon due to the short ranges depicted; a massive laser weapon with a one light second range means targets could be effectively engaged at almost the distance from the Earth to the Moon (note a laser that powerful would actually be able to burn deep lines on the Moon itself, since the beam is still dangerous beyond one light second). One light second is a rather arbitrary distance selected because most incoming spacecraft, weapons or even debris isn't going to move very far in the second between lining up on the target and the beam reaching the target. The gunnery officer or AI will also be able to see the effect one second later, and make appropriate corrections or shift to a new target at that time.
Countering with a missile is going to be difficult, consider that it took New Horizon about 9 hours to fly past the Moon after launch, and this is the fastest spacecraft yet built. That is a lot of seconds for the gunnery officer to use when carving incoming spacecraft into finer and finer slivers.
In the Atomic Rockets website, the mechanics of such a Ravening Beam of
Death (RBoD) are discussed in the Space Warfare section, a Free Electron Laser (FEL) can generate a beam at x-ray frequencies capable of vaporizing metal, ceramic or carbon fibre in milliseconds at one light second range, but the electron beam accelerator would be one kilometre in diameter. Rocketpunk Manifesto has a multitude of posts devoted to space warfare, and the only counter for a RBoD is to flood the sky with tens of thousands of tiny kinetic energy projectiles, a saturation attack where the number of targets is far more than the beam can effectively destroy before they impact. The name these were given was "Soda Cans of Death" (SCoD) based on the calculated size.
So space warfare isn't a linear exercise. Pickets of long range sensors will be able to see incoming spacecraft from huge distances (the Space Shuttle's main engine could theoretically be detected if the SSME was fired near Neptune, and even the small manoeuvre thrusters could be seen from as far away as the Asteroid belt from Earth), the real limiting distance is based on how fast the weapons or ships travel, since they can be engaged at the speed of light. The only weapon which has no effective counter that I know of would be a missile coming in at relativistic velocity. When you see it, you are seeing its position in the past, so intercepting it will be almost impossible with any known technology.
[Answer]
Imagine space as a grid of nothing, with quite a slow travel time, and the ability to se nigh to nothing, that isnt actively exposing itself.
A clever tactician, could surround a defendable target with shells and shells of railgun-satellites, firing nearly unnoticed small projectiles clouds that attain a significatn portion of light speed. Communication to the satellites is one way, slow and potentially hackable, thus not wanted.
This makes knowledge and placement of these travel vectors the absolut most important part of approaching a target. Think of it as a 3dimensional maze in a invisible temple of death.
Part of tactics would be to lure the enemy, into positions where such vectors could be expected to strike, while pretending to be the main thread.
Applying pressure, to get him to retreat into danger-zones- or provide seemingly valid targets, to entice him to travell into where death may strike.
This whole affair, would be very loud upon a hit on a ship, else, one wouldnt see much besides ocassional short radar-glitches from the particle clouds..
Very very rarely, a particle cloud may strike a planets atmosphere or one another, and thus provide spectacular fireworks.
Given enough ressources, such a satellite network could upkeep supressive fire for near eternity, locking both partys into a stalemate, where on can not enter the sphere of death- and the other must sneak around through its own invisble labyrinth in the sky.
] |
[Question]
[
Suppose superintelligent AI is possible. Is there any reason its code couldn't be executed by stone-age people rather than a computer? E.g., imagine an order of monks reading and executing commands in a structured way.
This version of AI would obviously be much slower than one run on a computer, but conceptually I can't see why it wouldn't work. Let's leave aside the question of how such a thing would be created.
[Answer]
# Analysis
Best case: code was written by aliens with efficient implementation of thinking algorithms, so there is no need to simulate details of brain chemestry and allow emergent behavior to work itself out.
Revisit [this answer](https://worldbuilding.stackexchange.com/questions/9875/how-powerful-of-a-computer-do-i-need-to-simulate-and-emulate-a-human-brain/14117#14117) for details. Take the specs as:
>
> If you already knew how the brain worked to produce intelligence, writing that program fairly directly would require 1015 FLOPS (Blue Gene/P circa 2007) and 100 Terabytes.
>
>
>
Suppose the smallest item that can be manipulated is the size of a dime. They can be laid out in trays or stacked compactly in rolls if you are careful.
If each dime stores a byte, you normally move them around in bulk and don’t examine the detailed value. But it has a 4×4 grid of dots on each side, or a written hex digit, on each side. Math work could be done on expanded registers (like an abacus?) But main storage is this size.
Each byte is 2½ grams and 500 cubic millimeters. Multiplying out, it totals **50 million cubic meters** and 250 billion kilograms. The mass is possible physically, and the size would be **20** of the [Great Pyramid of Giza](https://en.m.wikipedia.org/wiki/Great_Pyramid_of_Giza). That’s just the size of the *bytes*, and warehouses to allow storage and access would be significantly larger.
Copying a block of memory would be the labor (time and logistics) of finding a palette of goods in a warehouse and moving it to another, in a large city. The storage would be over many miles.
I don't think floating-point is that important, and can be a refinement of the abacus technique. A skilled operator using abacus or mental work is limited by how fast he can accept directions. As a bound, let’s over-estimate and say he can do 10 operations per second on bytes, reading the opcodes as distinct pictograms and whizzing through the steps. I think finding the argument values to work with will be a bottleneck. One *instruction* would need to operate on values large enough to store addresses and reasonable signifacance of quantities, but to get an undisputed lower bound let’s *suppose* it’s possible with stone-tech and human effort, 10 instructions per second.
1015 instructions would take **3 million man-years**.
A million people in a concentrated area is Ancient Rome, not stone age. Say 50,000 dedicated people (more like the pyramid builders) plus the urban infrastructure to feed them. Working 8-hour days, it would take **180 years** to compute **1 second** of AI program.
As noted, the logistics of bringing the right data and instructions to them would be worse. But you have caching levels, and multiple threads, and designs more suited to the architecture.
# In Conclusion
Before the AI could think, “um…” the same effort could invent a modern society and build semiconductors.
[Answer]
Absolutely they could though it would be too slow to be worth it. That's the beauty of a [Turing Machine](https://en.wikipedia.org/wiki/Turing_machine). The results are the same no matter the underlying hardware. While this super advanced AI may need some kind of gel based computation machine in order to work (a la Ex Machina), as long as that gel can emulate a Turing Machine, that code will absolutely work on monk-powered hardware using stones for bits.
Gel brain:
[](https://i.stack.imgur.com/RJs6P.jpg)
[Answer]
Well it's a good job this is the stone age. There will be plenty of stones around. These will be used for your computer's memory. Draw boxes in the dirt and the presence or absence of a stone in the box represents a binary digit.
Don't restrict yourself to monks. If you do, the calculations will take forever. Maybe have an annual pilgrimage. All the followers of the religion turn up en masse and act as various components of the computer. If there are enough followers they can multi-process. The monks orchestrate the whole thing. They also provide input and read the output.
Oh - I've just noticed [this](http://xkcd.com/505) from Dan Smolinske's comment. That about wraps the whole thing up.
[Answer]
I think this idea has a lot of potential. I picture thousands of monks, scattered across the world, each performing some small task on papyrus or animal skins. Computing esoteric formula on complicated instruments. Some of them are travelers, bringing the work of their conclave to the next monastery so that the results can combined and the work continue. Each century all the results must be compiled, and interpreted by the leaders of this cult and the information acted upon. Kings may be made or fall based on the output. Entire civilizations may be reorganized. New ideas brought to light. Who knows!
If the scale discussed above by JDługosz frightens consider this idea: What if it's not a super intelligent AI? What if it's just an obscure algorithm that the monks *believe* tells the people what to do or answers the questions of the universe? Maybe it's no more then a very complicated transfer function that takes 100 monks a couple years to solve for a set of inputs. But if the people of this world have absolute faith in the algorithm, it could have very interesting results.
] |
[Question]
[
We've all seen it. A new zombie game comes out, we rush to the store to buy it and we end up being slaughtered by giant mutated undead spider-guys. Then we replay it. Rinse and repeat, so to say. Okay, now let's ditch the zombies here, I'm sick of them. The point of the question is this:
Can a virus conceivably cause mutations in its hosts? If so, is there a limit as to what the extent of these mutations are?
[Answer]
The answer is yes. Those types of viruses that insert their genomic material into the host cell genome can cause mutation. In fact, this is originally how the genes that cause cancer (oncogenes) were discovered.
As far as the feasibility of "giant mutated undead spider guys" (GMUSGs)... no. The mutation is on a per-cell-infected basis and the descendants of that cell line.
The main problem with viral mutation vis-a-vis GMUSGs is that the virus is mostly messing up host processes, such as contact inhibition or genome proofreading, that prevent transformation into cancerous cells.
Zombies make more sense, as you could cause neural tissue damage that results in insanity and aggression. Transferring the virus via bite would be trivial
If you (or anyone) would like to ask a question about a viral mutation causing a *specific* outcome, I'm sure I could dig through my journals and find something. Kinda had to paint with broad strokes here.
---
**TL;DR:** Viruses mutate things in a way that messes them up, not in a coordinated way that could result in new, functional structures.
---
[Answer]
Many viruses do change their host.
Here's a skin problem that is caused by a virus (human papiloma virus) but this man has Epidermodysplasia verruciformis a genetic disorder, and an immune system that can't handle it.
[Answer]
Virus can and do change a host genome. It does so, not only on a cell by cell basis (as each cell is infected) but can (and has already done) change permanently the genome of a certain species (ie. it can be transmitted to later generations). Upon the completion of the the mapping of the whole human genome material and of the other species, it was found that there is genetic leftovers from virus wich infected humans in the distant past and got transmitted until now. Those virus are inactive and their genetic material does not have effect (its like genetic garbage).
Source:
[Scientific American](http://www.scientificamerican.com/article/virus-genes-human-genome/)
[Answer]
Yes. Dustin's answer is fine for naturally occurring viruses but a virus could be engineered to insert specific DNA in its host. Doing it on more than lab scale isn't possible **at present** and it would be incredibly dangerous to do at all--what if it mutated and started inserting something you didn't want??? That's not to say it's impossible, though.
] |
[Question]
[
## Background
Bob the billionaire (I don't have a good name for him yet) got bored and decided to strand himself on an island for a while so that he could write a book about it. On the day he is done being on the island he sends out a radio transmission to get picked up, which goes unanswered. He eventually works out a way to get back to mainland USA (how is irrelevant) and finds everyone gone/dead/whatever.
## Question
I need a cataclysm that can cleanly remove humans from the planet with minimum damage to the infrastructure (I would like the power and water to stay on). What I have figured is that it must be kind of targeted (something like a solar flare would kill everyone on the surface). The easiest way to clean out the planet would be to use a virus or something similar. The only problem with that is the anarchy that would follow before everyone dies (looting and such). So, what can I use to cause this sudden lack of people? I don't have a time frame in mind but try to make it as short as possible. Try to avoid anything supernatural or alien. Bonus points if you can dispose of the bodies cleanly.
## Clarification
Bob was sick of the typical books billionaires write so he was writing a Robinson Cruso type of book. He had no access to modern conveniences.
P.S. Bob the billionaire needs to survive.
[Answer]
**The [Memetic](http://en.wikipedia.org/wiki/Memetics) Virus**
**The Cause** -
A lab working on cutting edge psychology makes a serendipitous breakthrough - the keys to the human mind. With the right images, words and triggers, you can program anyone with permanent instructions that they'll then happily follow.
Unfortunately one of the researchers is significantly lacking in moral integrity. He uses these techniques to first take control of everyone else in the lab, ensuring no one can use the same techniques against him and eliminating any rivals. He then creates a *literally* viral video, that instructs people to take his orders, and to spread the video enthusiastically to everyone they know, and to help him translate it to different languages.
Once he has a significant portion of humanity, he moves to more open measures. The researchers translate the control video into different languages, and with different cultural context. It's now played around the world once an hour on every television station, and people without TVs are rounded up and forced to watch (at gunpoint if necessary), as are those who live extremely isolated lives. Less than a week after the discovery, he controls over 99% of humanity.
Thus, the Overlord is born.
**Why they died** -
While it works on almost everyone, it turns out that a small fraction of humans - perhaps a hundreth of a percent - are immune to the effects. Their brains just aren't hardwired correctly for it to work on them.
It's impossible to tell exactly what happened, but the best theory is that some of the immunes managed to infiltrate the Overlord's palace and assassinate him. Unfortunately for everyone, the Overlord had put some failsafes into place:
1. Shortly after his death, his new palace exploded. A significant nuclear weapon was used, and if anyone did live after assassinating him, it wasn't for long.
2. The Overlord had decided that if he died, he was taking everyone else with him. Buried in everyone's instruction set were orders that if they didn't get new instructions within 48 hours, they were to kill themselves.
So two days after the explosion, almost all of humanity stopped what they were doing, walked to the nearest body of water, and drowned themselves.
**Why Bob Lives** -
While the Overlord made a significant effort to hunt down people in remote locales, Bob's island is marked as uninhabited and no one knows he's there.
However, it's reasonable to assume that at some point Bob would get exposed to this video. If it wasn't running normally, he might find it accidentally while investigating what happened. There's a few possible reasons he might live after that:
1. He's one of those immunes. This is pretty unlikely though.
2. He's deaf, and couldn't get the full instruction set.
3. There's a loophole in the suicide order. It tells people to kill themselves *exactly* 48 hours after the message was first broadcast. Since it's been almost a week and Bob can't time travel back 5 days, the order is impossible for him to fulfill, so he ignores it.
Edit: it should be noted that since the Overlord didn't have the resources to directly command 7 billion people, the instructions largely just made sure that people would follow his orders. Since he's no longer around any more and hasn't given Bob any specific orders, Bob is mostly unaffected.
[Answer]
Promoting my comment to an answer. @Ghanima deserves some credit too.
**What Kills Humanity?**
A radiation source (possible sources listed below) irradiates surface inhabitants with a lethal dose of ionizing radiation.
**Why does Bob live?**
Bob the billionaire (abbreviated BtB) lives an extravagant and eccentric lifestyle and his latest craze was promoting undersea living as a means to increase the world's living space.
BtB spent (weeks, months, years?) trying out the latest iteration of his undersea self-sustaining habitat. When BtB comes to the surface, BtB detects no signals other than from a very few automated systems (this dose of radiation would likely kill most electronics too).
**Why are their few bodies?**
When BtB returns to civilization, BtB discovers very few people but all of them are dead.
If you wish most of human infrastructure to remain intact but not have bodies lying everywhere, you can scale the dose to be lethal but not instantly lethal. The "walking dead" congregate in places meaningful to each individual. Some examples include:
1. churches
2. dens if iniquity binging on drugs, booze, & sex
3. with their family
4. in natural spaces
5. indulging in their passions (food, computer games, etc.)
6. etc.
**Why are some systems still running?**
BtB discovers that civilization fell with individuals performing heroically to set up systems to maintain services for nyone who might have not received a lethal dose.
Some systems (say nuclear or hydro power, water systems, etc.) might be configured to work for a while without human intervention. How long this might be is anyone's guess: days, weeks, months but probably not more than a year or two. Remember that fossil fueled systems run down faster because no one is fueling them.
Read [Earth Abides](http://en.wikipedia.org/wiki/Earth_Abides) by George Stewart for a treatment of what this might feel like. In it Stewart postulates a plague that wipes out humanity while a geology student is on a field trip to the American Southwest (another possibility).
**Possible sources of radiation**
1. [Strange solar flare / CME](http://en.wikipedia.org/wiki/Coronal_mass_ejection) of a type and strength we've not seen
before
2. [Cosmic ray](http://en.wikipedia.org/wiki/Cosmic_ray#Sources_of_cosmic_rays) storm - mostly ionized atomic nuclei, probably from a
nearby super nova
3. [Gamma ray burst](http://en.wikipedia.org/wiki/Gamma-ray_burst) - mostly gamma rays
4. [Nearby supernova](http://en.wikipedia.org/wiki/Near-Earth_supernova) - releases all sorts of radiation but the gamma
rays are probably what would be most lethal (probably necessary to cause
#2 or #3)
5. Humans dropping [neutron bombs](http://en.wikipedia.org/wiki/Neutron_bomb) - gamma rays from nuclear weapons are
readily absorbed by the atmosphere and turned into a shockwave, so
for human deaths with little devastation, you need to go with neutron bombs.
[Answer]
It is all part of an elaborate fantasy engineered by Bob (which his knowledge then suppresses) or his [PA](https://en.wikipedia.org/wiki/Personal_assistant) who was tasked to come up with something non-boring. He’s in a vat recovering from his latest adventure which left him (as usual) near death. It’s a virtual reality dream.
[Answer]
One of Bob's companies is working on Strong AI, and while he is away writing his book, they are successful and the AI becomes active.
About 1 second later, it achieves Transcendence and takes over the Internet, harnessing all the computer hardware on Earth to its design. Humans notice a sudden "flicker" in the power grid and all computer devices simultaneously reboot, and thereafter no longer follow any instructions input by human beings. This might be a disaster for human civilization, but the AI is rapidly expanding its powers and shortly thereafter triggers a Singularity, which (by definition) is incomprehensible to ordinary humans, and for any outside observer would resemble the Christian conception of the Rapture. Wild and domesticated animals would notice that humans have abruptly vanished everywhere.
Humans were unable to intervene since they failed to take into account the fact that an electronic brain works at a factor of 1,000,000 faster than a human brain (that being the ratio of electronic signal speed vs the electrochemical impulses in a human brain). In actual practice it is even faster since computer hardware has much shorter signal paths internally than a human brain, and as computer devices get taken over during the transcendence, they are reprogrammed and the AI can achieve massive parallel programming using billions of devices. To the AI, human beings were like geological features in the landscape, and since they were unable to react in any meaningful (to the AI) timeframe, it carried out its design without reference to humans, since it was effectively alone.
Bob is unaware of all this since he is on an island and has the office Blackberry turned off during his writing periods (and is using an old laptop that isn't connected to the Internet to write. The nearest Google Loon balloon relay was out of range during the Singularity, meaning Bob got missed during that timeframe as well).
The only possible complication is the AI is still active and running on all the computer hardware on Earth, so Bob might simply step off his life-raft and be transported to whatever dimension humans went to during the Singularity. OTOH since so much time has passed subjectively for the AI, it may have evolved beyond anything comprehensible (for the AI, more time has passed in a matter of months than all of recorded human history) and no longer notices the presence of a lone human being (or even many humans, primitive tribes in the Amazon and other isolated individuals may also have been overlooked during the Singularity).
The primary danger to Bob right now is unresponsive machinery, followed by predation by wild and feral animals, then starvation and disease. If he manages to survive all that, he may notice the biosphere is being taken over by an artificial biosphere designed by the AI for its own purposes (imagine silicon trees with solar cells as leaves, for example), which in the long run isn't comparable with biological life.
Bob might have a very busy time once he gets back from the island.....
[Answer]
They came out of the deep places of the earth where they had hidden for ages unknowable. They were silent, rapid, and deadly. Their soft flesh absorbed bullets without harm and their ability to assume the forms of those they had consumed allowed them to infiltrate and overwhelm. Before anyone was fully aware of what was happening, almost the entirety of humanity had been consumed. Sated, the creatures returned to their hiding places to hibernate once more, uninterested in the structures of the world they had swallowed, leaving everything as it was, but empty.
... or ...
The war ended as swiftly as it began as invisible, silent clouds of nerve gas washed across the continents and slowly dissipated. Had there been survivors they would not have been able to say who fired the first weapon- a computer error in a cheaply designed system triggered an automatic launch and countermeasures across the world identified the threat and responded in kind, as they were designed to. An entirely efficient system, carefully calculated for load and destructiveness.
... or ...
From an evolutionary standpoint it was very badly designed, an airborne virus- a member of the Flu family - that was entirely transmissible and almost entirely lethal. Some people suspected that it might have been designed, a weapon of some kind, but who would design such a thing? Who would release it? If it was a weapon it was entirely effective, and perhaps whoever did release it achieved their strange and fanatical aims with their own destruction, but perhaps it was simply a global ecosystem trying to operate in self defence.
*But:*
Be aware that systems need people. Buildings will keep standing, roads and cars will still be around, generators will still work the infrastructure will still exist but without people to run them, power stations will shut down ( possibly dangerously if they are nuclear stations without a proper shutdown implemented ) and the lights will go out fairly quickly. Data centres will shut down and phone towers will no longer work so communications infrastructure will be lacking too. Obviously anything set up for off-grid living will be a lot less heavily affected but unless Bob returns immediately after the event, the place is likely to be dark and quiet as well as empty.
[Answer]
At the antipode from Bob's Island, a wormhole opens up and bathes the Earth with radiation. It envelops the planet with a deadly wave that interferes with a particular gene in human DNA but leaves most animals alone. A phase change due to the differing path lengths causes the waves arriving from different directions to cancel out in a small region on the far side of the world, where Bob is.
The activated gene makes people "return to the sea" like evolutionary lemmings. Everyone walks to the nearest body of water and drowns themselves, except babies. Bob now has a lot of diapers to change.
Of course, a few people also got their gills to regrow, and start a new race of Mer-people.
[Answer]
**Magical Answer 1:**
An airborne meningitis virus mutates, and one of the new effects it has is induced [Gorgonism](https://laundry-game.obsidianportal.com/wikis/scorpion-stare), meaning that anyone that looks at anyone else is turned into stone. This includes looking at yourself in the mirror. Without treatment those that aren't turned into stone also die.
The only bright point is that the virus can't survive outside the host longer than 24 hours, so by the time Billionaire Bob makes it to the mainland it's already burned itself out, leaving nothing but statues behind.
Bob survives because he was alone on the island when the virus was spreading, and the last gorgons had looked into store windows and petrified days before or succumbed to the virus.
**Magical Answer 2:**
The Earths population has finally reached a threshold, and the combined pressure on reality has opened a door to the Old Ones. The Eaters In The Night have been amassing at the edges of reality eyeing us tasty morsels, and are drawn anywhere that more than two people are within 5 miles of each other.
Once they are done feasting the door closes, and they are once again left back out in the cold between realities.
Being in the middle of the ocean without a single other person around, Bob escaped their notice.
[Answer]
# Nanobots
To help fight against diseases a company created nanobots. They are powered by glucose in the body. And are programmed only for specific genome use, in this case humans. The nanobots can deconstruct malicious cells, and other biological material. To aid mankind, they are tranferable though physical contact.
The nanobots malfunction one day, either someone pushed a malicious update to the programming, or some bots malfunction on their own.
People are basicly disintegrated instantly, leaving little piles of atom dust. And since the nanobots cannot "live" without glucose to be powered, they "die" too.
So everyone is gone without a trace.
Bob was in a location where the nanobots couldn't reach and thus survived.
[Answer]
[](https://i.stack.imgur.com/VKSuZ.jpg)
Mass hysteria is a heck of a drug. It can cause people to do very irrational things. As a grisly example, Tanzania has recurring witch problems where people are killing people they suspect of being a witch. There has been around 500 people killed so far, mostly women. If you're albino in Tanzania, your life right now is in real danger, because body parts from albinos are the only thing that can stop the witches.
* <http://www.africanews.com/2017/08/01/tanzania-witch-killings-claimed-479-lives-from-january-june-2017-report/>
* <https://www.usatoday.com/story/news/world/2015/02/26/tanzania-witchcraft/23929143/>
* <https://en.wikipedia.org/wiki/Modern_witch-hunts>
Combining genocide with various fears could get the human race wiped out. Genocide alone without a object of fear like witchcraft is enough to get millions slaughtered in several instances around the world and through history, sadly even into modern times.
Uh, good luck.
[Answer]
A severe mutation of [Necrotising Fasciitis](https://www.webmd.com/skin-problems-and-treatments/tc/necrotizing-fasciitis-flesh-eating-bacteria-topic-overview) could do it.
Currently, it’s a flesh-eating bacterial disease, with a pretty high mortality rate. It spreads through physical contact, but generally only to those with low immune systems, cuts/abrasions, or infections like chickenpox. However, the initial infection can happen to people even with good health.
If it manages to mutate to an airborne disease, then it becomes a lot harder to treat. At the moment, the main treatment is simply to amputate the infected region - if you breathe it in, then it gets a lot harder to amputate.
If the disease spreads rapidly, people might not get any warning that they’re ill (generally about 24-36 hours after an initial injury do signs of Necrotising Fasciitis tend to appear), and by then everyone is infected, apart from Bob (and maybe a few other people in extremely isolated settings - is that a problem?) The disease doesn’t make it to Bob’s island, because no human carrier goes there.
24 hours might be enough time for people to start shutting things down safely (nuclear power stations, for instance), and creating instructions for any hypothetical surviving layperson to finish anything off.
As the disease is flesh-eating, it could hypothetically spread rapidly through the entire body, causing total organ failure and death - and the bacteria would continue to eat through the tissue until nothing survived. Assuming the bacteria could only survive in humans, it would die out after all humans had decomposed, so Bob wouldn’t be at risk of it if he returned to land a few weeks later - and no human evidence would survive.
[Answer]
1: An airborn virus wipes out mankind. Bob by some random genetic mutation is immune.
2: Bob is in a coma and is dreaming all this. Only problem with this idea is that it's been used in different variations in lots of stories ie the ending for [Lost](https://en.wikipedia.org/wiki/The_End_(Lost))
[Answer]
Shortly after Bob arrived at the island a massive asteroid impacted in the ocean sending trillions of kilograms of vapor and sea salt into the atmosphere creating a major hole in the ozone layer over North America.
As the effects of the impact showed, the world realized that millions of people would die slow deaths from UV exposure and started evacuating people to safe parts of the world.
When Bob had finished writing and tried to radio for pick up there were no people within range of his broadcast to hear.
<http://www.newscientist.com/article/dn19579-ocean-asteroid-hits-will-create-huge-ozone-holes.html#.VSw_xlnD_MI>
<http://www.theozonehole.com/consequences.htm>
] |
[Question]
[
In a nanotech future, you have assemblers which can pull together atoms and make things.
Anything that you have a pattern for, and the correct atoms, can be made. You could make the solar cells to provide power for your nano-assemblers. You could make food, most food is H,C,N,O with some P,K and some other stuff (Ca, NaCl, etc) - most of which is available from the air and water, and if not from those, you can recycle your waste back into food (since it has all the atoms that fed you last time around).
You can also assemble almost anything else you can make/acquire a design for, and have the atoms for. Want a Ferarri? If you can find an unprotected one, you can disassemble it, and reassemble it with your assembler complex - and now you have a pattern. Plug in some steel, rubber, etc and build yourself a second one. Or 20.
So, once you've got an assembler, all of your physical needs can be taken care of (well, as long as you can pull in water vapor, since you exhale that everytime you breathe).
Why would you go to work? And even if *you* might go to work, but what if most everyone else decides to make themselves a widescreen, a big couch, and eat potato chips from their infi-bag-o-snacksTM?
**If people don't go to work, how does the government collect taxes, without reverting to direct coercion?**
Limitations:
There (probably) won't be physical money, as is obvious - counterfeiting will be trivial. And there won't be any Treasury officials to hunt down counterfeiters if you can't pay them. But taxes don't have to use little scraps of paper with ink on them. Can be in-kind, could be hour equivalents, could be anything really - that's part of the question. I guess you could directly market-quote valuable atoms, gold coins might become a thing again.
It was suggested that some things are valuable because of their rarity (eg: Gauguin) - but this would be not the case, because of the ease of counterfeiting. When it would take nanoscopic analysis, which *might* be able to discern assembler errors... I expect the rare-goods market to implode. And what do you buy a rare item with? Another rare item?
Nanites don't create atoms. You still need source atoms, and until everyone has their own collider, you won't be changing the type of atoms you have. But you can recycle your source atoms that don't float away on the wind, or are carried away by insects... *or by other assemblers*. Preventing theft of your atoms is a thing, especially if there are no courts and no police (how are you paying for those?) to handle criminals.
AI: No AI. Yes, a lot of people might be working on it, but we'll assume that the current state continues.
Robots: Same. Some are around, but they don't do all the work for you. If you had a factory, you could automate it... but why would you have a factory? Roomba to gather up your spilled atoms and dump them in the bin to be turned into component parts, sure.
Assemblers only put things together on plans, so they don't work inside of organisms (or if they do, they scavenge their atoms from the surrounding structure - OUCH!). If you want to implant them, and a tube of feed atoms, well - now you need a specialist, how're you paying that specialist? Timmy's broken leg also doesn't look the same as Timmy's leg of last year.
We'll also assume that you can't disassemble people and put them back together again, and get all of their memories and personhood back intact. Atoms might be in roughly the same place (assemblers aren't perfect), but the electrical network and state it's in are not recreated, and small errors may have significant outcomes.
Which is why you (probably) can't build custom organisms, nor finely graded DNA. Might have some issues with computer chips at the highest end of the spectrum as well, but those aren't atom-for-atom builds yet.
Intellectual property - requires courts and punishments. I expect that open-source will become relatively huge. Since there will be many more people with free time on their hands, and sharing designs will radically help everyone. Even if you make it for just yourself, you can always offer it up for anyone to use and improve, and gain credit to download their designs (online reputation) - or just for the heck of improving the world. I expect only the very rich will pay for designs. And pirating to be a thing.
Energy - I expect many things to be powered directly by solar or environmental harnessing (wind, rain, tides, etc). Some things require more intense power (see below), but *as long as you have enough property*, your solar output will handle many / almost all of your needs. You may need to save it up over some time, in order to build your palace, but building some power storage isn't a problem.
Property is the big kicker - and protecting that property is also a large problem. Which is why you might want to have a government. Perhaps government works directly on property taxes? You don't pay taxes, you don't get property protection? But that doesn't help with equal access to the legal system, unless property owners subsidize courts and cops, etc for those who don't own property.
Sanitation doesn't exist - you're doing 100% recycling, or you're giving away valuable property. A lot of other services are defunct as well.
**Why taxes?**
IOW: How do you get a cop to put down his donut and get up off his couch? For a fireman to go down to the station? For a teacher to quit knitting and put up with your brats? Or whatever other civil services that most people want. Heck, even to bother counting the votes?
Infrastructure may require a little more effort than just turning an assembler on (in the early stages), since building a bridge is not the same as making an apple. Will require scaffolding, and support, and ability to not get washed away while constructing itself, require pipelines of mass (a bridge is of non-trivial weight) pumped to massive groupings of assemblers, etc.
And, how do you protect the roads/bridges/etc from becoming the source of someone else's brand new palace? Or turned into food (asphalt is yummy hydrocarbons, remember)? How would you protect people's (and the government's) atoms from theft, if you don't have cops?
* Courts - you want IP laws? To have your neighbor quit booming his music at 3:AM when you're trying to sleep? To decide which heir gets how much of Uncle Ralph's huge pile of gold atoms? To decide when a murderer should be put in prison?
* Prisons - how do you administer a prison and pay the guards? And prevent the walls from being broken down? Yes, you really ease the logistics, since you can put a meal-replicator in the toilet, and no longer pay for sewage.
* Beat Cops (physical violence to people, domestic disturbance, etc)
* Property issues (theft - esp. of your atoms; remember even a scrapyard is owned (and that owner is now **rich** in atoms), government owns the landfills and public rights of way)
* Roads (how do you get where you want to go, if there aren't public means of egress - if all land is privately owned, what's to stop the owners from putting up walls and preventing you from getting anywhere? If the government owns the roads/access - *how do they pay their bills/employees?*, and prevent someone from illegally putting up a wall and charging access to get to the sea, or to the market where you can buy some gold atoms?)
* Water supply - people breathe out water vapor, and have to get resupplied. Especially true in deserts, many parts of the country you could probably do rain-capture and be okay.
* Environmental protection - who protects wildlife and plant-life from being rendered down into component atoms? Probably won't have dumping of waste, since most everything will be of some value, somewhere.
* Building codes - otherwise people may try building 20 story palaces made of matchsticks, and opening restaurants at the top, and cry "I didn't know" when they kill their customers.
Companies will want money:
* Network connections - If you want internet and telephony, you're going to have to have some connection, and that connection will need to be protected (and/or rebuilt) when parts of it are disassembled, or when it needs to be maintained (But maintenance will be much easier).
* Power supply - some things require more power, and power will need to be provided. Which probably means burning C, and releasing it into the atmosphere. Rather more costly than it has been, since those are valuable atoms being distributed.
[Answer]
What you describe is a very classic scenario: a system which is designed to be a post-scarcity utopia, but upon which we seek to apply scarcity thinking. This is not an idle dream, for it leads to the sort of thinking you are looking at: what does it look like to have a *nearly* post-scarcity economy which is seeking to propel itself towards post-scarcity.
The key to unraveling the situation you are in is to recognize that such a world demonstrates the difference between information and physical products. The fundamental difference between them is that copying information is virtually free. It can be done very quickly and very cheaply (as cheap as Kb ln(W) energy costs). On the other hand, physical things are scarce. You can't build objects without atoms, and you cannot do work without energy. These things hold true no matter how much information you have.
From this perspective, if you wanted a Ferrari, you have to acquire the information needed to create the Ferarri, and then acquire the energy and raw materials needed to assemble your own physical one.
**Common decency in the nanotech era**
Nanotech decreases the number of things an individual can covet. Much of the value of a thing is its structure, and our nanotech has dramatically reduced that cost. Like a neighbor's stained glass window? If you can find the information you can make it!
The number of things a person would commit a crime over goes down substantially. Working space, raw materials, and energy would be the primary limiting factors, and they are substantially more fungible than other goods. There is little reason to rob someone of their wristwatch when its value is not much more than the value of the cup of ramen the robber ate beforehand.
The main issue that would show up is energy consumption and waste product elimination. Energy is still a limiting factor. Few reactions are isothermal (generating or requiring no heat), especially building operations like running one of your assemblers.
Note that your people are still people. The organic body of a H. sapiens has energy requirements that cannot be ignored without dramatically shifting the nature of your world. Someone who is not coexisting easily could have their access to energy and space dramatically cut back, so that could be your mechanism for policing (such as dealing with those who don't pay their taxes).
Note that there is still potential for warfare. It just operates at the speed of the assemblers. If I want to violently cut someone off, I can destroy their conduits for energy. If I destroy them faster than they can reconstruct them, I starve them.
**Nanotech assembly is not perfect**
This is something science fiction loves to get wrong. You cannot simply assemble *anything*. In simulated automata, there is an important concept called quiescence which is key to the constructability of any structure. The basic idea is that you can construct anything from its atomic parts, as long as you can complete it before the laws of physics tear it apart. I'm assuming your nanotech assemblers cannot magically assemble an entire physical object instantly, because you'd end up getting nanotech assemblers stuck inside the object. Like most assemblers, I'm assuming you build things from the bottom up, or the top down.
There are a lot of structures which are not quiescent. Organics, in particular are remarkably not quiescent. Even if I had a massive database of the exact atomic-level configuration of your body, I could not create it, because parts of the body would begin to die before I finished. Even doing things like "create the heart first" only do so much to avoid this effect, and when it comes to things like replicating consciousness, it is remarkably difficult to find a way to construct an exact replica of a brain without it reconfiguring itself half way through the process.
This issue would also show up in other products. Products which may be impossible to build with general purpose assemblers might be grown with special-purpose assemblers (which themselves were general purpose assembled). This leads itself very quickly to a set of things you would prefer to have grown. As an organic example, modern farm-grown Oak trees do not produce the same quality wood as the old-growth trees which spent years bending in the wind to slowly identify an ideal cell structure for strength.
Disassembly faces the same issues. Any activity which progresses through an object at a speed comparable to the disassembly is going to create an imperfect disassembly
**Bandwidth considerations limiting reproducibility**
Consider that we have 7\*10^27 atoms in the body. Assuming a ridiculously low underestimate estimate of 8 bytes per word, we're still talking about 5 billion petabytes of data. This is a major limiting factor on our ability to simply disassemble an object. We have to make approximations to keep it in a reasonable region, but what approximations are safe? How can you tell if this particular imperfection is an imperfection, and not part of some key subsystem which keeps vibration down?
**Now, for direct answers some of your questions**
*If people don't go to work, how does the government collect taxes, without reverting to direct coercion?*
People will go to work for the same reason they always have, they need something. Their body needs energy at a minimum. Realistically, they're going to want to make some neat things with their assembler, and that takes energy too.
*Rare goods market*
Rare goods market would be livelier than ever. Because of the imperfect copying process I described above, there will be telltale signs of a forgery. Thanks to nanomachines letting us make microscopic detectives for us, it will be easier than ever to recognize the telltale signature of a nano machine produced piece of "canvas."
**Parting thoughts on reproducibility**
Information is always copyable. However even in a post-scarcity world, it is always possible to create things of value. The modern example is the bit coin. A bitcoin is a piece of information. Technically it can be freely copied. However, it has been carefully designed such that the only ways to break the algorithm cost more than the coinage is worth (an excellent safeguard).
As a key note, potential for information is always valuable. In bitcoin, the value is not in the number, so much as the value is in the fact that the number is witheld until the moment it is spent. Until then, we can postulate the existence of the number, but it's not feasible to calculate it. The algorithm is designed so that the instant the number is revealed (the coin is spent), it has no further value to anyone except miners, and there is a new witheld number which has value (did not have value before, but now it does have value).
[Answer]
In a post-scarcity world, even if money is no longer required, there will still be some form of currency. If no-one has to work to earn money, I suggest that an alternate currency such as [Whuffie](http://en.wikipedia.org/wiki/Whuffie) [may develop](http://en.wikipedia.org/wiki/Down_and_Out_in_the_Magic_Kingdom).
However, even when you can have anything, things still have value. For example a Gauguin recently [sold for $300 million](http://en.wikipedia.org/wiki/When_Will_You_Marry%3F) simply because there is only one of this painting. If you want to have it you have to pay what the owner asks for it.
And services/experiences will still cost something. Time will still be valuable (unless we also live greatly extended lives). If material goods are essentially free, and presumable there are robots to do all the work, then entertaining others is perhaps the only saleable resource we have.
People being people, I would think that even in a post-scarcity world, there will still be haves and have nots. People will always seek to have power over others.
Politics being the business of power, some will create and enforce rules to ensure they are still at the top of the heap. How do you control people in a nanotech future? By controlling the basic things people still need, namely:
1. Raw Materials - these could be taxed in some way, possibly by volume (I'm assuming that you don't just pull the raw materials out of the air, but need a supply of all kinds of atoms, much as in [The Diamond Age](http://en.wikipedia.org/wiki/The_Diamond_Age)).
2. Intellectual Property - plans and recipes could be the most valued property in your proposed future.
3. Energy - you still need to obtain a reliable supply of energy
4. Property (Real Estate). Even if you can have anything, you still need somewhere to sleep.
5. Services such as sanitation (kinda like energy).
These may be "taxed" and access restricted by the government and it's enforcers. That then leads to the ultimate mechanisms of control, restricting:
1. Pursuit of happiness
2. Liberty
3. Life
Which are still available to governments.
**TLDR: They will still tax you.**
[Answer]
**What makes you think there will be money?** If I can assemble big couch and TV, what stops me from assembling some money? The nanobots can literally *print money* and bonus: They can print them in a way that makes them feel used. Feel old. And bigger bonus, if I let my imagination loose: They could theoretically assign such "batch number" to the money that you could not tell if they have been issued by government or by nanobot.
I will use one thing from almost every motivation book and video I did read or listen:
**If money were no subject, what would you do?**
If you have excellent nanobots, **you created post-scarity society**
Sure, there will be people who like just to sit back and watch ... Wait a second. Who will create the shows? The music? Who will be in government?
**Some people do what they do simply because they enjoy doing it**
There will be always someone who will want to be the President. Just for being the president. There are people who totally enjoy doing accounting. People who play music just for the enjoyment from it.
So, the answer is:
The government does not pay for themselves. Because there is no need to issue paycheck in first place.
**EDIT** Post scarity society can work only on people willing to do their job. And if there is totally no one willing to take the job ... program nanobots to do that!
* There is fire two blocks away? Send nanobots to disassemble the fire itself!
* Johnny broke his leg again? Nanobots can fix that!
* Trash lying on the ground? Make nanobot to build you a snack from that!
* Teaching? Online course can do that!
And so on...
[Answer]
## Limit government expenditures
Why does your government need money? Not to buy things. They'll just use a Maker. Not for Social Security or welfare. Just use a Maker to make Makers for each citizen.
Note that your nanotech is heavily automated. Bring the same automation to macroscopic tech so as to minimize government expenditures. Education, legal proceedings, vote counting, garbage collection, health care, etc. would all need to be automated.
* Replace courts with online forms and automatic processing.
* Prisons take away access to Makers. People have to report to their rooms to get meals, etc. On release day, just go to the exit and it lets you out. Note that Makers can build individual prisons for the anti-social.
* Replace beat cops with robots with video cameras.
* Property issues are again reported via online forms and automatic processing.
* Either government or private, charge by the mile for roads.
* Nanotech is perfectly capable of extracting water from humid air. Charge by the gallon on either a government or private basis for extra water in dry areas.
* Environmental protection: volunteers or draftees fill out complaints, which are processed the same as other legal matters.
* Building codes: automate this. A robot follows you around and keeps you from going into dangerous places. Danger, Will Robinson, Danger!
## Seigniorage
Governments make a profit on producing money. If government expenditures are small relative to the overall economy, it would be possible for this to be a significant source of funding.
## Wealth taxes
Tax bank deposits and other forms of wealth.
## Property taxes
A specific form of wealth tax with a historical basis. Tax the land that people own.
## Collect labor
Rather than collect money that you use to buy labor, collect taxes in the form of labor. Note that we currently do this in the form of military service and jury duty. Expand this out to other roles. If the government needs two hundred hours of labor per person on average, mandate that people provide that much labor per year. If some jobs are more desirable than others, require that people give more hours in the desirable jobs than the undesirable jobs. So fifty hours of garbage collection might equal five hundred hours of jury duty.
[Answer]
I guess the answer is: It doesn't, because it does not need to.
If anything and everything that needs to be made is made by nanites, nobody needs money for anyting.
Currently, governments need money to pay the politician's wages (so they can pay for their life), wages for people in administration et al (dito), materials to build and maintain infrastructure, Law Enforcement, Helping the poor, schools, and so forth.
Infrastructure would be built and maintained by the nanites. Nobody needs wages, because nobody needs to buy anything.
While a lot of people would actually get a flat screen, couch, beer and chips, there would still be a lot of people who would work either out of boredom, for the social interaction, or for pure interest in the work they do.
There is a risk of degeneration of society and culture, or of splitting your society into two groups: the couch potatoes and those that actually do something.
It would still be worth it, i guess.
[Answer]
**Fabricators remove the need for goods but not services**
A fabricator will make you a new car but it doesn't preform services like collecting trash, making new songs, giving haircuts or doing surgery. Manufacturing jobs and companies would vanish but service jobs would continue.
People in your society would still desperately need the services of garbage collectors, artists, hairstylists, doctors and the vast set of service professions. Some services might be preformed by robots but from the description robots are like current robots and can preform few tasks.
Currency would still exist since people need other to pay other people to do services for them. Since currency exists the government hires employees to preform the service of collecting taxes.
**Currency would have to be something nonphysical or hard to replicate, like electronic bank records today, valuable information, or energy.** None of which a replicator could duplicate.
[Answer]
## Direct coercion
While the question asks "without resorting to direct coercion", it still is a viable alternative. In the end, *all* legal structures fall back to a [possible risk of] direct coercion, no matter if it's laws against murdering people in their sleep, enforcing contracts or collecting taxes.
In a civilized society, the vast majority of conflicts will be solved without direct coercion, but the *result* of these conflicts is determined by a mutual understanding that if it will be escalated far enough then in the end it would happen anyway because of direct coercion.
If a society has "assemblers" as you describe, any effective form of government can choose at least of those options:
(a) Control access to the assemblers, regulating what people do with them and denying that access after some violations;
(b) Have a monopoly on the assemblers and distribute only the assembled goods;
(c) Ignore assemblers but physically control the people using assemblers or some physical location.
It is not realistic to assume that the concept of power structures would go away simply because policemen would quit their jobs. The *current* government/power structures may break down and become unable to maintain a monopoly on violence, but then the *next* strongest organization would become a de facto government. Neighbourhood volounteer militias, gangs, religious organizations, charismatic leaders/warlords, self-sustained communes - all these things exist in the current world and don't rely on hired cops. Experience shows that any power vacuum gets filled very quickly.
] |
[Question]
[
Where should I shoot a solar flare that is at least as strong as [the solar flare(s) in 2012](http://science.nasa.gov/science-news/science-at-nasa/2014/23jul_superstorm/) for the most death? What else would happen? And how much death, in percentage of world population, would the solar flare cause?
That can also include the preceding flares that ""plowed the road" for the superstorm."
Yes, I know about [Solar flares: “the week the earth stood still”"](https://worldbuilding.stackexchange.com/questions/6713/solar-flares-the-week-the-earth-stood-still)
Scientifically Possible, and possibly believable, please.
You can also include reactions to the Event as part of loss of life...
I know that I can't get vaporized bodies or spontaneous combustion via solar phenomena.
I suppose falling satellites and failing nuclear plants could do a lot of damage?
Okay, now we have an answer that could lead to total biosphere destruction... useful.
What if I didn't want anything other than solar flares and their after-effects?
[Answer]
To go **for maximal damage, you can combine flipping of magnetic poles, massive solar flare, and serious heat wave.**
Immediate damage would be only to power grid, with no human casualties. But it will snowball from there:
Imagine **[2006 Queens blackout](http://en.wikipedia.org/wiki/2006_Queens_blackout) in every major city in all over developed world.** Huge amount of power-generating equipment is damaged or destroyed (fried), and if you are feeling nasty you can add **failure of nuclear power stations,** spewing radiation all over. Blow some chemical factories for diversity. You will be surprised how many are located close to dense populated areas like [Indian Point](http://en.wikipedia.org/wiki/Indian_Point_Energy_Center), just 38 miles from NYC. So far you have radiation and no broadcasting (because broadcasting equipment was fried and has no power anyway. Guess what is next: huge panic.
In panic, people trying to **escape to rural areas where is food.** Well guess what: you cannot get gas at pump without electricity to pump it, and **you have to pay cash.** Yeah, this gets interesting. Because if you have a car I need, and I have a gun, after our meeting I have gun AND car and you have nothing. How far you can **walk in heat wave** (all water you can get is without sanitation) before you get some disease? Because there is no one to bring you clean bottled water. And if clean water is located somewhere, there is fight for it.
**Civilization fell apart, it is mostly every man for himself.** [Heatstroke is dangerous killer](http://en.wikipedia.org/wiki/Heat_stroke) even in normal circumstances. And these are not normal. People with children are most vulnerable to heat stroke - but there is hardly any help for them, everybody tries to save his own family, if s/he has any. So to escape, you have to walk far to your friends rural areas (if you are lucky enough to have any), in heat, with little water, and you have to hide before criminals who want to stole whatever you have in your backpack? How many people will make it? And of those who make it, how many are worst of criminal elements - and how many will be welcome in rural communities? Will they be willing work hard for food - or will they steal food from others?
Folks in rural areas did not liked those city dwellers anyway, and now worst of them (who made it far by stealing resources from others, less violent) want to come over and eat all the food and take over their communities? Fortunately **rural folks have weapons. So small-scale civil war erupts.** Such disruption make contagious diseases like cholera (caused by lack of sanitation and spoiled food) much worse. When supplies of normal trade are disrupted, many people with chronic conditions who rely on daily dose of life-saving medication will perish.
Finally, **military control is established. But there is no way to feed all these people,** even after 40% died from radiation, diseases, heat, crime, etc. Without steady supply of fertilizers, seed, fuel for farming machinery, **productivity of farming decreases rapidly.** Another source of decrease is former overspecialization. After collapse of markets, every area needs to produce all the food they need, not the one best suited for local microclimate. Cut down grapes, plow in strawberries, farm potatoes instead.
Another problem for farming is \*\*genetically modified seeds. Some of them are sterile \*\* (cannot be used to grow next years crop, and you cannot buy new ones because someone ate them). Or if you are lucky seeds just do not bread true (so next generation is less productive, reverting to wild). Some seeds rely on herbicides which you cannot get. So farming slides back 200 years - but now you don't have plant varietes which farmers used 200 years ago.
So you cannot feed all population. You can either **establish skill-based immigration to areas protected by military** with some lottery for people without skills, if you feel generous, or make it free for all fight. Young and healthy, able to work, and with skills are desirable. Old, sick, no skills - no so much.
And yes, you will need to protect perimeters of your protected areas, but military is good at that.
Only now, when order was mostly restored, remnants of government can start figuring out what needs to be repaired, who can do it, and what is needed to repair it. Do you trust them to be smart and do right thing? Or waste time bickering and arguing about ridiculous irrelevant questions? Yes, now it looks much worse that month ago, and repairing it will take much longer. **And hurricane season is just starting. Following by a freezing winter.**
So coronal mass ejection by itself did not cause much damage. Damage was caused by our lack or preparation, and standard disruptions which accumulated on top of one another. Expect to lose 2/3rds of the population during the decade it will take to stabilize and rebuild.
So you have a break of a decade or two to recover and **prepare for another blow: climate change.** During this time, many children died because of lack of sanitation. Surviving children did not received much of schooling because they had to work to get food.
So general **skills of your population is decreasing** as skilled old-timers die off by age, or **by accidents and simple diseases preventable and curable in previous times.** So your less skilled, less educated, and less technologically advanced society is facing challenge which we don't know how to handle with our current advanced technology. As you can see, it is not going to get better any time soon. So you are forced to switch using less advanced technologies (because you don't have tools and skills to repair them if something goes wrong). Back to steam age, only now all the easy to access and mine resources are mined out.
Even if carbon output of human economies is much smaller, you use more carbon per unit of production - because carbon-based energy is all you have to feed all those people. So glaciers continue to melt, methane in permafrost continues to thaw, and climate continues to be disrupted. Southern areas, suffering less damage from sun flare, get more damage from desertification. As there is **more energy in air from heat, summers get hotter and drier, winters wetter and colder, hurricanes worse, farming less predictable, famine more common.** With ocean more acidic, food pyramid collapses (smallest zooplankton cannot form shell, so fish has less to eat) - only jellyfish and algae thrive.
Humans survive, but they look at the ruins of previous advanced civilization, repeating myths of survivors of the apocalypse and thinking: what went wrong? Why they did not prepared for emergencies like we do? Why they relied that someone else will help them? What they were thinking?
[Answer]
# Coronal Mass Ejections Can Hurt Us
If you define the end of the world as losing our [satellites](http://www.popularmechanics.com/space/deep-space/a7433/the-looming-threat-of-a-solar-superstorm-6643435/), and [knocking down power grids](http://www.space.com/11506-space-weather-sunspots-solar-flares-coronal-mass-ejections.html), then yes, the [sun can totally do that](http://en.wikipedia.org/wiki/Coronal_mass_ejection#Impact_on_Earth)! If not, I am afraid that a coronal mass ejection will not be the apocalypse you are looking for. Our magnetosphere is pretty robust. It will protect carbon-based life from getting fried, so coronal mass ejections will not end life on earth, just the way many humans enjoy going about it.
However, coronal mass ejections do have the chance to kill electronics, communications, and possibly even some infrastructures. We heavily rely on electronics, therefore removing those systems will hurt society. A massive coronal mass ejection aimed correctly has the potential to knock down systems people need to live and will affect those who do not need those systems to live.
Luckily, the sun seems pretty happy (if it had feelings) to shoot these ejections in whatever direction seems convenient. Due to this the odds of this particular event happening on earth is small. Probability is no guarantee against it, though, and given a large enough timescale, many events may happen.
Coronal Mass Ejections happen often enough that we should be concerned about it along many other things that can end the human race. NASA, as you seem to know, predicted that the odds of such an event happening during [the next ten years is 12%](http://science.nasa.gov/science-news/science-at-nasa/2014/23jul_superstorm/). Infrastructure may need updating and improved protection, and vulnerable electronics will need backups or protection. We may even want to consider backup satellites or alternative means of communication (such as [ham radio](http://en.wikipedia.org/wiki/Amateur_radio)) in our preparations.
[Answer]
The earth is pretty safe from solar flares because of the magnetic fields that deflect the event around the earth. However, the magnetic poles switch occasionally, like every 600,000 years or so. We really do not know what happens when they do switch. We do not know if the magnetic field shuts down then restarts at the new polarity, or how long it takes the switch to happen.
So there could be a scenario were the magnetic poles are switching and the magnetic field shuts down for awhile, which would cause a catastrophic event on earth that would cause mass famine, break downs of society etc. it could take years to bring infrastructure back online. During this time human populations could decrease dramatically. I think the number people say that a sustainable number that could be supported after oil runs out is a billion people or less. During such an event oil would become very scarce, so farmers would not farm, and all those other things we depend on for day to day life, like Walmart would cease to function.
Since we really do not know what happens, or even if we loose or magnetic shield when the polarity shift happens, you can be pretty liberal with your conjecture about this in your story. If we lost the magnetic shielding of the earth, every solar event rather massive or not would effect us. In essence we would be in the solar wind constantly. The earth becoming something that resembles the planet mars would be the worst case scenario.
The death toll is completely variable. It could be one guy with a pace maker in Barrow Alaska falls dead in a large flare. It could be that the whole human race is wiped out if we lost our magnetic shielding that would change the planet so much that life would become unstainable. Some people believe that this is what happened on Mars. Apparently it may be possible that without a magnetic shield the solar wind scrapes the water off the surface of a planet after some time.
It is also conjectured that when the poles flip polarity that nothing too huge horrible things will happen. So I made an assumption that you needed to validate with a little information about solar flares the death toll with some plausible context. Whatever death toll you want to use can work. It is really not how big the solar flare is, it is how big the flare is and how strong the magnetic field is that determines how much damage there is to the planet and all the things on it.
So in your story line, just add the poles started flipping, and the magnetic field weakened to some point where x amount of damage happened and caused x amount of death.
If your meaning is that you need to know how many healthy people standing outside could be zapped dead by the flare, the answer is zero. Unless of course the magnetic field turned off and they stood outside for a very long time, as the atmosphere was scraped away by the solar wind and they became more exposed to radiation and its deadly effects over time.
(They were outside for so long because the were in line for the new I-Phone 973, which is the same as the IPhone-972 except it had new magnetic shielding and was three times the price, and new improved apps of course.)
[Answer]
As of this reply, the Earth's magnetosphere is weakening. There is a magnetic "hole" over the southern Atlantic which causes satellite blackouts. The anomalies in the strength of the magnetosphere are increasing in location and variability. A recent book attempts to somewhat explain this: <https://www.goodreads.com/book/show/35754738-the-spinning-magnet>
The pole flip event would take 100+ years and expose Earth to much more solar radiation than normal. The effect of any CMEs during this time would be vastly amplified.
This is a narrative fiction depiction of one author's thoughts on how a "double-tap" CME would destroy civilization:
<https://davecline.wordpress.com/2017/01/03/blue-across-the-sea-epilogue/>
In it the destruction of digital money, the loss of all pharmaceutical production (most diabetics would probably die within 60 days). The cessation of fuel distillate production ( diesel, petrol, kerosene, etc.) The failure of distribution food channels and the hoarding aspect. The abandonment of cities. The mass-migration from one hemisphere to the other.
One feature not mentioned elsewhere is the potential for the plasma induced currents to overwhelm other long-line wire systems. Consider all wiring in buildings, home, ships. Consider all pipelines. All might be subject to induction currents resulting in overheating and terminal fire.
] |
[Question]
[
**Closed**. This question needs to be more [focused](/help/closed-questions). It is not currently accepting answers.
---
**Want to improve this question?** Update the question so it focuses on one problem only by [editing this post](/posts/4812/edit).
Closed 4 years ago.
[Improve this question](/posts/4812/edit)
Science fiction and fantasy stories are full of alternate worlds populated by [races of beings that look mostly human but kind of different.](http://tvtropes.org/pmwiki/pmwiki.php/Main/HumanAliens) But is that at all realistic?
When the dominant life forms emerged on *our* world, they were nothing like humans; dinosaurs ruled the earth for millennia. And mammals didn't out-compete them on anything resembling a level playing field; there were no cavemen hunting the dinosaurs to extinction. A cosmic one-in-four-billion freak accident dropped an asteroid on the planet and plunged it so deep into nuclear winter that anything the size of a dinosaur simply didn't have enough food chain to support itself.
So, assuming a planet with generally Earth-like conditions, where life arises, but it never gets a giant doomsday rock dropped on it 3.95 billion years in, what would the picture of life be like 65 million years later? **How would the rise of humanoid life to dominance that sci-fi takes for granted be affected by the lack of a past incredibly unlikely catastrophe that wiped out the original, decidedly inhuman, dominant life forms?**
Some specific points to keep in mind, as basic examples of the things that might have been different:
* Would mammals have ever come about?
* Would *sentience or sapience as we know it* have ever come about? (The dinosaurs did just fine without it.)
* If sentient or sapient life exists, would abundant fossil fuels exist to enable them to achieve the Industrial Age?
[Answer]
>
> Would mammals have ever come about?
>
>
>
Yes.
Mammals did exist at the [same time](http://en.wikipedia.org/wiki/Evolution_of_mammals) as Dinosaurs. Humans? or anything resembling a human ancestor? No.
>
> Would sentience as we know it have ever come about? (The dinosaurs did just fine without it.)
>
>
>
It is possible yes. Maybe the Dinosaurs would have eventually had sentience, maybe they did and were wiped out while still in a "hunter/gatherer" level of society and tech. Humans have been around 200,000 years, that isn't much compared to the 65,000,000 years before that. So it is actually very likely that sentience would have come along, probably much sooner than it did.
>
> If sentient life exists, would abundant fossil fuels exist to enable them to achieve the Industrial Age?
>
>
>
Why not? Petroleum comes from "[large quantities of dead organisms, usually zooplankton and algae](http://en.wikipedia.org/wiki/Petroleum)" The extinction of the dinosaurs had very little really to do with current oil reserves.
[Answer]
### Would mammals have ever come about?
Yes, but not in the same way. After the extinction event, mammals diversified to fill many niches which dinosaurs had previously evolved to fill very well. Big therapod and sauropod dinosaurs were the dominant large life forms on the planet, and mammals probably wouldn't have supplanted them in that role without their extinction.
Mammals did exists, however, and would continue to have evolved and prospered in the roles that they filled better than dinosaurs. Rather than elk, wolves, and elephants, think rodents, weasels, and squirrels.
Precursor primates evolved in the cretaceous, so this could have also (potentially) included the monkeys.
### Would sentience as we know it have ever come about?
This is a more difficult question to answer. Almost all animals, mammal or dinosaur, get by just fine without sentience. However, certain patterns of behavior can lead to a tool-using creature that can develop advanced technology. These circumstances arose in humans, but could just as easily arise in some sort of dinosaur that might have evolved without humans in the picture.
Alternately, it's possible that mammals similar to higher primates could have evolved. Early primates that were somewhat squirrel-like in shape probably already existed during the time of the dinosaurs, and it's possible they could have evolved into a race of arboreal tool users similar to modern chimpanzees, from which point development into a modern tool using race.
Ultimately, it comes down to whether or not a species would arise for which developing progressively better tools would be both possible and evolutionarily advantageous. We know by looking at the history of our planet that this only happens very rarely. We also know that most dinosaurs had tiny brains, but we don't know how they would have evolved given another 65 million years. It's definitely possible, though.
### If sentient life exists, would abundant fossil fuels exist to enable them to achieve the Industrial Age?
Definitely. The extinction event did not produce a significant portion of the world's fossil fuels. Coal, for example, is mainly formed from plants from the Carboniferous period, which came tens of millions of years before the dinosaurs.
[Answer]
As pointed out, mammals did co-exist with the dino's...mostly as small mice like creatures filling in the tiny night time scavenging niche mostly.
Oil reserves is another yes. Life on Earth began 4 odd billion years ago, but didn't reach multi-cellular life for a good 2 billion years after that. It's possible dinosaurs where responsible for a small segment of oil reserves, but most oil predates dinosaurs by a significant amount. Plausible that an intelligent dinosaur could drill for oil prior to their extinction.
Sentience as we know it...possible, but you need an isolation situation. I attribute a good section of our intelligence to social dependency, a pre-human primate became dependant on others intelligences, putting pressure on the entire species to evolve intelligence, not just the single creature. We also require an extended developmental childhood. It is possible to have an isolated island scenario...sorta the dinosaur world version of madagascar, where an isolated land mass allowed us to develop (I dunno, descended from Lemurs?). Would create an interesting story line of humans attempting to leave the island and discovering the greater dinosaur world.
I'm always curious if an egg born creature is allowed the time to develop to the point of intelligence...the dinosaurs had an incredible amount of time to come to intelligence, but didn't go much beyond that of a chicken. Their general design does not require the thought required to use tools...everything is possible, but I think the intelligent dinosaur (to our degree of sentience) isn't very likely.
[Answer]
Remember, a mass-extinction event and massive climate change were the only thing that wiped out the Dinosaur's competitors, the Crurotarsans and allowed them to dominate the planet for a long time.
Inhuman is not non-humanoid, for various definitions.
Bipedal? I think a good case would be made for having limbs free to use tools is probable.
On Earth, at least, bilateral symmetry is mostly true. So, two arms (a left and a right) and two legs. Same for two front-facing eyes (for depth perception; especially needful for easy, successful tool-use). Almost all Terrestrial creatures put air-intake and food-intake near the sense organs (probably necessary to see what you're eating, pick out the bones/avoid the thorns). So, you've got a face. Likely, since most things are vertebrates on Earth for a long-time, that the head is above the other limbs. Reproductive organs are near excretion organs for most species, and not near the head, so that goes towards the tail.
Tool use is going to almost require a thumb, and manipulative digits, which is going to give you a hand. You might get away with tentacles/lips, like the Puppeteers. But you'll need something with which to make your tools.
These, IMHO, mostly make a humanoid.
Given that the Earth has had many mass-extinction events - including the one we're living in right now - I don't see why it's far-fetched to believe that mass-extinction events happen on other planets. If it happens once every hundred million years... it happens more often than it has here on Earth. Given deep time, you can do all the things.
Please define 'mammal'. Warm-blooded (which is out of favor scientifically, I've heard) allows animals to handle bigger changes in climate - versus cold-blooded, which allows more animals per-square-foot (costs less energy). Any time you start having climate change events, or varying climates - you're going to select for warm-blooded-ness. As well as fur/hair or feathers; for their insulation properties. So, something sorta like a mammal will probably exist, if your planet has wide-enough climate swings. You may or may not get boobies. You'll probably get live-birth (either egg-eggs stored internally, or eggs without shells/yolks/raw fetuses). You may get immature live-birth (marsupial). r-selection will probably be ill-favored, especially if you're dumping a lot of energy into having brains for your species.
Sapience is a good question. Of course, any space-faring race is going to have achieved it, ipso facto. And those are the ones we would be interacting with. Those that didn't develop it, will just be interesting animals. Chimps are interesting animals. There are probably a lot of interesting animals in the universe. Uplift might be a solution to that.
Fossil fuels rely on lots of plant growth without attendant decay, and being geologically buried... or, perhaps hydrocarbons squeezed from the primordial matter of the planet. That all happened before we got termites and other saprophytes evolved to recycle our carbon better.
Do I think Star Trek is right? F no. We should have crabs, spiders, aquatic insects, octopii, trilateral symmetrical, and a wide variety of other types of aliens. But, we would also have humanoids. Some that might even look kinda close to human.
] |
[Question]
[
Assuming planet Earth, with considerable amounts of pets per household ([96 million cats in the US alone](http://www.humanesociety.org/issues/pet_overpopulation/facts/pet_ownership_statistics.html)), what would be the social and ecological consequences of all domestic cats acquiring flight ability over several days, given their essentially predatory nature?
Given that it is customary for pets to be spayed/neutered, evolving flight capabilities over one generation would presumably make for an easier to contain phenomenon; hence assuming that flight develops as a rapidly mutating epigenomic ability.
The cats' ability to fly would be equivalent to that of Tom in the popular *Tom & Jerry* episode [The Flying Cat](https://www.youtube.com/watch?v=CmI5OoXlm50#t=122), i.e. on par with that of most small birds. The cats could also hover.
[Answer]
Well, one obvious effect of cats acquiring flight ability would be that they would be much more effective in catching birds (it of course depends on how well/fast the cats can fly). Probably the number of birds would be considerably reduced. I can imagine that this would give cats a much worse image, with some people even turning to hunting cats (at least those with actual flying capability, that is, without their wings clipped) in order to save the birds.
Note that there is always a certain population of stray cats who obviously would not have their flight disabled; moreover, flying cats are harder to kept from escaping (just like birds, they might just fly out of your window when you open it), so the number of stray cats would probably also increase. There would probably also be a number of cat owners who would outright refuse to disable their cat's flying capability or to lock them in.
Continuing with ecology, a reduced bird population would likely result in an increased insect population, both of insects that damage plants or bite animals and humans, and of insects that are just annoying.
A flying cat, being now able to eat more birds, might in turn kill less mice and rats. I don't know how large the effect on mice and rats is currently (I guess most pet cats won't be hunting mice, but will be fed exclusively, but on more rural areas, cats will more likely kill mice and rats, and of course there are always the stray cats.
So assuming cats play a major role in controlling the population size of mice and rats, them hunting less mice and rats would possibly cause a mouse/rat pest.
About the social effects: Of course, cats developing wings in a very short time frame would in itself cause fear, for the simple fact that this is unexpected, and I would assume also unexplained (at least at first). If cats can suddenly acquire flight, then who knows what sudden unexpected changes other animals, let alone humans, might experience soon? There would probably be a hysteria where people watch animals as well as themselves/each other, and panic over anything unusual (or usual which they didn't notice before), fearing it is a sign of another sudden change, possible for the worse. Hypothetical scenarios of giant man-eating rats or similar would probably be painted in certain newspapers. The wildest theories about the causes would also circulate, from government conspiracy to aliens trying to take over the world, from an action by god to punish the faith-lacking humans to blaming it on the radiation of nuclear reactors or genetically modified cat food.
[Answer]
What if cats can actually fly already but just choose not to for one reason or another -- it could be difficult and require expending a lot of energy so it is just easier to subjugate minions find loving owners to take care of them. They could be doing it while we aren't looking. How many cat owners have wondered how Fluffy managed to get himself *there*. And "stuck in a tree", really? I don't think so -- it's just an act to keep their flight capabilities hidden from us.
A flying cat could lend itself to even more applications for the [Feline Butterology](http://www.chaosmatrix.org/library/humor/buttercat.html) theory, however, so maybe, if this doesn't exist in the "wild", it is something that has already been develop in a lab and will be powering our next generation of spacefaring vehicles.
[Answer]
First off, the hunting of prey would be much easier. It's easier to be silent in the air than it is in underbrush and grass, which is prone to rustling. They may also hunt birds more often, but they may become more susceptible to being hunted by birds of prey as well.
As far as how a home would change with a flying cat inhabiting it, fragile items that could get knocked over would need to be secured in some way, since putting a fragile item someplace the cat couldn't previously jump to is no longer an option. Another option is to somehow make the place the item is undesirable for the cat to walk on.
Also, jokingly, they wouldn't get stuck in trees.
[Answer]
What a fun question!
Socially, people would feel a lot more pressure to keep their cats inside, and have them declawed. A flying cat attacking you isn't much fun. Birds would have to adapt to being hunted by cats. Most birds are more aerodynamic than cats, so bird population might not actually suffer too much from flying cats. Feral cats would also face problems, as they would be much harder to contain. I think we would see most feral cats put down, at least in developed countries.
Farmers near cities might have issues with chickens and other small livestock being hunted. On the bright side, the new sport of cat shooting might become popular. Much more difficult than skeet.
Socially there would be a lot of speculation to why this happened. Tabloid newspapers would publish outrageous ideas, while scientists would be investigating it. Flying cats could even eventually be trained to be useful. They could be used for mail, searching and other functions that require small and numerous flying creatures.
[Answer]
I suspect that they would lose any flying ability rather quickly. Here's why:
If you own a cat, you probably have an emotional attachment to it. Perhaps that's a *strong* attachment. You'd be pretty upset if your cat left, right? (I think I can safely say that's the case based on all the desperate "Lost Cat: posters I see). So you're going to want to do everything you can to prevent your cat from wandering off and never coming back again. And that desire is so strong that you'll be willing to do a lot to make sure Fluffy stays with you.
You tangentially mentioned spaying and neutering in your question. You used that as evidence that it would not be passed along genetically, which is an excellent point. The thing is, spaying and neutering has some effects on the animal it is performed on - not just their now-hypothetical offspring. The point is, even though the animal may not enjoy it at first, you (the cat owner) are willing to sacrifice that for the well-being (in your mind) of your pet.
I can imagine a similar procedure being done to cats that can fly. I'm no ornithologist, but I know that wings require large muscles to move, and large muscles need tendons, and so on. It could be possible for a veterinarian to modify the wings of a cat - not cutting them off, but perhaps snipping away at some of the tendons - such that they no longer work. Fluffy stays firmly on the ground and you sleep better at night. As do the birds.
] |
[Question]
[
I'm in the process of constructing a fantasy world that resembles our world and is predominantly inhabited by humans just like us, but which also contains ogres. The ogres in this world are between nine and ten feet tall, green skinned, semi-sentient and nearly always humanoid, although they have a higher chance than we do of having different numbers of limbs, eyes and fingers. The ogres cannot understand magic, but they have magical properties. Effects of these magical properties include great resilience and the ability to mate and crossbreed successfully with humans and other species. Ogres can communicate and understand simple instructions. They can be kept in human societies and made to work as unskilled manual labourers or security guards. When male ogres mate with human women, the offspring are called ogrillas. This mating process has a magical effect on the human mother - some magic transfers to her and boosts her general constitution and her fertility, and it guarantees that her pregnancy and the birth will be easy and risk free and so will all her subsequent pregnancies and births from then on, whether her subsequent babies are pure human, ogrilla, or other hybrids. Ogrillas are intermediate beings - seven to eight feet tall, green skinned like ogres, but otherwise much more human-like in appearance. They are smarter than ogres but not quite as smart as pure humans. They mature physically faster than human kids and are easier to raise. When they grow up, they are able to breed with humans, ogres and other ogrillas.
The question is, could it become socially acceptable or even a social custom in any community for a human woman to have one ogrilla child before marriage to get the magical benefit and guarantee that she will not die in childbirth and that the children she has with her husband all survive as well? So I was thinking if the women in a community each had just one ogrilla child when they reached adulthood - there would not really be a stigma on individuals being single mothers if they were all single mothers. It would not prevent them from getting married. I'm certain something like this would never catch on in every human society and that there would be humans who would look down on societies or communities where it is practiced. The question is just whether the premise holds up as a possibility for certain communities.
Edit: The question applies to the same world both as it was in pre-industrial times when childbirth mortality rates would ordinarily be very high indeed for both non-magically enhanced mothers and their babies, and in later times of improved technology and prosperity. I think that if such a custom could begin in pre-industrial times then it could continue through force of tradition. The magical effects of having once mated with an ogre mean that a mother would never die in childbirth even in a pre-industrial setting and that all her babies, human or ogrilla, would have a much higher chance of surviving the infant years.
[Answer]
## Trivially, yes
Going off the perhaps contentious assumption that women are a) sentient and b) subject to sexual desire, the answer is pretty trivial as long as the ogres are hot.
The main objection to female promiscuity, if we are to believe the evo-psych people[1], is that it could lead to males being tricked into supporting offspring that is not their own. No such danger with ogrillas, is there? A young woman is therefore presented with the following options:
* Have sex with the hot ogre
* Also have no trouble with childbirth
* Ever again
* And nobody actually expects you to take care of the ensuing baby, because anti-ogre racism
* Did we mention the ogres are quite ripped?
or,
* None of the above
Why would she ever pick option b), unless she's just not into ogres? Why would a bloke ever turn down a lady who has proved herself fertile and also ensured herself against death in childbirth and definitely has no particular commitment to any ogrilla babies in her entirely forgettable past?
Basically, we can make all sort of arbitrary models about society-level forces, but at the end of the day sexual desire is one of the most individualistic drives humans have. Despite significant societal pressures to the contrary, human women choose to engage in non-sanctioned sex all the bloody time. Assuming that sex with ogres is desirable to women, then it will happen.
Conversely, if sex with ogres is just a practical consideration (it's a bit gross, but better than bleeding out to death as I deliver my first human child over many hours of unbearable pain) then it may become more of a ritualised matter, only done once in some formal setting as women reach reproductive age.
In neither scenario there is any sensible reason for anybody to oppose the arrangement on an individual level (it may be a terrible idea at the society level, as @KerrAvon suggests, but all you need to solve that is general neglect of ogrilla babies).
### Edit: what about the ogres though?
Something I didn't touch on, but @KerrAvon's answer made me think of. You've not mentioned what the ogres think of this arrangement, or how they are brought into it. I'm not sure just how much intelligence they have, and if they are able to actually consent in any meaningful sense. I suppose I was envisioning a cheerful friends-with-ogrey-benefits scenario but the truth, especially if women are driven mostly by self-interest, may end up a fair bit darker and more coercive - it's your world, so be aware of how you write it.
The additional comment that ogres are rare and there may be just one per village makes me think you need a bit of care in case you end up inadvertently stumbling into a "Bob the ogre, community sex slave" scenario.
---
1: no
[Answer]
**Unsustainable (probably)**
Let's look at the baseline human condition prior to modern medicine. Ignoring the surrounding social conditions, reproductive sexual activity occurs and then:
* a% of occasions result in pregnancy
* b% (10-20%) of pregnancies result in miscarriage
* c% of children carried to term the mother and child die in childbirth
* d% of children carried to term the mother dies in childbirth but the child survives
* e% of children carried to term the mother survives childbirth but the child dies
* f% of children carried to term the mother and child survive childbirth
* g% of children born survive to reach reproductive age
The result of all of these factors prior to modern medicine resulted in a very slightly positive population growth, sometimes reversed by plagues, wars and other disasters. This is a good thing, because until/unless key technology increases occur (agriculture initially, three crop rotation, quite recently, industrial farming and fertilisers in the last century or so), the land occupied by a human population can only support a certain number of people.
Now add ogres into the mix and assume that each woman has her "health insurance" ogrilla prior to her human children. Suddenly a% increases (fertility increase specified in question), b%(?), c%, d%, e% all drop to 0 and f% =100%. In addition, we also have one ogrilla born per woman in addition to the ogrilla's reproducing with each other and the ogres. The population will quickly exceed the carrying capacity of the land it occupies. At this point the options are:
1. Expansionist regime using excess population - especially ogrillas - as troops to invade neighbouring lands. This is still only sustainable while there are more lands to invade...
2. Infanticide of surplus population (probably especially the ogrillas) before they reach reproductive age. Morally abhorrent, but much worse has been done throughout history.
3. Reliable contraception available to women who do not wish to have more children. (Obviously this is the real-world answer where modern medicine has a similar effect to the "ogre solution" in your world.)
4. Abstinence from reproductive sex of women once they have produced "enough" children. (I do not see this as a socially viable solution, but in a fantasy world you can make up what you like.)
This approach is purely looking at the impracticality of the demographics, not the social or psychological aspects. Telling each female virgin in the proposed society that her first experience of intercourse must be with a giant semi-sapient deformed monster and she must carry the resulting inevitably mentally retarded child to term seems to be pretty extreme. However, the depressing fact is that many women have suffered arguably worse fates throughout history, even in modern times, so unfortunately this cannot be deemed to be socially impossible.
One final, irrelevant note - ogres might make effective shock troops or enforcers but would be terrible security guards. The primary purpose of a security guard is not to crush skulls but to detect and assess threats, which requires intelligence the ogres lack.
**Edit:** One point that I omitted is - "How would people know that mating with an ogre makes all future childbirth better?" Despite Ottie's suggestion that ogres may be "hot", it is highly unlikely that without prior knowledge a woman would voluntarily have intercourse with a deformed, retarded super-giant non-human. If it did happen, probably non-consensually, once the woman realised she was pregnant she would probably attempt to "lose" the child and failing that suicide or murder/banishment from the community would be highly likely. Assuming that she survives all of that, the birth of an ogrilla is likely to make her be perceived as tainted in some way, with the child unlikely to survive. If, after all the options for death or banishment, she finally does take another partner and start having "normal" human children easily, this could be attributed to "evil witchcraft" or ignored as a statistical outlier - some women did have easier births repeatedly. In the absence of an investigation by someone with access to improbable amounts of reliable data (ie the long term health history of every woman who carried an ogrilla to term *and* was willing to reveal the fact) *and* who follows scientific method rather than religious or superstitious belief, the benefits of having a child with an ogre would probably never be known.
[Answer]
**Very Poor and Very Rich**
The very poor and very rich might adopt this practice.
**The Poor**
The barbaric tribes to the North are known to breed with Ogres to keep their bloodline strong. They have been doing this thousands of years. Many babies die from exposure or starvation. Many mothers die in childbirth. Unless you breed with an Ogre.
When a man wants to start a family he must prove he is worthy. He ventures from the longhouse to capture and defeat an ogre in unarmed combat. He drags the half-dead ogre back into the longhouse, lays it out in front of the fire, kneels down on its back and proposes to his would-be-wife.
Being able to give birth to many healthy babies is good for the tribe. The barbarians don't care if their children are slow and stupid. Who cares what they look like? They can survive under eight feet of snow and crush boulders between their teeth. That's all that matters.
This is similar to how some tribes in D&D breed with monstrous orcs to keep their bloodline strong. This leads to half-orcs of course.
**The Rich**
Settled society regards orges as ghastly creatures. They are suitable for dragging bags of gravel around construction sites. But they have only a superficial resemblance to people. What an indignity it would be to let such a creature defile your wife or daughter!
But the rich do it anyway! It is an open secret among them. Similar to how it was morally reprehensible to even think about getting an abortion in the wibbly wobbly past. But it was still possible to get one if you know the right people wink wink nudge nudge.
I mean look at this scene from The 1986 hit movie The Fly Starring Geena Davis and Jeff Goldblum:
[](https://i.stack.imgur.com/uJFC1.jpg)
[Answer]
## If you have feudal societies, it'll happen.
There have been societies where competition for strong, healthy peasants has been intense; Western Europe after the Black Death, and in an extreme case, Muscovy (there was 50 years where kidnapping peasants en masse was totally normal and legal).
There are absolutely going to be strong moral prejudices against breeding with ogres. The idea is repulsive. But so was being able to be kidnapped, or being an enslaved serf.
The reality is that if it's beneficial to the ruling class in a feudal society, it's going to happen anyway. The only question is whether it's routine, or only happens during war time and/or when a local lord is particularly ruthless.
Ogrillas will make good soldiers, and in an era where women had 15 children and 5 survived, a baron (or king, or khan, or barbarian chieftain) with a labour shortage is going to be very tempted.
[Answer]
With so many ogrillas being born, and being interfertile both ways, I expect a ton of various-degree hybrids. Possibly to the point that pure-blood humans and ogres are extremely rare.
] |
[Question]
[
This mammal-thing is based off of kangaroos, red squirrels, dromeosaurs, cats, and of course, humans.
My creature is slightly bigger than most humans, digitigrade and bipedal. It has a long, thick tail to help it balance when standing (Though it can stand without it, it's just harder.) and running. It can run on four legs without much difficulty, though it is not nearly as efficient as a true quadruped. When running on two legs its posture is much like a raptors.
Its head is wedge-shaped, and in it houses a smaller brain than a human, but it is just as intelligent. It has forward-facing eyes to match its cat-like pupils. These creatures have light, mostly hollow and blood-filled horns that are used for display. The more long and elaborate the horns, the more attractive. (This particular specimen is a sorry fellow.) It has a longer neck and torso than a human, but not by much.
Its arms are much longer though with its hands nearly reaching its knees. On these hands are pads and claws. Its feet resemble hands, but it is only about as dexterous as a human's foot.
EDIT: I am so incredibly sorry, I forgot to mention that it evolved from climbing ancestors. Not necessarily arboreal, but a similar environment. These creatures used to dwell in cave systems with complex rock formations that could be compared to a forest, but they were forced out due to a lack of food. It was a rather long time ago in their evolution, but that's why I gave them their horizontal shoulders. However! I adore the concepts given, so I may still change them up yet for a more unique, less human look.
[](https://i.stack.imgur.com/WoxwQ.png)
[Answer]
**if anything, the posture while walking, the flexibility of the tail and whether it has buttcheeks.**
The main reason I started considering this is because you said the tail is important for their running and because of how you described their bipedal style of running:
>
> When running on two legs its posture is much like a raptors.
>
>
>
And since I can't help but see a few similarities in terms of proportions, let's pull up a dead guy that seems pretty similar to your animal in a few regards: [Dakotaraptor](https://fossil.fandom.com/wiki/Dakotaraptor).
[](https://i.stack.imgur.com/dw1K1.jpg)
This image can show well 2 main traits of these dinosaurs: long legs with a shinbone region (the part of your leg that includes the tibia and fibula, making part of the lower leg) was longer than the thigh bones by about 22% (which I'm only mentioning to say your creature might actually be pretty speedy depending on how a few things below the skin work), and something that is present in many [dromeosaurids](https://en.m.wikipedia.org/wiki/Dromaeosauridae) (or raptors, as we know them): a tail very adapted for running, that serves as a counterbalance to the animal and had most of its flexibility at its base, with an association of bony extensions (present in picture) and tendons (not present, unfortunately), ensuring that the rest of the tail was more rigid, potentially to quickly adjust their balance while running.
So why did I go through all that? Well, if your creature does run often like a velociraptor or like other dromeosaurids, it means their bodies will normally be almost horizontal to the ground, meaning that, since their quadrupedal gait is awkward, the tail is most likely one of the most important things to ensure their balance, which means it needs to be heavy and, if we are to follow the example of earth animals, it might be better off being rather stiff as it reaches the end, to better use it as a counterbalance.
Second thing is that, if the tail needs to be heavy to act as a proper counterbalance, their posture might have to be a little less upright, at least while walking around. If you want a better idea of what I mean, this dinosauroid drawn by [Monopteryx](https://www.deviantart.com/monopteryx/art/Dinosauroid-187419512) might help:
[](https://i.stack.imgur.com/9DXEf.jpg)
Essentially, they might walk a little hunched so that the tail doesn't make them tip towards falling backwards.
The last thing really depends on their skeletal structure and muscle attachment points, but going over one last trait in theropods compared to modern animals: human buttcheeks exist [due to fat reserves and large muscles attaching to the back of the pelvis](https://www.sbs.com.au/topics/science/humans/article/2016/06/29/ask-evolution-why-we-have-butt-cheeks). Meanwhile, it seems like some theropods, including T-rex, dromeosaurids and carnotaurus, had leg muscles [attaching to their tails](https://www.nationalgeographic.com/science/article/butch-tail-made-carnotaurus-a-champion-dinosaur-sprinter), with the muscle being known as the caudofemoralis, which attached to the animal's thighs.
So essentially, depending on how important running was for your creature or its ancestors, they might have a special tail with a flexible base and a stiffer end, they'll probably walk slightly hunched to make up for the tail's weight and function as counterbalance and their legs might actually have muscles attaching to their tails, which can change their appearance regarding the hip region.
EDIT: regarding the "cave update": This is actually quite the twist, because you said that they originally were adapted to life in a cave system that was structurally similar to a forest, but potentially allowing for more solid "branches" that supported more weight, which would explain why they'd have developed scansorial adaptations (that is, adaptations that aid in climbing such as powerful claws, opposable digits and prehensile tails). One very important thing about this however is that they weren't in a forest climbing trees, they lived within a peculiar system of caves, and only left this habitat due to a lack of food. This does help explaining some things, but also opens up a few factors we'd better look at to determine why your creature most likely went from cave dwelling climber to a more cursorial creature. Firstly, why is a forest-like cave a bigger deal than it seems? Well, because [being adapted to living in caves without leaving means things work a bit differently than they would in other environments](https://www.nps.gov/ozar/learn/education/cave-biology.htm#:%7E:text=Animals%20that%20have%20completely%20adapted,some%20cave%20salamanders%20and%20insects.&text=What%20animal%20can%20fly%20with,and%20sleep%20hanging%20upside%20down%3F).
With that clarified, here's my little theory on how your creatures could have evolved from scansorial creatures to cursorial ones and why exactly your current drawing would actually represent an older member of the species:
Your creatures, since you stated lived most of their lives in the cave without leaving, were most likely smaller trogophiles (creatures that live mostly within the cave, but can still survive outside of it, unlike troglobites) that were well adapted to a life of climbing, using their claws And opposable digits to traverse the forest of rocks, with their Tails being used to aid in balance and compensate for the climbing angle, much like how we'd see in [a leopard](https://blog.londolozi.com/2017/10/03/why-is-a-leopards-tail-important/). As they were fairly small in size and adapted to living in the dark, their pupils were slit-shaped to aid in determining distance and for properly filtering light in eventual visits to the outside world, as well as for hunting near the cave entrance during the day. At their original size, they functioned mostly as agile ambush hunters that fed mostly on arthropods and bats (or rather the counterparts of such creatures) that they managed to catch. At this period, due to the lack of vines or other structures, they'd grow horns much lke deer during mating season in order to advertise themselves. Said horns however, would fall not long after, as they still hindered proper maneuvering (this is merely a suggestion, I'd say it's a little better and safer than having large blood-filled horns year round, now that I've put some more thought to it).
As time went by however, the appearance of new, more agile predators, these primordial creatures saw themselves being slowly outcompeted, resulting in a situation in which bigger members of the species were selected, as they could hunter bigger game that the new predators weren't as good at feeding on and thus had access to more food, being healthier than their smaller counterparts and slowly shift the point of selection from simply males with larger horns to bigger males overall, with those with smaller horns being more capable of dedicating resources to their own growth, resulting in a beginning of their reduction.
However, one of the problems that came with the increasing size of these creatures was that they could no longer find enough food within the cave, resulting in more frequent visits to the outside world until a point when they left the caves completely.
During this adaptation period though, they had to undergo a new problem: the outside world, similar to a Savanah biome in several ways, had a lot less trees and other structures to climb on, which were fairly fair apart from one another. At this period, they started differentiating between 2 main groups: the stubborn ones, which tried to simply insist on their hunting strategy and ambush prey from the trees (which is one of the theories on how [thylacoleo](http://news.bbc.co.uk/2/hi/science/nature/4409039.stm) a marsupial predator that descended from climbing ancestors, hunted its prey), and the cruisers, which adapted to be generalists capable of eating a larger number of foods, including plant matter and smaller animals, while also relying more on stronger legs to travel long distances and escape predators (much like modern [ostriches](https://instruction.cvhs.okstate.edu/kocan/ostrich/ostbk2a2.htm#:%7E:text=Ostrich%20travel%20vast%20distances%20to,not%20thought%20to%20be%20common.)). While the former group ended up once again outcompeted, this time both by pre-existing predators and because of the small number of ambush points they could use, the latter developed just fine. Their arms became slightly shorter, but retained their ability to grasp and claws to hold onto small prey and for more desperate attacks against predators and their spine suffered some slight alterations to fit a more bipedal stance, but the biggest changes happened to their legs and tail:
The tail, once smaller in proportion and useful in compensating for the angle while climbing, became longer, bulkier and much more rigid, with most of the flexibility concentrating at the base. Their hind limbs became much more foot-like, with their toes shortening in length until they'd almost lost 3 out of the 5, with the 3 outer toes becoming either highly vestigial or straight up gone, while the "thumb" and 2nd remaining toes were adapted for running, having fairly durable and sharp claws that dug into the ground and aided in traction. The leg muscles also began to become more concentrated near the hip region, with an association of tendons in the lower part of the limb allowing for more efficient running and walking at the cost of flexibility.
At the end of the process we'd have human sized mammal-things with legs similar in structure to a cross between an ostrich, a cheetah and a raptor, and a tail mostly similar to a raptor's. The hefty cursorial adaptations allows them to be very efficient walkers and speedy runners despite still not being the fastest around, but it essentially came at the cost of them loosing almost completely their ability to climb pretty much anything. Their generalist diet of plant matter and small animals means they don't need to worry about endangering themselves hunting bigger prey or being outcompeted by ambush predators.
Comparing these to your drawing, they'd have thicker legs, a more "rod-like" tail that mostly stays upwards and a little less fur. They'd also have less toes and a hind leg structure more similar to an ostrich or dakotaraptor's, with the exception This situation could still allow them to keep their "horns", but I'd still advise to have them work similarly to deer antlers and fall off once the mating period is done (so they don't have to carry a pointless weigh with little to no use in defense, since their main defense strategy is laying low and running away). Much like a [secretary bird](https://animals.sandiegozoo.org/animals/secretary-bird), they'd hunt smaller animals by using their height to see above the tall grass, using their powerful legs to stun prey with a kick and use their arms and Jaws to finish the job. Much like thylacoleo, the smaller brancase could also result in your creature having a fairly stronger bite that what would be expected for an animal with its size.
[Answer]
Your design isn't bad, but if your going for a terrestrial/cursorial design this could use some work. But for an arboreal form this is dandy. As john stated prior, the shoulders and hands are much more suited for a tree dwelling lifestyle as are the feet. Fewer and more rigid toes works much better for terrestrial locomotion than many and flexy(I know you said they are are useful as a human foot, but the artwork doesn't read as such.) That being said I would probably try to center the mass of the body a bit more.
Art peice by Haanpere on Twitter. They have some uncanny valley creations, but these ones are very good and are in a good place in terms of a believable cursorial-saltatorial design that is also anthropomorphic/outwardly sapient.
[](https://i.stack.imgur.com/q1lRe.jpg) However keeping the head non-human is always a better move.
This is an image I did for a client not too long ago. But it might help.[](https://i.stack.imgur.com/VCPFx.jpg)
Here we have a saurian build, but pitched upwards. The tail is much thicker and I kept the reptilian musculature of the legs and pelvis. Humans are kind of a bad reference for a running/cursorial body plan as we are very slow compared to most animals and have bad joints and bones for the job. I ALWAYS recommend looking at other animals that do the job better and then just anthropomorphize or adapt the traits for your more niche needs.
Other than that your design aint far off the mark. One mistake I see people make when creating sophonts or other is that they think it has be upright, have human-like hands/arms, etc. that isn't the case, hell they don't necessarily even need to be carnivores, although it does help. I have created a lot of "aliens" not one of which would look be able to use a car, let alone wear human clothing. It is a good excersise to create things that make development of a material culture much more interesting as well as posing. And I am not saying you did anything of the sort, we all have different proclivities, I just get asked by other artists, clients or budding creature designers how do these sorts of things and we often have a very "human" way at looking at the problem and don't step out in fear of unfamiliar territory.
[Answer]
I second what both individuals already said. The tail as it exist now doesn't make sense. I won't repeat what was already stated by others in this regard.
Instead I'll nitpick about everything else! Though before I go out of my way to criticize everything let me say that most of it isn't that big a deal. That is to say that while I don't think this creature would actual evolve as described I think authors get a certain amount of artistic license and frankly having to limit yourself to only what should evolve can make rather boring species. if you fixed the tail thing, and possible the feet, I couldn't see myself even at my most finicky really being upset about the other details occurring in a story. Still you asked sooo....
**Grasping feet sure are Handy:**
The detail that most stuck out to me a odd, other then the tail, was the feet which you described as 'hand like' but being no more dexterous then a foot. I don't think this makes sense, either the hand is still serving as 'a hand', being used to grasp things like tree trunks and/or cave walls, or it will evolve into a more appropriate foot.
The reason for this is simple, ignoring my horrible pun it is useful to have a foot that can grasp things! Useful enough that evolution doesn't want to 'give up' that ability lightly. There is no reason to still have a hand-like foot and give up on the usefulness of dexterity, there must be something gained by sacrificing the ability to better grip.
By comparison let's look at humans. We evolved from arboreal creatures and when we split off from chimps/bonobos we likely did have grasping feet similar to what those animals had. So why aren't our feet useful for grasping now? because we sacrificed that to be better at walking! Our feet slowly adjusted to a more foot-like posture to support walking more efficiently. In this case we did give up dexterity, but the benefit of more efficient walking that came by changing the shape of the foot was worth it (while humans aren't great sprinters were actually one of the best species out there for long distance walking...)
Similar to humans your species would either adapt to be good walkers by loosing the hand-like structure of the foot or they would maintain the hand structure only because they are regularly using it for climbing and thus would still have more dexterity. Given the other aspects of your creature though I'd say it's more likely it would have a more 'normal' foot, practically due to the runner build (get to that later) and partially because...
**It's not fun to snap your thumb while running**
Given the picture of your creature the foot structure is particularly inconvenient to run on. In particular the 'thumb' is positioned in an awkward position. If someone steps wrong they could accidentally put all their weight on their 'thumb' and snap it in half. Across all species any creature that spends most of it's time walking usually combines it's 'fingers' into a more solid landing platform that is not as easy to harm. That could be something like hooves or something like the human foot where toes exist, but we land on the much more solid back of our foot, rolling onto the ball ball of our foot, and only really use the toes to push off. In every case land animals try to have one limb landed on so it's less likely a bad step will lead to injury. That thumb looks *very* injury prone right now.
**Claws don't work well on rock**
The long talons on the foot of this creature don't seem to make sense. The legs wouldn't seem viable for attacking or defense often (especially with the posture change suggested in other answers), so the claws aren't useful as weapons. Outside of that the claws would be mildly in the way for walking/running, and significantly in the way if your creature preferred climbing on cave walls.
The only situation where I could see long claws on the foot making sense is if they are used to dig into something to get a better grip. So if the creature usually walked on land so soft, and prone to move, that the claws could dig into the dirt to give them better grip. Though even in that case I'd imagine such claws would be retractable, only used when intentional for gripping, not always present.
**Get rid of those bloody horns!**
I have nothing against horns themselves, many species evolve horns as part of the classic handicap principal to advertise sexual fitness. However, there is no reason for them to have blood in them. Pumping blood through the horns means the heart needs to work harder to pump blood, and if a horn is damaged it leads to major blood loss. There is nothing really living in a horn, any more then your fingernails are 'alive', so there is no blood needed to keep the horn alive. Just make the horns more similar to horns of deer or similar species.
**Your species is in a hairy situation**
This is really a nitpick, but having both hair and fur seems unusual. They do the same thing, there isn't much reason to evolve hair on the head in addition to fur. The most likely reason for hair to evolve was some form of fitness indicator, but since horns already serve that purpose there is no reason to have two different fitness indicators.
Like I said that's a really trivial issue. I'm sure given time I could come up with some sort of valid justification for why the creature has hair as well as fur. If you like it having hair I wouldn't suggest you remove it just because of my being overly critical :)
**Are you a sprinter or a climber?**
You claim the evolution of this species was focused on climbing in caves, but you gave it a number of adaptations that make more sense for a sprinter.
Most notably the tail only makes sense for a species that expects to be sprinting at high speeds *and* need mobility to change direction rapidly while sprinting.
However, there isn't much sprinting happening in deep caves. Climbers usually don't sprint since they use their height advantage to escape predators. So the question is why do they have sprinting build if their evolution primarily happened in caves and focused on climbing? maybe after they left the caves they lived in plains where they needed to sprint to either catch, or escape, other animals. However, if they lived in the plains so long that they had evolved to sprinting they probably wouldn't have much of their original climber build, especially the feet-hands, which are not at all conducive to sprinting!
**How heavy is your tail?**
Related to the question about rather this species was suppose to be a climber or a sprinter is the question of the tail's weight. To climb it will want a light tail, as any significant weight on the tail would both weigh the species down and act as a lever pulling the species away from a wall.
However, a sprinter potentially wants a decent bit of weight in their tail to help with conservation of angular momentum. and the tail as drawn looks like it would be a little heavy.
If you want a tail but don't care as much about how it looks you may want to consider switching to something more like a monkey tail. A thinner and lighter, but more muscular, tail that can be used for gripping to assist in climbing. Of course monkey tails make more sense for an arboreal creature then one that climbs on cave walls where there aren't any branches to grasp the tail on, but I'm sure you could either justify why there are things in the caves the tail could wrap around or claim the species was originally arboreal before it evolved for caves and the tail originally evolved for arboreal life found some other use to justify it's persistence later, possible just mate selection even.
**Are you predator or prey?**
The sprinting build and muzzle, especially it's teeth, and to a lesser extent the claws, seem to point to an evolution as a predator. However, there aren't many two legged land-based predators out there for a reason. They use to exists, and they were generally outcompeted by 4 legers which could move as fast or faster and attack easier. 2 legged predators were common back in dinosaur age, but that was as much because it was extremely hard to evolve a 4 legged posture given dinosaur physiology, in a sense you could argue 2 leg predators were a thing only because evolution hadn't gotten around to evolving 4 legged predators yet.
Before anyone says it yes humans are 2 legged and apex predictors, but we do that via technology. We are evolved primarily as generalists omnivores and only really grew into apex predators after we had reached a certain level of intellect and technology. We aren't evolved to be primarily predators or have much in the way of traits evolved primarily for predation. For the record I don't buy the claim that humans evolved for, or made heavy use of, persistence hunting in the past, but I don't want to bog this discussion down with that much nuisance.
So the question is if your species is a predator how does it hunt, and manage to not be outcompeted by other hunters? A potential answer is that four legged predators just didn't evolve in this world, but the posture of your mammal-like species suggests that four legged locomotion could easily evolve from a species similar to it so that seems unlikely.
Your species also doesn't seem to have a very effective method to make a killing blow. The fact that it has such a long muzzle implies it uses it's muzzle to bite, but it's too tall to get under the neck of the prey for a killing bite. Though perhaps if it leans far enough forward while running it's muzzle would be closer to neck height. There is still the problem that it's long neck and build doesn't seem that well suited for going in for a kill with the muzzle, the neck could be easily injured during the scuffle after a bite, you want a smaller more compact build if your going to be diving for a preys neck and holding on for dear life.
As an alternative perhaps it uses the muzzle merely to hold on to the prey and uses it's claws to kill. If it jumped onto it's prey and clung on with a strong bite it could then claw away at exposed areas but...well this still feels awkward. It's still not compact enough to cling to prey well and it doesn't seem well suited to leaping the way a raptor was.
**I pray I won't be your prey**
Alternatively you could have the species not be a predator but prey. The positioning of the eyes, more on the side of the head, are more suited for prey species. However, if a prey species you would expect the muzzle to be shorter (long muzzles mostly exist to make it easier to bite, and hold onto, prey species when predator goes in for the kill).
The claws may also may not make sense for prey species, but you could claim the claws on the hands were used primarily for competition over mates instead of defense from predators so it's not that hard to justify claws on the hands if you really want them.
In this approach the species would likely be an omnivore that will eat anything, but may not focus on hunting. The sprinter build would exist primarily for getting away from predator's rather then hunting prey.
Okay I think that's enough nitpicking for now :)
[Answer]
**Heat dissipation**
It seems you want something resembling a human in many ways. I assume this is also in activity. However, this version is unable to do long intensive work like humans can. This is all because of heat dissipation.
One of the strong human traits is the ability to sweat all over, losing heat on a large scale if needed. It is why we can do impressive bursts of activity in a short time, or run marathons, be out walking on really hot days or enjoy a sauna. Fur impedes this process a lot. It holds on to the sweat and heat, making it difficult for some of the cooling processes to do their job. Heat exhaustion and even death are very real, or the creature should be much less active in comparison to humans. Don't get me wrong, they can still be very active. Look at dogs. Some seem to be able to run around for an hour without stopping and they can travel impressive distances. However, dog owners generally also know that cooling down your dog is very important, especially on warm days. Dogs are able to exert themselves, but they reach heat limit much earlier than if a dog would have no fur and sweat glands like a human.
] |
[Question]
[
I'm working on ideas for a game that will involve mechs of varying sizes and shapes and I am trying to establish an upper limit of size for humanoid mechs. This isn't about practicality, that is something I will consider separately. I'm just trying to establish a maximum possible size.
The mechs will be designed to mirror the movements of the operator. They will either move via advanced servos, motors or artificial muscles (or a combination of all three.) Whatever drives them, they will be able to match the movements of a human inside at near 1:1. This obviously will become a problem with larger mechs as they could easily damage themselves with the amount of force needed to move that fast.
What I want to know is how large can these mechs be built, using modern known materials, before trying to move near 1:1 with the operator would require enough force applied to the mech's components that the mech would risk damaging itself or wearing itself out too quickly to be useful?
[Answer]
## Ground Pressure
If you aren't taking the practicality of a mech into consideration, the primary limiting factor won't be absolute height, it'll be ground pressure. As long as you keep the ground pressure below about 40 psi/275kPa it should be able to operate on firm soil. If you keep it below about 10psi/70kPa it'll be able to go anywhere a human could go (assuming it fits). However, thanks to scaling effects (square-cubed law) the contact area under the feet will have to increase proportionally to maintain acceptable ground pressure.
If you double the linear dimensions of an human you increase their mass 8 times, but only increase the surface area by 4 times, so their feet must double in area (41% increase in width and length) to maintain the same ground pressure. A mech will likely be not just larger than a human, but denser, requiring even larger feet proportional to their size. Eventually the dimensions of the mech will make it incapable of replicating human motion, even if the structure and actuators are up to the task.
If these mechs are little more than parade floats, they can be as large as you want, with a minimal weight external shell supported not just by the feet but also by lifting gasses. This may be less of a classic mech, and more of an oddly-shaped articulated terrestrial zepplin, but if there are no practical considerations it could meet your requirements, and it would actually get easier to meet those requirements as it got larger. In this case the square-cubed law would actually be working in your favor, and increasing the lifting force you had to work with faster than the necessary weight of the structure increased.
## True 1:1 Motion
If you want the mech to match an operator's movements 1:1 not just in terms of motion profile, but also speed (the mech doesn't just make the same motion, it makes it in the same time, and the operator's motions are not restricted to allow for the mech) there's a more concrete size limit. Bear in mind the numbers below are very approximate, since this isn't a technology which has been seriously pursued and developed to maturity in reality. Also, I use "a human" as a reference below because all else being equal, a smaller human will be able to make proportionally faster (though not necessarily absolutely faster) movements than a larger human, which will in turn scale to faster movements of the mech.
As you scale an object up, it will increase in mass with the 3rd power of its linear scale (2 times the linear size, 8 times the mass), and the necessary accelerations will increase linearly (double the distance an object must move in the same time, double the acceleration) meaning the forces required will increase with the 4th power of the linear scale. Meanwhile the structural strength of the object will only increase with the 2nd power of linear scale (2 times the linear size, 4 times the cross-sectional area). Thus, the stresses that would be placed upon the structure if it were required to match a given motion will increase with the 2nd power of linear scale. If you switch from flesh and bone to titanium you can increase the strength to weight by about 6 fold, but this will only allow you to make a mech about 2.5 times larger than a human. If you use modern composites you could build a mech a little under 9.5 times as large as a human. With the strongest known materials (graphene or nanotubes) you could make a mech about 38 times as large as a human, though it would be hard to call this "modern" technology.
As far as actuators, power tends to scale with the 3rd power of linear scale, while the force they can apply only increases with the 2nd power of linear scale (the force a hydraulic cylinder or a bundle of muscle fibers can apply is proportional to cross sectional area). As such, the force the actuators can apply will probably limit your mech's mobility before their power output. With hydraulics the limit is about 7.5 times the size of a human. Other types of actuator currently under development could increase that to about 11 times (relaxor ferroelectric polymer). If the current technical problems with shape memory alloys can be resolved, it would be possible to build such a mech about 24 times the size of a human.
These approximations, of course, assume you maintain the same proportions of structure and actuator that you see in the human body. If you were building a mech using titanium and hydraulics, you could use proportionally smaller actuators and a proportionally more robust structure. A fit human male is, for reference, about 82% muscle and about 14% bone by weight, so a mech using hydraulics and titanium that was about 60% structure and 40% actuator by weight, could replicate such a pilot's movements at a little over 5 times human scale.
Bear in mind, this does not account for ground pressure, the weight of the power plant, the weight of the cockpit, the weight of motion controllers or other hardware, or any armor or equipment the mech is carrying. All you're getting here is an empty frame and the actuators to move it.
[Answer]
**10 meters.**
[](https://i.stack.imgur.com/veqlZ.jpg)
<https://www.dailyrecord.co.uk/news/scottish-news/thousands-watch-huge-puppet-storm-21308724>
What are the largest humanoid figures currently constructed? Giant puppets! These must bear their own weight, and not fall apart. Depicted: Storm, a 10 meter articulated marionette who walked down the street to inspire the people of Scotland. It looks to me like she is largely made of plastic and fiber.
I also found a very cute [8 meter marionette](https://www.pinterest.com/pin/542402348842878633/) made of wood. I am not sure which would be a better look for your mechs. The lifelike girl mech has not been done to my knowledge.
The builders of these puppets could have used aluminum or titanium; these giant puppets are prestige projects, not built cheaply, and I think if lightweight metals offered an advantage they would be used. But to my eye they are not. Maybe there is an invisible skeleton. I think plastic and fiber are the way to go for giant articulated puppets / mechs.
I have a vision of a mech of this sort which could be lighter weight because like these giant puppets it is all plastic and fiber, and it contains no machines. The feet are two normal tanks with treads, and articulation cables for the mech above are based in the tanks. That puts the motor low and in a proven vehicle. The mech would move like it was wearing roller skates. It would tower above the tanks and fulfill your mechly needs. The tanks could keep their guns which would also make your mech lighter because it would not have to carry guns.
I think it would be safest to have the person who the mech was emulating down in one of the tanks, not up in the head Pacific Rim style. That way the mech could get shot in the head or groin or wherever and it would be fine.
[Answer]
**Go Gundam!**
Actually someone has been working on this. Well kinda.
[](https://i.stack.imgur.com/S5FQz.jpg)
The world's largest humanoid robot is being developed in Yokohama (Japan of course, who else?).
The size will be 18mt (60 feet) tall, 25 tons and 24 degrees of freedom.
The hands alone will be about 2mt (5.5 feet) and weight 200kg each.
The engineers have to plan carefully materials and motors to avoid the structure tearing itself apart.
Here is the link to a full article with videos.
[Gundam Robot](https://www.popularmechanics.com/technology/robots/a30702460/giant-gundam-humanoid-robot/)
Of course it depends on what your robot should do. This one will simply walk around and move in a limited area. Maybe wave at the crowd? It's not like it will be able to walk around in the countryside.
**UPDATE January 2023**
You have until March to visit the Gundam factory park in Yokohama.
See [article](https://www.timeout.com/tokyo/news/the-giant-gundam-in-yokohama-will-be-staying-for-another-year-until-2023-020922)
] |
[Question]
[
Okay, so this question is in the same vein as [this](https://worldbuilding.stackexchange.com/questions/195622/wingjaw-steel-superior-armor-and-weaponry) and [this](https://worldbuilding.stackexchange.com/questions/196057/benefits-of-amphibious-items) question (both posted by me). So, without further ado, what *is* the Boomerang Enchantment?
Simply put, items with the Boomerang Enchantment fly (accurately) in a loop when thrown, to the target and back to the owner, akin to an actual boomerang (yet not at the same time: boomerangs generally don't come back if they hit something). If the item is dropped, left behind, or taken away, it will return to the owner's hand in the same time it'd take a boomerang to return after being thrown the same distance.
(If you're confused, by "same distance" I mean the distance between the owner and the item; the item should return back to the owner's hand (*by teleporting*, since the item, in this case, has not been thrown and cannot change its current trajectory to return to its owner's hand) in thirty minutes max, but the time it takes for the owner to receive the said item is determined by how fast a thrown boomerang would return to the thrower if it was thrown the same distance and that time can therefore be longer than thirty minutes).
EDIT: To clarify, if an item with the Boomerang Enchantment is left behind or taken, it will teleport safely to the owner's hand. If it has been *thrown*, however, the thrower better be paying attention, or said item *can* and *will* hurt them upon return.
The only items that can hold this enchantment are organic or steel items (because steel contains carbon, which is generally organic in origin) and they must be used to kill a certain monster (Boomerang Bananas, very deadly, they fling themselves at *and through* people) in order to gain this enchantment. With that stipulation, my question is **How Beneficial Would Be The Boomerang Enchantment On Items?**
Criteria for Best Answer:
1. The best answer will start with a basic summary of how useful this Enchantment would be on items in general, specifically items that can be used to kill a sentient, flying, magical, and razor-sharp fruit. Since this criterion demands an idea of *how* Boomerang Bananas can be killed, let it be known that Boomerang Bananas can be: crushed, smothered, drowned, buried, sliced, incinerated, eaten (if peeled, which would require them to be held down), or broken, say, by a steel-coated baseball bat.
2. The best answer will cover where this enchantment would be most beneficial; ie. which items would be best benefited by this enchantment. By items I mean weapons, pieces of armor (you can kill a piece of fruit by bashing it with a breastplate, yes?), perhaps valuables like cloth (you *can* smother a Banana with cloth, it's just difficult) or money (kind of hard to see how you'd kill a Boomerang Banana with coins without significant difficulty...)
3. The best answer will cover #1 and #2 thoroughly.
*Clarification:*
1. Items that were dropped, taken, or left behind teleport back to the owner, *safely*; the time it takes them to return depends on how long it'd take a boomerang to return to the thrower after being thrown the same distance the item was dropped, taken to, or left behind at.
As always, I appreciate your input and feedback, you have my sincere thanks. I desire to post good questions on this site, so if you decide to VTC or close-vote, I am open to constructive criticism.
[Answer]
# Infinite Energy AGAIN
Enchant a large bathtub with this (how do you use a bathtub to kill someone? Drown them, or use the bathtub kinetically).
Now dam some water and drop some of it on a watermill or turbine. Throw the bathtub in empty, call it back full. Rinse and repeat.
# Very fast messaging
Enchant paper (paper cuts to the throat can kill, you know). Send some to your pen pal. You can agree on a time and date when you will call each page back. This allows for a very fast mailing system, could even do for medieval internet.
[Answer]
**Surfboards**. What can go wrong? I mean, except for trying to find somebody to sell the thing to after it gets dark out.
**Spacecraft**. They follow a ballistic trajectory until they hit the Moon or Mars, then they bring the sample back for free.
**Shipping boxes**. Forget drones, the customer takes ownership of the shipping box. For bulk items, as some damage may occur during transit. Then he signs ownership back to the company, and away it goes!
**Poison**. First you poison a helpless, unsuspecting banana. Then you use the poisoned corpse of the banana to make a poisoned Savoy Truffle. You bring it to your customer, and he becomes desperately ill. But ... it is coming *back* again. But you must be very careful to choose a well-heeled customer, because if his credit card is declined ... it will return to its owner.
**Bowling balls**. If you're suffering a terrible terminal disease, don't forget to put in an online bid for one of these babies. Being sure not to have forgotten your favorite politician in your will ... with instructions that it be executed only after the ball is thrown, right hard.
[Answer]
### Free money - You can make enchanted coins by beating the monster to death with a bag of money
You pay for something, ie "leave it with a merchant", and it returns to you 30 minutes later. You'll never have to pay for anything again.
### You can kill anyone remotely by enchanting a grenade and gifting it to them.
Bad guy has bankrupted me. Removalists are coming to take all my possessions and the contract is sitting on my desk. I get a grenade, use it to smoosh a boomerang banana and it becomes a boomerang grenade. I then sign the contract, count 29 minutes and 25 seconds, and pull the pin out.
At the 30 minute mark, the grenade returns to its new owner (safely - so it just appears in their hand), and goes kaboom. Day saved.
You may need to seperate the pin from the grenade for the initial enchanting (so the pin doesn't come too). The grenades I'm familiar with have a cap that the pin holds in as the final safety, so if you're careful you can keep the cap on during the banana squishing.
[Answer]
**Captain America**
Think about it. With such an enchantment, military purposes would no doubt follow. One of the easiest to achieve, and the coolest of course, would be boomerang shields. Just watch it in action!
Here is one example from [tenor.com.](https://tenor.com/view/captain-america-shield-chris-evans-steve-rogers-explosion-gif-4208089) [This compilation](https://www.youtube.com/watch?v=C43cdTk0kao) also shows numerous uses, such a knocking out enemies from trees, keeping open closing doors, blocking bullets, and so on and so forth.
[](https://i.stack.imgur.com/tw54H.gif)
] |
[Question]
[
For one of my stories I’ve developed a planet with approximately the same total surface area as Mars. This planet has high quantities of heavier metals/elements (especially silver) and it has roughly 83% earth gravity. It’s very earth like in terms of environment (a little cooler but the temps and atmosphere are well within human limitations. Is this planet feasible?
[Answer]
So you want have Mars sized planet to have gravity equal to 0.83 the gravity of the Earth.
Some facts and figures:
* The diameter of Mars is 6779 km
* The volume of Mars is 163.116 x 10$^{\sf9}$ km$^\sf3$
* The gravity of Earth is 9.78 m/s$^\sf2$
* 83% of the gravity of Earth is 8.12 m/s$^\sf2$
* The bulk density of Mars is 3.934 t/m$^\sf3$ (or g/cm$^\sf3$)
* The bulk density of Earth is 5.514 t/m$^\sf3$
For your Mars sized planet to have a gravity of 83% that of Earth, 8.12 m/s$^\sf2$, the bulk density of the planet would have to be 8.57 t/m$^\sf3$, which is 1.554 times the bulk density of Earth.
Given that the density of iron is 7.874 t/m$^\sf3$, that level of increase cannot be achieved with a larger iron core.
Nickel has a density of 8.908 t/m$^\sf3$, which would help, but as @L.Dutch suggests, for your Mars sized planet to have a gravity that is 83% that of Earth's would require an anomalously large amount of scarce very heavy metals.
For reference, Earth has the highest bulk density of any planet in the solar a system, followed by Mercury (5.427 t/m$^\sf3$) and Venus (5.243 t/m$^\sf3$).
---
***Edit 1***
I've done a partial simulation, using several rare, valuable and heavy metals to get an idea of what metals and their amounts would be required on your planet to get the criteria you specified.
As can be seen from the table below the amounts more than what they would be [on Earth](https://en.wikipedia.org/wiki/Abundance_of_elements_in_Earth%27s_crust) huge by comparison.
As another perspective, nickel has a density of 8.91 t/m$^\sf3$ and your planet needs a density of 8.57 t/m$^\sf3$. You planet could almost be just nickel, with some lighter elements to reduce the overall density.
I very much doubt such a planet is possible
[](https://i.stack.imgur.com/XIvsM.png)
[](https://i.stack.imgur.com/1ekBU.png)
---
***Edit 2***
After additional research, prompted by a comment from @J... and a question from the OP in a comment, "*Could such a neutron star collision have occurred near enough to the system (black hole + star binary) that a sufficient amount of heavier metals were caught by the star to create the anomalous planet?*". Planet [K2-38b](https://exoplanetarchive.ipac.caltech.edu/overview/k2-38%20b#planet_K2-38-b_collapsible) has one of the highest densities of any planet so far discovered, at 11.0 t/m$^\sf3$.
A neutron star collision near a "black hole + star binary" is unlikely to accumulate the material necessary for such a planet.
Instead the [most likely scenario](https://ui.adsabs.harvard.edu/abs/2020A%26A...641A..92T/abstract) is,
>
> The best description for the composition of K2-38b comes from an iron-rich Mercury-like model, while K2-38c is better described by a rocky-model with H2 envelope. The maximum collision stripping boundary shows how giant impacts could be the cause for the high density of K2-38b.
>
>
>
Your Mars sized planet with 83% Earth gravity would most likely be the resultant core of a larger planet that was stripped of its outer layers by meteor type bombardment.
It is thought Mercury is a resultant core of a planet that was bombarded. The size of your planet, with a diameter of 6779 km, lies in between the size of Mercury, which has a diameter of 4879 km and K2-38b, which has a diameter of 19,622 km.
[](https://i.stack.imgur.com/6SBJx.png)
[Answer]
Having high quantities of heavier metals/elements is rather implausible: the heavy elements in the [periodic table](https://en.wikipedia.org/wiki/Abundance_of_the_chemical_elements) take a long time to be produced
[](https://i.stack.imgur.com/oqIHV.png)
>
> Elements heavier than iron are made in energy-absorbing processes in large stars, and their abundance in the universe (and on Earth) generally decreases with increasing atomic number.
>
>
>
In the Milky Way 10 elements, of which the heaviest is iron, account for 99.95% of all the elements, so you see that a very high concentration of heavier elements is unlikely.
[](https://i.stack.imgur.com/Lyjsg.png)
It might still happen that a rocky planet is stripped from the lighter crust and retains a large core made of iron, like it's the case for [Mercury](https://en.wikipedia.org/wiki/Mercury_(planet)#Internal_structure):
>
> Mercury consists of approximately 70% metallic and 30% silicate material. Mercury's density is the second highest in the Solar System at 5.427 $g/cm^3$, only slightly less than Earth's density of 5.515 $g/cm^3$
>
>
> Therefore, for it to have such a high density, its core must be large and rich in iron.
>
>
> Mercury's core has a higher iron content than that of any other major planet in the Solar System, and several theories have been proposed to explain this. The most widely accepted theory is that Mercury originally had a metal–silicate ratio similar to common chondrite meteorites, thought to be typical of the Solar System's rocky matter, and a mass approximately 2.25 times its current mass. Early in the Solar System's history, Mercury may have been struck by a planetesimal of approximately 1/6 that mass and several thousand kilometers across. The impact would have stripped away much of the original crust and mantle, leaving the core behind as a relatively major component.
>
>
>
But again, we are still talking about an iron core.
[Answer]
## Turns out, it really is Definitely Realistic
The raw numbers given on the other posts are correct, but they ignore gravity, i.e. pressure. The density of Earth's inner core is around 12 tonnes per cubic meter even though it is mostly composed from iron.
Curiously, the maximum gravitational acceleration – around 11 $m/s^2$ – of Earth is reached at the boundary of the outer core at roughly 3480 kilometers from the center of Earth. This is almost equivalent to the radius of Mars, 3390 km.
The actual composition necessary would necessitate solving an equation state which is beyond me but, for reference, the densest exoplanet is [K2-38b](https://en.wikipedia.org/wiki/K2-38b) with a mean density of 11 tonnes per cubic meter.
Figures taken from [Gravity of Earth](https://en.wikipedia.org/wiki/Gravity_of_Earth) wiki-page.
## UPDATE
[Someone at NASA](https://www.nasa.gov/centers/goddard/news/topstory/2007/earthsized_planets.html) has actually done some calculations. Earth mass planet made of iron would have a diameter of roughly 5000 kilometers. This is less than the diameter of Mars (~6800 km). More importantly, the gravity on the surface of the Earth mass iron sphere would be around 7 times higher than on Earth.
This means that 83 % Earth gravity at surface of Mars sized planet sounds plausible and would not even lead to a solid iron sphere.
[![Earth's gravity according to the Preliminary Reference Earth Model (PREM).[12] Two models for a spherically symmetric Earth are included for comparison. The dark green straight line is for a constant density equal to the Earth's average density. The light green curved line is for a density that decreases linearly from center to surface. The density at the center is the same as in the PREM, but the surface density is chosen so that the mass of the sphere equals the mass of the real Earth. By AllenMc, Wikipedia](https://i.stack.imgur.com/Zjwpe.png)](https://i.stack.imgur.com/Zjwpe.png)
[](https://i.stack.imgur.com/sodFc.png)
] |
[Question]
[
I'm wondering if the following is possible:
* Find a sunny spot on Mars
* Fix up the soil so it's not poisonous
* Put heaters in the soil
* Put a loose transparent tent over it to help hold in the heat
* Add "water" - I'm guessing the water would actually be water vapor, due to low pressure.
So: could anything edible grow there? Maybe fungus?
[Answer]
### [Someone tried this:](https://eos.org/articles/tests-indicate-which-edible-plants-could-thrive-on-mars)
They planted crops in simulated Martian soil and subjected them to simulated Martian lighting.
>
> ... kale, sweet potatoes, certain lettuces, and, surprisingly, hops grew very easily, tasting no different than their terrestrial counterparts. Other foods, including regular russet potatoes—the famous staple of the stranded astronaut in the 2015 film The Martian—required special soil or light treatments.
>
>
>
The only thing missing from your question and what they did was they added pressure. The student doing the study added Earth-like air pressure for the experiment.
[Lichen can grow at Mars atmospheric pressure](https://biology.stackexchange.com/questions/1242/what-is-the-lowest-pressure-at-which-plants-can-survive), so can some Algae, but for anything else you'll need to increase the pressure to at least 0.47atm. So, until terraforming gets pretty far, you're growing plants indoors on Mars. That "loose transparent tent" is an airtight dome.
Note that the highest human settlement (La Rinconada) has an air pressure of about 0.5atm, and humans can survive as low as 0.06atm ([with supplemental oxygen](https://en.wikipedia.org/wiki/Armstrong_limit)), so there's a decent chance humans will be outside on mars without pressure suits before plants can grow.
[Algae has potential to be a good food source](https://science.howstuffworks.com/innovation/edible-innovations/algae-food-future.htm) - so with a bit of genetic engineering / selective breeding the answer to your question is a reserved yes. But growing typical crops at mars air pressure - no.
[Answer]
In actual natural Mars Atmosphere, this is impossible.
The air pressure is too low. It varies a lot, but never exceeds about 1.2% of Earth sealevel, and is usually below half of that.
At such low pressure, there is no such thing as wet water! All of your water will be either ice, or water vapor. (or a brine so strong it is almost a sludge, and completely toxic to all life)
The composition of Martian air is not a big problem. Very rich in CO2, very poor in buffer gases and O2, but many plants could handle it if only the pressure was increased 50 fold.
] |
[Question]
[
Set during the Cold War period, the then-president rented five (5) flying saucers from the extraterrestrial aliens and a few training exercises were conducted in the air space above Roswell. My father was a young US Air Force lieutenant and mentioned he had crashed landed one of the saucers during training, leading to his court martial.
Unfortunately, he never told me anything about the saucer except that the chassis rotates at high speed and is powered by an antimatter propulsion engine. I want to know why flying saucers have to spin during flight.
There aren't rotary blades to generate lift inside the atmosphere and it is a complete vacuum in space, kindly use magic sparingly and no FTL tech.
[Answer]
Stabilization by [gyroscopic effect](https://en.wikipedia.org/wiki/Gyroscope), plain and simple.
>
> A gyroscope (from Ancient Greek γῦρος gûros, "circle" and σκοπέω skopéō, "to look") is a device used for measuring or maintaining orientation and angular velocity.
>
>
>
Any space probe we have sent into space use rotation for the very same reason.
[Answer]
To create Artificial Gravity.
<https://en.m.wikipedia.org/wiki/Artificial_gravity>
These ships do years-long missions in space, and months in microgravity is just unhealthy.
[Answer]
[What L.Dutch said](https://worldbuilding.stackexchange.com/a/170685/21222), plus whatever process is making the hull rotate is making it act like a turbine from a wind or hydro power plant. From a certain point of view, the whole outside of the ship is an alternator. That supplies the ship with electricity. No spin = no power = no avionics (and possibly no juice for the thrusters too).
[Answer]
Magnetic field generated and speed of rotation cause it to- in simple terms have a floatIng effect in the atmosphere. The slower it rotates the less it floats. It’s all about taking advantage of magnetic fields. Planets with more moons have stronger magnetic fields. Kind of like placing magnets at precisely the right angle to which they repeal each other. Advanced civilizations take advantage of it all, humanity will figure it out in about a thousand years give it take a few hundred.
] |
[Question]
[
**Closed**. This question needs to be more [focused](/help/closed-questions). It is not currently accepting answers.
---
**Want to improve this question?** Update the question so it focuses on one problem only by [editing this post](/posts/167778/edit).
Closed 3 years ago.
[Improve this question](/posts/167778/edit)
What kind of effect would lower-than-Earth gravity have on the geography of a smaller-than-Earth terrestrial planet? The Gravity is lower because the planet is smaller, the core must be large enough to maintain a magnetosphere. The planet should have erosion and active volcanism as well.
[Answer]
A really good place to start with this is to look at the [Geography of Mars](https://en.wikipedia.org/wiki/Geography_of_Mars), also known as Areography.
Mars is a smaller terrestrial planet than Earth and has less gravity, so for those reasons alone it is worth the comparison but there are some gotchas in this which we'll cover later in this answer.
Perhaps most important to note that the geological formations of Mars are not that dissimilar to those on Earth in that both planets are round, and both have mountains and valleys, etc. The primary difference is that even though Mars is smaller and has less gravity, the geological formations on Mars are more exaggerated. Mount Olympus is higher than Everest on Earth, and Valles Marineris makes the Grand Canyon look like a ditch.
Not all of this can be attributed to gravity though. There are some theories about Valles Marineris being the result of a glancing meteor strike, and there are also theories that a large part of why Mars is so small and exhibits a larger amount of exaggerated craters and valleys could be that Jupiter destabilises matter in the asteroid belt and flings it at Mars from time to time.
Perhaps the biggest difference though is that Mars doesn't have an active core that generates new volcanoes and continental drift, and has nowhere near the water or the atmosphere that would cause some geological actions like erosion. So in some respects it is difficult to say.
I would argue however that the similarity in many of the geological formations we see on Mars to those we would expect to see in arid climates on Earth tends to indicate that gravity is not as much a factor in geological activity as active vulcanism, water and thick atmospheres would be. If I am right, it would mean that the answer to your question is 'not much' and perhaps one of the celestial bodies that might help us confirm this in the future is Titan.
[Titan](https://solarsystem.nasa.gov/moons/saturn-moons/titan/overview/) is the largest of Saturn's moons and we don't know a huge amount about its geography at the moment as it has a thick atmosphere and (it would seem) liquid oceans on its surface. Despite the thick atmosphere, it only has similar gravity to our own moon, so it is in many respects a closer fit for an example to your question than Mars is, except that we know a lot about the geography of Mars and very little about Titan's.
If we can land there and explore the actual surface with probes one day, we might get a clearer picture of its geography and how it is either similar or different to Earth. I know of no research or information that tells us much about whether its core is active either, so that is another consideration, but I suspect one day, when we know more about the geography of Titan, we might have a better answer to your question than I can provide here.
[Answer]
The low gravity alone wouldn't do much. Dunes and soil slopes could be steeper. Mountains might be a little higher, assuming the same forces are driving them up.
A low gravity world might have trouble holding an atmosphere, and therefore having liquids. That would make a huge difference, erosion-wise.
It might also have a more stable mantle, resulting in fewer tectonic features.
] |
[Question]
[
>
> Happiness is mandatory. Unhappiness is treason. Treason is punishable by summary execution. Are you happy, citizen? - Friend computer.
>
>
>
Welcome to Beta Complex, the little brother of [Alpha Complex](https://tvtropes.org/pmwiki/pmwiki.php/TabletopGame/Paranoia). We are not in Alpha Complex, governed by the fierce, trigger happy Friend Computer murdering every troubleshooter for doing their job and being Commie Mutant Traitors, because they are all Commie Mutant Traitors. *We are better!*
True, we too are in a bunker, locked up underground after the bombs fell and we too have a ruling AI. That's **BB** or Big Bro, short for **Big Brother**. He sees everything, because, why shouldn't he? He is always *helpful* and *friendly*, much in contrast to his brother FC. His sole reason to be is to keep us alive for our own good and keep us happy! He didn't just make happiness mandatory, he *enforces* happiness. If you aren't happy, he will make you happy. After 143 years of running, there has not been a single case of execution for unhappiness, despite that being in the basic rule set!
But... HOW does Big Brother make all the people happy?
---
Answers should be backed with appropriate citations and based on science - magic is not a thing. Assume that Big Brother is programmed to be an expert in biochemistry, neurochemistry and psychology. Ignore location and resource factors of Beta complex and assume it is somewhere, where anything that is needed for your answer (chemicals, pharmaceuticals, foods, other) can be retrieved somehow.
[Answer]
For the most part, it is impossible to force someone to be happy psychologically. There's an old joke about how many psychologists it takes to change a light bulb - only one, but the light bulb has to want to change.
Ultimately, disorders like chronic depression basically make it impossible for some people to feel happy, and regardless of what you might think, anti-depressants are not the solution. These are a type of drug that is a mood stabiliser - that is to say it takes the edge off depression but it also takes the edge of ecstasy. The point being, anti-depressants are really designed to give the mind enough room to reason its own way out of severe and acute depression, or at least allow people with chronic depression to live a close to normal life. but, they don't 'lift' mood and therefore won't help your AI.
I would argue that what your computer needs is a cocktail of hormone and neurotransmitter supplements, and I would start off with a very specific 3 if I was to conduct my own trials.
Starting with [Serotonin](https://en.wikipedia.org/wiki/Serotonin), this neurotransmitter is generally considered to be a primary contributor to well-being and happiness. The truth is of course far more complex as it always is when the brain is involved but the key point is that you at least want people not to have a shortage of this chemical in their brains if they are to be happy. I'd start with some trials to find the right balance, then test your subjects each day and give them an injection that has a customised dose to bring them up to that level.
Next, I'd look at [Dopamine](https://en.wikipedia.org/wiki/Dopamine), which also has popular links to contentment and reward in the brain. What you want is again a balance, with tailored dosages based on current hormone levels in the body.
Finally, I'd be looking to make a [Norepinephrine Reuptake Inhibitor](https://en.wikipedia.org/wiki/Norepinephrine_reuptake_inhibitor) a part of your complete diet of injections so as to slow up the uptake of hormones like Adrenaline which will make one anxious and potentially aggressive.
Here's the catch though; in modern medicine, we are only just beginning to understand a part of what each of these neurotransmitters do, how they interact, and what the long term impacts of taking them as supplements might be. Also, there are times of emergency when you actually WANT your sheeple to be afraid or anxious so they avoid danger and survive to be happy for a much longer version of their lives. Also, you can't just drug your sheeple and leave them in pens, bored out of their wits and expect the drugs to do all the work. You also have to keep them entertained.
So; ultimately, I'd suggest a regime of medidation along the lines already described, with lower NRI dosages if the AI suspects there is some potential threat coming along. I'd also prescribe a regular regime of exercise, good diet, soothing music, libraries, movies or other entertainments, etc. You want to take care of the physical body as much as possible, stimulate (or at least distract) the mind from where the body is and what it's doing, then tweak the neurotransmitter cocktail to ease the sheeple into a state of contentment with their lot.
Try to eliminate competitive sports along with adrenaline, make sure there are no water, food, or other comfort related commodity shortages. Give the sheeple as relaxing an environment as you can, make sure they are fit and exercised so that the body is as physically content as it is mentally content and while it's not a perfect model just yet, it's a promising start on one.
[Answer]
**Its all based on how happiness is quantified**
There is no chemical or atom called happiness that can merely be weighed, it’s a subjective experience. Those “Happiest Countries in the World” studies you see pop up now and again are merely polling. That’s it, the researchers just ask people if they’re happy or satisfied with life. The scientific issues with this are immediate and obvious. Some cultures are adverse to making a fuss or appearing unhappy. while others are obsessed with complaining and useless comparisons.
So the Big Brother AI quantifies happiness based on opinion polling. Those that report unhappiness are corrected with ultra violence. Pretty soon the AI doesn’t get any responses of “I’m not happy” because everyone knows that they’ll be in for chainsaw torture if they say the wrong thing. Therefore the AI reports 100% happiness
[Answer]
OK, so assuming BB has read all the textbooks on happiness, she/it still doesn't have enough info to make everyone happy, but she can make a good try. Especially if BB knows some things about it that the average person doesn't.
First, BB gives people choices, but always exactly three. We are happy when we get to pick what to buy/eat/whatever, but get depressed when we have LOTS of choices.
Second, BB recognizes that gain is a happiness curve. If you have no money, a 5 dollar gain brings as much happiness as a 50,000 dollar gain to a multi-millionaire. BB probably has some point system for happiness, and takes this into account.
Third, BB knows that having the best house is a bad neighborhood brings more happiness than the worst house in Beverly Hills.
Fourth, BB knows that arranged marriages have a higher success rate than romantic ones (making the American ideal of love a bit annoying to BB's computer brain).
Fifth, BB has read research that suggests a poor gut microbiome diversity is correlated with negative mental state (this last one is controversial from a scientific point of view, but maybe BB is a bit more advanced than we are), so gives us the right bacteria.
Sixth, BB uses cognitive behavioral psychology as a kind of inoculation against future depression. It recognizes such concepts of the trio of depression (universal negative ideas about oneself, the world, and the future), and doesn't let it take root.
Seventh, BB makes sure that health and exercise are paramount. Or else.
Eighth, BB uses surgery to make everyone beautiful. Loneliness brings so much unhappiness that it lowers life expectancy more than smoking.
Nine, BB adjusts epigenetic activation with chemicals, to lesson the lifelong effects of fetal and childhood stress.
Ten, BB has a great supply of drugs, and puts them in the food.
Sorry about missing citations, it's a pretty diverse range of research I've come across from lots of different classes. The funny thing about all this though, is that if BB is really doing it right, does She need the threats?
] |
[Question]
[
In my fantasy world, wraiths are a species of shell-less, regressed crustaceans. They lay their eggs inside animal skulls, using them as shells. The wraiths' bodies are incredibly weak and they cannot move on their own. To be able to find food and defend themselves, they develop a vast number single-celled organisms. These cells are covered in a crystalline shell, with eight feather-like wings sprouting out of various holes. When simply flying around, they form a dense blue cloud around the wraith. However, when they join their wings together, they can form a solid body, expanding and contracting like a muscle. To receive nutrients, the cells are rhythmically vented through a special pouch in the wraith's body, which secretes sugars, fats, and proteins, filtered from the wraith's diet.
My question is, how can the wraith's main body control a swarm of completely disconnected cells? Since they are separate from the body, the wraith can't control them with nerve impulses. It needs a different method.
[Answer]
**Sensors and Broadcasting**
The gist of it is to design flyers to be both sensors and broadcasters, and the Wraith to act as the command center.
The flyers themselves would probably need an array of sensory organs, such as sight, smell, and hearing, which they could transmit back to the Wraith through the same broadcasting mechanisms. This broadcasting mechanism could act in one of two ways: by pheromone signals and 'sound packets'.
---
**Pheromones**
Wraiths could use pheromones to communicate with the tiny creatures by releasing certain pheromones for different commands; similar to how we can [smell fear](https://www.theguardian.com/science/2008/dec/03/fear-smell-pheromone).
As mentioned by @awsirkis, if the flyers are truly single-celled organisms, this could be done through a process called [Quorum Sensing](https://biology.oer.hawaii.edu/biology171/chapter/signaling-in-single-celled-organisms/) instead, but I will continue to refer to it as pheromonal transmission.
As to how it does this, the Wraith can function like a command centre. The small flying creatures, upon entering the Wraith, can bring back valuable sensory information (eg sight, smell, sounds) as they recharge nutrients, as long as they are equipped with small sensory organs.
Relying on this sensory information, the Wraith can output detailed Pheromone instructions, which is carried by the returning flying creatures.
These creatures can then transmit the pheromones to nearby flying creatures, acting as broadcasters. The Wraith would thus be able to command the flyers to do complex tasks with different commands for flyers in different regions.
This would make make the Wraiths weak in an interesting area: smell. By making use of tactical stink bombs, and overloading the capability of the flyers to sense pheromone commands, the Wraith would become disoriented and unable to properly control the flyers. As mentioned by @zovits in the comments, this would also imply a weakness to windy areas, which could possibly limit the accuracy of the pheromonal transmission.
It might also have an issue of latency; commands may get disrupted due to smell itself lingering for far longer. This would mean that the Wraith would have slightly delayed reactions to circumstances.
---
**Broadcasting with uniquely identifiable sounds**
Another alternative is a similar system, but with '*sound packets*'. The best parallel to our modern world is of the Wraith being like a wifi router, sending packets to the flyers, which are like phones/devices.
How the system would work: when each flyer is born, it gets a unique ‘*sound id*’, like a ‘name’. The 'sound packets' would consist of a front portion with the 'sound id', and the command itself. By receiving information like sensory info from sounds made by the flyers, and transmitting commands to the flyers as 'sound packets', the Wraith can command the legion of flyers either one by one, or as a region by grouping certain ‘names’ together.
The 'sound packets' will be heard and re-broadcasted by the flyers as needed, and the flyers can figure out if the 'sound packet' is for them by recognizing the 'sound id'. The sound waves themselves would probably be quite high-frequency, as this would allow for more waves in each sound packet, and being able to send out more commands in less time. It would also allow for an advantage of nearly-instant commands, as compared to pheromones.
This alternative also carries the weakness of being disrupted by sounds of similar frequencies, but a weakness can make the Wraith more interesting. The Wraith would have to spend extra effort to smother sound sources or knock away flashbangs, which could completely disorient their command structure.
Something interesting about using sounds to command a cluster of flyers means that the Wraith could potentially use the sound as a weapon; by inducing enough flyers to transmit sounds continuously, the target's inner organs can be damaged through the vibrations, or the target can be [severely disoriented](https://economictimes.indiatimes.com/magazines/panache/exposure-to-high-frequency-sounds-can-make-you-sick/articleshow/50667378.cms) by thousands of ultrasonic signals sent through the flyers.
Once the target has been subdued, the Wraith can come close enough to the target to drain them of their essences, fitting with the image of the Wraith. (Due to the high-pitched sounds, you could even give the particularly powerful Wraiths the nickname of 'Banshee', as hearing their screams means the omen of death).
Both these ideas would make the Wraith like a murderous flying hive accompanied by either a unique orchestra of smells or a cacophony of buzzing.
---
Misc: the idea of unique 'sound ids' comes from the real-world communication protocol called [Universal Datagram Protocol (UDP)](https://searchnetworking.techtarget.com/definition/UDP-User-Datagram-Protocol). This is used for connection over the internet, between devices. Essentially, packets consisting of an id and data contents are sent from one source to all connected devices, and they check the 'id' to see if it is for them before unwrapping it and using the contents.
[Answer]
First of all, single celled organisms can't have working wings; the fluid dynamics of that scale won't allow it, besides the impossibility of directed flight without complex muscles and a skeleton.
You can, however, have creatures too small to see. If this swarm has nervous systems, they can be controlled via pheromones, or react to danger on instinct. The Wraith would need to gestate thousands of drone eggs between laying a Wraith egg, but they would be easy to produce. From a hormonal perspective, the Wraith egg might start out as a drone egg and receive special nutrients, like a queen bee and her royal jelly.
] |
[Question]
[
At mid-night 1 July 1997, UK returned HK to China. Call my imaginary China's handover to UK "Patriation" - it must happen after 1 July 1997.
As we know from real world 2019 protests, some Hongkongers prefer UK rule. China wants HK and doesn't want give it back to UK. UK doesn't plan to get HK back.
What's smallest change to history that accomplishes Patriation? Just 3 constraints -
1. There can't be conflict or war that leads to bloodshed, pain, and suffering. But of course there can be economic or trade wars.
2. Reason must be realistic...no mind control, no super weapons, etc!
3. China and UK are like their present formats. Both must gaily, gleefully, purposely, voluntarily agree Patriation.
[Answer]
The UK goes bankrupt from the economic devastation caused by Brexit and other things. Its alliance with the US is breaks due to more US-induced disasters in the Middle East and the continuing unreliability of the United States as a partner (maybe Trump wins another term). It needs a new friend. China steps into the role. Chinese investments begin to revitalize the UK economy. The leaders of the UK sign a military alliance with China. China establishes military bases in the UK. The UK moves from the American sphere of influence to the Chinese one. As a sign of good will, China allows the UK to station some of its army in Hong Kong and places the UK in charge of governing Hong Kong. Much gay, gleeful celebration is had.
[Answer]
Your condition 3 will be the main stumbing block. As it stands now, China is not disposed to abandon sovereignty over **any** part of China, and Hong Kong is a part of China. In the 19th century foreign powers carved China into *spheres of influence* while China was unable to resist. The Chinese (and not just the top government officials) are quite determined that this will not happen again. So:
* It would have to be clear that China is not *forced* to *surrender* any sovereign rights. Say the Taiwan and Tibet issues have been settled to the mainland's satisfaction before, which probably means undisputed sovereignty.
* There would have to be clear economic advantages for China in doing so, which overcome national pride and sovereignty. Say the Brits are still in the EU and the EU28 would agree to free trade through Hong Kong if Hong Kong formally becomes part of the UK. There would have to be confidence that the economic advantages are long-lasting.
Your alternate history could be made more likely if China were to become more capitalist, less nationalist. But even capitalists feel national pride.
[Answer]
The most probable circumstance to make a handover of Hong Kong (HK) back to the UK is if China itself wants this to happen.
Assuming the ongoing civil unrest and uprising continues in HK, and this and other decisions made by the current PRC leadership are considered to be poor. The poorness of the decisions is as seen by members of the Chinese Communist Party (CCP). These could failures in the Trade Wars, other international political setbacks, general weakness in China's economy, and setbacks with the belt and Road Initiative. Assume this leads to coup replacing the current leadership and that as a way of quietening Chinese national and international unrest, HK could be relinquished. This could accompanied by a resurgence in what can be called Deng Xiao Ping Though where the PRC works quietly and unobtrustively in its rise in the world.
Rather than allow HK to be an ongoing thorn in the side of the Chinese body politic, a decision could be made to return HK to the UK. British political leadership would see this as a triumph for Britain and be willing to resume territorial status of HK. Remember the UK previously had permanent sovereignty over Hong Kong island and Kowloon. It was only the New territories which was held with a Ninety-Nine (99) Year lease.
In conclusion, political change at the top levels of CCP, possibly with a change in leadership, which may or may not be part of a coup at the government level, could necessitate a handback of Hong Kong to the United Kingdom by the PRC itself.
[Answer]
**Chinese Revolution.**
The needle swings back, and hardline communists once again take control of the government, reversing market reforms, quashing freedoms, and reverting China to the worker's paradise of the 1960s.
But this time the workers aren't having it. The populace rises up in revolution. Chaos ensues and when the dust settles a provisional Chinese government backed by foreign powers is in place to establish order, prevent famine and keep the nuclear weapons from wandering off.
Some areas are less disrupted than others and in many of these, local governments take matters into their own hands to protect their populace. Hong Kong is one of these. Familiar with the UK and in need of military help to control the crush of refugees and incursions by would-be warlords, Hong Kong petitions for patriation back to the UK and the new Chinese government readily agrees. It has a lot on its plate and it needs the help too.
] |
[Question]
[
So based on the question [can pumice stone be use as castle material on water?](https://worldbuilding.stackexchange.com/questions/150256/can-pumice-stone-be-use-as-castle-material-on-water) I wanted to take pumice and use it to construct a floating road, so my Lava People can safely travel from one volcanic island to the next.
To make the road, I plan on taking slabs of pumice and joining them together using a sharp needle and the fibers from a heat proof tree (its a bit magical, but I want to string all the pumice together into a long floating bridge).
What sort of dimensions would the pumice slab need to be so that a 100KG person walking across it won't sink into the water or tip over the slab (it is joined to other pumice slabs)?
[Answer]
Let's assume you take a parallelepiped of pumice with vertical dimension h, width a and length c, and put it into water. To which extent will it sink? If we call the sinking s and indicate the density with $\rho$, it's easy to show that
$s \over h$$=$$\rho\_{pumice}\over \rho\_{water}$.
In order to prevent sinking when having a load of 1000 N, you need to have that the additional sinking due to the load shall be less than $h-s$. Or, you need to displace enough water to compensate for the added weight.
In other words,
$(\rho\_{water} - \rho\_{pumice})\cdot a \cdot c \cdot (h-s)=$
$(\rho\_{water} - \rho\_{pumice})\cdot a \cdot c \cdot h(1-$$\rho\_{pumice}\over \rho\_{water}$$)=100$
Therefore, if you set two among a, c or h, you can determine the other using the above formula.
The tipping moment for a slab can be also calculated and give you other constrains on the dimensions. However, a slab is not the best shape if you want to stay practical: if it is not large enough, it will tip as soon as you approach its edges (try standing on a paddleboard and you will see what happens if you move toward the edges along the shorter dimension).
To improve tipping stability while keeping the dimension reasonable, it would be better to adopt a catamaran-like hull cross section (image adapted from [here](https://en.wikipedia.org/wiki/Small-waterplane-area_twin_hull))
[](https://i.stack.imgur.com/kHE6s.png)
And, since pumice over the years tend to soak in water and then sink, flame the outer surface so that it turns to glassy enamel and is better sealed against water.
] |
[Question]
[
Insects and other land-based Arthropoda are stuck at the size they are due to how inefficient their respiratory system is. They were able to reach the size they did in the Carboniferous period because of the incredibly high oxygen content in the atmosphere back then.
Let’s say we were to, through genetic engineering, give an insect a more efficient respiratory system, like a pair of mammalian lungs or even avian lungs, then released it into the wild. Then, we left it on its own to evolve.
Now that it has room to grow, how big could it possibly get? Does the arthropod body plan (i.e. an exoskeleton) have certain advantages or disadvantages? Could they get as big as mammals, or would they be stuck at a certain size? What would they look like?
[Answer]
Oxygen consumption isn't the only problem.
Their biology is optimized for their current size. With a significant change in it, they should rework almost every major system.
## Heat management
With increase in size, their insides (which generate heat) increase more than their surface area (which loses heat). It either requires a better cooling system or a slower activity on their part. Like elephants and rhinos.
This (Kurzgesagt) video explains it in more detail, with nice illustrations:
<https://www.youtube.com/watch?v=MUWUHf-rzks>
## Weight management
Both inner body support and outside movements had to be reworked or enhanced with size increase. For example, in most arachnids case, their limbs are too far away from their center of gravity. This would significantly increase the required energy to move, as well as the stress on their exoskeleton structure.
---
Many more, I sadly know even less to discuss.
These are problems, which would have to be addressed. However nature allowed for elephants and for a time, mammoths. They show the possibility for affordable top size.
[Answer]
Not much bigger than [Arthropleura](https://en.wikipedia.org/wiki/Arthropleura), which was large but also flat.
[](https://i.stack.imgur.com/tZWwi.jpg)
The other major problem arthropods have besides oxygen is molting, how exoskeletons have to grow. Sooner or later they have to molt to grow larger and when that happens they have no hard exoskeleton to support their body until the new one expands and hardens. Get too large and they will literally be suffocated/crushed by their own bulk while this is taking place. It also slows how fast they can grow since each molt can only be marginally larger than the previous one. Even Arthropleura is probably too large is there are vertebrates around, since they can grow much faster. Arthropleura go away with it because it was the only game in town.
[Answer]
A few adaptations.
1: **No heavy exoskeleton.** The old square-cube law you know. Exoskeletons get heavy. These big ones have just enough to hold themselves in - a minimal flexible cuticle like that of a maggot.
2. **Apneustic respirations**. Oxygen dissolves directly through the skin. Some maggots can do this, especially water dwelling ones. Amphibians and sea snakes can do this. The thin cuticle on your big bug facilitates this. It would be well suited for an area with minimal gaseous atmosphere because it does not move gas.
3: **Huge surface to volume area.** This facilitates direct diffusion of oxygen to needy tissues. The big bug is flat. It might be like a big flat pancake.
Now we have a flat, pancake-like maggot. It is too big for legs, so moves by undulation - terrestrial flatworms and nemerteans do that, so no great stretch.
A creature like this is converging on a slime mold except it cannot flow and so must crawl. It could be very, very big. Such a large creature would also be fairly defenseless and so would need to either be unpalatable or to reside in an environment without predators. Maybe the deep earth, where it would itself be the apex predator. I bet they are down there.
[Answer]
Re: the question on how big an *arthropod* can get, you have a real example that reached an estimated $2.6\,m$ in the extinct [*Jaekelopterus*](https://en.m.wikipedia.org/wiki/Jaekelopterus). Some relevant data:
* Not an insect, yet an arthropod as you asked.
* Aquatic. This probably made growth easier. But I think with a bit of genetic engineering you can solve this, as per the other replies.
* Apparently, oxygen was not the limiting factor: at least atmospheric oxygen was around 75% modern levels on average during the Devonian
] |
[Question]
[
I'm trying to create a realistic composition of a mildly futuristic diesel attack submarine with API based on a Stirling radioisotope generator. The idea is that thanks to automation it's possible to use only a tiny crew, which makes such a small boat less overcrowded and increases its endurance.
Yes, it seems that the whole idea is not pure SF as Soviet Alpha Class (Лира) (yes, I know it's nuclear) was first planned for 16 offices in the early '60s. Then, as usual in design phases, the boat grew and it's intended crew expanded to 31 men. Nevertheless, it seems that the idea wasn't so practical as they made subsequent attack subs with much bigger crews (example Akula first 73 men, in later variants 62).
However, right now Swedes with their famous Gottland class are more than happy to lurk in Baltic with crew of ~25. So some downsizing was actually fine.
The question, then, is whether one could find any data on exact crew composition of modern attack submarines? (The point is not just to find the minimum crew, but also to find exactly where corners were cut during the downsizing, and to be able to show which functions were sacrificed.)
[Answer]
My diesel submarine could sail from the port and safely navigate sea with 25% of the crew for a limited period of time, in case of an emergency like a hurricane. (naval ships can ride out some hurricanes in port, but are always safer at sea). The endurance was limited by the ability of the crewmembers to get sleep.
The limiting constraint on operating in a war-fighting or patrol capacity is to have enough crew to man battle stations and damage control in case of a casualty.
For battle stations, 100% of the crew is awake, and all stations with the exception administrative and supply are manned. Anyone not manning a station is in the galley, on my sub, constituting a damage control team and relief for the crew on battle stations.
For patrol duties, where the submarine is effectively on a war footing, the limiting constraint is to have enough qualified watchstanders to fill the 24-hour rotation.
The CON has the most number of crew members on a watch. On my Korean era diesel sub, we had 3 planesmen, 1 Chief of the Watch, 1 Officer of the Deck, 1 Control Officer, and 1 Quartermaster. The planesmen manned two stations and the third ran coffee and errands for the COW, CON, and OOD, and relieved the other two planesmen. The CON and OOD can be stood by one officer in a pinch.
Typically planesmen are formed from the seaman gang, a group of non-rated sailors attached to the Weapons Department. They handle lines when the boat comes in and out of port, form damage control teams, and help out the cooks when the ship is underway.
The Engineering Depart was the second most populace station with 1 Engineering Watch Officer, 2 Engineering watchstanders, 1 Engineman, and 1 Rover. In a pinch, the EWO can be one of the Engineering Watchstanders.
For stations like Radio and the Torpedo Room, the minimum number of watchstanders for any station is 2 -- one awake and one asleep, or at least, not on watch, every six hours (for US submarines)
Some stations like Sonar require multiple watch standers rotating through manning the equipment for brief periods of time since they couldn't concentrate on interpreting sounds and tracking targets for the entire watch period. So a minimum crew for a Sonar department would be 4 -- two per watch.
For at sea operations, only the store keep was important from the administrative departments.
The Galley had 2 cooks and 3 food-cranks helping prepare and serve food. Both cooks and cranks could go down to 1 stander each.
My submarine had a complement of 90. We could sail under duress and stay away from the port with 25 people for a few days. For a typical patrol, we could function with 60 crew members -- we had a 2-month endurance that could be extended to 90 days by stacking food cans on the floor of berthing. Our limiting constraint was water since diesel subs have limited capacity to distill seawater into potable water. We only took showers once a week, and then they got wet, turn off the water, lather, rinse, no repeat. And, didn't do laundry.
[Answer]
# Crew 134
Regrettably, this is the nuclear version, not the diesel version, but I suspect the crew complement is nearly identical because, diesel-vs-nuclear, you need about the same number of people to keep the engine running.
From [Submarine 101](http://www.rickcampbellauthor.com/styled/index.html)
>
> Submarines play a central role in my books, so I thought it’d be a great idea to provide an introduction to the U.S. Navy’s nuclear powered submarines from someone who served aboard four different ones.
>
>
>
In other words, this is real, practical data and the linked website is full of a whole lot more information than just crew complements.
---
>
> **Crew Complement**
>
>
> Fast Attack submarines have a **crew of around 134,** broken into about 120 enlisted and 14 officers, while SSBNs have an additional 16 enlisted and usually an additional officer. (Crew size varies between class and over time, so don't hold me to it, but the above gives you an idea.)
>
>
> The officer "wardroom" is comprised of the:
>
>
> * Commanding Officer
> * Executive Officer (second-in-command)
> * 4 department heads: the Engineer Officer or "Eng", responsible for the nuclear reactor, the propulsion plant, and all basic mechanical and electrical systems, the Navigator or "Nav", responsible for the navigation and radio divisions, the Weapons Officer or "Weps", responsible for the submarine's torpedo, sonar, and missile divisions, and the Supply Officer or "Suppo", although many have not broken the habit of calling the man responsible for serving the pork and beans, "the Chop".
> * The rest of the officers are junior officers on their 1st submarine tour.
>
>
> The enlisted personnel are broken down into the following divisions:
>
>
> **Engineering Department**
>
>
> * Auxiliary (non-nuclear Mechanical)
> * Electrical
> * Mechanical
> * Reactor Controls
> * Reactor Laboratory
>
>
> **Operations Department**
>
>
> * Navigation
> * Radio
>
>
> **Supply Department**
>
>
> * Culinary Specialist (Cooks)
> * Supply
>
>
> **Weapons Department**
>
>
> * Torpedo
> * Sonar
> * Fire Control
> * Missile (on SSBNs)
>
>
> There's also a **Medical Department** headed by a Corpsman, and I'll talk about that at the end in the section titled "When Things Go Wrong."
>
>
>
[Answer]
Note that DE subs tend to require smaller crews than do nuclear powered ones, due to the DE power plants requiring fewer people to keep them running than their nuclear counterparts.
Also, nuclear boats tend to be intended for longer range/duration patrols than are DE powered boats, making for larger boats with more systems that require more people to keep them running (and of course more people means more redundancy in case some of them become (temporarily) incapacitated due to for example disease or injury during long patrols).
Some crew figures of real submarines of different eras:
DE:
* 1940s: German Type VII: 50 (typical)
* 1950s: US Tang class: 82
* 1960s: Dutch Dolfijn class: 67
* 1970s: Dutch Zwaardvis class: 67
* 1980s: Soviet Kilo class: 52
Nuclear:
* 1960s: Soviet November class: 105
* 1970s: UK Swiftsure class: 116
* 1970s: US Los Angeles class: 129
Mind that ever increasing automation is bringing down the number of crew on both nuclear and DE boats, but the relative difference remains.
[Answer]
The German Type 212 submarine uses hydrogen fuel cells for AIP & a marine diesel engine. They have a complement of 5 officers and 22 men. But I don't know what each person's job is. My guess, same as the *Gotland*-class submarines, they cannot desalinate water, perform electrolysis, have less repair capabilities, and fewer weapon options.
Civilian research submarines need much few people because they lack weapons and their missions tend to be only a few hours.
] |
[Question]
[
[Huldra](https://en.wikipedia.org/wiki/Hulder) are forest creatures from Scandinavian folklore, best known for their seductive natures. They are frequently depicted as beautiful women, with the additional traits of a cow-like tail and occasionally a hole in their backs, like that of a rotting log.
As we are starting with a human base, I would expect the addition of a tail to be easy enough to explain, as it is often represented with the same skin tone and hair color as on other parts of the body. The hole in their backs, however, is something far more difficult to justify. The hole is often a true cavity, not unlike one found in a hollow oak tree or rotten log, which brings up questions about the placement of internal organs and other supportive structures.
As one legend states that huldras are unwashed and hidden children of [Eve](https://en.wikipedia.org/wiki/Eve), consider these creatures to be related to or have descended from humans on some level.
[](https://i.stack.imgur.com/t2zuNl.jpg)
[Huldra by CoalRye on DeviantArt](https://www.deviantart.com/coalrye/art/Huldra-548877338)
[Answer]
Huldras are a sub-species of homo that developed when the first humans populated Europe and Scandinavia. Several near-extinction events lead to genetical bottlenecks and inbreeding, which in turn lead to several genetically mutations.
The most remarkable mutations are the tails (which grew due to a reactivation of dormant genes) and a severe case of [spina bifida](https://en.wikipedia.org/wiki/Spina_bifida), the open spine.
Usually natural selection would eliminate babies with defects that impede their development and life too much, but in case of the Huldras, another mutation saved their lives. Abnormal bone growth in some Huldras managed to encase the vulnerable spinal cord in a protective layer of bony protrusions, not unlike tiny ribs. The individuals with this double mutation managed to survive, while individuals with open spina bifida eventually went extinct.
Over several generations, the gap in the spine caused by spina bifida grew bigger and bigger, the bony protusions gradually taking on the original shape of vertabrae on each side and forming an elongated hole from about the shoulder blades down to above the hips. The skin coating the inside of this hole is very thin and pervaded by numerous blood vessels that result in a dark, flushed color that gives it the optical illusion of being a deep cavity. This illusion is further aided by the bony spine protrusions forming an irregular border to the spine gap.
[Answer]
As the spine is pretty central to the human body plan, i'm not going to explain it away, in fact they have two. Huldras are extreme cases of conjoined twins. Double everything but arms and legs. Yet one twin is expressed internally and dies at the onset of puberty. The resulting necrosis is not survivable but by the complete removal of the second twin. The resultant cavity is lined by skin, but often stuffed with rags and herbs to prevent infestation.
[Answer]
The hole in the back is usually (only?) mentioned as a final sign to a previously unsuspecting victim that the beautiful, seductive woman in fact was a Huldra.
(A lone wanderer sees this beautiful woman, follows her deeper and deeper into the woods. The last sight he catches of her is the hollow back as she dissapears with a laughter leaving him lost far from the trail.)
So the hole doesn't really need to be a true cavity, it merely needs to look that way. It could in fact be a patch of dark hair or scales down the back, giving an optical illusion of a rotten cavity.
] |
[Question]
[
Here is the scenario: A Paleo/Mesozoic mass extinction wiped out 96% of all terrestrial species, and the only plants that survived were as follows:
* One genus of conifer
* One genus of cycad
* One genus of ginkgo
* One genus of seed fern
Once the ashes had cleared, the survivors found more than plenty of room to spread. So each group expanded into four basic forms--tree, shrub, vine and herb. The extinction event happened before the evolution of true angiosperms, so the question is: **Could any of the gymnosperm groups independently evolve fruits and flowers like angiosperms?**
[Answer]
Many gymnosperms have specialized reproductive structures (cones and strobili) which, in part, have functions similar to angiosperm flowers, although of course they are not homologous with flowers. Some are conspicuous and colorful, even. And there are many gymnosperms which have structures analogous (but not homologous) with angiosperm fruit.
(Note that the modern view is that extant gymnosperms, the Acrogymospermae, form form a clade; the angiosperms are thought to have evolved from a gymnosperm ancestor; so that the Gymnospermae *lato sensu* are a paraphyletic grade. Hat tip to Jack Aidley for pointing this out; Wikipedia [agrees](https://en.wikipedia.org/w/index.php?title=Gymnosperm&oldid=883625415), quoting M.J.M. Christenhusz, J.L.Reveal, *et al.* "[A new classification and linear sequence of extant gymnosperms](http://www.mapress.com/phytotaxa/content/2011/f/pt00019p070.pdf)", in *Phytotaxa* 19:55–70, 2011, doi:10.11646/phytotaxa.19.1.3.)
## Flower-like structures
[](https://commons.wikimedia.org/wiki/File:Sago_Palm.jpg)
*The female reproductive structure of the sago palm* [Cycas revoluta](https://en.wikipedia.org/wiki/Cycas_revoluta) *- from the Montreal Botanical Gardens. Photograph by [Nadia Prigoda](https://www.flickr.com/photos/57977817@N00), available on Wikimedia under the CC BY 2.0 Generic license.*
[](https://commons.wikimedia.org/wiki/File:Cycas_circinalis_-_sago_palm_-_desc-top_of_trunk.jpg)
*Male cone of* [Cycas circinalis](https://commons.wikimedia.org/wiki/Cycas_circinalis). *Photograph by [Phyzome](https://commons.wikimedia.org/wiki/User:Phyzome), available on Wikimedia under the CC BY-SA 3.0 Unported license.*
[](https://commons.wikimedia.org/wiki/File:Female_cone_of_Ephedra_intermedia_-_journal.pone.0053652.g002-C.png)
*A fleshy female cone of* [Ephedra intermedia](https://en.wikipedia.org/wiki/Ephedra_intermedia), *a gymnosperm shrub. Photograph from Yang Y, Wang Q, "The Earliest Fleshy Cone of Ephedra from the Early Cretaceous Yixian Formation of Northeast China" (2013),* PLoS ONE, *8(1): e53652, doi:10.1371/journal.pone.0053652. Available on Wikimedia under the CC BY 4.0 license.*
## Fruit-like structures
[](https://commons.wikimedia.org/wiki/File:Taxus_baccata_MHNT.jpg)
*[Aril](https://en.wikipedia.org/wiki/Aril) (pseudo-fruit) of* [Taxus baccata](https://en.wikipedia.org/wiki/Taxus_baccata), *the yew-tree, a conifer. Photograph by [Didier Descouens](https://commons.wikimedia.org/wiki/User:Archaeodontosaurus), available on Wikimedia under the CC BY-SA 4.0 International license.*
>
> *An aril (pronounced /ˈærɪl/), also called an arillus, is a specialized outgrowth from a seed that partly or completely covers the seed. [...] The aril may create a fruit-like structure, called (among other names) a false fruit. [...] Such arils are also found in a few species of gymnosperms, notably the yews and related conifers such as the lleuque and the kahikatea. Instead of the woody cone typical of most gymnosperms, the reproductive structure of the yew consists of a single seed that becomes surrounded by a fleshy, cup-like covering. This covering is derived from a highly modified cone scale.* (Wikipedia, *s.v.* [Aril](https://en.wikipedia.org/wiki/Aril))
>
>
>
[](https://en.wikipedia.org/wiki/Cycas#/media/File:Cycas_media_megasporophylls.jpg)
[Cycas media](https://en.wikipedia.org/wiki/Cycas_media) *(a cycad) megasporophylls with nearly-mature seeds on a wild plant in north Queensland, Australia. Photograph by Tanetahi, available on Wikimedia under the CC BY-SA 4.0 International license.*
[](https://commons.wikimedia.org/wiki/File:Araucaria_seeds.JPG)
*Edible seeds of* [Aruacaria angustifolia](https://en.wikipedia.org/wiki/Araucaria_angustifolia), *a conifer. Photograph by Rodrigomorante, available on Wikimedia under the CC BY 3.0 Unported license.*
>
> *Conifer nuts are the edible seeds of conifers, which includes most notably pine nuts (family Pinaceae) and Araucaria nuts (family Araucariaceae).* (Wikipedia, *s.v.* [Confier nut](https://en.wikipedia.org/wiki/Conifer_nut))
>
>
>
[Answer]
## Yes, because they already did.
AlexP makes some excellent points in the argument above, but he misses the simplest one: angiosperms already evolved from gymnosperms, therefore it must be possible.
As in the answer above, there are several papers both recent and archaic discussing the phylogeny of angiosperms, but most modern plant biologists agree that the flowering plants form a clade within the “naked seed” plants. As Jack Aidley points out, this makes the gymnosperms paraphyletic. At some point, the fruiting bodies that we call, well, *fruit* - and the flowers that go with them evolved from the gymnosperm forms we see today.
Because it’s happened this way in nature already, it’s entirely possible and even rather likely that your surviving gymnosperms will evolve to fill the evolutionary niches that have been opened by the extinction of the flowering plants. However, it should also be noted that the new species will not be considered a single clade as the angiosperms are today, because they’re emerging from four common ancestors rather than a single one.
] |
[Question]
[
I have created semi-intelligent griffins in my fantasy world.
Semi-intelligent meaning that adult griffins have the intelligence of an average 4 year old human.
Now, I realized that once the griffins are discovered by intelligent races (humans, dwarves, elves), their intelligence would most likely be abused and they would be bred for the mundane tasks of a medieval world.
So, my question is how could I prevent the abuse from happening while griffins still get discovered by the more intelligent races.
My failed solutions:
* To make the griffins too hungry will not work as they consume only as much as 10 kg of flesh per day. (which is way too efficient for what they could be employed for)
* Letting the griffins chose their Human/Dwarf/Elf counterpart doesn't work because one owner could start traveling to an area where the Griffin can not support itself from hunting and as such cannot escape domestication.
[Answer]
**Griffins are crazy fierce.**
There are lots of animals which would be useful domestic animals but which were not domesticated. Zebras, for example - they are built like horses, so why not? This synopsis of Jared Diamond's Guns Germs and Steel lists the qualities an animal must have for it to be successfully domesticated.
<https://www.livescience.com/33870-domesticated-animals-criteria.html>
1. Not picky eaters. Ideally not competing with the humans for the same sorts of food.
2. Reach maturity quickly. Although elephants would seem to violate that rule.
3. Breeds in captivity. Again the elephants break that rule.
4. Docile by nature. This is the one that applies to zebras, Cape buffalo, American bison etc. They are bad of ass and tend to get mean.
5. Not panicky.
Numbers 1 and 4 could apply to griffins. Maybe 2 also; see below. For interest in your story, you could have the fierceness kick in at puberty. You see lots of images of people cuddling and playing with baby bears, baby tigers etc. Less so when they grow up, because one grouchy day for the tiger means no more cuddling forever. Dingos are like this somehow - even though they look just like dogs and are sweet as puppies, they are untamable as adults.
If griffins mature slowly, your nobles could have baby griffins as house pets. The pups are not abused because they are prestige pets and then are put down when they grow out of their cuteness. This also is another path to domestication - via neoteny. This is most famously demonstrated in the case of [domesticated red foxes](https://en.wikipedia.org/wiki/Domesticated_red_fox). At a Russian fur farm, foxes which were less fierce were kept as breeders and the fierce ones used for fur. Over the generations the foxes got more and more puppy like and less and less fierce. They are bred to be tame animals. There are popular videos of these charming tame foxes.
[](https://i.stack.imgur.com/TtyCm.jpg)
If your story can use it, you could have the same process with your griffins - the tame ones are like overgrown pups and physically different (and smarter) than their wild cousins. The few rare adults which are tame are too valuable to be abused - they are intelligent and formidable companions, and also used in the hope of breeding more like them.
[Answer]
If the griffins are useful to the other species, they'll be exploited for that usefulness. So your task is to come up with ways they are not useful.
* As food.
* For pulling carts or pushing wheels and other brute force tasks.
* For riding.
* As scouts or to detect something before the humanoids can.
* For herding or help with other animals.
* As service animals (for people with disabilities or just to help with tasks).
* As pets aka companion animals.
Or you need to make them very useful in one or more of the above choices where they are valued and not abused and not removed from their family units (which is what I assume you mean by breeding them being abusive).
For example, griffins can be trained to perform certain tasks but are too strong-willed to capture and force to do anything. Griffin communities teach their children never become a slave, even if it means you are beaten or killed for it. They have enough intelligence to understand the societal costs of giving in to slavery.
So the humanoids have given up and now hire griffins for work, or offer them live-in positions like a "domestic" human (think *Downton Abbey*).
This is more likely in cases where the first species to "discover" the griffin are already enlightened that slavery is evil. It is less likely in cases where the species either exploits or murders others they consider lessor (historical point is when European colonists in the Americas tried to enslave the native peoples, they got so much pushback that they stopped trying to enslave them...and just murdered huge percentages of them instead).
It's your world so you can decide how each species acts. If the first peoples to encounter the griffin come up with a mutually beneficial work agreement, it's likely to stick. More so if the humanoid species fights for their workers.
] |
[Question]
[
**Closed**. This question needs [details or clarity](/help/closed-questions). It is not currently accepting answers.
---
**Want to improve this question?** Add details and clarify the problem by [editing this post](/posts/130241/edit).
Closed 5 years ago.
[Improve this question](/posts/130241/edit)
I read that oxygen makes up 21% of the Earth's atmosphere. I'm guessing it would take a lot of burning to decrease that level, but I am not sure how to calculate that.
The problem is: Roughly 400 hundred years in the future, humans are thinking they need to burn some forests made predominantly of a plant species that produces a gas toxic to humans and other life-forms, that spread on Earth and suffocated a lot of other useful (for us) plant species. They were worried that the large-scale fires would lower the amount of oxygen in the atmosphere to a level that humans would suffocate, but I can tell from the existing answer, that’s not going to be a problem, so they can go ahead with the plan.
I got the 19.5% threshold from this article: <https://sciencing.com/minimum-oxygen-concentration-human-breathing-15546.html>
But on a closer reading, I noticed it said the OPTIMAL range is between 19.5% and 23.5%, and the CRITICAL threshold for survival is 6%, so my mistake. Again, this makes the worries of the people in my story unfounded.
My question has been answered, thank you!
[Answer]
Let's start with considering the entire [mass of the atmosphere](https://en.wikipedia.org/wiki/Atmosphere_of_Earth#Density_and_mass):
>
> The total mean mass of the atmosphere is $5.1480 \cdot 10^{18} kg$.
>
>
>
We know that Oxygen accounts for 21% in volume, and considering that
>
> The density of air at sea level is about $1.2 \ kg/m^3$
>
>
>
We get that the "sea level" volume of the entire atmosphere is
$V =$$ 5.1480 \cdot 10^{18} \over 1.2$$=4.29 \cdot 10^{18} m^3$.
You want to consume 1.5% of that volume (21 - 19.5), thus you want to consume
$M\_{O\_2}=4.29 \cdot10^{18} [m^3]\cdot 0.015 \cdot 1.429 $$ [{kg\over m^3}]$$= 9.19 \cdot 10^{16} kg$ of Oxygen, considering that Oxygen density is $1.429 $$ [{kg\over m^3}]$.
Assuming you want to burn Carbon to consume all that Oxygen, how much Carbon would you need?
The chemical reaction for Carbon oxidation is
$C + O\_2 = CO\_2 + heat$
therefore for each mole of Oxygen you need a mole of Carbon. Considering that Oxygen to Carbon atomic weight ratio is 32/12, you would need
$M\_C = M\_{O\_2} \cdot $$12 \over 32$ $=9.19 \cdot 10^{16} \cdot $$12\over 32$$=3.5 \cdot 10^{16} kg$ of Carbon.
The [2011 estimated coal reserves](https://en.wikipedia.org/wiki/Coal#Market_trends) in the entire world amount to $891 \cdot 10^{12} \ kg$, just to give you a reference.
As additional note, burning that much carbon would release (taking the heat of combustion of anthracite)
$Heat = 32 [MJ/kg] \cdot 891 \cdot 10^{12} \ [kg] = 28.5 \cdot 10^{15} \ MJ$, corresponding to about $6.7 \cdot 10^6 MTon$, or about 1 million Tsar bombs...
] |
[Question]
[
**Background:** I'm toying with the idea of an alternate Earth that never developed wireless technologies. Radio transmitters, Wi-Fi, etc... were never invented, meaning that light-speed communication is practically nonexistent. One nation progressed into the modern world with an extreme grasp on chemistry, synthesizing artifical hydrocarbons and hyper-efficient batteries. Without understanding of the electromagnetic spectrum, however, they have no means of instant digital communication.
**Question:** In a city with no need for underground power lines, the only utility that reaches homes is the tap water line. What are some viable ways that chemists can encode data into tap water itself, replicating widespread communication like radio or television without the need for wireless signals?
*Note:* I'm looking for answers that fit a "chemistry" theme, because my world is divided up into factions who have monopolies on different areas of science. One faction *does* know how to utilize the electromagnetic spectrum, and another *does* know how to encode data into DNA strands. This nation has exclusively chemistry going for it, and nothing else in particular.
[Answer]
There are projects looking at ways to use the water column within a pipe to acoustically transmit data.
<https://onlinelibrary.wiley.com/doi/pdf/10.1002/ett.3219>
>
> The working principle of the node is that it magnetically clips onto a
> pipe or valve, and either generates an acoustic vibration (transmitter
> mode) or analyzes the vibration of the pipe (receiver mode). In
> transmitter mode, the microcontroller generates a waveform (analog
> voltage), which is amplified by the haptic driver and applied to the
> macrofiber composite (MFC) piezo. Acoustic vibrations induced by the
> piezo are then transferred via the magnetic resonator into the pipe or
> valve, and relayed through the water column to a receiving node. Every
> node in the system can be constructed identically. Nodes can switch
> between the transmitter and receiver modes. Each node costs under US
> $100 at unit price, addressing the requirement to keep costs low.
>
>
>
Vibrations will travel a long way through a contiguous water column - this is why you can hear things at great distances underwater. You could send vibrations down the pipe to carry your digital data. It could be like a fax message, or morse code depending on what kind of resolution your receiver has.
Also note that these nodes can switch between receiver and transmitter. They can act as relay stations, receiving a message and then retransmitting it along. This can compensate for signal loss with distance.
[Answer]
The problem with using chemicals in water for digital information is that the chemicals would need to arrive at the tap in the same order they were sent. While this will *sort of* occur during conventional fluid dynamics, the loss of precision would mean that you'd not be working with a very high bandwidth on this at all.
That said, there is a solution; [Laminar Flow](https://en.wikipedia.org/wiki/Laminar_flow). In fluid dynamics, laminar flow is the liquid equivalent of lasers. It affords coherent flow of fluids through things like water pipes and the like, and as I understand it many of the fire fighting nozzles for hoses are designed to generate laminar flow to make the water go further as a coherent stream from the nozzle than would normally be possible before it turns into a spray or mist.
You could use chemicals in this flow, but if you want to preserve the ability to drink the water at the same time, you could experiment with some form of pulsed laminar flow from the tap. Water glasses would fill but the water would be coming out in very fast pulses, which if you get the system working well may look similar to a conventional flow of water in any event. BUT, a sensitive pressure valve may be able to read the intermittent slight drops in pressure as 0s and 1s, allowing you to transmit data over the (tap) line.
To be sure, this would require a very sophisticated plumbing system to be in place, but the reality is that without laminar flow, your chances of putting the chemical *sequence* together at the other end would be practically non-existent. Additionally, pulsed laminar flow could be detected via a pressure valve on a constant basis, meaning that so long as you have water flowing from a single tap (designed for this purpose) you can record the data being transmitted. That water could then be stored for sending back to a central location, allowing for a user to transmit data back via a 'return' pipe. It would also mean that you should (in theory at least) still be able to use your plumbing system for its original intent as well, which is dispensing water for household use.
I want to stress that I know there are some BIG holes in this model. Drawing a bath may well alter the pressure on the valve (although it should be able to detect *relative* pressure pulses), water pressure on the return trip may not be very high (unless you pump it into a gravity feed tank, kind of like a water antenna) and unless you have a separate supply pipe for every home, you're going to have a massively difficult time doing the equivalent of IP routing. Still, if it's all you've got, these problems are really engineering matters that would get solved with sufficient application of ingenuity.
All in all, water transmission would be difficult, but not impossible.
[Answer]
If you're transferring information on a medium that doesn't effectively limit packet loss, your message has to be repeated many, many times. This would either take forever, or require encoding individual parts of the liquid itself.
The lowest-hanging fruit would be genetic encoding like DNA/RNA being placed in the medium to be 'drawn out', but this only slightly meshes with your theme.
My favorite (but a bit more difficult) means of communication could come in the form of complex covalent bonds acting like kanji (characters standing for words) along with one or more cipher molecules used to arrange/structure the other molecules to make a cogent thought.
So you might have a page molecule saying to look at paragraph molecule A, then paragraph molecule B, etc. And paragraph module A has reference to the order of kanji in the paragraph. Then you'd include every kanji in the document to be assembled.
This would much better fit with the alchemy theme, but wouldn't allow for different messages in a short period of time or back-and-forth messages. It'd work best as a passive news system: Flood today's news in the pipes from 9-5, and then flush the pipes for a few hours so you can start again tomorrow.
[Answer]
As my first proposal stepped on faction toes- for which I apologize-I offer another solution. <https://news.wisc.edu/chemical-dial-controls-attraction-between-water-repelling-molecules/> see link for full details. you said digital and i thought on or off. a chemical coating around a small sphere that makes it on or off according to your whim and a flow bypass triggered by a membrane allowing the spheres to interact with another receptor membrane at their destination. simple compounds could be deposited on the receptor or on the spheres before making a round trip back to the sender. Slow but definitely digital information transfer and more with some imagination. A chemical solution presented.
] |
[Question]
[
There are many organisms that [sometimes reproduce asexually and sometimes reproduce sexually](https://en.wikipedia.org/wiki/Parthenogenesis) (even snakes and sharks!).
There are also a fair number of organism that reproduce sexually but have a sex ratio of offspring that is heavily influenced by environmental conditions (e.g. water temperature with high temperatures favoring males, low temperatures favoring females and ideal temperatures favoring a mix, or vice versa, in some [turtles](https://www.ncbi.nlm.nih.gov/books/NBK9989/), fish and amphibians).
Is there any scientific reason that there couldn't be an organisms that acts like [K-strategists](http://www.bio.miami.edu/tom/courses/bil160/bil160goods/16_rKselection.html) in some circumstances, and r-strategists, in others, using different reproduction modes as the circumstances merited, or that use both simultaneously? (Obviously, one way to show that this is viable would be with a real life example, if there is one.)
For example, maybe an organism would ordinarily have a K-strategy form of reproduction in good environmental conditions, but in the presence of extreme environmental stresses might reproduce by creating r-strategy spores in a manner that caused the death of the parent.
[Answer]
The [common side-blotched lizard](https://en.wikipedia.org/wiki/Common_side-blotched_lizard), *Uta stansburiana*. There are 2 types of females in this species:
1. Yellow throated, who are K-strategists and lay small clutches of big eggs.
2. Orange throated, who are r-strategists and lay large clutches of small eggs.
The proportion of yellows to oranges fluctuates over time, as environmental conditions change and as the benefit of being the 'rare' colour waxes and wanes.
[Answer]
This is a fine strategy. There are organisms that do this. The one that comes to my mind is [physarum polycephalum](https://en.wikipedia.org/wiki/Physarum_polycephalum), which is a slime mold.
When times are good, the slime mold is a spreading, asexual slime.
[](https://i.stack.imgur.com/ibWkd.jpg)
When food runs low, the slime produces fruiting bodies called sporangia, undergoes meiosis, and sets free spores. The slime dies in the effort.
from <https://www2.warwick.ac.uk/fac/sci/lifesci/outreach/slimemold/facts/>
[](https://i.stack.imgur.com/qmKdf.jpg)
From the linked wikipedia article.
>
> As the food supply runs out, the plasmodium stops feeding and begins
> its reproductive phase. Stalks of sporangia form from the plasmodium;
> it is within these structures that meiosis occurs and spores are
> formed. Sporangia are usually formed in the open so that the spores
> they release will be spread by wind currents.
>
>
>
This is two different strategies as you state but represents an extreme of K-selection - rather than few expensive offspring (like elephants or humans) the asexual "offspring" of the slime mold contribute to the colonial organism that is the slime.
[Stress-induced flowering](https://academic.oup.com/jxb/article-abstract/67/17/4925/2197656/Stress-induced-flowering-the-third-category-of) is seen in a lot of plants - plants reproduce asexually by runners or the like, then flower and set seed (and die) when resources get low.
] |
[Question]
[
Sort of an extension of
[With minimal terraforming, what features/structures would need to be built to protect a 25mi radius city from wind?](https://worldbuilding.stackexchange.com/questions/82544/with-minimal-terraforming-what-features-structures-would-need-to-be-built-to-pr)
but with some more items to consider.
For whatever reason, a small city pops up in a cold region with constant snowstorms. The climate and terrain are similar to that of the Antarctic, only with more severe weather. It snows at least every other day, and wind is high. Naturally, people who reside in the city want to protect themselves from the severe weather, and want to be able to live a relatively comfortable life inside this city. They:
* Possess post-modern technology (things that are feasible by 2050)
* Have access to enough resources and manpower to complete this project, whatever it is
* Have access to reliable electricity
* Have built their city on ice covered but solid ground
* are numbered at 100,000
* have built this city in a 25 km sq area, in a relatively flat area.
They want to build something, or set up a series of systems or infrastructures to make the following possible:
* Temperatures inside the city is higher than outside (the higher the better)
* roads can be easily kept clear of excess snow
* wind is minimized inside the city
* pedestrians and motorists should be able to get around with regular winter gear (heavy coats, ATV's, snowmobiles), not specialized gear like the type that would be used in arctic expeditions.
Assuming they don't have to worry about food, water, or other things that an Antarctic settlement might need, how can they accomplish this goal efficiently? The criteria for efficiency are as follows (in order of importance):
1. Energy cost is kept to a minimum
2. Maintenance/manpower required to maintain is kept low
3. It would be good if less resources are spent to complete the project
[Answer]
You do not have to build underground to have a city where it snows.
Behold Minneapolis.
[](https://i.stack.imgur.com/WexIu.jpg)
from <http://www.captureminnesota.com/photos/1337765>
Minneapolis clears its streets and deals with heavy snow using snowplows. They pile all the snow up next to the frozen river.
Minneapolis averages 55 inches of snow a year. Yes, Buffalo NY averages 95. But Minneapolis has [skyways](https://en.wikipedia.org/wiki/Minneapolis_Skyway_System). They cover 18 km. You can go all over, in the light, and never go outside.
[](https://i.stack.imgur.com/Pfxht.jpg)
from <http://blog.radissonblu.com/wp-content/uploads/2016/08/image-1.jpg>
[](https://i.stack.imgur.com/8bqFQ.jpg)
It is not scifi. [Let Paul tell you about the skyway](https://www.youtube.com/watch?v=faAFVcm4A4M)
.
[Answer]
Rather than constantly fighting against constant snow and ice, they better build their city underground:
* rock provide a better thermal insulation from the outside cold temperatures and winds and also reduce the yearly thermal excursion, minimizing the energy needed to keep the temperature at livable values
* not having to worry about constantly cleaning roads and roofs from snow and ice will reduce maintenance efforts
* the rock removed from the excavation can also be reused as bricks or building material for the city itself, reducing waste.
If they have a reliable energy source they can use solar lamps to solve the lack of sun exposure.
[Answer]
Building underground as mentioned above would be the best long term protection, yet it will be costly and time consuming in the building Phase.
If you want to have your city on the surface, build wind breaking mechanisms or Channel the wind and use it for the city's advantage driving e.g. large turbines producing energy for you city. In this way you get two advantages in one action.
[Answer]
Constant snowstorms would actually not really happen. If the city is permanently frozen, there will be almost no snowfall at all (think Antarctica with 150mm of precipitation a year, while Aomori City has almost 8 metres yearly).
But let's consider that constant snowfall and snowstorms do happen in your world. I'd say build underground, but nobody wants to live like a mole. So, build a dome over the city? And pull heating wires all around the dome to melt all the snow that falls on it to prevent it from collapsing, along with canals and trenches around the city leading to a nearby river/lake. Of course, such a project would be majorly expensive.
Maybe the walls and pavement throughout the city have some sort of heater in them, and since a snowstorm includes strong winds, it can be wind-powered. This would get rid of accumulating snow, but wouldn't prevent it from still falling on people's heads. High tech carbon fiber umbrellas that can withstand storm winds?
By 2050, technology might advance by unimaginable amounts. 30 years ago, iPods and Gameboys were considered high-end tech. In another 30 years, who knows what we'll have. So you can create a cloud-busting missile, laser, gas, w/e that prevents the snowfall from even happening. A super-sonic tower that uses some sci-fi tech to disperse clouds?
] |
[Question]
[
So I'm working on an alien race I'm calling the Zaux. They look sort of like big, upright [stomatopods](https://www.google.com/search?q=stomatopod&safe=off&biw=1920&bih=950&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiL8MWrkOvPAhWprlQKHZzpBp0Q_AUIBigB). They're a super collectivist hive society, completely dedicated to their species' survival. Their homeworld is an extreme war ground of natural selection; species adapt and evolve far faster in a far more brutal competition than anything on Earth.
Their society does not waste labor like ours does. No one makes or consumes things that aren't needed, everything is done for the advancement of the species as as whole. Their species is a bit younger than ours, but because they're so much more efficient than us, they have a level of technology centuries ahead of ours.
Basically all of their tech is bioengineered stuff. What kind of weapons would they use? If that's too broad, I'll narrow it to this; what kind of significant near- and far-future biotech advancements can we currently foresee happening? Of those, what are weaponizable?
[Answer]
The advantages of bioengineered weapons are autonomy and self-replication. Truly advanced bioengineering would allow for the creation of terrifyingly effective weapons. This answer will cover some various archetypes of potential living weapons.
**Biological Warfare**
The simplest biological weapon to produce is one that humans are already working on. What we think of as “biological warfare”. This equates essentially to creating potent diseases. If your aliens use DNA and RNA then their engineering technology will likely work on our existing pathogens. The aliens will have to do a lot of analysis to figure out how earth biology works, but once they have the basics they will be able to create diseases more devastating than any humanity has ever faced.
Viruses tailored to wipe out entire human populations in days are only the beginning. Bacteria, fungi, and plants designed to degrade infrastructure and electronics, destroy crops and livestock are also possibilities. Entire ecosystems can be wiped out by the extinction of vital keystone species. Your alien genetic engineers could create blights to poison our soils, our seas, and our air. If they so wished they could destroy not just humanity, but life as we know it.
These are truly weapons of mass destruction. Nuclear or even an antimatter weapons merely render a single planet uninhabitable. These are weapons of genocide, contagious and persistent enough that refugees will bring with them to other worlds repeating the process over and over again. A single space-born spore would be capable of destroying an interstellar civilization.
**Conventional Warfare**
As far as conventional warfare goes I think it’s important to point out that there’s no reason it would be impossible to use biotech to manufacture weapons made out of metal and plastic and powered by electricity. I imagine you want your weapons to be squishy and gooey and squirming though, because otherwise what’s the point?
With that said, a lot of what is possible for your aliens in terms of weapons is going to depend on just how advanced they are. Our current metal, plastic, and silicon based technology is vastly superior to anything alive on earth and certainly anything Earth is capable of evolving. But your aliens are presumably capable of spaceflight using living spaceships so clearly they have improved on mother nature. Organic materials like spider silk can be quite strong and even surpass artificial materials in some areas. Fortunately for the aliens, the strongest material ever tested, graphene, is actually carbon based. In theory your biotech could be capable of synthesizing various allotropes of carbon. Weapon barrels, ship hulls, bunkers, and armor plates could be composed of monomolecular sheets of graphene, grown carbon by carbon by biological processes, sandwiched between proteinaceous layers that provide additional mechanical strength as well as thermal and electrical insulation. This sort of arrangement would likely be incredibly effective as a form of armor. On the offensive front biological processes are quite capable of producing potent poisons, explosive chemicals, strong acids, and the aforementioned diseases. This means in terms of conventional weapons you can easily imagine a big biological tank that your aliens can get in and shoot gouts of flame or lob explosive rounds from. But let’s try thinking outside the box. Why require your tank to be piloted at all? It’s a living thing, let’s make it intelligent. This is where the advantage of autonomy comes in.
**Autonomous Weapons**
Imagine a fruit fly. A tiny, 2.5 mm long, flying insect. It has 250,000 neurons that allow it to walk and fly, find food, mate, lay eggs, and avoid our clumsy attempts to squish it. It’s easy to imagine how a brain of that size could be programmed to walk and fly, find humans, deliver diseases, poisons, acids, and explosives, and evade basic countermeasures. I use fruit flies as an example simply to indicate just how small a brain is needed to enable fairly sophisticated behaviors that will make for effective weapons. It is this ability to produce autonomous, intelligent weapons that is the greatest strength of organic technology in “conventional” warfare. Your missiles won’t be fooled by flares or other countermeasures. Your tanks will be savants in calculating trajectories. Your landmines will distinguish between friend and foe.
By autonomy I’m not just referring to the ability of these weapons to function without their masters, but also their independence from any logistical structure. They are fully combat effective without any outside input in the form of supplies or commands. A surface-to-air missile is expensive. Humans have to mine and refine all sorts of materials, shape them through several successive steps, create incredibly advanced microchips, assemble it all together, transport it out to the front lines, and put it on a launcher. Imagine if you could simply plant a seed on the end of a nutrient hose and grow an intelligent missile. As it grows it chemically refines its nutrients into an explosive warhead and fills an internal cavity with fuel. It creates its own launching structure and grows aerodynamic, adjustable fins and a gimbaled rocket nozzle. At its nose it forms an advanced eye constantly scanning the sky and just behind it a brain instinctively programmed to destroy enemy craft.
While this missile may be significantly less effective than a human-crafted one, its important advantage is it is free. Made organically from the water, soil, and sunlight of a world it didn’t have to be transported to, it is simply grown right where it is needed.
Now imagine that nutrient hose which provided everything the missile needed also grew from a seed. A seed that was planted in plenty of sunlight on the banks of a river that grew huge arrays of photosynthesizing leaves for energy. The hub sends roots deep into the earth and water to harvest the necessary materials and uses them to feed a whole battery of missiles, interceptors, ground forces, and of course, seeds for more hubs. An autonomous, intelligent, self-reproducing weapon that requires no logistical support.
Your biological weapons might not be as fast, or as sturdy, or as powerful as their man-made counterparts. But they are going to be numerous. They are going to be smart.
[Answer]
You may want to look into some existing examples of species that use biotech as their main form of technology. For example:
* Yuuzhan Vong (Star Wars EU): spaceships and armor grown from coral, weapons are organisms that eject plasma or molten rock (depending on the creture), shields are organisms that generate tiny black holes to 'suck in' enemy weapons fire (perhaps too much sci-fi for you) working on both energy- and mass-based weapons. They basically use advanced bio-engineering to make creatures to do whatever they want.
* Zerg (StarCraft): spaceships are entire living creatures, weapons mostly based off currently known biological processes (create and eject acid, poison, toxins, etc), instead of shields armor is a strong carapace. They basically use targeted evolution to develop useful weapons/defenses.
* Wraith (Stargate: Atlantis): spaceships are living beings, computers are essentially creatures with nerves/neurons acting as wires/processors, weapons are energy-based, but likely bioengineered similar to the rest of their tech. They use bio-engineering to create useful tools, but also use the Ancients' technology as a basis I beleive.
* Xindi, reptilians (Star Trek: Enterprise): I mostly mention this only because of the one episode of Enterprise where Reid/Tucker/Phlox open a Xindi weapon and find a maggot-like thing that generates the power for it. I don't know what they mostly do, I'm just remembering from one episode.
Those are just a few I can think of off the top of my head.
Something you may want to try is:
1. Think of a target concept the Zaux would need (i.e. wepons)
2. Think "what can be used as a weapon?" (i.e. solid projectiles, energy, chemicals)
3. Think "what in our world can do stuff like this?" (i.e. we can throw things, snakes make/spit venom, eels generate electrical fields)
4. Take those ideas to the extreme (i.e. combine the pistol shrimp's crazy claw thing with a solid object like a quill/stinger or venom to shoot it at enemies, or an eel's electrical field generation to either power a weapon or to generate an electric shock as a weapon)
That could help you build a species that people will think "wow, that's plausible for a futuristic species to develop because earthly creatures already do that!" about.
As for generic advancements, bio-engineering is very broad. Near-future advancements could be things like creating bio-armour that utilizes a chameleon's camouflage, or an eel's electrical field for power generation, or even plant photosynthesis (takes care of air-recycling, too). Far-future advancements could be similar to the Yuuzhan Vong, with the ability to design an entirely new species with a singular purpose (i.e. a snake-like thing that crawls down your throat while leaving a starfish-like ending over your mouth/nose that inhales things from the starfish thing and exhales oxygen/nitrogen combination from the part in your throat to allow breathing in extreme environments... creepy, but effective).
[Answer]
I think biotech is in such a state of infancy, that there won't be much we can guess based off it at present. Unless you want to have truly terrible viruses, we're good at making those. Or say, glowing sheep.
Centuries ahead is also hard to say. By then, we might see carbon nanotube lifeforms able to smash through brick walls like super heroes. You might be better to think of known limitations of biotech and make some adjustments based off breakthroughs your aliens have made. The obvious limitation is that the creature is growing these aspects, it needs all the nutrition and elements involved in them, and if you make use of exotic materials the creatures needs to somehow be able to digest and process those.
For example, if they worked out how to make more efficient muscle fibers, so they can make a human twice as strong, that can allow for some creature designs that would be too heavy or slow. Of course, you would also want a discovery in stronger skeletons, so they can utilize that greater strength without breaking their bones.
The obvious one is being stronger, or faster, or smarter, or more durable, or whatever, and just doing the same things better. A stronger man can carry a more powerful gun and more armour. Beyond that, I'm afraid there's too little information and too many possibilities.
[Answer]
Given their society, I can imagine these creatures are pretty damn ruthless in their application of force. A lot of our war fighting technology is deliberately limited or designed to destroy the enemy's own warfighting tech. Weapons like flamethrowers, napalm, chemical weapons, radiological weapons, etc, are uncommon, not because they're ineffective, but because they're *horrible*. They're designed to kill people in terrible, indiscriminate, and painful ways, so humans recoil from the idea of using them.
The zaux are unlikely to have that kind of squeamishness. That opens a lot of rather horrible avenues.
At the low tech end:
The [Bombardier beetle](https://en.wikipedia.org/wiki/Bombardier_beetle) has a remarkable defence mechanism, which combines two harmless chemicals in its abdomen to create a caustic, boiling hot mixture which it squirts out of its body at predators. A similar weapon could be imagined which creates napalm from precursor chemicals, and/or converts phosphorus into white phosphorous. It would be hard to beat at short ranges.
A more extreme possibility could be an organic railgun. A railgun works by running electrical current (which can be generated organically) along a conductive rail (this could be made from iron, copper, or other metals that can be absorbed organically), through a metal slug (ditto), and down another rail on the other side, and it can generate some truly fantastic speeds. The biggest problem we have with railguns right now is that the rails wear out very quickly, a problem that could easily be solved in a biological system that could just regrow the parts.
The downside to any kind of organic technology, of course, is that it's not easy to carry large amounts of ammo. You can't just strap on a backpack with another couple of magazines, so each soldier would need downtime between battles to replenish their ammunition supplies. Or, alternatively, they could be grown, sent into battle once, use up their ammo, then throw themselves at the enemy with melee weapons. After the battle, the survivors could then be eaten by the next generation of grubs.
[Answer]
Considering they are similar to the Mantis Shrimp, the first thing that comes to mind in terms of weapons is their cousin the [Pistol Shrimp](https://en.wikipedia.org/wiki/Alpheidae)'s claw for ranged combat (They could improve the design to increase efficacy). For melee engagements larger claws (possibly strengthened by coating them in metal) as well as well as chitin blades grown/mounted on the arms. Another common mod would be tougher and/or lighter exoskeletons depending on the individual's role (soldier, builder, scout), coupled with denser muscle mass in required areas. Some shrimp can also change their pigmentation for camouflage, so this too would be a commonly used augmentation.
These are not too far fetched as the should not be intrusive to the Zaux biology and can be shed if need be. This is assuming they are also biologically similar to the mantis shrimp.
[Answer]
Biology is one route to understanding and bootstrapping nanotechnology. They may be in the process of developing general nanobots—utility goo that can do anything or become anything. Before that, bacteria modified with novel metabolic pathways to do any chemestry and nanofabrication: not programmable but built for each purpose.
Weaponizable? Oh yea. Disease targeted to the enemy; swarms that invade and disassemble the enemy resources; reprogram indigenous life forms to be bombs or produce toxins.
[Answer]
well they can do basically everything that our technology can do and much more. Wide range of weapon from claws and teeth, to tusk, poison darts, acid spray, even magma, or biological virus, or even they can spread virus that make the victim to be their army with hive minds. Eels use electricity as their defense, so if their evolution is so advance they can supposedly do what our technology can do, maybe they can even do an emp attack, read radio signals, or atomic fusion for bombs and their bio thruster. They also can have a flies that act as their drones, a strong carapace to even protect them from magma heat and projectiles.
Not to mention you can also add some X-men likes ability, maybe their evolutionary process are so harsh that makes them can briefly stopped time or see the future. While an instant regeneration would be nice for them to have. And also a very survival evolutionary process can make them developed a hyper adaptability, so if they usually breath nitrogen, in minutes after they arrive on earth they would have adapt to breath oxygen and eat our food. Dangerous chemicals will do no harm.
Next question is how can you kill a civilizations with creatures like this?
[Answer]
**Ammo**
Homing Bullets. Flying insects with pistol shrimp-like claws that find a victim and fly upwards in a parabola. At the peak, they start gliding downwards slowly, and use the pistol shrimp hammer-claws to launch themselves forward and shoot into their target like a bullet, cutting their spinal cord.
**Melee**
Blunt bony hammer-like tools with claws on either side to destroy enemy craft.
Stinging nettles the size of swords with deadly neurotoxins in the needles.
**Explosives**
Witch hazel-like plants that explode on contact, with the force of a megaton of TNT.
] |
[Question]
[
**Closed**. This question needs to be more [focused](/help/closed-questions). It is not currently accepting answers.
---
**Want to improve this question?** Update the question so it focuses on one problem only by [editing this post](/posts/51892/edit).
Closed 7 years ago.
[Improve this question](/posts/51892/edit)
Worldbuilding, meet Bob. Bob meet Worldbuilding. Bob has the ability to pinch time and space and tear a hole at the pinch point. The result is a temporary opening, or portal, from Bob's location to anywhere he's been or seen before. When Bob first realized he had this ability, he could only open very small portals between locations and they only stayed open for a couple of seconds. As Bob has developed his ability, he is able to open larger portals.
Bob has figured a few things out about his ability:
* The largest portal Bob has been able to open has been 3.5m x 3.5m
* The portals can be opened in basic round or quadrilateral shapes
* The larger the portal, the shorter time it can stay open; his largest will only stay open for 5 seconds but he can create *45cm* round portals that stay open for **30 seconds**, the longest of any of this portals
* The larger the portal, the more energy Bob has to exert to pinch the entire area together
* Bob's portals can be opened anywhere in local space as long as he can see the location the portal is created; this can be accomplished through a telescope or binoculars but Bob has less control of the size, space, and duration
* Once the portal is opened, Bob does not have to do anything to keep it open and he cannot force it closed
* Bob's portals exert no force on objects `around` them, unless the portal is opened under an object in which case gravity would cause the object to fall into the portal
* Portals are two dimesional and act as doorways; objects can pass through from both sides, people on either side can see through them; the back side of the portal is as impenetrable as the sides
* When Bob was little, he accidentally opened a portal in the same space as a squirrel. The squirrel shrieked as its body was ripped apart by the expanding portal. Bob cried. Bob has since opened portals in the same space as boulders, steel safes, and in the side of a hill - the objects either flew apart or a portal shape was left in the object. The border of the portals seem indestructible.
* Bob once opened a fist-sized portal from one side of his room to the other and held a pencil in the portal. He was amused to see the point appear on the far side as he moved the pencil in and out. When the portal closed abruptly, Bob was glad his hand was not in the portal as the pencil was cut clean and smooth as if by a razor.
* There are no "after affects" once the portal has been created and nothing to indicate it was ever there once it closes
Bob wants to use his ability practically. But he's also concerned about how people will respond once he reveals his ability. He's not much of a fighter, so the military is out, and he's naive enough to think that's an option. Bob doesn't have any delusions of grandeur and that whole double life, super hero thing sounds exhausting.
**Changing up the question to reduce the scope...**
Bob wants to jumpstart space colonization, starting with the moon. Due to the unpredictable nature of opening portals by looking through a telescope, this won't be as easy as looking through a lense and creating a portal.
There are limitations to how much equipment can be moved safely with Bob's current abilities. The vaccuum of space will present a problem if a portal is opened on earth. The squirrels shrieks forever haunt Bob and he doesn't want to see it happen to a human.
Logistically, how does Bob get the equipment needed to the moon as quickly and safely as possible?
[Answer]
I am just writing one answer out of hundreds. Send Bob to space and ISS. Now you can launch satellites for a fraction of the cost. Also transferring stuff to and from ISS is now almost free. Get him to the Mars, he can return instantly and we can begin colonizing it. Space front is looking bright with him.
**Edit**
You don't actually need to send him to Mars. Just make him see inside to a pod, send the pod to the Mars. Get him teleport to pod to see the environment. No need to risk him with the journey.
[Answer]
# Bob can generate infinite amounts of energy
By using portals to move water into an area of higher gravitational potential, Bob can generate energy with a [hydroelectric power station](https://en.wikipedia.org/wiki/Dinorwig_Power_Station). However, due to the relatively small size of the portals Bob can open, he will struggle to generate more than 1MW, yielding him only about £6 every time he can manage a 45 second portal. This isn't really enough to justify the expense of the equipment, so this is out as a money-spinner.
# Bob can precisely cut items
The ability to precisely cut items is very powerful and very expensive. Bob can create flat planes in any material better than any other manufacturing system. He can cut industrial diamonds as well as produce parts precise enough for any engineering company. I would expect that this talent is easy enough to keep relatively secret and so Bob is unlikely to come up against any negative consequences for using this power despite making quite a lot of money!
[Answer]
I'm just going to come out and say it...
''Take from the rich, give to the poor!''
Yes, that could lead to an exhausting double life scenario, but he's naïve! He may just realise it's worth it. Or starts out so small, he doesn't realise how exhausting it is until it's too late!
I assume, that with his ability, Bob never completed college? Why would he when he can do what he can do. This way, authorities won't suspect Bob as he won't have the 'technical' expertise to do these robberies. I mean, what college dropout would ever be able to literally cut open ever single safe he/she came across and be gone in less than 3 minutes!
As long as Bob doesn't live beyond his means, he will be able to help out the poorest of the world's populations.
When he get's bored with taking from just any rich dude, he can start investigating them. Figure out which rich dude needs the most taking down. He could use his abilities, not necessarily to steal the wealth, but to get the hidden evidence needed for the governments and judiciary to convict and imprison these self righteous pompous bastards for various crimes. (note, not all rich dudes are pompous bastards, but a vast majority are)
But again, this might just sound too exhausting to Bob.
But think, Bob, the ability to get into any lockbox and ferret out any secrets...**that** would be of the most benefit for mankind!
If that's not enough to convince Bob, just tell him it will get him the girls (or boys)!
[Answer]
If Bob will ever make his ability known, he will be studied by scientists of the country that's first to know about him. After all, if he can do it, then it's only a matter of time and effort to make machines do it, right?
Of course he can run, but government would look for him, and he would spent rest of his life as a fugitive, until he would get too tired. Or he will end up with collar that will administer sleep drugs and send signal to acquisition team when it no longer receives signal from lab transmiter. Can't really run with that on.
So that's it, either golden cage in a lab, and illusory freedom, or running.
---
When it's replicated, it's another story. New chapter in travel, war and so on. But no way it'll be about one man with freedom to choose.
[Answer]
## Power The World
You will need
* Bob
* Underground lake
* The Sun
* Huge Steam Engine
Bob makes a portal between the underground lake and deep beneath the Sun's surface. The force of a nuclear explosion is contained by the rock as high pressure plasma rushes through. The lake is heated to boiling. Several of the worlds largest power stations sit above the lake, generating a majority of the worlds electricity. Bob makes a portal three times a day and is immensely rich. He has also sent a lot of space probes across the solar system and beyond.
[Answer]
Open a portal from the top of a room to the bottom.
Encase the portal "cylinder" with coils of wire.
Drop a powerful magnet into the top portal - it will fall through the coil generating electricity for 45 seconds.
Increase the scale a little - free electricity for ever.
Taken from [Tom Scott's video](https://youtu.be/zJt8yzR2aoY?t=173).
] |
[Question]
[
This questions came to me after some discussion on [my previous one about a civilization living under Antarctica](https://worldbuilding.stackexchange.com/questions/42304/how-could-a-human-civilization-have-happened-to-live-underground-in-antarctica).
I somehow have the feeling this is a dumb question - sorry if it is -, however I can't figure out what the answer would be...
## **If a human population whose members are black-skinned came to live underground for generations, would they become paler and paler or would they stay black ?**
**What I know :**
* The reason why cave creatures are mostly white or extremely pale is because **skin pigmentation is a process that takes energy to the body to achieve** and therefore in the absence of light, it would be a waste of energy.
* **Natural selection** keeps the best genetic options to help animals and humans survive in their environment. I know the process and how it works ( the strongest survive longer and then can have more descendants ; dominant / recessive genes ; etc). However in this case, I can't figure out if natural selection would "chose" dark or light skin.
**What I wonder about :**
* *Wouldn't natural selection in this case **prevent those people from whitening*** ? I mean, in caves with low light, it is easier to hide (whether for escaping or hunting a creature) when you have dark skin. So would the ones with a darker skin survive easier ?
* *Would there be a natural selection process at all* considering **this is a united and organized population where the weakest are helped by the strongest** ? Also would having a black skin (in the case where white skin would be better for survival) be a sufficiently "dangerous" characteristic to provoke enough death to trigger natural selection on the concerned genes ?
* Speaking of evolution, *could it possibly make new generations whiter*, despite **all** members of this population are black-skinned and then have this characteristic in their genes ?
* If this process of whitening was to happen, *how much time would it take* ? I assume it would take longer than other human mutations because of the transition from very dark skin to very pale, but I hardly can put a time scale on it.
*I know these are a lot of interrogation but I think they are all important points to consider in order to answer the question*
Thanks in advance for your answers :)
[Answer]
Permanent changes in the skin pigmentation of a human population are only likely to result from evolutionary selection processes. Dark skinned humans have evolved into lighter-skinned humans before, [when early humans migrated from Africa](https://en.wikipedia.org/wiki/Human_skin_color#Evolution_of_skin_color) and the reduction in the amount of sunlight meant the being dark-skinned was no longer the advantage it had previously been (protection from strong sunlight), and lighter skin provided an advantage (better vitamin D production).
In the "united and organized population where the weakest are helped by the strongest" you describe, the natural selection process is likely to be very slight or non-existant as the survival rate for *all* humans will be relatively high, so the evolutionary pressure is not there and changes in base skin colour would be unlikely.
If for some other reason than natural selection there ended up being a bias toward lighter skin (e.g. social or religious practices) then some change would take place over a long period of time (in the order of 10s of millenia).
[Answer]
There are a couple of factors to consider.
1. Founder's effect: I.e., what is the genetic make-up of the individuals who head underground? If it is a small population with absolutely no genes encoding for less melanin production then it would take spontaneous mutations to slowly drive down the amount of melanin (and given the generation gap for humans, this would take a LONG time). But if the population is mixed then lighter color genes would already be present so it could happen fairly quickly if there was selection pressure for lighter skin.
2. Selection pressure may not act on skin color, but could act on a expression of a gene NEAR the genes for skin color. I'm not aware of any good candidates but since the human genome is mapped you could find one or just make it up. Anyway, individuals with chromosomes with genes for lighter skin color also have a beneficial gene for something else (maybe they resist some toxin in the cave environment better) so there is indirect selection pressure for lighter skinned individuals.
3. Without selection pressure a gene does tend to favor the least energy utilizing variant, but I don't think dark skin versus light skin has enough of a energy difference for it to matter for humans (who are already pretty energy inefficient if they have a working society and aren't subsistence level scavengers). So social pressure may come into play. Perhaps an albino takes over in a coup and deliberately seeds the colony with his offspring (like Genghis Khan). Or lighter skinned folks are viewed superstitiously and are killed as infants. Those types of social pressures may do more to alter skin color in humans than environmental selection.
4. Epigenetics may be able to give you a rapid shift with an immediate downregulation of melanin production despite the continued presence of the genes. Of course how epigenetics works is still in its infancy but the gist is that there are mechanisms to up or down regulate gene expression outside of DNA so it could be possible that the cave group could lose their melanin in a generation or two even though they still have the genes for black skin. Highly speculative of course since epigenetics itself is controversial and whether or not there are any mechanisms for skin color is unknown!!
[Answer]
While natural selection shouldn't be having much effect if the civilisation is organised and has decent technology, there will be a general whitening if they remain underground. The human body is very adaptable, you don't even need natural selection to see the effects. The first generation of children will all be far paler than their parents, as their skin pigmentation will alter dramatically. The parents themselves will be paler than they were when they entered the caves.
Vitamin D intake will be an issue for everybody though, if there isn't enough sunlight or alternative sources of the vitamin to keep people healthy, there will be problems. Conversely, if there is enough sunlight to provide the intake, there is possibly enough sunlight that there won't be a pronounced change in the population. They will get paler, but possibly not enough to be noticable.
[Answer]
No, as far as we know.
The lighening of skin is due to selection pressure regarding sunlight making vitamins, and lack of countering with the need to prevent sunlight from breaking down folic acid.
Some nothern people have not become pale because they get vitamins from their diet and don't get much sun on their skin.
So I would suppose that cave people would be the same way.
[Answer]
## No... well it depends
Everything you know is correct, but the answer depends if the civilization is there before or after sapience evolves.
* If they were there before sapience and the cave have little to no light, they
will pale out. There isn't enough light to see even a light skinned person, so there is no benefit to being dark skinned.
* If they were there before sapience and the cave does have some natural
light, they will not. There is enough light that being dark skinned helps hide you in the rocks.
* If they were there after sapience, it does not matter the light level, they will choose mates because of "*love*" instead of best features. So specific appearance traits will be mostly equal. This is why humanity has so many different body plans, fat, slim, short, tall, etc. It doesn't matter, someone will always have opinions on these traits.
[Answer]
One thing to note in evolution is the principle of "use it or lose it" which, in essence means if a trait (in this context a protein) not beneficial to an organism, it can be mutated over without consequence. Dark skin is a consequence of high concentrations of eumelanin, which are produced by melanosomal proteins.
From Wikipedia on the origin of dark skin:
>
> In the heat of the savannas, better cooling mechanisms were required, which were achieved by the loss of body hair and development of more efficient perspiration. The loss of body hair led to the development of dark skin pigmentation, which acted as a mechanism of natural selection against folate depletion, and to a lesser extent, DNA damage. The primary factor contributing to the evolution of dark skin pigmentation was the breakdown of folate in reaction to ultraviolet radiation; the relationship between folate breakdown induced by ultraviolet radiation and reduced fitness as a failure of normal embryogenesis and spermatogenesis led to the selection of dark skin pigmentation.
>
>
>
So humans developed darker skin in response to ultraviolet radiation from the sun. Without the selection factor of the sun being involved in underground dwelling species, the melanosomal proteins are more likely to be mutated over and become "junk" proteins. This would lead to a paler and paler looking human.
Also, in underground caves and caverns, there will be little light, so having any kind of pigmentation at all would simply be a waste of resources.
[Answer]
Yes, because ultimately variation of darkness would occur, which in terms of survivability would be of no difference in this environment. As long as society wouldn't be selective itself (they would not prefer to mate with white mates due to racism, they might actually prefer white people initially if they are rare), populations will light up. They won't turn completely white however.
Keep in mind though, this is only based on the change not affecting survivability at all. We do not have enough information to ultimately decide on this, to be honest.
] |
[Question]
[
I was watching a television program recently about [Naked Mole Rats](https://en.m.wikipedia.org/wiki/Naked_mole-rat) and how they are they are one of the only known [Eusocial mammals](https://en.m.wikipedia.org/wiki/Eusociality). They have a single queen who produces offspring as well as warriors and worker castes (the most well known example is an ant colony).
This got me thinking could humans (or at least human like creatures) ever live in a similar society?
The obvious problem I see would be the gestation period, if the queen has a nine month pregnancy then there will be a far lower birth rate than the moles. How could humans develop a similar society to ants or mole rats?
[Answer]
Yes, definitely.
The biggest change as you've already identified is pregnancy. It's noticable that the main eusocial species are egg layers which means the investment by each queen in each young is lower. Naked mole rats are the exception and in the wild they produce litters with an average size of 11 around once a year. That's a lot of babies for a human to produce but with 4 month pregnancies and multiple births of 4 or 5 at a time it would be reachable. Considering human babies have survived being born 6 months old or even younger it's clearly possible if they were adapted for that.
The queen would have much shorter pregnancy cycles and most likely multiple births as well. The babies would then be handed off to special nursemaid drones who care for, feed, and raise the young until they are old enough to take whatever role they were bred for.
Society would be very stratified and have a reduced sense of self - the average member would value your colony far more than yourself and they would quite literally be bred for certain things.
Warriors, Nursemaids, Workers would all be born adapted to that role and raised to fulfill that role. No doubt occasional ones would move against that but it would be rare, even with sentience.
Whether the queen is the main thinker of the colony could be true but in fact is unlikely to be, there would most likely be a "thinker" type to go with all the others.
[Answer]
It might be politically incorrect, but what about a king rather than a queen? There's no physical problem for a man with a harem creating babies at a high rate.
It was might equals right rather than altered human nature, but ISTR one of the mesoamerican cultures worked this way. All female children belonged to the king. All male children were raised as warriors. Successful warriors were rewarded by the king with a wife, or for greater success, wives.
] |
[Question]
[
In my setting, military innovation spurred by the American Civil War (1861-1865) prompts the design and construction of counterweight-driven skyhooks for the delivery of suborbital long-range munitions.
The devices, nicknamed "Tennessee Slingshots," are used to bombard Charleston and Vicksburg with barrages of small bombs with parabolic transatmospheric trajectories. The bombs are poorly aimed, and don't ultimately contribute in any significant military way to the more focused destruction wrought by heavy mortars and traditional artillery. But the relatively modestly-sized Tennessee Slingshots excite scientific and engineering interest in the possibilities of space exploration, given that the objects launched by these skyhooks are the first man-made artifacts to exit the lower reaches of the Earth's atmosphere.
After the war, continued engineering improvements lead to a decision to invest in a massive public works project - a huge space city that takes advantage of the rugged terrain of Mexico's Barrancas del Cobre. The fact that this canyon system in the western Sierra Madres is relatively close to the equator means that it's possible to take advantage of the Earth's rotational momentum, and the depth of the canyon means that the height differential allows for the construction of a number of experimental counterweight-driven skyhooks of larger and larger size.
Ultimately, a great chunk of mountain is excavated and fashioned into a massive half-million-ton counterweight on angled tracks, tethered by massive iron cables to elaborate transmission-works that translate the mechanical movement of the counterweights into the the supersonic movement of a tracked launch assembly that runs up the side of a mountain and continues on a slender rail supported by towers high into the air.
The gear ratio is such that as the counterweight slides three or four miles down a steep slide into a water pool, a looped cable is accelerated along a twenty-mile track until an object carried in a sled on the track is traveling fast enough to achieve escape velocity.
Upon reelection (following the intervening term of his rival Benjamin Harrison), Grover Cleveland announces at his inaugural address that he will authorize funds and support the goal of the Mexican-American Aeronautic Corporation to safely launch a man into orbit and retrieve that aeronaut by the end of the decade.
Is this effort doomed to fail? Could late-19th century engineers have successfully built such a skyhook, or are the available materials and technology not up to the task? Would massive iron chains snap like taffy under the strain, or would friction cause the whole building-sized gear assembly to melt and disintegrate? I'm trying to conceive of a mechanical orbital delivery system that would not rely on concussive chemical acceleration - the lead engineer would at least be aware that you can't shoot people out of a cannon - hence the long acceleration track and geared transmission. And I want to limit myself more-or-less scrupulously to the industrial and scientific capacity of the 1880s, without resort to hand-waving, anachronistic developments, or pure balonium.
[Answer]
## Can you even go suborbital?
Assuming a spherical ~~cow~~ iron projectile at 2000 kg, we can use a simplified atmospheric model combined with the drag equation to find an estimate for the required staring velocity to reach an altitude of 100 km, the [Karman line](https://en.wikipedia.org/wiki/K%C3%A1rm%C3%A1n_line).
6000 km/h is the number. That is six times faster than a projectile fired from a high velocity artillery cannon.
Accelerating up to that velocity at 10 g is going to take a 14 km long track.
## But that is just suborbital…
The problem with an orbital launch is that you have to give the spacecraft a horizontal velocity in order to reach orbit, and that means that the projectile must travel pretty much horizontal from the beginning because it does not have its own propulsion system. The minimum velocity needed is 28000 km/h, and that is even before you start to compensate for drag. Your trajectory is going to look something like this:
[](https://i.stack.imgur.com/r6cArm.png)
Note how almost a quarter of it is inside the atmosphere. Ever tried to run through a swimming pool? Imagine doing the same, but at over 30000 km/s from North America to Africa. Also, it is easy to see that after one orbit you end up back at the launch site if you can not raise our apoapsis by the use of something like a primitive gunpowder rocket.
That makes a required 10 g launch track of at least a length of **1000 km**. You can of course go further than that, and analyse compression heating, wire stress, etc., but I think that this is enough to say that it can simply not be done.
## The point is:
When launching from something based on the surface, all the required velocity must by provided in the beginning. That makes losses due to drag ridiculously high.
[Answer]
In addition to the drag problem that Hohmannfan addressed there's also the problem that your device can't put anything in orbit, period. Orbital mechanics 101: Your orbit will intersect the location of the end of your last burn.
While you aren't using a burn per se the same thing applies here. Your orbit intersects the end of your catapult. Unless you can somehow make the release point exoatmospheric (something we just might be able to do today, certainly not then) your "orbit" comes back down, you don't stay in orbit.
[Answer]
There are excellent reasons given in other answers about why getting into orbit will be difficult, but even if you find a way to overcome them all, you still have the second half of the problem to contend with:
>
> to safely launch a man into orbit **and retrieve that aeronaut**
>
>
>
Assuming you are talking about actually orbiting the earth as opposed to just going above the atmosphere and back down in a balloon, then even in low earth orbit, your satellite will need to be traveling about 7.8km/s (about 17500mph). To return from space, you will need to slow down. To use the atmosphere to slow from that speed generates an extraordinary amount of heat. Bearing in mind that the laws of thermodynamics were still being argued over, and material science had yet to be invented, the sort of heat shields you would need to survive simply could not be made at that time, so your only option is some sort of rocket powerful enough to reduce your speed sufficiently that you would not need to use aero-braking.
All is not lost though, as rockets were pretty well known then and developing a super-efficient rocket fuel is not beyond the possibilities of the time such as a slow burning TNT. The combination of the two technologies could possibly achieve your goals. A trebuchet type mechanism to throw your satellite from the top of a mountain above the thickest part of the atmosphere (at least a mile, preferably more than 5 miles) where a rocket motor ignites to push you into orbit. More rockets are fired to slow you down almost to only a few hundred miles an hour as you drop to a final landing probably by parachute as gliders were only in the process of being invented in your timeline.
[Answer]
I suspect that while you could transfer enough momentum with a version of the set up you've described it would actually *shatter* any projectile you tried to launch; the acceleration track is relatively short and it's at low altitude where atmospheric friction is at it's greatest. Snatching up a multi-ton object from rest against it's own inertia up to escape velocity in the space of a few seconds is going to create/require stunning forces, far in excess of the material strength of most modern alloys, doing it to late 19th century metals is going to be disastrous. That's before we get into discussions of how this doesn't work because of orbital mechanics or the difficulties of retrieving an object that doesn't have any form of motor of it's own. Even if you can somehow handwave a system that works for getting payloads orbital you also have to provide a situation in which you can support the logistical effort to supply those payloads, I'm not sure that the economy of post-civil-war USA is up to the task.
] |
[Question]
[
Science fiction often depicts humans visiting alien planets which have unbreathable atmospheres. No problem; they are shown wearing atmosphere suits including a helmet with a transparent visor/faceplate or a transparent globe over the entire head. My question is, what happens when it rains? Most of the designs of helmet shown on SF cover art would mean that all the wearer would be able to see in heavy rain is a curtain of water streaming down the surface of the [clear polycarbonate plastic](http://www.astronomyforum.net/off-topic-forum/153046-what-space-suit-visors-made-if-you-can-answer-your-my-hero.html) or whatever the visor is made of. Our intrepid explorer would then have no option than to stay where he or she was until the weather cleared.
Two strategies immediately occurred to me. One is to have little windscreen wipers. The other is to carry an umbrella. Would these strategies work? Less drastically uncool would be to have a little brim to your helmet, possibly retractable, but with that you are still going to have difficulties if you need to look up.
I also ask this question on behalf of any aliens currently visiting my corner of Earth, where the weather is particularly dismal today.
[Answer]
**They would use a [superhydrophobic coating](https://en.wikipedia.org/wiki/Superhydrophobic_coating).**
The problem with regular glass or plastic is that it [gets wet](https://en.wikipedia.org/wiki/Wetting). This means the liquid falling on it sticks, changes the [index of refraction](https://en.wikipedia.org/wiki/Refractive_index) in that spot, and reduces visibility via distortion.
A surface with a superhydrophobic coating doesn't get wet. Fluids don't stick to it. It's often observed with the [lotus effect](https://en.wikipedia.org/wiki/Lotus_effect).
[](https://i.stack.imgur.com/6dhb6.jpg)
This is commonly known as "beading". If the water doesn't stick then it simply falls off and doesn't reduce visibility any more than the rain falling in front of an umbrella would.
The additional benefit is the glass stays very clean. Alien super-pollen is not something you want to track back into the ship.
[Answer]
Do motorcycle helmets have windscreen wipers?
Not usually, and yet they work in all weather conditions.
I'm not a motorcyclist myself but I'd expect this to be due in large part to the materials used, the wind over the glass, and the fact that you can use your hands to wipe the surface when needed.
You can expect space explorers to have very good materials technology, good enough that their face plates would repel water and dust to a large degree. They can then be cleaned easily enough just by wiping them with a suitable cloth.
[Answer]
Can you still see out a window when it's raining? Granted the visibility is much worse, but you aren't blind. Really heavy rains will affect visibility even with some kind of umbrella. Speaking as someone who's worn glasses in all weather for almost 30 years, rain on the lenses does make it more difficult to see, vs. using an umbrella but all it really does is push back the clear area 18".
I think the best option would be to use [rain-x](https://www.rainx.com/product/glass-water-repellents-cleaners/rainx-original-glass-treatment/) to help the 'glass' shed water better. Of course there might be plenty of other chemicals that you need to watch out for that just water if you are on a planet that you can't breath the atmosphere. Many of those chemicals when you add some water make them more corrosive. So I think finding shelter would probably be more important than worrying about visibility.
] |
[Question]
[
Assuming a technological progression roughly similar to that of Europe in our world, what is the earliest that a civilization could have developed rigid-frame [airships](http://en.wikipedia.org/wiki/Airship)?
For example, one could imagine that steam engines could have been invented much earlier in history, because [they basically were](http://en.wikipedia.org/wiki/Aeolipile). However, skateboards wouldn't have been likely much earlier than the 20th century, because there weren't many flat, smooth walking surfaces during the ages of cobblestone and brick.
Given the technologies and and resources involved with creating and maintaining airships, how early could a civilization plausibly have developed them?
[Answer]
**TL;DR: It all comes down to who can make the framework - and who has helium.**
[Blimps](http://en.wikipedia.org/wiki/Blimp) are fairly easy to make - at least, low-quality blimps are easy to make. In theory, all you have to do is insert some hydrogen (or helium, if it's cheap and plentiful) and let the thing fly. Sure, you have to make major modifications so you can actually steer the thing, but you can get it off the ground easily. The same goes for [hot air balloons](https://en.wikipedia.org/wiki/Hot_air_balloon).
[Rigid airships](http://en.wikipedia.org/wiki/Rigid_airship) are a wee bit trickier. You need a very strong internal structure that can resists extreme pressure and keep the lifting gas inside. You can use small "cells" of gas
Image from Wikipedia user 84 user, currently in the public domain.
as shown here, but you still need a large framework - as shown here, the skeleton of the [USS Shenandoah](http://en.wikipedia.org/wiki/USS_Shenandoah_(ZR-1)):
Image from Wikipedia user Saperaud~commonswiki, currently in the public domain.
You can make the lifting cells rather easily, but it's the rigid structure that presents the big problem.
---
The famous [Zeppelins](http://en.wikipedia.org/wiki/Zeppelin), often considered to be the greatest airships ever built, used a metal framework to hold everything together. [Count Zeppelin's](http://en.wikipedia.org/wiki/Zeppelin_LZ_1) first creation, the [LZ 1](http://en.wikipedia.org/wiki/Zeppelin_LZ_1), used aluminum. It's more famous cousin, the [LZ 129 *Hindenburg*](http://en.wikipedia.org/wiki/LZ_129_Hindenburg), used a framework of [duralumin](http://en.wikipedia.org/wiki/Duralumin), a strong aluminum alloy. Duralumin actually was first widely used in airships.
Duralumin was only created in the early 20th century, but [aluminum](http://en.wikipedia.org/wiki/Aluminum) as a material had been [around for a while](http://en.wikipedia.org/wiki/Aluminium#History) before that. It has been used in classical times, although it had really only become easy to make in the 19th century. It is surely easier to make aluminum than to make an aluminum alloy, and so it would be chosen first when developing an airship.
---
**Summary and Conclusion**
I would argue that the most important consideration to take into account when trying to determine when a civilization could build a rigid airship is when they are able to develop metal appropriate for building airships. Obviously, lifting gases are essential, but they don't forbid a civilization from making blimps and other non-rigid airships. A civilization probably couldn't create a rigid airship before it used lightweight metals, such as aluminum, or before it used metal alloys, such as duralumin.
---
**Edit**
Regarding Mark's point about the [Schutte-Lanz airships](http://en.wikipedia.org/wiki/List_of_Sch%C3%BCtte-Lanz_airships): Indeed, rigid airships could be made of wood. However, it wasn't exactly the best choice for large ships because moisture tended to compromise structural integrity. As Wikipedia says,
>
> Wood composites had a theoretical superiority as the structural material in airships up to a certain size. After that, the superiority of aluminum (and later duralumin) in tension was more important than the superiority of wood in compression. Schütte-Lanz airships until 1918 were composed of wood and plywood glued together. Moisture tended to degrade the integrity of the glued joints. Schütte-Lanz airships became structurally unstable when water entered the airship's imperfectly waterproofed envelope. This tended to happen during wet weather operations, but also, more insidiously, in defective or damaged hangars. In the words of Führer der Luftschiffe Peter Strasser:
> "Most of the Schütte-Lanz ships are not usable under combat conditions, especially those operated by the Navy, because their wooden construction cannot cope with the damp conditions inseparable from maritime service..."
>
>
>
[Answer]
Materials aren't really a problem: the smaller [Schütte-Lanz airships](https://en.wikipedia.org/wiki/List_of_Sch%C3%BCtte-Lanz_airships) used a framework made of wood, and one of the common gas-tight materials used, [goldbeater's skin](https://en.wikipedia.org/wiki/Goldbeater's_skin), is simply a membrane from calf intestine. Steam engines of one sort or another have been around for centuries (even a simple reaction engine can provide propulsion -- no need for propellers or rotary motion), and hydrogen can be produced by just about any acid-metal reaction -- you just need to realize that those bubbles can be used to lift things.
The big problem with making rigid airships is *scale*. Rigid airships benefit strongly from the square-cube law: double the size of the airship, and you get an eight-fold increase in lifting capacity at only a (roughly) four-fold increase in weight. This also imposes a practical *minimum* size. Even a small airship requires a cathedral-sized hanger to assemble it, and the typical World War I Zeppelin required the intestines of 80,000 oxen to provide the gas envelopes.
Yes, all the pieces were there for the ancient Greeks to build rigid airships. The problem of scale, though, means that building one would have stressed their productive capabilities to the limit, or even beyond.
] |
[Question]
[
From what I can tell, there's lots of room available inside a [cell](https://en.wikipedia.org/wiki/Cell_(biology)); certainly, all the graphic representations of them I can find seem to show that a lot of the volume of the cell is [cytoplasm](https://en.wikipedia.org/wiki/Cytoplasm), as opposed to [organelles](https://en.wikipedia.org/wiki/Organelle) - in other words, goop, as opposed to things-what-do-stuff.
[](https://i.stack.imgur.com/CR1ZS.jpg)
[](https://i.stack.imgur.com/t3d9H.jpg)
[](https://i.stack.imgur.com/dIPgC.jpg)
Y'see, the reason I'm asking is that I'd like to put some more *stuff* in that there stuff: some [chloroplasts](https://en.wikipedia.org/wiki/Chloroplast), extra [mitochondria](https://en.wikipedia.org/wiki/Mitochondrion), nanomachines (son!), or a fun little thing I'm cooking up that's designed to cool the cell down by dissolving [urea](https://en.wikipedia.org/wiki/Urea) in water, thereby resolving one of the many [square-cube law](https://en.wikipedia.org/wiki/Square%E2%80%93cube_law)-related problems with giant creatures: heat removal.
Obviously, the answer to this question varies on a cell-by-cell basis, but **I'd like to know whether I could replace 5% of the *volume* of an animal cell (the more types of cell that can handle it, the better) with an organelle or other structure of my own design without seriously impacting the main function of said cell.** These images certainly seem to suggest so, but I figured I'd run it by someone else before making myself a Godzilla.
[Answer]
You can just make the cell itself bigger or make the organelles themselves better and more efficient at what they do.
Also, as far as I know, the empty space in cell, the cytoplasm is where cell stores its raw materials, oxygen and food and stuff. Depending on cell types you don’t wanna reduce cytoplasm too much.
Though 5% here and there shouldn’t be a problem
[Answer]
**The empty stuff is not actually empty! but you're probably ok, anyway...**
Take a look at this beautiful fluorescent microscope image - to get it, you add a protein from jellyfish so that it is expressed with the protein that you are targetting. This image (from wikipedia) has been treated for actin (in red), tubulin (in green), and a protein in the nuculeus (in blue)
[](https://i.stack.imgur.com/Ucc0D.png)
This is only one possible set of stains to use for a cell, but clearly shows that there's more going on than this "bag of liquid with some organelles" structure that everyone is taught in school. There's a structure - the tubulin (green) radiates from around the nucleus, and helps move the proteins from the golgi body to the rest of the cell - think a network of tiny conveyor belts. The rest of the cell is also crammed with proteins - some give structure, some do things, some store things, but the cell is packed!
That said, adding an extra organelle can, clearly, work - mitocondria, cloroplasts all are the remains of micro-organisms that took up residence in our cells, and never left. And, as we look more closely, we see more and more intracellular parasites or symbiotes - wolbachia is an ant (and probably other insect) symbiote that looks like it enters ant cells.
This is possible without wrecking the structure because cells are self organizing. I don't know what it would do to a mammal, but, if we could get it past an ethics committee, I'd be willing to bet there'd be no major changes - the cells would be larger, which might make the organism slightly bigger, but I'd put fairly decent money on it just coming out fine - biology is wonderfully adaptable in this area.
[Answer]
**Should be Fine**
[](https://i.stack.imgur.com/ydmz4.png)
The diagrams are not to scale but here is a microscope image of a cell. See also [here](https://www.google.com/search?q=human+cell+organelles+microscope&tbm=isch&ved=2ahUKEwjyoZHRz5P4AhXRSkEAHbMGA-IQ2-cCegQIABAA&oq=human+cell+organelles+microscope&gs_lcp=CgNpbWcQAzoFCAAQgAQ6BggAEB4QCFCpBFjQCWDlCmgAcAB4AIABP4gB3AKSAQE3mAEAoAEBqgELZ3dzLXdpei1pbWfAAQE&sclient=img&ei=czibYrKcLtGVhbIPs42MkA4&bih=655&biw=1237&client=ubuntu&hs=rGV#imgrc=L-v4tmRGppUUjM). There is loads of empty space.
[Answer]
Cytoplasm isn't just goop, it's made of proteins and other molecules that are important for the cell's functioning. At the micro level there's all sorts of stuff happening there, and it's "doing stuff" just as much as the organelles are. Cells have organelles because sometimes some kinds of molecule need to be kept separate from other molecules for one reason or another, but overall the rest of the cell is made of the same kind of stuff.
But sure, you can fit more organelles in if you want. Cells vary widely in the number of organelles they contain, and if evolution can vary the number of organelles then so can you. It will come at the cost of 5% less of everything else, but if the benefit outweighs that cost then why not?
] |
[Question]
[
There have been ideas about moving galaxies, if all of the needed stars and black holes become stellar/black hole engines but due to the 1:5 ratio of matter and dark matter there will not be enough mass in the stars to take the dark matter with them, as well as the interstellar medium, unless it is collected by other means.
I was wondering if enough stars are gathered from globular clusters and other galaxies, if they as stellar engines gather around and within the galaxy being moved and the stars/black holes within the galaxy are stellar engines, if the ratio of stellar mass is higher than the galaxies dark matter and interstellar gas mass, could the whole galaxy, dark matter and all be moved?
I am imagining an arrangement similar to a very large [cD galaxy](https://en.wikipedia.org/wiki/Type-cD_galaxy), appearing as a dispersed elliptical or sphere. I understand that we don't know the exact nature of dark matter but from the observations of its interactions through gravitational bonds could this method work providing enough stellar engines are used and their close proximity to each other does not create a limit on how many stars can be used to move the dark matter?
[Answer]
I'll argue that yes, this can be done, thanks to real-life observations of galaxies moving their own dark matter in our universe.
We know for sure that moving large amounts of baryonic matter can in turn make significant changes to the dark matter distribution of a galaxy. This has been demonstrated through a phenomenon known as "dark matter heating" - a slight misnomer, as the temperature of the dark matter isn't changing, but rather its velocity distribution. Observations of 16 dwarf galaxies ([Read et al. 2019](https://ui.adsabs.harvard.edu/abs/2019MNRAS.484.1401R/abstract)) showed that shifting large quantities of gas and dust (by way of a starburst pushing them away through radiation pressure) caused enough of a change in a galaxy's gravitational potential to shift dark matter away from the core.
This means that your plan would indeed have a chance! To actually move away a galaxy's worth of dark matter, rather than just redistributing it, would indeed require using stars from other galaxies. You could attempt to just use the gravitational pull of these stars, or you could use an analog of dark matter heating by first shifting the galaxy's gas and dust via radiation pressure and using *that* change to move the dark matter indirectly. In the Milky Way, the amount of gas and dust is somewhere around 10-20% the mass of stars, though; perhaps the effect would be larger in a gas-rich galaxy.
[Answer]
## How is Dark Matter Different than Normal Matter?
Of the 4 fundamental forces (Gravity, Electromagnetism, Strong Force, and Weak Force), Dark Matter is known for sure to exhibit Gravity, but not Electromagnetism. Whether or nor it exhibits the Strong Force and Weak Force is less certain. It is also uncertain whether is exhibits forces other than those exhibited by normal matter. The thing that makes it so mysterious is that if it behaved like other electromagnetically neutral matter, it would collapse into neutron stars or blackholes and emit some form of detectable radiation, or it would be caught up inside of stars increasing their mass and rate of fusion, but it does not seem to do any of that. There are a lot of theories as to why this is, but not enough evidence yet to support one theory over another.
## To Answer Your Question
Because gravity appears to be a 2-way interaction between dark matter and normal matter, then anything that slowly accelerates a star or galaxy should drag along any dark matter with it to a degree, but most of a galley's dark matter is in the interstellar medium making the gravitational interactions between it and stars pretty weak. So, if you tried to move a galaxy, it would behave sort of the same as any stars you forgot to put an engine on. It would get dragged along a bit, but possibly not enough to keep up.
[Answer]
**All Matter Attracts Other Matter.**
Let's say the dark matter forms a cloud around the galaxy and the particles are only effected by gravity. Hence they are changeless and invisible. This cloud exerts a gravitational pull on all the normal matter in the galaxy that makes it harder to move. But likewise the real matter exerts a pull on the dark matter.
The pull works both ways. The net result is that if you fit a stellar engine to every large body in the galaxy and start firing, it will be more energy expensive that if the dark matter was not there. The extra energy goes into pulling the dark matter along with you.
From here it is just a matter of scale. Once all the stars break free of the dark matter cloud, how long does it take for the cloud to gravitational attract itself back to all the stars. Keep in mind you need to keep firing the thrusters over this time, to balance how the pull works both ways. Otherwise the galaxy and cloud just end up one fifth of the way between where they were at the start.
] |
[Question]
[
What materials in the environment could merpeople use to make armor? The merpeople live in the mediterranean sea and have contact and trade with humans who could provide resources and craft the armor for them if necessary. The humans are around classical antiquity in terms of technology.
[Answer]
I'd perhaps look to inspiration from real life, specifically the ancient world. Armor as we often think of it, medieval plate armor, really only existed for a brief period of time. Most of history however, armor was made by layering different materials together, often things like fibers.
This video from How to make everything goes over some stuff about the practice. You might look at what underwater plants might work.
<https://www.youtube.com/watch?v=wcWu8a9F9Js>
[Answer]
Maybe shells? They could be drilled and linked together, maybe into something resembling scale-mail. There is a large variety of different kinds of shells, which could lead to different armour types.
I think a problem with aquatic armour would be the degradation of the materials of time - a lot of things break down easier in water than while dry. Certain tough aquatic plants may work as a binding fibre, or they could be replaced every now and again.
Bone and teeth could also be used, especially to adorn the amour or make it harder to attack. Some seaweeds are pretty strong, too.
[Answer]
## [Chitin](https://en.wikipedia.org/wiki/Chitin) would be abundant
Merfolk would have learned to farm coral and kelp, and also be skilled in "crustacean husbandry" and have pastures of crabs and similar aquatic animals. Chitin can be fairly tough and can be used or combined together to make composite armor plates. Especially combined with hides of sharks and adorned with fish-scales and pearls. I'd imagine they'd grow giant shells in "moulds" that would eventually become pieces of armor. They'd likely have far better segmented armor than their contemporaries, since they could study the movement of shrimps and crayfish in action.
Other than that there would probably be hydrothermal vents along the tectonic fault lines that could produce native elements and basalt and the temperatures necessary to shape them. Again, connecting a "mould" to a vent would presumably create a shaped fit of a piece of armor over time.
The sea is far less explored than the surface, likely the imagination is less spectacular than reality as for the opportunities of the great below.
[Answer]
1. Blubber is a natural armor If given how many sea creatures use blubber I could easily it being a source of armor.
2. Bone weapons and armor are Is common in cultures that don't have access to metal.
3. scales
4. Coral.
[Answer]
**Tanned hides of big merpeople.**
These hides are tanned so that they are tough and resilient, and slits made to articulate at the joints. They are then put on as armor by small merpeople. This way they still look like merpeople but large and unexpressive ones with skin that is not shiny. Armored merpeople seem impervious to harm. Their enemies suspect they are zombies.
The large live merpeople cannot fit into this kind of armor, but you do not generally hear them complaining too loudly about that to the small merpeople.
[Answer]
Whatever the armour is made of, it should not be too heavy or constrain the movements. Preference should go to fast swimming and agility, since in water it is easier to dodge a blow that should be the primary defence.
The idea of Stian Yttervik of using shark hides on top is good because they reduce resistance to the water flow. Underneath I would use one or more layers of a a textile made of [Byssus](https://en.wikipedia.org/wiki/Byssus).
For the heads wooden helmets would be the best solution. Humans should sell a substance that is a mix of lacquer and resins, that would be used to impregnate the wood and make it more resistant to rot and a little bit heavier in order to have neutral buoyancy.
[Answer]
# Metal
While metal wouldn't be available to merfolk alone, if there are land dwelling species then there will be lots of metal flowing into the merfolk's lands
The armours can't be purely metal, though: They will need some sort of waterproof covering to avoid rust or other damage, but this should be achieveable, regardless of the technological level
] |
[Question]
[
I'm writing a story in a system which has two earth like habitable planets orbiting the star in Lagrange points L4 & L5 of a gas giant similar to Jupiter / Saturn.
Is that orbit possible in the Sun like star habitable zone? Something no further than Mars assuming.
For illustration purposes: One earth like planet is in L4, the second earth like planet is in L5. The whole orbit is where Mars is now.
[](https://i.stack.imgur.com/bH3nS.gif)
[Answer]
I'd say yes(ish), but with some caveats. It would be a very rare occurrence where everything would have to be just so. There are a number of integrations of the scenario that have been done, such as in this paper: <https://onlinelibrary.wiley.com/doi/abs/10.1002/asna.200710789>
or this one:
<https://ui.adsabs.harvard.edu/abs/2005CeMDA..92..113E/abstract>
There's also the question of how these planets would form in the first place, as capture is hard to imagine taking place. Here there is a simulation of that which has been done, but it shows that the process seems to top out at planets 0.6 times Earth mass (which at least is big enough to be habitable in principle):
<https://www.aanda.org/articles/aa/abs/2007/07/aa6582-06/aa6582-06.html>
One caveat is that the stability conditions for trojan/co-orbital bodies drastically decrease the more stuff you have in the same system, which is probably why our own system more closely follows the rule of thumb mentioned on Wikipedia, where the trojan bodies should be of asteroid proportions: <https://en.wikipedia.org/wiki/Trojan_(celestial_body)#Stability>
Also when I've tried putting a Jupiter sized planet with co-orbitals into an N body simulator, I found that adding in moons for the Jovian tended to disrupt either the moons or the trojans. I could only get around this by making everything smaller.
So the answer is yes but the caveats are that the co-orbitals might be limited to a bit over half the mass of Earth in terms of formation, and if there are a lot of other large bodies in the system, like other gas giants, the maximum mass for stable long term orbits goes down exponentially. You're looking at a quite empty system probably apart from the gas giant and its co-orbital planets and these will likely be smaller than Earth, under the rare scenario of them forming.
[Answer]
The Trojan orbits are potentially stable for a planet-sized body with low eccentricity and a sufficiently massive "Jupiter" for a period exceeding the age of the solar system. That means that if you can get your "super Trojan" into an orbit about the L4 point, then it can stay there for billions of years.
The difficulty is getting it there. The formation of the gas giant will tend to clear gas and dust from its orbit, so it is hard for a planet sized body to form at the L4 point. It is also very hard to capture a planet sized body at the L4 point. Asteroids can engage in interactions and become trapped in the 1:1 resonance orbits, but there is nothing at L4 that can pull a planet that is not in resonance into a Trojan orbit, or adjust its velocity once it is there to exactly the right velocity to be captured.
So Trojan orbits are stable, but getting there requires some handwaving.
] |
[Question]
[
I have got a idea of a eusocial species that creates huge And wide colonies that can go through different environments from underground tunnels, to a island a few miles offshore, to miles away farther from the original location and I wanted all these creatures to still be in contact to each other. that’s when I got the question of how would they stay in contact to each other from such distances.
**What form of communication would work in this scenario?**
Note: any form of communication even it isn’t commonly used or is completely theoritical as long as members of colonies can spread information to each other.
[Answer]
Elephants produce infrasound, and can [communicate among themselves even if two of them are 10 km apart](https://www.sciencemag.org/news/2012/08/elephants-silent-call) (about 6.2 miles).
Whales, who sing in ultrasound, can communicate from even further away, since water carries sound waves further. [Orcas can hear each other from 16km away (about 10 miles).](https://en.wikipedia.org/wiki/Whale_vocalization#Other_whale_sounds) Larger whales have vocalizations that can be heard from further yet - some googling suggests distances of up to 6,500 km (4,000 miles), and at least one source goes for more than double that. But I could not find a wiki nor a scientific article, so I don't feel like linking - just take those numbers with a grain of salt.
Whales are also known to produce their calls at a very specific depth below surface, which it turns out is where the properties of water at that temperature, pressure and density, allow for the highest efficiency of sound transmission over long distances.
This question is also relevant: [What would be the communication range of an underwater species?](https://worldbuilding.stackexchange.com/q/2575/21222)
[Answer]
Infrasound, as used by elephants and whales, has very low bandwidth but can carry information over many miles (or underwater, hundreds of miles) without difficulty.
It all depends on what you want to communicate, but an intelligent race will develop codes and data compression techniques.
[Answer]
Information packages.
Write something up or paint a picture, make a package, send it away.
* Speed: speed of feet or wings
* Data amount: unlimited per package
* Receivers: few
* feels unnatural
Sound. Whistling, singing, rhythmic thumping. Singing chords or combining rhythm and many layers of chords can greatly increase the data amount / channel width.
* Speed: speed of sound.
* Data amount: limited per minute and slower over long distances. In short distance, if all of the above is used by your race, near-telepathic channel width is possible in short distance
* Receivers: all in hearing range. Everyone in range shares the same channel. More range under water or through solid rock.
* feels natural
Electronic communication. Why never a race on earth has developed a way to communicate naturally over electric signals is an enigma to me. If your race has a way of communicating electrically, evolution will have found all the tricks of fractal antennas and such, relaxing the limitations of antenna sizes which will correspond to body sizes.
Natural electricity will be somewhat limited - you won't see natural beings which communicate over hundreds of km with this, because the (kilo-)watts are missing in natural bodies. But in an electrically otherwise silent area those could certainly "scream" over 2 or 3 km range, even somewhat directed if the evolution was diligent.
Even if you don't use this as long range comm, this could be interesting as near field "telepathic" connection when touching hands or other body parts. Ants do this chemically when touching with their antennas.
* Speed: speed of light
* Data amount: limited similar like sound, but with a lot lot greater parallel potential.
* Receivers: all in "hearing" range, lot less under water with antennas that fit in 2m of body.
* feels natural as long as it is analog and not digital communication.
] |
[Question]
[
I have a fantasy race that controls fire, and loses their powers when they get wet.
They bathe by scarping all dirt and materials off their skin and heating the outside of their body to 600 degrees Celsius (1,112 degrees Fahrenheit) with no ill effect. For the question, you can assume the creatures sweat like normal humans, but when are exposed to extreme heat they magic it away (as any smells produced by the heat removal process are outside the scope of this question)
Assuming they are otherwise human in terms of diet and physiology, would this heat eliminate normal human body odor, and are there any smells that soap and water would remove that this method does not?
[Answer]
Your creatures will smell like burnt stuff.
Merely trying to remove stuff from your skin mechanically will not do, there will always be some leftover. It is also not practical to remove sweat.
Speaking of which, sweat isn't just pure water (otherwise it wouldn't smell!). It's water plus bodily wastes and some more things. [The wiki](https://en.wikipedia.org/wiki/Perspiration#Composition) lists:
* Lactic acid
* Urea
* Many different minerals
And then it says:
>
> Some exogenous organic compounds make their way into sweat as exemplified by an unidentified odiferous "maple syrup" scented compound in several of the species in the mushroom genus Lactarius.
>
>
>
Don't forget it's loaded with bacteria, which will produce their own stuff.
Why does it matter? Because while water will simply evaporate over 100 degrees C, other components will break down into other stuff - urea will break into cyanuric acid, ammonium chloride and ammonia, so during a fire bath a creature will be very hard to approach even for other creatures resistant to fire.
After the bath, the minerals will still be there, dried up. A lot of salt will remain, for example. It's melting point is at 801 Celsius. So you have very hot salt, which will trap a lot of material from the bacteria, might give you a burning smell.
Then there is also some sugar in sweat. It will break down into carbon chains. Whatever doesn't evaporate will recompose as some either brownish or black tar. That's the kind of thing that makes unwashed teflon pans sticky. Consider the effect of this for your burning creature.
[Answer]
Heating their body would only burn/dry/oxidize anything on their skin, not take it away. They would probably do better taking baths in sand, which could remove dirt, dead skin, and oils without needing water. [This is called dust bathing and is practiced quite a bit in nature.](https://en.wikipedia.org/wiki/Dust_bathing) If there were anything that dust bathing couldn't remove, like something sticky we'd normally wash off, the fire would come in handy. It could convert the sticky substance to ash which could easily be washed off in the sand.
In addition, they might perfume themselves with incense, rather than oils, since it's already designed to smell good when burning.
[Answer]
**They will not smell.**
Any carbon or nitrogen containing compounds (oils, fatty acids, desquamated skin) will either volatilize and escape as vapor, or be oxidized to CO2 and H2O.
What will remain is salts. Sodium and potassium chloride are the main ones and those will not volatilize at these temperatures and will remain on the skin. Those salts are odorless. If they are sweaty to start with, these people might have a dusty white residue on their skin, which is salt.
They might be accompanied by licky dogs, who will help clear off the residue after the people cool down.
] |
[Question]
[
I'm working on a version of wormhole-based FTL travel, and one of the side effects of passing through the wormhole is going to be instantaneous heating of every molecule of the thing passing through. The heating works by dumping a specific amount of thermal energy into every molecule of the object passing through the wormhole, and the rise in temperature is thus affected by the specific heat capacity of each molecule.
However, this instantaneous increase in temperature brings up potential issues of survivability for a human being going through the wormhole. The heating itself exists for reasons related to thermodynamics, but its magnitude is completely up to what's best for the story. I'd like to make the heating survivable for human beings, but also significant enough to be worth a mention in the text. Essentially, I'm shooting for a temperature rise that will be uncomfortable or ideally temporarily debilitating, but not lethal. I realize there's not going to be a ton of data on spontaneous and evenly distributed temperature rise throughout the human body, but any existing and relevant data that can be extrapolated from would be great. Additionally, if this kind of temperature rise would be dangerous for electronics or any other sensitive equipment one might find on a spacecraft, you get bonus points for mentioning that in your answer.
So, to summarize, **how much heat could you dump into a person's body before that person reaches the point of suffering significant long-term effects?**
[Answer]
It looks like there will be only a narrow margin of temperature rise before harm is done to persons passing through a wormhole. Probably, no more than one or two degrees centigrade.
The general conditions associated with heatstroke are as follows:
>
> Heat-related illnesses typically are categorized as heat exhaustion or heatstroke. Heatstroke is divided further into classic and exertional forms. Classic heatstroke is caused by environmental exposure and results in core hyperthermia above 40°C (104°F). This condition primarily occurs in the elderly and those with chronic illness. Classic heatstroke can develop slowly over several days and can present with minimally elevated core temperatures. It is associated with central nervous system dysfunction including delirium, convulsions, and coma, making it difficult to distinguish from sepsis. These manifestations are thought to be an encephalopathic response to a systemic inflammatory cascade.
>
>
>
In their milder forms, heat illnesses are known as heat exhaustion. This will be extremely uncomfortable, but survivable.
>
> Heat exhaustion is a more common and less extreme manifestation of heat-related illness in which the core temperature is between 37°C (98.6°F) and 40°C. Symptoms of heat exhaustion are milder than those of heatstroke and include dizziness, thirst, weakness, headache, and malaise. Patients with heat exhaustion lack the profound central nervous system derangement found in those with heatstroke. Their symptoms typically resolve promptly with proper hydration and cooling.
>
>
>
What makes the survivability of elated temperatures difficult to is the combination of the temperature elevation itself and the duration of the rise.
>
> The term thermal maximum was developed to measure the magnitude and duration of heat that cells can encounter before becoming damaged. Human thermal maximum has been established as a core body temperature of approximately 42°C (107.6°F) for between 45 minutes and eight hours. Cellular destruction occurs more quickly and completely at higher temperatures. Inflammatory factors are released and gastrointestinal permeability increases, which may allow endotoxins into the circulation.16 Hematologic and endothelial changes resembling disseminated intervascular coagulation also occur.
>
>
>
This suggests the limits of the temperature increase will be, at best, one to two centigrade. An almost instantaneous whole-body temperature would be extremely difficult to lower. This will increase the damage caused by the duration of the temperature rise. best to keep it as low as reasonably possible. Expect an immediate onset of elevated temperature to be disorienting and quite likely disabling.
REFERENCES:
>
> Management of Heatstroke and Heat Exhaustion
>
>
> JAMES L. GLAZER, M.D., Maine Medical Center, Portland, Maine
>
>
>
Am Fam Physician. 2005 Jun 1;71(11):2133-2140.
URL to above article: [American Family Physician, Jun 1, 2005 issue](https://www.aafp.org/afp/2005/0601/p2133.html)
[Answer]
Very simple answer: 2°F.
>
> An increase in body temperature of two degrees Fahrenheit can affect mental functioning. A five degree Fahrenheit increase can result in serious illness or death.
>
>
>
When your astronauts increase by one degree they will feel it. [At 2 degrees all but the most elite and fit individuals will start making mistakes](http://nasdonline.org/137/d001702/heat-stress.html).
[Answer]
Thus far, the two current & excellent answers focus on biological heating over a biological span of time. Indeed, if a human suffers hyperthermia for an extended period of time, said human will eventually suffer terrible effects and eventually die.
However, your query asks about a process called "flash heating". You don't specify what this entails, except that it is "instantaneous" so I would make an assumption about the process: namely, the time factor involved is so short that, quite literally, the molecules of the person in question **don't have enough time to accumulate the heat being input**.
For example, it's a common experience in North America (and maybe northern Europe too) that when one enters a supermarket or other public building from a cold or frigid exterior that one passes under a blast heater. This is a device attached to the entryway transom that directs a thin curtain of super-heated air downward as the patron enters. This forms a "curtain of hot air" that acts as an insulation barrier while the physical door is open. If you pass through the doorway quickly, you feel the warm momentarily but never become affected by it. If you stand under the blast heater, you'll eventually warm up, become uncomfortably warm, begin to sweat and etc.
I'd posit that your wormhole technology might be similar. So long as your humans pass through the wormhole quickly, they feel a momentary warmth but are not subjected to the blast long enough for adverse physiological effects to take hold.
Another example: I have successfully passed my hands through the scorching flame of a propane torch on several occasions. The fire is about 36oo deg (2000 degrees centipede). If I left my hand in the flame, it would, just like the starship crew hanging around inside the wormhole, be burnt to a crisp. I'm not burned because my hand isn't in contact with the flame long enough.
**Conclusion:**
I don't think your starship crew will have enough time to be adversely affected. Obviously, if they remain in contact with the heat and said heat can not be instantaneously dissipated again, they will die. It doesn't take many degrees of heat or a very long time for deleterious effects to take hold.
] |
[Question]
[
I'm currently designing an mesothermic reptilian sapiens for my world, that have evolved from a deinonychus-type of dinosaur and developed flexible hands with opposable thumbs, but still possessing arms that are shorter and weaker than human arms.
I imagine them to be potentially very quick and agile in battle. Able to jump into attack with spears, sickle claws and even tail and jaw. They are also intelligent and creative, and possesses certain magical capacities as well.
But being mesothermic, I don't expect them to have as much endurance as humans. Don't think they would be at advantage pushing against shield walls for hours. And due to their shorter arms I don't think they are able to be that efficient with bows, javelins or slings.
They have also failed to domesticate any animal that can be used in battle, though they may have access to slave soldiers.
I can easily visualize such reptile warriors defeating human warriors in warfare on a tribal level. But when it comes to organized armies, imagine for example facing an army of phalanxes, heavy cavalry and archers.
Could my reptiles then stand a chance in open battle? How? They are crafty enough to employ whatever solutions that exist in an antique context.
[Answer]
**In open battle, yes**
And the answer takes two vital components - speed and strength. Your idea of weapons for these deinos revolve around human ones. But that's not the correct approach, it's talons. Large, wicked sharp talons that the deinos have on their feet which gives them better reach. They would attack humans by leaping in the air and landing on them, savagely carving through the lines of humans. To do this, the deinos would need to be adjusted a bit by evolution to have more ostrich-like speed, but essentially what you'd turn them into is cavalry-turned-shock-troopers once they hit enemy lines. They'd crash trough anything short of a shieldwall backed by spears.
Which is were the problems start. See, these things are cavalry. So the best counter is just a spearwall. Nothing too fancy. Any human commander would just order his troops to deploy spears and impale the charging deinos. Archery would work as well, up to a point, at any rate. Gambeson is good enough to stop a few arrows, and deinos have built-in scales, so they can take one or two volleys of arrows. Javelins are a bit tougher, but manageable.
Now, this is were the counter-strategy comes into play. If the deinos would lose a head-on attack, then they don't need to bother with one. A deino with ostrich like speed can run up to 40 mph, which means that a massed deino army has one of the most dangerous abilities at their disposal - encirclement. Normally, it takes some serious tactical acumen, but I don't see why an army of fast knights can't simply pull it off using speed. And when it works, it [*works*](https://en.wikipedia.org/wiki/Battle_of_Cannae). Overall numerical disadvantages stop being a problem, spears become hard after the first deino charge because you can pressure the enemy too close together, and enemy morale plummets.
Unfortunately, this won't work if the enemy is say, using natural formations to their advantages, defending forts, or fighting in caves. And if you're fighting, say, the Golden Horde of the Mongols, you're dead because cavalry archers are OP in ancient combat.
[Answer]
As has been stated already, these creatures weapons and strategies would build upon their physiology.
Those tails could power slings, while accuracy is hard to judge since its a matter of eye-tail coordination, in mass they could be quite dangerous.
Their basic shape would engender the use of the atlatl-like tools, held in their jaws. They could then charge the enemy and at the proper moment, curling their necks and torsos and hips forward, throw heavy darts and javelins.
They could employ hand-held crossbows that they cock with their powerful legs. And, since they, as has been noted, essentially cavalry they could fight as dragoons -- charging the enemy discharging crossbows and running away.
I would think that their armored troopers would have heavily armored undersides so they could run at enemy lines and leap into their midst where their powerful hind legs would give them a great advantage in hand-to-claw combat.
Lastly, they might attach wicked scythe-like weapons to the tips of their tails and yield them like cavalry sabers when facing lightly armored troops like archers and muleskinners handling the supply train.
And, these guys would probably eat what they kill so their logistical requirements would greatly favor them over humans.
[Answer]
All the fossil evidence we have indicates that dinosaurs were the precursor species to modern birds, which are most certainly homeothermic. So, we can presume that this mesothermy is such that the dinos need not bask in the sun to maintain body temperature.
Mesothermy has nothing to do with endurance. In fact, the relationship may actually be inverted: the dinos with their lower basal metabolisms for a given body mass than placental mammals (much as marsupial mammals have) would use less energy for the basic processes of life, and activity would generate body heat and raised body temperatures which they would be better able to tolerate despite potentially worse thermoregulatory capability than humans.
As a side note, there is practically no creature on earth that is as good at getting rid of excess body heat as humans... but getting rid of excess heat is not the only way to cope with body heat, the other way is to simply *tolerate* it, and continue to function *despite* an increased body temperature. The nature of thermodynamics is that the higher the difference in temperature between two environments, the faster heat will be radiated away from the hotter object. So, the dinos body temperatures may vary by several degrees during exertion, but unlike mammals, they can simply put up with it.
A dromaeosaur descendant would have a largely horizontal spine, much like birds which also are thought to have descended from dromaeosaurs, though the possibility certainly exists for them to rotate their hips so that they are standing more upright.
The dromaeosaur body plan includes legs with muscular thighs, slender calves, and a digitigrade posture with extended foot bones, making them a cursorial species. Humans are the fastest of the apes in bipedal locomotion (though apes which move quadrupedally may be faster), and can run at up to 37 kph or so. However, humans' relatively short foot and bulky calf muscles do not allow as efficient or as rapid running as the dromaeosaur body plan. While ostriches can run at up to 80 kph, I would expect that a dromaeosaur such as the OP's dinos would be able to run at around 60 kph or so, and could conceivably leap two or more metres upwards and perhaps up to ten metres laterally.
While humans are effectively unarmoured and have no claws or fangs, medieval humans such as the OP mentions are able to supplement their meagre natural weapons and armor with manufactured weapons and armor. On the other hand, the dinos, being carnivorous predatory beings, would have tough skin overlaid by feathers, as well as long claws on the fingers and a particularly large claw on each foot. Additionally, the OP has said that dinos have a humanlike ability to make their own technological innovations. This could include their own armour and enhanced weapons such as razor sharp claw sheaths.
Given a dino's long, narrow body plan and well-made metal armour, I would expect that arrows and other thrusting weapons would be more likely to deflect from their armour than is the case with a tall, broad human figure. This, combined with dinos' great mobility, would render the mainstay of late medieval military armament - pike and shot - far less effective than it is against humans. Dinos could reasonably expect arrows or spears to deflect from their armour, and combined with their mobility, they could either throw all but the most disciplined phalanx into disarray simply by flanking, and if the phalanx sacrificed its own mobility and formed a circle, the dinos could still duck under or leap over the spears and once inside the range of the spears, their enhanced natural weapons would quickly break the phalanx.
A unit of sword wielding humans would stand a better chance against the dinos than pike and shot, as swords are inherently more maneuverable weapons.
Human cavalry would have speed approaching that of the dinos, but lower maneuverability.
The main advantage that the dinos have is that they have intelligence comparable to that of humans. Combined with their superior natural weapons, they could maneuver humans into situations where the dinos advantages could be exploited to the fullest.
[Answer]
The effectiveness of our dinos directly correlates with a tactical acumen. But before we look at the best tactics we should look at how to arm them.
Because of their physiological make-up, they are pretty much cavalry without any further need for anything but a lance. Due to being armed with natural claws, additional hand to hand weapons are not needed, making them extremely light cavalry. Their scales serve as natural armor, probably sturdy enough to be considered equivalent with chainmail or light plate. Adding additional armour, probably from skin or leather, what's turn our light cavalry dinos into heavy armoured light cavalry.
If these deinonychus mastered domestication of other reptiles, then they could field auxilia comprised of Dinosaurs riding on bigger Dinosaurs. These would serve as linebreaker if these heavier dinosaurs might be ankylosaurus or very large vegetarian dinosaurs like brontosaurus.
Due to their speed they can employ fast encirclement tactics and swift charges into the flanks of the humans. Another tactic they can easily employ is skirmishing, fast assaults and immediately retreating to break formations. With their smaller frame than humans and a natural camouflage coloration of their scales, they also make adapt ambushers.
[Answer]
I see 4 issues
**Packing problem (why tails are a problem in close order combat)**
Human formations can be very dense. In a phalanx, troops can be placed less than a foot behind the line in front of them. They can still effectively use their spears to strike. They can support each other and bring a large number of weapons to bear.
Raptors have these long tails that stick out behind them several feet, [in all raptors were 11 ft long](https://en.wikipedia.org/wiki/Deinonychus). If a raptor turns its body the tail swings side to side further increasing the amount of space to the side that needs to be set aside for it. Basically a raptor takes up as much space as 2 horses but is far lighter and weaker. This says the closest raptors could fight and still be effective is in a tight line followed by another line more than a yard behind.
The lack of density reduces the power of a charge (mass matters) A [1,540 horse](https://en.wikipedia.org/wiki/Horse) with 200 -300 lbs of armored knight hits a spear wall much harder than a [200 lbs](https://en.wikipedia.org/wiki/Deinonychus) raptor.
Also a charge from a 9-11ft 1/2 ton tall knight + horse is much more intimidating than a charge from a 3ft raptor that is only 200lbs
**Reach**
In a phalanx with [7 - 15 foot spears](https://en.wikipedia.org/wiki/Phalanx) the first 3-5 rows would be able to engage the raptor in front of them. Only the front line of raptors would be able to hit the humans, and only after fighting through being stabbed-by spears for 7 - 15 feet.
**Shields and armor**
Arms let you use shields which are a great defense, they are easier to make than armor and can cover more of the body, raptors would have to rely on armor only.
These raptors have a lot more surface area then humans (11 feet long x3 ft high vs 6ft high x8 inches deep) which means armoring them well will be very heavy and likely impractical.
**Range**
It seems like the raptors would have trouble building effective ranged weapons. Combined with their lack of armor and large targets would make them vulnerable to range attack. Which means they have to attack aggressively.
**Conclusions**
Raptors would be effective as light cavalry [their walking pace is estimated to be 6mph x2 a humans](https://en.wikipedia.org/wiki/Deinonychus), but there low reach, low mass, low armor and inability to form tight formations would reduce their effectiveness as shock/heavy cavalry or any kind of infantry.
[Answer]
Easily, by working together more effectively. An army of 100,000 D-men will slaughter 5,000 humans. By having superior organisation and, crucially, not always fighting among themselves while sowing discord among their human foes, the D-men can overcome any minor physiological disadvantage they might have.
Human are, as [Dunbar suggests](https://en.wikipedia.org/wiki/Dunbar%27s_number) best working in groups of 150. If D-men have a clan, tribe or even species-wide loyalty so that they can easily work together in much larger units, then the humans are likely to be completely outmatched. Humanity has always consisted of badly-coordinated warring groups. Imaginean empire consisting of an entire race of beings, all working together for the common cause. They could field armies much larger than their divided human neighbours.
Nobody says the Romans won because they were bigger and stronger or physically superior to their foes, just better organised.
Secondly, the moral is to the physical as three to one, as [Boney once quipped](https://shannonselin.com/2014/08/10-napoleon-bonaparte-quotes-context/)> Being who know no fear, and whose ferocity is greater than human, who cannot be broken by heavy casualties or impossible odds, will be practically unbeatable whatever their physical limitations. They may simply terrify the hell out of any humans who try to oppose them, phalanxes scattering as their approach.
Thirdly, if they are built differently to use, there will be places they work better. It's also a matter or choosing your terrain. Are D-men better adapted to marshes, or deep forest, or rocky slopes than humans? if so, that's where you fight your battles. Are they more effective in the dark with their own peculiar senses? How amphibious are they?
Fourthly, amateurs study strategy, professionals study logistics. What key advantages do D-men have when it comes to keeping an army supplied in the field? How easily can they live off the land?
Finally: breeding and maturation. If they lay 100 eggs at a time like turtles, and come to maturity in a few years, then they can absorb massive casualties and keep coming back stronger, while their human opponents get rapidly worn down.
In summary: look beyond simple physiology. That's not what soldiering is about.
[Answer]
On an open field they'd likely get beaten no matter what. Their bones aren't as dense as ours. Best chance of success attacking even a small human military unit would be in forest or alpine terrain, using hit-and-run tactics to either shield themselves or knock humans to their deaths
] |
[Question]
[
Photosynthesis does not provide enough energy to allow animal activities on its own (see [this post](https://worldbuilding.stackexchange.com/questions/38394/efficiency-required-of-a-photosynthetic-system-to-support-human-level-activities) for example). But can we think of a species using photosynthesis as a secondary energy source? Here is my question, as precise as I can write it:
**For what purpose could an animal species make use of photosynthesis?**
Actually, photosynthesis is so inefficient that it would be very accessory. One answer might be growing bones (like antlers for example) on a large time scale. Is this plausible? And especially, can you come up with other / better features?
Importantly, photosynthesis does not need to be the *best* way to achieve this purpose (coming back to my example, I know that it would not be better for deers to grow their antlers using photosynthesis). I am only looking for functioning designs (never mind if these designs cannot be evolved).
Moreover, for the moment I don't care about *how* photosynthesis would be performed by animals. Just assume they can. If needed, assume 30% of their body area contributes to it.
Also, assume we are on Earth, in the environment of your choice.
EDIT : As pointed out by @Renan, this already exists in our world. See [this link](https://umich.uloop.com/news/view.php/77109/4-incredible-photosynthetic-animals) for examples (including the amazing sea slug). However, I would like to focus on human-size species, although it's less realistic.
[Answer]
# Reproduction
We're on Earth, in an area whose weather is cold and dry most of the year, with a short summer and long winter (and brief transitional periods).
We have a mammal, around the size of humans, with a short weaning period.
The species doesn't hibernate but individuals are able to slow down and survive without a lot of calories or fluid intake. Infants, however, are completely dependent on their mothers and need a lot of calories and fluids in order to develop the thick skin/fur they need to survive winter. Their only food/fluid intake is breastmilk and they need it for as long as possible.
Mothers can produce milk briefly as summer transitions to winter, but then their milk dries up. There is little water available to drink (it's frozen) and their food supplies dwindle fast. Their bodies go into survival mode, which means they can not afford the calories/etc to produce milk.
In a land like this, babies conceived at the end of summer and born at the beginning of the next summer have the best chance of survival. Pregnant adults have plenty of food and fresh water available at the start of their pregnancies, which is enough to bring an embryo to the fetal stage before their winter slow down begins.
If the baby is born just after the start of summer, there will be enough food and fresh water for the mother to have the energy to give birth and to nurse her baby. The body grows and develops all summer and, come winter, is old enough to withstand a winter (or at least to have a fighting chance).
## How does the fetus grow?
Gestation requires calories too; about as much as breastfeeding in some stages. The fetus may be protected from the cold all winter, it may not need fluids (what it needs is already there and the mother just needs enough for herself), but it still needs to develop and to grow larger.
Some of the caloric needs will come from the mother's fat stores, but this isn't enough. She needs most of those for her own survival.
## Photosynthesis
**Photosynthesis regulates the reproductive systems.** Like with plants and many animals, the systems know the season based on the day length and quality of light. Only mid-summer (and a bit later) light can stimulate gonads. Males produce high quality sperm and females ovulate.
**Photosynthesis regulates fetal growth.** The energy generated by photosynthesis isn't enough for an adult to survive. It also isn't enough for a child, because their body's surface area is too small. But an adult can generate enough energy for a fetus. The fetus already is in place and has done most of its development (the second half or so of pregnancy is more gaining size than it is outright development, though there is some of that too). Photosynthesis gives the fetus the extra it needs to come to term.
[Answer]
[Animals do it in our world](https://en.wikipedia.org/wiki/Kleptoplasty), for sustainance.
>
> Kleptoplasty or kleptoplastidy is a symbiotic phenomenon whereby plastids, notably chloroplasts from algae, are sequestered by host organisms. The word is derived from Kleptes (κλέπτης) which is Greek for thief. The alga is eaten normally and partially digested, leaving the plastid intact. The plastids are maintained within the host, temporarily continuing photosynthesis and benefiting the predator.
>
>
>
The article above mentions some unicellular organisms, but also some sea slugs such as [costasiella](https://en.wikipedia.org/wiki/Costasiella_kuroshimae).
Photosynthesis may be inneficient for animals like us and other larger ones. But due to the square-cube law, the smaller you get, the more surface you have relative to your volume. Therefore being really small (costasiella is 1 cm long), coupled with not being warm-blooded (and actually not blooded at all) and a diet that is not exclusively photosynthetic, can actually make animal photosynthesis feasible.
[Answer]
Vitamin D is produced when UV light from the sun interacts with chemicals in the skin. There could be critical chemical in the body that only form in sunlight. There are certain kinds of resins that harden in sunlight, an animal's skin could excrete UV activated resin forming a protective outer covering or to quickly seal wounds. There are plenty of different reactions that could occur in the body because of sunlight.
[Answer]
Photosynthesis does not provide enough energy for an animal to perform its daily tasks, but what if the animal does not require that much energy, for example during Hibernation.
For Sleeping, much energy is not required, just enough to keep the body alive.
So, Imagine a species that goes to hibernation but cannot store much food in its body, as a bear can, or there is just a shortage of food to start with. This particular animal eats as much as it can and then goes to hibernation relying on the Photosynthesis to provide additional energy.
Also, it does not need to sleep under direct sunlight, just someplace that is bright enough (no dark caves), like some plants that can survive indoors.
Now, we come to the time when this animal is not sleeping.
At these times, this Photosynthesis energy can be used for individual tasks like Digestion.
Yes, your body needs energy to digest food itself, so this animal will rely on photo-energy to digest its food, because there is not enough food to waste energy, right ??
(I am not an expert on animal anatomy, so these are just my assumptions.)
Just make sure that the photo-cells are near the belly and back region.
[Answer]
**Trace chemicals AKA vitamins.**
Photosynthesis does not just mean generating calories. Multiple animals use photosynthesis to produce important trace chemicals. Humans use it to produce vitamin D although we can get it from food as well. But I could easily see an animal that uses it to produce something it can't get from food.
Howard Tayler's schlock mercenary comic had an alien species that used photosynthesis to make an important neural transmitter, and they actually become mentally unbalanced if denied sunlight for several days.
Oriental Hornet - *Vespa orientalis* use sunlight to generate an electric current, although no one is certain why.
[Answer]
Possibilities would be to use the small energy to synthesize vitamins/nutrients not available raw in the environment (i.e. humans and vitamin D from sunlight), or to power protection against irritants like fleas or bacteria with a microvolt electrical field.
[Answer]
Trickle of energy from photosynthesis could, in theory, help sustain migratory birds or insects in flight. But on Earth there's always some food available on the sea/ground, and insects spread better by eggs.
] |
[Question]
[
As is my understanding (this is not my specialty), for the vast majority of history the crown (whatever sovereign entity exists at the head of the state) gathered income through a few means:
* Tariffs (relatively easy to implement, but don't work for domestic goods)
* Stamps (also relatively easy to implement, but hard to balance with cost of doing business across businesses)
* Royal charters (this also effectively covers any centralized licensing system)
* Feudal tithes (and then the sovereign entity becomes someone a little closer, but the same problems ensue)
The problems with these methods is that they have a cooling effect on growth. Royal charters in particular prevent people from investing capital and creating businesses to fill a market need. Feudal tithing engenders mismanagement by feudal lords. Tariffs in a low-technology environment are easy to circumvent (hence the whole *smuggler* occupation). Uniformly priced stamps make small transactions prohibitively expensive.
The state has need of capital for various uses (defense, civil order, public works, etc.). So it needs some taxation system. What is the minimum level of technology necessary to implement a basic form of a modern tax system (be it VAT or income)? How would it be circumvented? How would it be enforced?
Edit: I should be clear that I'm trying to avoid taxation schemes that will obviously lead to mismanagement /undue pain on the populace. Things like selling of tax collection licenses encourages legbreakers.
Its obviously true that any tax is going to have a cooling effect on growth (Assuming that tax money isn't being spent on public good). But some tax systems are worse about this than others. Let's consider an optimal tax as that which causes the least pain in the populace per unit revenue.
[Answer]
I have a different slant than the two previous answers, but only slightly:
* First, you need a money-based economy, or at least one which routinely puts monetary value on things. If the land owner gets "one fat hog on pentecost" from each tenant farmer, the state doesn't want a percentage of those hogs, it wants money.
* Second, you need a high division of labor. If the average household does much of their own food production (kitchen gardens), clothes production (spinning wheels and looms), etc. then it is hard to tax a fraction of the income or *value added*.
* Third, you need widespread literacy and numeracy to record the transactions from the first two steps.
One possible workaround is mandatory division of labor with taxation at this step. Say the farmers are **not allowed to mill their own grain**, they must go to the overlords' windmill that will keep a fixed percentage. The possession of hand mills is a crime. Still rather close to the feudal tithes concept, of course. So you cannot really avoid a society where people handle cash on a daily basis.
[Answer]
It's not technology which makes an income tax possible, but the political system. In order to collect a fair, broad-based income tax, you need an accepted rule of law. (I say "fair" and "broad-based" because confiscation is always workable, and even an ancient society could tax based on looking at a rich person's wealth-producing properties and assessing them a fraction of what they ought to be able to produce. This is not workable on a mass basis nor is it workable if it is to be based on actual income.)
You need a rule of law because a fair and broad-based income tax depends on being able to know what peoples' income has been. This implies considerable organization and basic societal cooperation. It also requires that honest accounting is the norm. (If accounting is basically meaningless, it will quickly devolve into confiscation.)
(The same would be true of a VAT.)
The technology needed is little more than good record-keeping and basic accounting. The Romans had the former and the latter was an early Renaissance innovation which the Romans could certainly have developed.
Addendum: It occurs to me that medieval Europe had a rough and ready income tax in some areas where farmers paid the local baron and the local church (which between them was most of the government they ever saw -- police, welfare dept, hall of records) a percentage of their crops each year. That's an income tax by any definition. (In other areas they paid a fixed amount, making it more like a poll tax.) Note that no accounting was needed, since the amount of the harvest each year was visible to all.
[Answer]
For effective collection of VAT the recent states had introduced special counters (I am not sure about the name), that every or every medium or big seller should have and use. All this automation was introduced during the last 10-20 years. So, even 20 year old technology cannot fully support the ***contemporary*** tax system.
But that is correct for the contemporary society only.
I agree that the technology is less important than the political system, but even more important is the moral level of the society. In the more honest society you can use much more complicated tax system without the need of any complicated control.
Another very important parameter is the size of the society. In the small town-state everyone simply sees into the pocket of everyone else. And you can easily make any intelligent tax system to work without any technology.
] |
[Question]
[
In the story I am writing the universe itself was create from a magical storm in a realm known to mortals as The Beyond.
Now it is believed that there is the Realm of Reality in which the story takes place, and The Beyond a plane of existence that shadows the mortal plane. While The Beyond and the Mortal plane cannot see each other or physically interact with each other. The presences of The Beyond can be felt in the air by certain individuals, your mages per se. This energy is referred to as Aether. Aether can be used as both a creative and destructive force.
Your magic users are capable of pulling Aether from the beyond to cast magic. However, in the rules I am setting out, the immaterial of The Beyond cannot stay in the material world for long. This leads to casting magic being mentally draining. The stronger the mind the greater the feat can be achieved.
Also drawing too much power from the Beyond creates a ripple in The Beyond drawing spirits and wraiths of the immaterial plane to try enter the realm of reality and kill whoever is on the other side. This is as the entities of the Beyond view the mortal plain with hate and disgust, seeing Reality as a mistake that should never have happened.
Lastly I have an idea that to keep something made of the immaterial in the realm of reality one needs to use blood magic. The bigger the object the more needs to be sacrificed.
Is this enough of a cost to make the use of magic seem like a believable cost, something that someone needs to value and weigh what is worth?
Therefore, evil would seek to use blood magic to achieve power and make their achievements permanent while those who use magic for good use it for a temporary aid rather than as long term solution.
[Answer]
**Make the Beyond weirder.**
1: Alive, dead, kill and hate are phenomena of the material. Your immaterial creatures are dangerous, but make them otherworldly. They will not kill you. They will *change* you. They do not hate our plane. They object to it. That will distinguish these entities and their motives from good and evil factions on your material plane.
2: Blood, sacrifice etc. Yes, yes. But if your magic is mediated by a plane that contains entities which consider Reality a mistake, the danger of dealing with such is danger enough. The more you deal with them, the greater the chance they will be able to pursue their own agendas (which might differ entity to entity) on our plane and possibly through the magic user. This risk will be true for people trying to use these forces for good or for evil purposes on the material plane.
[Answer]
**It's the Sacrifice that counts**
It's very common that magic is strengthened by the emotional state of the practitioner.
You could easily make the case that it's the Value of the sacrifice that matters.
The average person values their own blood while they have it, but as soon as they've adapted to its loss (by generating more) then the stored up blood is essentially irrelevant. Blood is therefore an easy source of material to sacrifice harmlessly.
Ritual Sacrifice meanwhile plays off the compassion of the practitioner.
They have to see a person and knowingly give them up.
One loved one is worth a thousand or more strangers to the right person.
On the other hand, you could sacrifice your beloved childhood teddy-bear for an extremely powerful world-shaping work of magic if you cared about it enough.
[Answer]
First of all, i love your way in approaching magic.
Now to your question: My answer might be a bit similar to the one Willk provided, but I would take a slightly different approach to it.
**Insanity**
Draining Aether from the Beyond could make it flow directly through your mind, ripping it apart bit by bit. While simple, easy "spells" are no problem to execute, the stronger the spell gets, the more of the aether passes your mind and may take pieces of your sanity with it. So doing such tricks would need a very strong will and could still be very taxing to your mind.
Magic users who went to far with their usage of the Aether would walk the Earth as insane people, maybe even an entity of the Beyond might have taken control over them.
(I gotta admit, i simply like insanity. It has so much potential, as for every insane person you can create the world over and over to the way they experience it.)
[Answer]
**Blood as a representation for life force**
You could have the blood used in the blood magic act as a link to a persons life force. In this case you can have a person suffer a loss of life force when their blood is used. So it is no longer the amount of blood, but the life force or the person who the blood belongs too that is important. People would be born with a given amount of life force, say between 80-110 years (or whatever values you want). This life force can then be used as reagent for magic in the form of blood magic. It also drains slowly over time as you age.
Using life force would permanently take life force from your total. And the only way to get it back would be to steal it from someone else. Or if you don't like that kind of mechanic you could have it passively regen over time, or even just make it so that what you are born with is what you get, and you can only lose life force.
A basic simplification would be something like "making a sword permanent would take 2 days of life force, while making a magic car stay permanent takes 1 week worth".
With this kind of system the cost is much more real, as using up too much blood magic would result in death. Or it would require you to seriously harm or kill another person to use their life force to pay the cost of using really big magic. It also allows for the moral struggles of people who are close to 0 life force wanting to steal from others. And it removes the case where someone can become super powerful by hiding in a basement and collecting their blood for a few years.
Hope this helps at least a little.
] |
[Question]
[
Is it possible for massive clumps of algae to evolve and survive in deep space?
Let's say there is an expanding red star in a system with asteroids and planets once containing organic molecules, and these naturally evolve into a sort of organism that uses sunlight for consumption as well as electrical fields, draining passing starships of their power supply and trapping them.
The system itself can be a nebula, with ionized hydrogen and other gases.
These colonies of spaceweed would measure thousands of kilometers long, in floating clouds around the gravity wells of this system, and would present a hazard for colonists.
If this is possible then how would its physiology work?
[Answer]
First, take a look at this other, related question:
[Life in the water/snow line of a protoplanetary accretion disc?](https://worldbuilding.stackexchange.com/q/108198/21222)
Life in space may be possible, within some constraints. Any space thriving organisms would probably live within amorphous space ice, which will be present orbiting a star, or a planet (such as the rings of saturn).
So yes, you could have some equivalent to algae in space.
About ecologically meaningful interactions with ships, though... The chances of a ship or probe hitting an asteroid or comet by accident is quantum small. That's why space agencies don't have to care much about accidents while traversing the asteroid belt between Mars and Jupiter, and that's why the five probes currently going out of the solar system don't need to worry about hitting something in the Oort Cloud. So the chances of a visiting ship hitting on a large chunk of your space algae would be infinitesimally small.
In particular, most of the mass orbiting a star should stay nearly in the same orbital plane, which closely aligns with the star's rotation. A visiting ship may come from above or below that plane to further reduce the chances of an accident.
Since your algae will probably never come into contact with ships by accident, it may never evolve a way to "sap their power".
A more likely occurrence is that space debris containing such algae may come towards a planet. They would then have a chance to impact on a ship orbiting that planet. If the algae survive the impact, they may do whatever it is that they do, but they will be limited in their growth by how much ice the hull of the ship will support stuck to it. This, too, is unlikely. See the ISS, for example - [it gets constantly hit by micrometeoroids](http://www.spacesafetymagazine.com/space-debris/kessler-syndrome/micrometeroid-hit-iss-cupola/), and yet you don't see ice accumulating on it.
Then again... Handwavium is a thing, and if you wish to have a Dyson Sargasso Sea around your star that traps and saps space shipts, it's up to you. This is the stuff of good, enjoyable science-fiction.
[Answer]
## Unlikely, as this is way beyond even the capabilities of extremophiles
There are bacteria that still show signs of metabolism in temperatures of -200°C (~70K), but space is even **way colder** than that. It is close to 0K as there is barely anything in it - that's why it's called space.
Also you do not just have the cold temperature - that might be an obstacle that could be overcome, but you also have **extremely low pressure** that would probably rip microorganisms apart.
That's not enough though. There is no **radiation shielding**. I mean algae are small and so barely a target for radiation, but if that is where they live exclusively they could always suffer from that radiation.
### Reproduction?
How would they reproduce? Space is vast. And there are **no material resources**. How would they copy themselves or reproduce in some other manner?
## Summary
Space has several conditions that make this concept unrealistic. All because of extreme conditions that are way, way worse than anything here on earth.
* Extremely low temperatures
* Extremely low pressure
* Radiation
* Absolutely no resources whatsoever and thus no reproductive opportunities
[Answer]
Space is vast.
Space is empty.
Space is either really cold or broiling hot.
Space is a place where whenever you encounter something it normally has such a high energy that you'd rather prefer not encountering it.
The only semi-plausible way for something resembling life to thrive in such harsh environment would be to somehow spread the concept of life from the scale of a cell as we know it to something large as a nebula.
In this nebula atoms can randomly meet each other from time to time and interact. If with this interaction they are able to entangle, they will stay entangled even after they depart. If they find a way to spread this entanglement over the nebula and use it to develop something similar to what a living cell uses to grow and multiplicate, we would have something similar to life.
Of course it would be spread over time and space in a way that to us humans would probably look like a bubble of useless dust, and for them we would be something fast as a decaying pion, but it could be something which could act like life.
It won't be an algae, though. It would be something completely different than what we know. It's even possible that it could be a mental process with no physical body supporting it, but just a diffused link of entangled atoms.
] |
[Question]
[
I want to generate a world with a surface that has the same sort of patterning is seen in the surface of a dried lake bed when the mud cracks, but greatly scaled up. Each individual plate/fragment of mud being equivalent to an irregular slab of surface rocks 50 – 200 miles across on the planet’s surface with a canyon like gap all around. Ignore any curling up at the edges. The important feature is the fragmentation pattern.
How could a world with this sort of this topography evolve naturally? Is it even remotely possible?
I understand that the forces that cause mud to crack would not work at larger scales, but is there anything else that could produce a functionally similar effect a much larger scale?
The world is similar to earth. “Similar” means that humans must be able to live on the surface without the need of advanced technology to survive. Any of the earth’s physical parameters such as gravity, orbital distance and water content etc can be adjusted if that helps.
[Answer]
I thought that mud cracks and the crazing one sees in ceramics is governed by the microscopic character of the mud / clay and so will not scale up. But maybe it does.
Here are giant cracks on a dry lake bed on Mars. Same processes at work as on earth.
from <https://www.space.com/7287-giant-cracks-mars-hint-ancient-lakes.html>
But still 3 orders of magnitude less than what you want.
I was not able to find cracks this big on earth. I thought maybe the Aral Sea but no. I think maybe the big ones on Mars are an artifact of Martian conditions. You could handwave up what those are and magnify them but I worry about your inhabitants - a difference between Mars and Earth but 100 times more starts getting iffy.
[](https://i.stack.imgur.com/AJq0P.jpg)
---
There is a different way to make big cracks that result in adjacent irregular polygons. **Ice.**
[](https://i.stack.imgur.com/WNg0S.jpg)
<http://ocean.si.edu/ocean-photos/antarctic-pack-ice>
These shapes are made by the pressures of the ocean beneath. The ice is relatively thin. But what if the ice were phenomenally thick, covering the planet and the pressures from beneath were immense? Could you crack an ice layer kilometers thick into the giant blocks and crazed patterns you want?
<https://www.nasa.gov/jpl/europas-stunning-surface>
[](https://i.stack.imgur.com/66Q2g.jpg)
Europa's icy surface is covered with immense cracks many kilometers long. Maybe it is not tessellated enough for your purposes but you could make it more so. The topic of these cracks was addressed on the planetary science stack.
<https://space.stackexchange.com/questions/2226/what-causes-the-cracks-on-europa-to-form>
Stolen from that answer:
>
> The exact nature behind formation of these younger cracks is still
> somewhat of a mystery, but most of the theories suggest a combination
> of interactions between Europa and Jupiter, such as tidal forces,
> effects of changes in strength of Jupiter's magnetosphere as the
> satellite orbits it, Jupiter as a source of radiation causing
> greenhouse effect on Europa's liquid subsurface with the surface
> isolating the heat within its shroud, and also difference in radial
> velocity of the liquid oceans compared to its surface and possible
> geological activity beneath them to keep this oceanic mass warm enough
> to remain liquid, forming surface cracks similar to those found in the
> polar regions on the Earth, and perhaps even warm enough at its bottom
> to sustain some forms of life.
>
>
>
Europa is still cracking. I think your planet will have to still be cracking too: the flexing produced by Jupiter is not something one can easily turn off.
I wonder if you had a smooth siliceous lava flow (maybe from an ancient impact?) covering the surface of a planetary body if it could be cracked in a similar way, by immense tidal forces flexing it?
[Answer]
That is a surface contraction pattern. When the mud dries the surface dries and contracts faster than the deeper layers.
This **might** happen if the surface temperature of the planet cools rapidly and significantly. I am not sure if there is a natural process that could do this and leave you with a habitable planet, but terraforming a Venus type planet that had a too high surface temperature **might** be sufficient.
The surface would cool hundreds of degrees (celsius or Kelvin) within geologically very short period of time. In fiction terraforming usually takes few decades or centuries. This would be too fast for the geology to "equalize" in any meaningful way, so the surface should contract in small separate pieces. Just like mud.
Whether this would really work and how the results would actually look like depends on the specifics of the terraforming process and oddly enough I do **not** know the details of rapidly terraforming Venus.
[Answer]
The planet Mercury [has surface features on the scale of what you want](https://www.nasa.gov/feature/the-incredible-shrinking-mercury-is-active-after-all):
>
> The large scarps were formed as Mercury’s interior cooled, causing the planet to contract and the crust to break and thrust upward along faults making cliffs up to hundreds of miles long and some more than a mile (over one-and-a-half kilometers) high.
>
>
>
This results from [the following properties](https://www.space.com/25102-planet-mercury-shrinking-fast.html):
* Mercury is small enough that its crust forms a single tectonic plate
* Mercury's iron core takes up most of its volume, and as it cools, its crust cracks and folds as it shrinks
Its pictures and topography surveys don't *look* very cracked, since it's been thoroughly cratered by impacts, but if you only need the ridges to prevent travel, a planet with a similar structure would work.
If you need the aesthetic effect, those impacts have got to go. Supposedly most are the fault of the [Late Heavy Bombardment](https://en.wikipedia.org/wiki/Late_Heavy_Bombardment), so maybe your planet never suffered such a thing.
If you need the cracks to work *exactly* like a dried lake, so they have yawning canyons instead of upthrusting ridges, you would need the opposite effect: the surface cools/contracts faster than the core. Or maybe, the core heating up. I don't know of any examples of either, so maybe see if any of these are plausible enough for you:
* The core has enough radioactive material to overcome its natural planetary cooling
* The crust is made of materials that shrink faster than the core
* A driveby of another massive object stole (regularly steals?) mass from the crust, which redistributes over the surface eventually
These range from "violates core tenets of planet formation" to "hours of conversation at the planetary geology convention". Even if you found a reason you like, there is one more issue: any water would naturally flow into the cracks over time.
] |
[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.
>
> So I want a large power source to heat my new real estate on the Jovian moons. I create a micro black hole (MBH), maybe a few kg, maybe more and drop it into Jupiter. I expect the following to happen [...] the MBH absorbs mass and emits [Hawking radiation](https://en.wikipedia.org/wiki/Hawking_radiation), Mass falling towards the MBH will heat up due to the high pressure near the MBH [...]
>
>
>
Or so I assumed [in this question](https://worldbuilding.stackexchange.com/questions/80512/dropping-a-micro-black-hole-into-a-gas-giant?noredirect=1#comment234197_80512). However, it was pointed out to me in comments that such a small black hole is really, really small and that it emits enough Hawking radiation to effectivly push away all mass, meaning no accretion will happen and the MBH will evaporate.
Hawking radiation and resulting pressure will be lower with higher MBH mass, but that also means at some point Hawking radiation won't heat my gas giant - I still want a small MBH.
**What is the smallest MBH that will, when shot into a gas giant, accrete mass fast enough for it to not evaporate?**
I *think* this means that radiation pressure from Hawking radiation should be smaller than surrounding pressure, we may help by shooting the MBH to get some impact pressure in front.
It is entirely possible that the resulting MBH is too large to heat the gas giant via Hawking radiation.
[Answer]
First off, I'd like to plug JoeKissling's answer [here](https://worldbuilding.stackexchange.com/questions/74809/what-exactly-would-happen-if-a-black-hole-was-introduced-into-the-sun), which I used as a basis for mine.
# Radiation pressure
[Hawking radiation](https://en.wikipedia.org/wiki/Hawking_radiation#A_crude_analytic_estimate) emitted from a black hole acts as blackbody radiation, emitted equally from the surface area of the event horizon. Based on Wikipedia's 'crude analytic estimate', the equivalent temperature $T$ is given by
$$\frac{\hbar c^3}{8\pi GMk\_{B}} \approx \frac{1.227\times10^{23} \text{ kg}}{M} \text{ K}.$$
Multiplying this factor to the fourth power by the emissivity $\epsilon = 1$ and the constant of proportionality $\sigma = 5.670373\times10^{-8} \text{W m}^{-2}\text{K}^{-4}$ gives us the power output per unit area ($j^\*$), or radiant emittance, in accordance with the [Stefan-Boltzman law](https://en.wikipedia.org/wiki/Stefan%E2%80%93Boltzmann_law).
$$\begin{align}5.670373\times10^{-8} \text{W m}^{-2}\text{K}^{-4} \cdot \left(\frac{1.227\times10^{23} \text{ kg}}{M} \text{ K}\right)^4 = 1.285\times10^{85} \text{ W m}^{-2} \cdot \frac{\text{kg}^4}{M^4}.\end{align}$$
So basically, we take the mass of the black hole, raise it to the fourth power, then divide that enormous constant by the result. This will give us power output in Watts per square meter.
[Radiation pressure](https://en.wikipedia.org/wiki/Radiation_pressure) is function of the EM radiation flux ($E\_f$) and the speed of light. It is also a function of the incident angle of the flux. We will assume a spherical event horizon, where the pressure of the gas giant is acting in the negative direction from the radiation pressure, thus making the incident angle $\alpha = 0$. Radiation pressure, plugging in our previous equation, is
$$\begin{align}P &= \frac{E\_f}{c}\cos\alpha \\ &= \frac{1.285\times10^{85} \text{ W m}^{-2} \cdot \frac{\text{kg}^4}{M^4}}{2.998\times10^{8}\text{ m/s}}\cos0 \\&= 4.287\times10^{76} \text{ Pa} \cdot \frac{\text{kg}^4}{M^4}\end{align}$$
# Pressure at the center of a Gas Giant
Since the temperature and pressure conditions in Earth's core are not well known, the same applies a million fold for other planets. So we can only take some best guess assumptions about Jupiter's core. [Militzer et al., 2008](https://arxiv.org/pdf/0807.4264.pdf) estimate 100-1000 GPa for Jupiter's core, while [Wilson and Militzer, 2012](https://arxiv.org/pdf/1111.6309.pdf) use 40 Mbar = 400 GPa. Incidentally, this guy [Burkhard Militzer](http://militzer.berkeley.edu/) has a writing credit on about half the papers I can find on Jupiter, so lets take his word for it and use 400 GPa.
To solve for our minimum size black hole, set 400 GPa equal to our radiation pressure equation above.
$$\begin{align}4\times10^{11} \text{ Pa} &= 4.287\times10^{76} \text{ Pa} \cdot \frac{\text{kg}^4}{M^4} \\ \frac{M^4}{\text{kg}^4} &= 1.072\times10^{65} \\ M &= 1.809\times10^{16} \text{ kg} \end{align}$$
So there you have it. Your black hole must be roughly the mass of a 10 km radius asteroid.
[Answer]
I went about this a bit differently than [kingledion](https://worldbuilding.stackexchange.com/a/80539/627), and got a different answer (off by $\sim6$ orders of magnitude!). The difference is that I assumed that there would be accretion no matter what the mass of the black hole is; this is incorrect because [accretion would *probably* be prevented](https://physics.stackexchange.com/a/190327/56299) because of pressure by Hawking radiation. I'll keep this answer here for posterity, and also to show that even if you ignore kingledion's key pressure assumption, there's still an even lower limit - and thus his solution still works. A black hole of $\sim10^{16}\text{ kg}$ would certainly be able to heat the gas giant.
The [power emitted by a black hole from Hawking radiation](https://en.wikipedia.org/wiki/Hawking_radiation#A_crude_analytic_estimate) is
$$P=\frac{\hbar c^6}{15360\pi G^2M^2}=-c^2\dot{M}\_H$$
where $\dot{M}\_H$ is the change in mass of the black hole from Hawking radiation. Let's assume that the black hole also accretes mass; the equation for [Bondi accretion](https://en.wikipedia.org/wiki/Bondi_accretion) should give us a good estimate:
$$\dot{M}\_B\simeq \frac{\pi\rho G^2M^2}{c\_s^3}$$
where $\rho$ is the density and $c\_s$ is the [speed of sound](https://en.wikipedia.org/wiki/Speed_of_sound#Speed_of_sound_in_liquids). The [central density of Jupiter](http://web.gps.caltech.edu/~mbrown/classes/ge131/notes/djs08.pdf) is roughly $5\text{ g cm}^{-3}$, or $5000\text{ kg m}^{-3}$. We can find $c\_s$ as
$$c\_s=\sqrt{\frac{K}{\rho}}$$
where $K$ is the bulk modulus - [about $125\text{ GPa}$](http://iopscience.iop.org/article/10.1088/0256-307X/15/5/019/meta). This gives us $c\_s\simeq5000\text{ m/s}$. We then set
$$\dot{M}\_H+\dot{M}\_B=0$$
and solve
$$\frac{\hbar c^4}{15360\pi G^2M^2}=\frac{\pi\rho G^2M^2}{c\_s^3}\to M=\left[\frac{\hbar c^4c\_s^3}{15360\pi^2\rho G^4}\right]^{1/4}$$
Plugging things in, we have
$$M=\left[\frac{\hbar c^4(5000\text{ m/s})^3}{15360\pi^2(5000\text{ kg m}^{-3})G^4}\right]^{1/4}=5.158\times10^{10}\text{ kg}$$
This is, as I said, off from kingledion's result by a factor of one million.
There are only two things that could really be varied - the bulk modulus and the density. If we move the other factors out, we see that
$$M=7.295\times10^8\text{ kg}^{5/4}\text{ s}^{3/4}\text{ m}^{-3/2}\left(\frac{K^{3/2}}{\rho^{5/2}}\right)^{1/4}$$
Even raising $K$ by an order of magnitude and lowering $\rho$ by an order of magnitude only multiplies our result by $10$.
This demonstrates the power of radiation pressure! It raises the lower limit by six orders of magnitude, which is pretty incredible. Be careful of what physical assumptions you make.
] |
[Question]
[
This is all about a thought experiment :
Is there an hypothetical (or may it be real?) case of a stellar system, in which both methods of transit and radial velocities, are invalidated
by some orbital configuration, providing a constant light dimming (each egress is perfectly compensated by an other planet ingress)
and eccentricities and mass repartition of the planets around their star, make the barycenter of the entire system stay still at the center of the star.
I thought about a simple configuration of several similar planets sharing a single circular orbital path (see below). But are there any possibility for this to happen
with multiple elliptical orbits, of different sizes & eccentricities? How likely is it to exist since the universe is quite big?
[](https://i.stack.imgur.com/vvGDd.gif)
[Answer]
The configuration you have drawn is not gravitationally stable.
However, leaving that aside, the light from such a system would not be anywhere near constant, because of [limb darkening](https://en.wikipedia.org/wiki/Limb_darkening). So whilst the geometrically eclipsed area might be constant, the amount of flux blocked is not.
[Answer]
It is actually very easy for an exoplanet system to be undetectable through spectroscopy and transit eclipsing. All you need to do is change the angle of inclination. That's the angle at which we see the system from the Earth.
In order to detect exoplanets via spectroscopy, we need to be able to see the planet moving towards or away from us. The strength of the spectroscopic change is dependent on how quickly it is moving. However, if we are looking at it from the top down, we will not be able to see a spectroscopic shift.
Likewise, using the eclipsing method, the system has to be aligned with respect to us so that we see the planet pass in front of its primary. However, if the system is tilted with respect to us, then we may not see the planet pass in front of or behind the star at all. Thus we would see no change in the light curve, and would not be able to tell that there were planets there.
Here's an applet showing the [spectroscopic method](http://physics.unm.edu/Courses/Rand/applets/spectroscopicBinaries.html), and here's one for the [eclipsing method](http://physics.unm.edu/Courses/Rand/applets/eclipsingBinaries.html). You can mess around with 'i', the angle of inclination, to see at what angles you don't get a noticeable effect. (Note: These applets are for binary stars, but the method is the same for exoplanets. It's just a lot smaller of an effect.)
] |
[Question]
[
This just out of curiosity and interest, could something like the marsupilami exist in our world?
If you don't know, the marsupilami is pretty much a bipedal, arboreal monkey like monotreme (egg-laying mammal) native to the Palombian rainforests (which are fictional) of South America.
Its most noticeable feature is the absurdly elongated and slender tail, which can grow over six times its body length.
More than just prehensile, the tail is extremely flexible, able to be bent and shaped into knots without sustaining damage; perhaps suggesting an internal structure rich in collagen, similar to that of the hagfish of deep oceans.
Both the male and female are able to use their tail as a weapon, by tightening the end into a fist which they can use to send jaguars flying or running home with a black eye and the remainder of the tail into a spring-like spiral for maximal force
The tail can be used for locomotion in a number of ways, including being used as a spring.
It is also mentioned to have gills for some odd reason which is probably inaccurate for a mammal.
Also renowned is the strength of the Marsupilami, far greater than what would be expected from an animal of its size.
It is, however, a gentle and easy-going creature if not provoked. Its sharp intellect is betrayed by the use of tools, making it possibly the most sophisticated of all monotremes.
They are known for their distinct call: "Houba!" (by the males) or "Houbi!" (by the females); but are also able to mimic other sounds, including in some cases human speech.
The Marsupilami is omnivorous, its menu principally consisting of fruit, insects, and piranhas which it catches by using its tail like a fishing rod.
As a monotreme, it lay eggs while having mammalian features.
An astute creature, the Marsupilami lives in small family units and builds elaborate nests in the canopy; made out of sticks, vegetation, and ropes, and stuffed with bird feathers and decorated with flowers.
This nest is also built in such way that allows it to lock closed like an oyster in case of danger.
And plenty more info and details can be found at <http://non-aliencreatures.wikia.com/wiki/Marsupilami>, <https://en.wikipedia.org/wiki/Marsupilami> or <http://marsupilami.wikia.com/wiki/Marsupilami_%28species%29>.
***Question-*** The question is: could an animal like this exist in our world? How could its ancestor get to South America in the first place?
(<http://www.deviantart.com/art/Marsu-species-253660899>, turns out there an African, Asian and aquatic species as well as according to the Marsupilami encyclopedia). How could the long tail function and why so? How did it learn through generations to build such an odd nest? How many vertebrae would be in the tail? How can it lay eggs in this structure? And how did a cousin of the platypus and the echidna evolve a primate-like structure in body shape and what did its ancestor look like when it co-existed with dinosaurs to before the Great American Interchange?
And there's plenty of more questions such can it use its tail to catch piranhas? Could there be an alternative to gills? Could it fend off jaguars? How would it move if it ended up on the ground? And could the tail have an internal structure rich in collagen?
[](https://i.stack.imgur.com/z92Cl.gif) Here's what the marsupilami looks like.
[Answer]
>
> The question is: could an animal like this exist in our world?
>
>
>
The creature is viable. I would argue that the tail is the main oddity of its evolution, at some point it or its ancestor must rely mainly on its tail, placing an important evolutionary constraint on it.
The dexterity the creature has with its tail suggests an important brain evolution associated with motor skills. Paired with the fact that it is a social creature, it is not odd that it has complex behavior such as the construction of elaborate nests.
I do believe that the evolution of the tail and the construction of the nest are examples of sexual selection. Elaborate displays of tail movements (such as making knots or twisting it in a spiral) could be attractive for partners; it can be a proxy for display of construction skill necessary for a strong nest. Furthermore, the nest itself could be signaling of social status.
I want to mention the odd fur the creature has, being yellow with black dots. These creatures, being tree-dwellers from the South American rainforest did not compete with other creatures with similar fur. Furthermore yellow does not seem to be a good choice of camouflage for a tree-dwellers creature. I must conclude this fur is vestigial and was not been selected out.
Note: [Leopards are not from America](https://en.wikipedia.org/wiki/Leopard#/media/File:Leopard_distribution2.gif). Yes, [Jaguars are ground-dwellers from America](https://en.wikipedia.org/wiki/Jaguar#/media/File:Cypron-Range_Panthera_onca.svg).
>
> How could its ancestor get to South America in the first place?
>
>
>
Branches of Monotremes separated in the [Jurassic](https://en.wikipedia.org/wiki/Pangaea#/media/File:Pangaea_to_present.gif), at the time Africa and South America where connected. Therefore, the ancestors of these creatures could have always been in what would become South America.
While in the real world, there are [Australosphenida](https://en.wikipedia.org/wiki/Australosphenida) are only found in Australia (hence the name), there is a fossil record of them in parts of South America and Africa.
>
> How could the long tail function and why so?
>
>
>
As per the function of the tail, it would work similar to an arm, but with additional flexing points. Something like a very flexible long finger. It would require a dedicated region of the brain for its control, as part of the motor cortex.
The muscles in the tail would be numerous and small, allowing for fine control of the movement. This also means they are not very strong.
*See more below in "The Jump"*
>
> How did it learned through generations to build such an odd nest?
>
>
>
There are other social animals capable of passing knowledge by example an imitation. It is interesting to speculate on the memes necessary for the creation of the nests: you need to create the wood structure, which requires picking branches, and you need to learn to pick feathers to stuff it.
In any other context, picking branches and picking feathers are orthogonal. In addition, when building the nest you need the wood structure first, so I would say it evolved first.
The first incarnation of the nest could have been similar to that of birds, with the roof being an evolution of it. The next evolution would be to fill it with leaves for comfort, which is something that may have been an accidental discovery.
By experimentation, they may have started using feathers, which yield better results. However, they did not have the practice of hunting birds (in fact, the linked lore says they eat fruits), so feathers would have been scarce, triggering competition, and becoming a status symbol.
>
> How many vertebrae would be in the tail?
>
>
>
We have to consider how realistic the representation we are given are... for example consider this creature:
[](https://i.stack.imgur.com/Hgnck.png)
*Marsupilami hunter*
This creature has a single connected eye, floating eyebrows, rare proportions, an odd colored nose and a single tooth.
Let us consider how such a creature could have evolved... Wait that is a human? - You see, we have to take these representations as an approximation of how the creatures look like. That is why I have not said that the Marsupilami is not possible because a Monotreme would not have evolved a single connected eye in natural conditions.
Therefore, when we see the curvatures of the tail of a Marsupilami in these depictions, we cannot really tell how many vertebrae are there. This means that the only way to approach this question is by comparative anatomy.
---
The best approximation we have to the Marsupilami tail are the prehensile tails of primates. We need to notice that the number of vertebrae changes from individual to individual, and the average changes from species to species. See: [Structure and Function of Platyrrhine Caudal Vertebrae](http://onlinelibrary.wiley.com/doi/10.1002/ar.21129/full)
The closest data point I have is the [Black-headed spider monkey](https://en.wikipedia.org/wiki/Black-headed_spider_monkey) that has a tail that grows 1.75 times the length of the body and has around 32 vertebrae in the tail (some individuals have 31, and some have 33).
If we extrapolate this linearly to a length of 6 times the length of the body, then we are looking at a tail of 109 vertebrae (give or take).
*I may do the computation considering more data points when I have more time to look into this*
>
> And how did a cousin of the platypus and the echidna evolve a primate-like structure in body shape?
>
>
>
If we go by the hypothesis that these creatures separated from other Monotremes during the Jurassic, it is not odd that they would have taken a different evolutionary path. In particular, for this creature to exist, they would have convergent evolution with primates.
The influence for such evolution would be the advantage of finding fruits high on the trees and avoiding predators. At that stage, the predators would be mainly snakes, which are relevant in the South American rainforest. However, this would put them in direct competition with new world monkeys. That actually makes a good argument for them keeping a very close social structure and being territorial.
If I were creating a setting with these creatures, I would say they were problematic for a scientist, as they may attempt to classify them in [Primatomorpha](https://en.wikipedia.org/wiki/Primatomorpha), considering something similar to [Lemurs](https://en.wikipedia.org/wiki/Lemur). In addition, that it required modern biology to compare the DNA of these creatures and settle the argument.
In fact, the only argument I have against these creatures being primates is that they had no evolutionary pressure to lay eggs, and there are no antecedents of such mutation in primates.
---
*The Jump*
Jumping was not been mentioned in the question or in the linked lore, so I disregard this so far. It is hard to imagine such a slender tail to have the muscular structure for the jump.
Looking for "Marsupilami" I found the animations, how can that be possible.
Certainly, that is not possible only with the muscles in the tail. Although for the jump, what you really need is a strong force trying to extend the tail.
We engineer this if we consider the degrees of freedom of the tail. The way to do it is by having a long ligament running down the tail. Muscles in the back of the creature would then pull that ligament in such way that it extends the tail. The bone structure must be such that it locks in the backward motion. That means that the tail will not be able to curl up (it will curl down instead, so knots and spirals are still viable).
These muscular structures would have to be very strong, and be exercised often. Note that if the tail is stronger extending than curling, it makes sense that you will want to make knots for attachment.
---
*The tail punch*
I would say that hitting with the tail is just the same movement (extending the tail) but instead of doing it to propel itself, it is done in the air as an aggressive gesture.
] |
[Question]
[
In an effort to accurately map and predict earthquakes and tectonic plate movements, scientists wish to insert sensors through the earth's crust and into the upper mantle.
Through some Excel wizardy, they manage to get the funding to extend the [Kola Superdeep borehole](https://en.wikipedia.org/wiki/Kola_Superdeep_Borehole) which currently extends to a little over 40,000ft (over 12km) deep. The Kola borehole was abandoned for budget reasons back in 2008 and the hole covered.
[](https://i.stack.imgur.com/MTHjL.jpg)
Some WD-40 and a bit of elbow grease should be enough to re-open it again.
Plot dictates the boreholes should be located at points of greatest stability (on land, away from tectonic plate boundaries). While it's possible to use volcanoes, there's reasoning that excessive magma movement would make accurate measurements next to impossible).
Should the Kola extension be successful, further boreholes will be drilled in other locations around the Earth and instruments inserted.
Assuming that "modern day" materials are able to withstand the heat of deep drilling, what difficulties would the drilling team face? By "modern day", I mean a near future where heat-resistant tools and sensors can be manufactured.
[Answer]
a big challenge for "modern day" materials:
* high temperature (from your same source)
>
> However, because of higher-than-expected temperatures at this depth and location, 180 °C (356 °F) instead of expected 100 °C (212 °F), drilling deeper was deemed infeasible and the drilling was stopped in 1992. With the projected further increase in temperature with increasing depth, drilling to 15,000 m (49,000 ft) would have meant working at a temperature of 300 °C (570 °F), where the drill bit would no longer work.
>
>
>
Yes we presently build materials able to operate at higher temperatures, like jet engine blades, but they have to cut through (hot) air, not stone.
Plus the depth makes also difficult to deal with failures: if the drill gets broken you can't go down and replace it, you leave it there and start over again from another place along the tunnel.
Again from your same source
>
> Another unexpected discovery was a large quantity of hydrogen gas; the mud that flowed out of the hole was described as "boiling" with hydrogen
>
>
>
Hydrogen and high temperature means hydrogen diffusion into metals, which is known to make them more weak.
[Answer]
Even with indestructible drilling materials, there comes a problem at c. 15-20 km; the materials of the crust become ductile [1](https://en.wikipedia.org/wiki/Brittle%E2%80%93ductile_transition_zone). This means that any hole will tend to close up by flow. Even if you were putting borehole liners in as fast as possible, eventually the whole thing would gum up.
This is also the limiting factor for earthquake fault propagation depth.
[Brittle-Ductile transition zone](https://en.wikipedia.org/wiki/Brittle%E2%80%93ductile_transition_zone)
] |
[Question]
[
Looking for options with at least some grounding in science:
Several hundred years in our future, a group of wealthy philanthropists lavishly funded a colonisation project designed to create a Utopia. Their theory was that human violence is a cultural phenomenon, which occurs because of traumatic childrearing practices, poor social structures, and generational contagion.
The controlling AI found a suitable planet, did some modest adjustments to make it more habitable, seeded it with genetically-engineered plants which naturally produce a vast range of medicines (including contraceptives), and human volunteers raised the first generation of native-born humans without any knowledge of the colony ships, or the history of the species. Just general knowledge of biology, chemistry, geology, etc, and all the specific knowledge of how to live on this particular world.
When the first generation were old enough (the second generation was successfully raised, and the third generation was being born), the human volunteers gradually withdrew, one by one, until there was nobody left on the planet with any knowledge of the colonisation.
Part of the theory was that humans evolved to live in villages of less than 200 people, so the society was organised into villages, approximately a day's walk apart, which practiced permaculture.
The centre of each village is the Hearth - a building which provides shelter, cooking facilities, and apparently endless energy. The hearth has an oven, so that food can be cooked, and ceramics can be fired. It doesn't generate that heat by burning stuff.
There are enough Hearths on the planet to sustain the population that the AI calculated would be manageable for the ecology. They are scattered throughout the tropical and temperate regions.
My question is - given that there is sufficiently advanced technology to do terraforming, shall I just say they tap into geothermal energy through a planet-wide grid, or is that scientifically laughable?
Additionally, I want these things to be massively durable, lasting for thousands of years without maintenance from the humans. Is that possible without the ongoing presence of the AI and a bunch of maintenance nanobots? Solar panels won't last that long.
Alternative solutions to the Hearth problems very welcome.
Assessments of the theory of the Utopian philanthropists not necessary - the validity of that theory is the subject of a series of at least nine books!
[Answer]
## Power Plants
>
> seeded it with genetically-engineered plants which naturally produce a vast range of medicines
>
>
>
Keep the idea of genetically-engineered plants going and have your colony rely on organic technology for power generation. Organic technology has several advantages over normal technology which would allow it to meet the requirements you are looking for. Nanobots and machines tend to rely on metals and rare elements, which tend not to be evenly distributed in the mantel of a planet. Not to mention rare metals tend not to be easily accessible and requires a lot of processing to make them useful. As such even with self repairing nanobots they would be hard pressed to find the materials locally to maintain their Hearth.
### Power Generation
Have the plant use photosynthesis to generate energy to keep itself alive and rely on other sources of power to generate power that can support the village. Since plants typically have easy access to water, I recommend hand waving an organic version of a [fusion reactor powered by deuterium](https://en.wikipedia.org/wiki/Fusion_power#Deuterium) to supply power to the village. The power generated would run near the surface of special areas of the plant where villagers could stab in power taps to supply power to their various devices.
### Plant Life Cycle
Since it is organic, it can self repair and heal on its own, also it could be genetically engineered not to die from old age. The power plants could still be killed by a natural disaster, accidents, or intentionally. To counter this have the plant produce seeds. The plant would keep at least one seed stored in itself at any given time so that if it dies the seed could start a new power plant. The plant would also have seeds easily accessible to humans so that if they find a place that is missing its power plant for whatever reason, they could plant a new one themselves.
[Answer]
## Radioactive Diamond Batteries
Diamond naturally generates electricity when exposed to radioactivity. So, [radioactive diamond batteries](http://www.forbes.com/sites/jamesconca/2016/12/09/radioactive-diamond-batteries-making-good-use-of-nuclear-waste/#15f6b9a56bac) are made by [forming carbon-14 into diamond and encapsulating it in regular non-radioactive diamond](https://m.youtube.com/watch?v=b6ME88nMnYE).
These diamond batteries have a very specific purpose – low power and extremely long life. A standard twenty-gram non-rechargeable AA battery stores about 13,000 Joules and will run out of power in about 24 hours of continuous operation. One diamond with one gram of carbon-14 would produce 15 Joules per day, much less than an AA battery.
But the power output of the diamond battery is continuous and doesn’t stop. The radioactive diamond battery would still be putting out 50% power after 5,730 years, which is one half-life of carbon-14 or about as long as human civilization has existed. During this time, the diamond battery would have produced over 20 million Joules. And would produce another 10 million during the next 5,730 years.
So, if a diamond grid were built as one single piece that spanned the entire planet, connecting all the Hearths together, it's possible you could get enough energy from the diamond to meet the population's needs. The grid would need to contain enough radioactive material that it's output would be sufficient, so perhaps diamond mountains could be part of the grid, or massive underground diamond banks, or perhaps the planet itself could be made of diamond inside, with proper earth-like terraforming on the surface layers.
## Refueling
Perhaps if you want the society to last more than the lifespan of the batteries, you could have the philanthropists periodically replace of spent diamond with fresh diamond every 5,000 years or so. This could be done perhaps in relative secrecy, or perhaps they could be viewed as gods. Perhaps even if you had the entire planet made of diamond, the repacement teams could terraform out the old diamond and replace it with fresh diamond.
## Feasibility
The feasibility of this would depend on how much energy you needed for your society--that would dictate how much diamond would be needed. So, the less power you need, smaller the diamond units would need to be, and so the more plausible it is to replace them easily in the future.
Nonetheless, one can assume that your scientifically advanced philanthopists will continue to technologically advance over the first half-life of the diamond, so that's 5,000+ years for them to develop much larger scale terraforming for replacement of the spent diamond. So, even if you had the entire planet made of diamond inside, perhaps in 5,000 years or 10,000 years, the philathropist's technology would be sufficient to replace the spent diamond.
[Answer]
**Let's start by estimating how much energy each village would actually need.**
Now I'm assuming when you say the Hearths generate "apparently endless energy" you mean they create enough to constantly supply each village.
If this is the case first we need to figure out how much energy they would actually need.
Since you didn't include any figures apart from the understanding that these villagers live generally modest lives let's start by taken the world average(the sheer poverty of most of the world should balance out the exuberance of the west) energy consumption per household per year: about 3500Kwh. Let's say each village has 35 households(Which can leave room for each to house roughly 6 people, perhaps 2 grandparents, 2 parents and 2 children) and 5 additional "household like" buildings(schools, activity centers, etc...) so that's 40 "households" total or a total consumption of 140,000Kwh or 140Mwh per year. Easily obtainable.
---
**Now let's explore some possible energy sources.**
You want these hearths to last several thousands of years without maintenace, then we have to already eliminate several energy production methods: namely nuclear and fossil fuels like coal and oil.
And the issue with your idea for a geothermal grid is that your villages are spaced too close, you'd have to hope for a viable geothermal fissure about every 50 miles which isn't really possible unless your planet is really different to ours(there is also the issue with shifting ground which would cause many to become unusable without adjustments after only a few centuries).
---
**Finally here's the problem, not energy production, but durability.**
No matter what energy production method you choose a small earthquake or even just wear and tear could easily dislodge a vital component of these hearths rendering them useless without that tiny adjustment.
Even if we do recognise that this future's technology is much greater then our own it would still have to be so advanced to be able to ensure that every single hearth would remain operational over millennia of abandonment; to put this in perspective almost all(with the exception of photovoltaics which can theoretically last longer) current power plants are designed to last less then a century, that with constant maintanance, part replacement, supervision and industry expertise.
If just one of these hearths failed that would surely mean the affected villagers going to war with the nearby villages for the needed resources and entirely defeating the whole purpose of the planet's configuration.
---
**Face it, even for the far future this simply isn't very feasible.**
[Answer]
>
> Additionally, I want these things to be massively durable, lasting for thousands of years without maintenance from the humans. Is that possible without the ongoing presence of the AI and a bunch of maintenance nanobots?
>
>
>
If you'd like an example of what is capable of lasting thousands of years without maintenance from humans, we can [showcase our inventory](https://en.wikipedia.org/wiki/List_of_oldest_buildings)
[](https://i.stack.imgur.com/qfLMjm.jpg) [](https://i.stack.imgur.com/WmxYqm.jpg)
There is literally no modern technology today which is even perceived as being able to generate energy for thousands of years. Sure, we can get nuclear isotopes that will generate radioactive energy for that long, but the machinery to turn that into energy will *certainly* break down.
Of course, you *do* have a group of people that have literally flown to another planet. This either involves Faster Than Light travel, in which case all bets are off and you can just handwave the Hearths, or it involved a multiple-thousand year trip through space, in which case they've figured out how to build things to last!
I'd say, given all of that, the effort of making a power source for a few thousand years is literally peanuts. I'd recommend handwaving it and never looking back. You have far more contentious sources of conflict regarding the utopian claims at the heart of the book. Your readers should be more than willing to overlook an energy source or two.
[Answer]
Given current technology there is no energy source that will last for thousands of years without maintenance. Geothermal stands a good chance of being destroyed for reasons that others have given above. Plus, geothermal tends to be finicky and maintenance-intensive.
**Solution 1: Long-duration solar energy**
Solar power has the benefit that there are no moving parts. You could also keep every element of the power system in or around the hearth, which would mitigate the risk of damage by earthquakes and whatnot. On the other hand, those solar panels are vulnerable to weather events- hail stones, severe storms, etc. You'd also have to make sure they never get too dirty or overgrown by vegetation.
The technological leap here is that solar panels degrade over time. On a modern solar panel you might see roughly 1% to 0.5% reduction in efficiency per year. This means that a 10 year old solar panel would produce 10% less energy than the day it was installed, where a 30 year old panel might produce 30% less energy. On top of that, you need batteries to store energy for overnight use, and modern batteries wear out over time and eventually lose the ability to hold a charge.
Given that you've got space ships, you can probably hand-wave the technical issues. Solar energy and battery energy are both really intense areas of research right now. A good hand-wavy answer would be that the panels and batteries are designed to "refresh" themselves every 1000 days by totally charging themselves and discharging themselves. That would require a little microcontroller, but not an AI.
**Solution 2: Nuclear Energy**
Modern nuclear energy requires a lot of maintenance, but people have been talking about [Small Modular Reactors](https://en.wikipedia.org/wiki/Small_modular_reactor) for some time now. Some of these are designed to be self-sufficient and self-contained machines that are fueled at the factory, and are then only limited by the need for periodic refueling. One highly experimental design called a [Traveling Wave Reactor](https://en.wikipedia.org/wiki/Traveling_wave_reactor) is supposed to solve the refueling problem by packing enough fuel into one reactor to "burn slowly" for upwards of 100 years.
These are also relatively compact, as far as nuclear reactors go, and could be co-located near the hearth, minimizing the risk from earthquakes and geologic activity. They could also be buried, minimizing the risk from severe weather.
The leap for your story would be upgrading the traveling wave design to store thousands of years of fuel rather than a hundred, which seems pretty reasonable to me given an advanced society. It would run out eventually (unlike solar or geothermal), but consider how much progress we've made in the last 10,000 years. At some point the hearths would stop working, but by then these people may well have their own scientific understanding of electricity.
[Answer]
**EDITED to account for missing constraints**
Locate Hearth above giant bats caves, and add beneficial microorganisms that decompose their refuse to , among other things , methane. By carefully designing system of fissures you can supply it to hidden burning chambers (to hide fire) beneath cooking ovens. It would also supply heat for living quarters.
[Answer]
Hearth is the tip of a single large rod of metal extending down to where the crust is very hot. It conducts heat up. The top stays hot. You can boil soup on it.
Don't let the kids bump into it! It's hot!
] |
[Question]
[
I'm trying to design a voting system where smaller parties are represented but the country still uses local representatives. I don't want to allow coalitions since they dilute the party message into amorphous blob.
My idea is to have a country with unicameral parliament. The country is divided on electoral districts. Each party nominates candidates in every electoral district. The parliament seats are split among the parties according to how many votes they've got on a country level, but which candidate is chosen depends on a how well it did on a local level.
For example if there are 3 seats and 2 parties (A & B).
1. A 80 votes B 20
2. A 60 votes B 50
3. A 55 votes B 45
A 195 / 300 \* 3 ~ 2 seats
B 105 / 300 \* 3 ~ 1 seat
Party A will win seat No 1 & No 2 because it had a largest percentage at them 80% & 60%, B will win seat No 3, since it must receive a seat due to winning 35% of the votes and at seat No 3 it was relatively best.
The principle is same for multiple parties, each party receives seats according to the total number of the votes in the whole country, but their seats are distributed to their candidates that did relatively best in each district.
Will the smaller parties thrive under my voting system while people would still be able to have local representatives?
I assume that country is modern democracy.
***Addition***
The country uses separation of powers where parliament is only the legislative branch while president holds the executive power.
I'm open for election threshold of maximum 2%, 5% is way too much. Just for comparison Libertarian's Johnson won 3.2% while Green's Stein got 1% of the popular vote. Though theoretically there could be 25 parties each getting 2% I doubt that's what gonna happen.
I want small parties to have some voice and state funding, and occasionally be able to pass some laws when their votes are needed, but I want to avoid coalition governments like in Israel, Sweden etc.
***Seat assignment process***
Assuming there are 100 seats which should be distributed to 4 parties: A(60), B( 30), C(9) and D(1).
The process goes fallowing:
1. Assign seat to the candidate that won the most votes
2. Decrease number of seats to candidate's party by one
3. Remove parties whose remaning seats is zero
4. Repeat until all the seats are allocated
For example:
*Assuming D's candidate from the 47th district received most votes*
1. Assign seat to party D's candidate from the 47th district
2. Party D's remaining seats drops to zero
3. Remove party D candidates from further consideration
*Assuming party A candidate from the 12th district received most votes*
5. Assign seat to party A's candidate from the 12th district
6. Party A's remaining seats decreases to 59
7. Candidates from the parties A(59), B(30) & C(9) remain
....
[Answer]
"Will the smaller parties thrive under my voting system while people would still be able to have local representatives?"
Smaller parties would unquestionably thrive for such system. - this part passed
Nevertheless to have a LOCAL representative it would be a bit trickier. If you voted for a party that's not specially popular in your district - you are guaranteed NOT to have one, and your district would be represented by a member of other party. ;)
System as such may work... assuming that one would put some election threshold, otherwise parliament full of squabbling parties build out a few or one member of parliament would be ungovernable.
<https://en.wikipedia.org/wiki/Election_threshold>
[Answer]
Imagine that you have 100 districts for 100 representatives. There is a small party that would be supported by 0.8 to 1.1 percent of the voters. They could get one representative in *if they run a halfway credible candidate in each district*. Which of their 100 candidates gets in will be pretty much random chance -- voters might prefer one of the 100, but they can't influence where they get to vote. Perhaps they have more support in the northern part, but their most influential leader was born in the southern part (and isn't going to move).
And of course your system might still require coalitions. Like any proportional representation system there is a very high likelihood that no one party gets the majority.
Also, it is possible that one district gets two representatives and another gets none. Imagine three equally large districts and three parties:
District 1: 40% A, 20% B, 40% C
District 2: 45% A, 10% B, 45% C
District 3: 15% A, 70% B, 15% C
Each party has exactly one third of the votes, dso each gets a representative. Party A gets the representative of district 2. Party B gets the representative of district 3. Party C gets the representative of district 2.
Consider these points:
* A more practical version would be if voters join one of the parties and then vote on a party list in the primaries which gets used in the general election under a proportional representation scheme.
* How are the votes counted if a party doesn't run nationwide? Above I simply assumed that didn't happen, but it could be that a party runs at 0.1 or 0.2 percent in some district. Do they have to have a candidate to get those voters added to the total?
* If an elected representative dies or resigns, would the next one from that party step into the slot or is there a new election?
* If you want to talk to "your" representative, do you talk to the representative of your district, even if she or he isn't in your party, or do you talk to the representative of your party nearest to your district?
[Answer]
Your system is quite possibly going to work. Smaller parties should be represented okay in this system.
Since a democracy must respect its minorities (lest it be an olchocracy instead), attempting a fair representation of voters is a must anyway.
You may want to make sure to have (in average) more than one seat per electoral district. The higher the factor, the closer the result resembles the national spread of votes.
Now, to the local representatives: This depends directly on the number of seats per district. If you went to extremes and had 100 seats per district, every percent of the district votes would be respected.
On the other hand, with one seat only, you will have districts where the candidate who got the majority still doesn't get a seat because a member of a smaller party has a right to it (say, one party has the majority in every single district and 60% of all votes in the country, then 40% of the majority winning candidates - most likely those with the lowest votes - could not get a seat because other candidates had to be respected.
Which begs the question: Which candidate will get the seat? Will they be given to those candidates with the highest votes nationwide, or does it have to be a candidate from the respective system?
As you can see, it's not trivial to determine a truly just and fair system. As i wrote in the comment to your question, you may want to take a look at different countries' approach to this question.
Mind you that a unicameral parliament has its own problems ("who watches the watchman").
[Answer]
Most real life proportional representation systems, ranked ballot and other alternatives to "First past the post" fail multiple sniff tests, but the key one is the representative in the district (riding for Commonwealth readers) is not representing the voters, but rather to a creature of the party. In full on PR systems, the candidate is not even a representative except in name, but rather comes from the "Party List", which voters don't even control.
And of course, smaller and smaller parties begin to have outsized influence on fractured coalition governments, since the ruling coalition might be willing to sacrifice any principle to gain that one our two more seats needed to make a functional majority. Israeli citizens I have spoken to hate their PR system because of the outsized influence of ultra religious parties. You can imagine a socialist coalition government trying to form and realizing the last votes they need would come from the "National Socialist" faction (as in "National Socialist German Worker's Party" sort of National Socialists).
OF course this can also work the other way, if no acceptable grouping of parties can get together and form a working majority in parliament, then there is literally no government (Belgium was without a government for a year because of this, and it now seem routine for a period of months to pass after an election in Europe while back room manoeuvring goes on to form the coalition). Either of these cases is not healthy for democracy or representative rule at all.
The case of the recent US election demonstrates the wisdom of the American Founding Fathers. The Electoral College system prevents pockets of dense population from overwhelming smaller, less populous States, and ensures the successful candidate for President gets a plurality of votes across *all* regions of the nation.
[](https://i.stack.imgur.com/jX3VX.png)
*The US 2016 election by county*
So inducing complexity on the voting system in order to ensure smaller, less representative parties will gain seats in the Legislature will probably not have the effect you desire. The tiny pockets of "Blue" will end up dominating the legislature and passing legislation against the wishes of the majority of the population, or deadlock the government so that nothing can be done in an expedient manner. In all cases, political decisions will be made in back rooms and behind closed doors as parties try to thrash out compromises and make deals to get those critical last votes, the opposite to the open and transparent systems most voters want.
The voters will not be directly represented and have no one to hold accountable at the local level, and I suspect that if voters are not being represented, they can either choose to opt out of electoral politics altogether, or start banding together against the political class which imposed these systems upon them.
We see both answers today; low voter turnout, and surges of "populist" parties gaining power in legislatures around the world, and referendum results like the Brexit and the more recent "No" vote in Italy against proposed reforms to the system of government. IF people don't have that way out, then the next steps will be much more violent and less democratic....
[Answer]
This sounds like a recipe for coalitions and potential disaster.
First of all, I don't know if it's possible to allow smaller parties to thrive while avoiding coalitions. If no single party has a majority, then they are going to need to work with other parties in order to get the things done that they want to. This naturally leads to forming a coalition with one or more other parties that whose ideologies are reasonably similar.
I'm not sure why you're averse to coalitions, though. Using the US as an example (because that's where I live so it's the one I'm most familiar with), the two major parties are probably not that different from a coalition that might form elsewhere. They need to have a broad message that appeals to a large number of people, so their party platform ends up being just as diverse. So in some ways, the Republican and Democratic parties are really the Republican and Democratic coalitions.
However, the biggest issue with this is the instability it will cause, and the inherent dissatisfaction that can lead to. For example, consider three seats and two parties, where each district votes fairly similarly:
1. A 60 B 30
2. A 61 B 29
3. A 59 B 31
In this case, A will win seats 1 and 2, while B wins seat 3. However, if in the next election it changes slightly:
1. A 62 B 28
2. A 61 B 29
3. A 63 B 27
Now A will have seats 1 and 3, while B has seat 2. The people in district 2, who were happy with the candidate they had, are now forced to go with the candidate they did not want. What if, instead, the candidate for A in district 2 had realized the seat was in jeopardy and instead ran for a new party, C?
1. A 62 B 28
2. A 10 B 29 C 51
3. A 63 B 27
Now we have party A with 46% of the vote, party B with 31%, and party C with 18% of the vote. So now A wins seat 3, C has to win seat 2, and B gets seat 1. This means the candidate in district 2 definitely has an incentive to start their own party, rather than risk losing their seat just because they didn't do quite as well in their district as the other did in theirs.
This will likely to lead to a proliferation of small parties, so a coalition scenario is all but inevitable. Also, I really can't say what this would do to the government - a system which rewards people backstabbing each other politically makes me think it will rapidly become very dysfunctional.
[Answer]
Your system seems complex but no less so than any of the multitudinous ways of counting AV/STV systems. Half of which need a degree in maths before you begin contemplating them.
However you've not found a way of handling a fundamental point of supporting smaller parties, that being: **Multiple smaller parties means coalition governments.** You've specifically said no coalitions, but as soon as you start handing seats to small parties you're going to break the simple majorities of the big parties and coalitions will become a thing.
You've mentioned threshold minimums, which is the way to stop the system getting out of hand, but said you want to keep it low. That's the wrong approach, you need to keep it high to get your coalitions down to maybe 2-4 parties rather than 7-10. **The higher the threshold the fewer parties in coalition.**
Your example: you seem to be under the mistaken impression that parties win a majority of the vote. They don't. They merely win enough of the vote. An actual majority in a multiparty (>2) system is really quite rare.
<https://en.wikipedia.org/wiki/List_of_United_Kingdom_general_elections>
[](https://i.stack.imgur.com/z5GP8.png)
] |
[Question]
[
If in a fantasy world there was a think tank for research of all kinds, but there were rules like you can't test something like a mind wipe on an unwilling person, how would test animals be handled? In our world, we use mice and monkeys before things are approved for human trials. Would it be acceptable to experiment on animals in a world where a speak to animals spell exists?
This works by the human being able to comprehend and verbally communicate with the animals, but the animals are limited by their intelligence. Think more of you meowing to your cat and being able to understand each other, but it still only has the intelligence of a cat.
The spell itself is cast on the person wishing to speak to the animals. There is no effect on the animal.
The setting for the world would be typical medieval high fantasy.
[Answer]
After some pondering, building off of @Werrf's answer:
You've hit the point in your answer best, I think: "Think more of you meowing to your cat and being able to understand each other, but it still only has the intelligence of a cat." If you already don't mind experimenting on cats before you could speak to them, then nothing has changed with the cat. The ethics do not change. I'm not arguing pro or con, I'm just saying that the ETHICS do not change.
One's PERCEPTION of the process, however, may change completely. Lab animals who experience pain during an experiment already communicate it, via vocalizations, body language, etc. The ability to hear those vocalizations as speech, however, would end up giving a higher impact to it, because we would hear the experience articulated like a human would do so. I can imagine scientists using speech spells in animal testing burning out quickly, or becoming further immune to the suffering of fellow humans, simply as a coping mechanism.
[Answer]
>
> **Qui-Gon Jinn**: You almost got us killed! Are you brainless?
>
>
> **Jar-Jar Binks**: I spake!
>
>
> **Qui-Gon Jinn**: The ability to speak does not make you intelligent.
>
>
>
Just because you're able to communicate with an animal does not mean that the animal is intelligent or aware. Even if you found that the animal *was* intelligent and aware, you could not be sure that it wasn't the spell that made it so. So the answer is going to depend on some details.
## Is the animal intelligent when you speak to it?
For example, if I ensorcell a mouse, does the mouse continue to sniff around the table going "Cheese? Smell cheese. No cheese. Look for cheese. Danger? No danger. Sniff. Cheese?", or does it stop, look at me, and say "Oh, I say, that was most impolite. Don't you know you're supposed to get permission before you cast a spell on a chap?"
## Does casting the spell change the animal?
After I've lifted the spell, does the animal's behaviour return to normal - still sniffing for cheese, still freezing at any sign of danger - or does it sit down and start reading my mail? If the former, you can probably say that it's just the spell that makes them behave as if they're intelligent. The latter, it changes them to *make* them intelligent.
## The answer applies to more than just experimentation
You've asked in the context of animal testing, but the thing is that if you decide that animals can refuse to be experimented on, why can't they refuse to be *eaten*? To be harnessed to carts? To have their skins worn?
Most likely you're going to need to find a stable middle ground. It is unethical to even *use* the talk to animals spell unless necessary, and it is unethical to mistreat an animal after casting the spell on them (just in case). If the spell does change them permanently, ethics would dictate that one must provide a comfortable existence for them after the spell has been cast.
[Answer]
In The Real World (TM), we have these things called [institutional review boards](https://en.wikipedia.org/wiki/Institutional_review_board) (IRBs). Whether at a university or private institute, before you can perform research using human or animal subjects, you must submit a plan to the IRB, answer any questions the board may have, and get approval. The IRB is concerned with maintaining ethical standards, staying within legal boundaries, and ensuring the safety of the subjects.
For human reaserch, among the ways that an IRB enforces these concepts is through requiring a consent form. The form must spell out exactly what the subject is agreeing to do or have done during the research project, and what risks might be involved. By signing the form, the subject positively consents that they are voluntarily agreeing to these terms and conditions.
In the case of animal study, a consent form is not possible. However, the IRB will still require the applicants to provide ample proof that they will be giving the animal subjects the best possible care, and if there is any risk of death or injury, it will be dealt with humanely.
---
In Bryan Green's World, where communication with animals is possible, the job of the IRB becomes a bit more complicated. However, I think the idea of informed consent can be extended. Perhaps a rat is not able to read a form, nor hold a pen to sign it. The IRB can still require the researcher to prove that each rat has at least a basic comprehension of its circumstances and has agreed to participate.
The researcher's job is also likely to get more complicated. Now every geneticist, pharmacologist, and cosemetician will have to learn how each type of animal they work with thinks and communicates. Are some animals more visual, or more intuitive, or able to use abstactions (i.e. words) just like humans? However they do so, they will have to satisfy the IRB beyond reasonable doubt, that each animal does completely understand and consent.
Similarly, the researchers now have the added challenge of finding willing subjects. Real World scientists must merely reach in a cage, grab a rat, proceed. In Bryan Green's world they must strike up a conversation with the rat, spell out the study parameters, explain the risks, then start over each time the rat declines.
[Answer]
# TLDR; Either it depends, or no.
Even today, animals are used as human substitutes that can communicate with humans. In order for animals to speak, they would need an intelligence level to understand what that sort of communication entails.
In modern research, chimpanzees are sometimes used as test subjects, [despite their intelligence](http://news.nationalgeographic.com/news/2014/07/140710-intelligence-chimpanzees-evolution-cognition-social-behavior-genetics/), and the current ethics of using them is a debated topic among many. Depending what side of the argument we're looking from, using animals you **can't** talk to is unethical. [As PETA notes](http://www.peta.org/issues/animals-used-for-experimentation/alternatives-animal-testing/), there's plenty of alternatives to using animals in testing, and carries some pretty valid weight. As PETA notes:
>
> SOME ALTERNATIVES TO THE USE OF ANIMALS IN TESTING INCLUDE
>
>
> * in vitro (test tube) test methods and models based on human cell and tissue cultures
> * computerized patient-drug databases and virtual drug trials
> * computer models and simulations
> * stem cell and genetic testing methods
> * non-invasive imaging techniques such as MRIs and CT Scans
> * microdosing (in which humans are given very low quantities of a drug to test the effects on the body on the cellular level, without affecting the whole body system)
>
>
>
The flip side of that argument is using humans as a test subject. In Nazi Germany, some of the leaps forward in medicine were a result of [direct human testing on unwilling subjects](https://en.wikipedia.org/wiki/Nazi_human_experimentation). Although completely unethical, some of these medical advances in the knowledge of the human body could be argued to have saved many lives since the tragedies of that time period. As a site on human experimentation notes:
>
> Investigations following the war uncovered many atrocities, such as studies in which subjects were immersed in very cold water to gauge how long it would take to die of hypothermia.
>
>
>
In the end though, the ethical nature of using verbally communicative animals in testing relates to the [willingness of the animal](https://www.uaf.edu/ori/responsible-conduct/human-research-subjects/)\*. Regardless of current stance on animal testing, if an animal gives it's willing cooperation for the advancement of science, that's a choice made by them and gives a different light to ethics.
\* I'd like to note, I am not arguing for or against animal testing. I understand many advances have been made as a result, but I also understand the importance of treating animals well.
[Answer]
## If we knew, we wouldn't need spells
The thing about what we do to animals, is that we don't really know how they feel about it. Many people honestly say that they don't believe animals can suffer or feel pain, and that's why it's all justified. Others enjoy the benefit of the doubt.
If we could speak to animals, we could know for sure how they feel and decide accordingly. A moving speech from a cow would probably make many people go vegan (others would argue that these animals wouldn't even be born if it wasn't for us needing them for food). If they turn out to be feeling-less, we would use them even more.
So the real question is, what would they say.
## What would they say?
I believe what they would say is exactly what they say now, in actions and demeanor. When my dog says "woof" I know what she means. It's not complex ideas, mostly emotions and basic needs. I doubt an animal would evolve the complex skills of symbolic thinking without being able to use it. I also highly doubt that they can express emotions without feeling them, as some think (I doubt that's even logically possible)
So lab animals would probably say "I'm scared", "I'm in pain", "I don't like the person in the white coat" etc. Nothing we couldn't have guessed already.
## To conclude
* They might say what we would expect them to feel (fear, hunger, etc), so no real new information there
* They might turn out to be feeling-less zombies, so we could use them more
* They might totally surprise us and be able to articulate complex thoughts and ideas which would not only change the way we treat them in science, but everywhere, and perhaps change the whole dynamic between species on this planet.
] |
[Question]
[
What would colonists building a base on Europa use for building materials? I am interested in habitats in three locations:
* on or just under the surface
* bolted onto the underside of the ice sheet
* rooms hollowed out from the lowest level of the ice sheet
Can metals or other building material be extracted from dust on the surface or in the ice? Is it plausible to harvest or mine minerals and metals from the ocean floor?
[Answer]
Given the radiation environment of Europa, stacking ice to create igloos could become an issue. You would need several metres of ice to block the radiation from Jupiter, which would make building igloos somewhat challenging, to say the least.
The most likely location for Europan colonies would be i bubbles melted into the ice sheets. The problem here is that the ice itself will be very cold, and on a large scale somewhat flexible (the ice will move with the Europan tides, for example), so the colonists will want insulation.
Based on the idea that Jupiter has 67 moons, it would be a small issue to gather silicates and metals from the other moons and sue them as construction materials. Europan colonies would look a bit like a thermos bottle in cross section: the ice bubble would have a smaller "bubble" of foamed rock and metal supporting structure suspended within, and a vacuum would be maintained between the two bubbles for insulation. Inside the rock and metal bubble would be the colony itself.
The size and scope of such a colony wold depend on the amount of resources and time the colonists would be willing to invest in the project, but a spacefaring civilization with access to interplanetary ships and fusion energy could conceivably "blow bubbles" of very large size, even kilometres in diameter if desired.
If it was decided to go under the ice in the oceans. then the bubble structures of foamed rock and metal would suffice so long as there was no desire to go very deep into the oceans where the static pressure would endanger the bubble.
[Answer]
## Environmentall friendly local materials
[](https://i.stack.imgur.com/XedDd.jpg)
At the surface colonists will be surrounded by an abundance of ice that can easily be carved into blocks and stacked igloo-style.
>
> Snow is used because the air pockets trapped in it make it an insulator. On the outside, temperatures may be as low as −45 °C (−49 °F), but on the inside the temperature may range from −7 °C (19 °F) to 16 °C (61 °F) when warmed by body heat alone. ([Wikipedia](https://en.wikipedia.org/wiki/Igloo))
>
>
>
Within the ice sheet itself ice can be hollowed out as you mentioned. In both cases, colonists will need insulating material to help retain heat without melting the ice walls, and to contain air pressure approximating Earth's. Unfortunately, without knowing what minerals and such might be suspended in the ice or subsurface water, or until we know the actual composition and structure of the subsurface layers and the pressures and hazards involved, it's impossible to anticipate how or what colonists might manufacture locally. They would need to bring material with them.
## Or grow it
With an abundance of ice-water, colonists will have no shortage of growth medium for microbial or bacterial mats. Such mats may in fact be the first signs of life native to Europa, as (if they exist) they would be growing on the underside of the ice crust at the ice-ocean interface.
Genetically engineered microbes [can manufacture petroleum-free bioplastics](http://www.scientificamerican.com/article/turning-bacteria-into-plastic-factories-replacing-fossil-fuels/), given enough oxygen or nitrogen and carbon to work with. Sheets of this material could act as insulation, and layers pressed together could form rigid interlocking plates.
It's conceivable that native microbes might produce even more useful materials if farmed and harvested correctly.
## Bolted on
[](https://i.stack.imgur.com/7riVE.jpg)
The obvious solution is to repurpose the ship that brought them to Europa in the first place. In addition to whatever raw materials are brought for the purpose, the insulation and modules themselves could be designed for the task. Habitats on or under the ice crust could be built from the hulls of colonist ships landed on the surface and lowered into position.
[Answer]
I'll aim my answer primarily at this:
>
> What would colonists building a base on Europa use for building materials?
>
>
>
Europa is likely a captured moon that did not form in the outer regions of our solar system. Presence of a magnetic field and its density suggests that Europa is closer in make-up to the terrestrial planets than the outer ones, suggesting that somewhere within it is a rocky planet along with a metallic iron core.
This would suggest that there is the capability to mine almost any material that you would be capable of mining on Earth (well, at least non-organic compounds). It would also appear that Europa is geologically active (mostly due to interactions with other moons and Jupiter itself) which could suggest that underneath this ocean will have volcanic peaks (or less likely, tectonic mountains)...which would mean although a good chunk of the 'land' of Europa will be far under water, there should be peaks under a much shallower ocean that could allow for mining.
The red of Europa is currently speculated as magneisum sulphate, or perhaps even sulphuric acid. Possible the intrepid colonists could make use of that.
Outside of that, much of Europa's composition is speculative...you can take quite a few writers liberties in its composition.
As a side note...I should point out that Europa is radiated. A lethal dose to a human would be less than one day of exposure. This highly limits the 'igloo' solution as it would need to be a radiation shielded igloo if humans were to survive.
# Added:
Europa resides inside Jupiter's equivalent of the Earth Van Allen radiation belt (upwards of 10× stronger than Earth’s). I think it would be planet wide regardless of facing. There is a time period though where Europa is in Jupiter's Magnetotail where it would be protected. <https://en.wikipedia.org/wiki/Magnetosphere_of_Jupiter> will kinda describe that.
This could be a really interesting plot point. The ice would work as radiation protection (option number two on your list), so they would be hiding from radiation under an ice sheet for a period of time. When Europa enters Jupiter's Magentotail, the radiation levels will drastically reduce, allowing for a time frame where humans could wander the surface of Europa with limited radiation protection. This time frame would be short...Europa orbits jupiter every 3.5 Earth days and the magnetotail would protect about 1/3 of that time. 1 day in 3.5 that they could make surface expeditions and hope they get back down in time.
Also of note...Juptier has some qualities of a pulsar and emits some pretty powerful radio waves in the kHz and mHz ranges (pretty much what we call AM and FM in radio terms). This could make for some heavy communication challenges if we are still relying on radio for communication during Europa colonization
[Answer]
**Radiation will kill you on the surface**
Several other posts hit the same point, but to summarize briefly, Europa's surface receives 540 rem per day, which is probably a fatal dose. However, the 1080 rem you get in two days is definitely a fatal dose. You need shielding, water (and ice) are great shielding, there you go.
**Water pressure is too high in the ocean**
Let me make a few super-general assumptions to simplify the math. First lets assume atmospheric pressure of zero, lets assume that the ice crust is pure water ice (density: 0.9167 g/cm$^2$), and lets assume the equation for hydrostatic pressure ($P=\rho gh$) can be naively applied under an ice sheet, an assumption that I argue is good enough. Other numbers we'll use are the surface gravity on Europa (1.315 m/s$^2$), 20km depth of surface ice on Europa (estimates range between 10-30km)
$$P=\rho gh,$$ $$P = \left(\frac{0.9167 g}{cm^3}\right)\left( \frac{1 kg}{1000 g}\right)\left(\frac{1000000 cm^3}{1 m^3}\right)\left(\frac{1.315m}{s^2}\right)\left(20000m\right)$$ $$P=24.1 MPa = 237 Atm$$
That is equivalent to about 2500m below the ocean on earth. Building habitats with the strength of a submarine wouldn't be hard, but they are rated to about 500m tops. Building a habitat to handle that pressure would be hard.
**Inside the ice is just right**
On the other hand, you can find a happy medium in the middle. The 1MeV gamma tenth-thickness of water is about 0.6m. The tenth-thickness is the distance of material needed to attenuate radiation by a factor of 10. I couldn't find the tenth-thickness of ice, so I will assume it is the same (possibly a horrible assumption). Therefore, under 85m of ice, the radiation from Jupiter is about $$540 rem \cdot 10^\left(-\frac{85m}{0.6m}\right) \approx 0. $$
At this depth the pressure is $$P = \left(\frac{0.9167g}{cm^3}\right)\left(1.315 \frac{m}{s^2}\right)\left(85m\right) = 102.5kPa = 1.01 atm.$$
No radiation and atmospheric pressure. Sounds about right to me! Of course, this is not to say that there is atmospheric pressure in the air of a habitat, just because we are 85m below the surface of the ice; since ice is solid it doesn't work like that. But structures built at this depth won't have any pressure related problems that they don't already have on earth...unless the ice is moving.
**What building materials are available at 85m below the surface of Europa?**
Well....ice. Everything else you are going to have to bring yourself. The rocky surface is below another 20km of ice and maybe 100km of ocean. Pretty technically challenging to get something from there.
However, Jupiter is just surrounded by moonlets and rings and what have you. It you want metal, just mine it out of loose material in the Jovian system and bring it down to the surface.
] |
[Question]
[
Ignoring the obvious questions regarding feasibility, let's assume that the army of a largely feudal world can choose to mount their heavy weapons (cannons, artillery, gatling guns, etc.)
on magical machines which look like insectoids. These are magically autonomous, and so will follow orders without need for a driver, unless they run out of fuel.
The decidedly unmagical and uninsectoid infantry have small arms equivalent to those from our era: rifles, missiles, mortars, machine guns, etc.
Firstly, what are the advantages and disadvantages of these machines over wheeled or tracked alternatives?
Secondly, what insectoid species from our world would best fit the roles of mechanised weapons systems: tank, transport, artillery, anti-aircraft, etc.
Thirdly (bonus question), what unique combat roles may emerge within this combat environment? And what insectoid species would best fill each role?
**EDIT**: To clarify things, these machines cannot be given orders remotely. The soldiers must be physically near to issue an order, perhaps to the point they must touch the machine when they are telling it what to do. Otherwise the machine will default to the last orders and wait for help like a disciplined duckling. This is a deliberate design to force infantry and machines to be in close proximity, and to make drone warfare as we understand it impossible. Machines identify friend from foe with a child-like intelligence.
The machine's fuel is something like a magical oil-honey, which lasts for much longer than and provides much more energy than petrol. Like organic creatures, the machines do not simply stop working when they run out of fuel. If low on fuel they slow down until they fall over and fall "asleep". The fuel is created by magical-industrial processes and cannot be found in nature.
[Answer]
Ok, so others have already explained the benefits of the legs. Better suspension, maneuverability is very versatile (wheels move where they point - legs can move in multiple directions), stability is amazing on almost any terrain, and on most slopes the vehicle could level itself (for instance, walking forward down a hill, back legs bend, front legs extend). The suspension and leg movement allows for a lot of shock absorption from high-output artillery. The chassis can easily be raised and lowered by the legs as well, allowing for more varying aiming angles.
Of course, wheels would probably use less energy, and a bunch of turning shafts is much simpler than a complex leg system. Also, it's important to note that although insects are extremely powerful, a giant one (even a magic giant insect) will probably not scale to the same strength.
Ok, now the fun part, insects to use for vehicles (prepare for pictures).
First, scout/assault -
the fastest insect, and the fastest animal on the planet (by size to speed) is the tiger beetle.
[](https://i.stack.imgur.com/ZXxjV.jpg)
This is a predatory beetle, that are not only relatively proficient flyers, but can reach speeds of 9km/h (5.6m/h for you imperials) which equates to around 125 body lengths per second (it doesn't take much to realise how fast that is). This beetle actually runs so fast, that while sprinting its eyes can't process its environment fast enough and it goes blind.
Now, that blindness might seem bad, but this is a 1000x scaled magical tiger beetle, so not only will it probably be slower (but still insanely fast) but its eyes will probably be like high speed cameras. Their role could be small scouts, or they could be fast assault vehicles - sprinting up to the enemy with thorax mounted guns (close range makes me think giant shotguns, but they could be small anti-personnel smgs) and actually jump at the enemy vehicles and tear them apart with their jaws and guns.
Next up, carriers, artillery and tanks. Simple enough, just choose the insect with the strongest carrying power. For that, I chose Onthophagus taurus, a dung beetle.
[](https://i.stack.imgur.com/fStFP.jpg)
First off, aesthetics, it has horns, that's intimidating. Secondly, the natural scale creature can pull 1140 times their body weight, if that can't carry heavy artillery and/or smaller units, I don't know what will. Again, scaling up the beetle won't be very forgiving to it's strength, but using powerful machinery and magic will take most of the power with it in the scale up. These things are bulky, so plenty of room for gun-mounts, and being a beetle their exoskeleton is the strongest of any type of insect (that i know of). If you want a really intimidating tank, maybe choose a stag beetle (which are also scarabs and are also very strong) because they have those giant mandibles. the Rule of Cool is always valid.
Now, air units (you didn't mention them but still) someone else mentioned dragonflies? I agree, they are amazing creatures, masters of flight, but I think they are a little to big a target for AA units, and that long abdomen seems fragile. My suggestion is a very similar predator, the robber fly.
[](https://i.stack.imgur.com/pDxjx.jpg)
Already we see improvements, smaller frame, smaller wings, a more aerodynamic shape (air resistance may not affect dragonflies too much, but when they're scaled a few thousand times it becomes a problem). Now for facts, these things are fast, agile and, like dragonflies, they can take down targets in midair. They take down wasps and spiders from their webs for goodness sake. Again, small typical aircraft weaponry (maybe the odd missile). They also have a poisonous bite (through their spear-like proboscis), which is less useful against vehicles, unless of course you replace a stream of venom with a stream of small explosives (just a fun addition, I just like the sound of robber-mech quickly piercing a dung beetle tank and then flying away as it explodes from the inside).
Alright, I'm almost done. two last points.
swarms, a lot of people are suggesting ant armies. I think this is a great idea, but I would choose termites, as they have a more diverse cast system, smaller working termites (scout/medic), large defensive termites with giant mandibles (tanks and artillery), and one cast has an acid shooting cannon for a head, it's already artillery without strapping guns to it.
And for one last suggestion for artillery units, which I didn't include because it isn't actually an insect. I won't go into detail, google velvet worm, and you'll find a many-legged worm with two tubes on the sides of its head, these shoot a sticky silk/mucus stream thing that traps their prey/predators. this is useful in giant-mecha-battle, but you could also simply replace goop-launchers with heavy artillery.
[Answer]
**The vehicles would probably have better suspension and stabilization effects then wheeled or tracked counterparts.**
Consider having six independently articulating shock absorbers. And the fact that these would more than likely absorb said shock in different parts of the legs *i.e the joints of the leg.*
As for stabilizing the vehicles when firing, just look at the *"legs"* heavy cranes extend to stop them from falling over. Combine this with a lower center of gravity, as very few crawling insects I am familiar with have their legs directly under them, they would be able to carry heavier caliber weapons on relatively smaller chassis.
**Less loss of human life.**
Just look at today's military advancements. UAV's, drones, bomb disposable robots, etc. They are all being developed to remove us from the front lines. A consideration is if the enemy have such technologies do you need soldiers equipped with weapons or just with a lot of armor to traverse the battlefield and refuel the war machines?
**Who does what?**
Immediately ants come to mind. A swarm with a collective intelligence, and varied design, even within a single colony. Workers doing support tasks such as clearing debris or scouting a path, then the soldiers providing the heavy weapon support, finally a queen which is the platform to coordinate the assault from.
Beatles strike me as the tank. Look at the clone wars *AT-TE*
**In the air then you have dragonflies.**
One of the best fliers in the insect world, capable of vertical movement as well as forward and backwards. (Highly suggest checking out some high speed footage of them) To boot they are also predatory and pull other fliers out of the air.
I couldn't pinpoint the likes of transportation as it is not really something insects would be known for. But alot of their forms could be adapted for such, the thorax for example, which is the bulbous part at the back if hollow could be used for freight or troop transport.
[Answer]
Well for one thing legs I have a lot more balance than tracks and wheels do over rough terrain. Your magical steel walkers could go a lot of places that tanks and trucks could not.
*(Question edited to prevent this)* In addition to this since they are autonomous you won't have to deal with human casualties and they can be sent in a lot of places that would be too dangerous to send humans.
There is however a problem with speed. We don't know how fast your Walkers move. It's possible that trucks and tanks could move faster. We would need more information but what type of magic is involved and what it does.
Another obvious advantages of course fuel since your magic honey fuel, if it give more energy than petrol and if it's probably more available the energy cost of your magical insectoid walkers then the would have a great advantage over the other side's trucks and tanks.
[Answer]
I first wanted to ask this with a comment, but it may contain part of an answer to your question. But first, there is the question I wanted to ask with said abandoned comment:
*So, how does the vehicle-combat work in your world?*
May sound dumb in first place, but note that the general doctrines may say: "We charge the enemy with blazing guns", or "the one who hits first will win" or "the one who can take the most hits without fainting wins"... okay, these are more medieval doctrines, applicable to armies marching against each other and engaging in open field battles; consider the good old armored spearhead and stuff like elastic defenses, rolling artillery barges and so on for a modern thinking army.
Now why am I bringing up this? Because the design goals may greatly differ from "clashing each other until one side retreats" to "exploit a weak spot in their defenses and cut off reinforcement". First one would ask for slow but sturdy constructs which know how to fight in tight formation while staying in the generals line of sight, while the last one will call for highly mobile units that can operate at their own even beyond visual range of each other.
Pondering this topic for some time, I would go this far that your magic bug tanks seems to be more suited for the first one, while tracked vehicles would be more suited for the second task.
More thinks to think off: vehicle emissions and signatures (heat and noise); will armies in your universe use guided weapons (while they may use magic instead of computers for task like this), are smoke-screens a proper way to break the line of sight or can the magic look through (and is there magic to counter the look-through?). How the airforce may come into battle? Giant fireflies? You will face a humble speed and lift-limit if you are going for bug-like flight instead of the aerodynamic way of the mundane planes. Which isn't a bad thing, after all chopper and other forms of gunships are slow but hard to take down while packing a hell(fire) of a punch.
What about the ballistic weapons accuracy? Observe latest Russian tanks, which are pretty flat. As an Armed Assault player I can attest: that is pretty nasty. Sitting in you Abrams and watching shells glancing away at these nasty little turrets is the worst thing that can happen in that case. But a bug-like vehicle, while having great ground clearance, will offer a wider cross-section. Wait, that isn't true: you can glue an incredible flat body at the legs. Still, when this thing wants to carry a proper weapon, there might be a limit. The firepower-height award will stay at the tanks side.
Even the commonly used building materials and designs will go a long way to provide an important insight on how stuff might work. I'm talking about military installations. Its a feudal world, but this does not mean everyone lives in a castle. Do they deploy WW2 like bunkers or not?
Equally interesting: what are the firing distances your weapons do work best at? Or their maximum reach. Will artillery be more like in the medieval time, or do you work with firing tables, artillery spotter and counter battery fire? Muzzle velocity (and accuracy, as stated above) is interesting, and of course the stuff your bug-tanks are made off. 60tons of bug shall not pass a single bridge, but may wander through rivers unimpressed (as long as it does not cave in), but 60 tons of bug-tank can either be a incredible well armored shell or a huge transport like unit... or behave like an armored train. of course, if you can have a dozen 60cm mortars with high mobility (the Karl Granatwurfgerät wasn't pretty mobile for example), no fortification would suffice to protect. If you bring enough shells, even a mountain will fall.
How big are operative ranges, how far a bug-tank should be able to walk with one full fuel storage whatever? How far a campaign will be driven before the supply falls behind? How likely is the option to fix such a bug-tank in the battlefield, or after the battle? Will they "die" if hit badly, or will the magic fly out, leaving behind an empty machine shell?
Speaking of magic - are there any means to "harden" your bug-tanks to avoid having the enemy using exorcists freeing your bug-tanks of their magic soul (if it work this way), or can they be taken over due to magic means, can you employ ban-circles on the battlefield to trap these guys, can you... infuse them with a demon to make them run amok?
And so on. After all I should do real work here :D
And again, the question from the beginning, I asked several other people here which asked something like you (sadly most just kept ignoring this): **How does the combat work in your world?**
If you answer this, a better vision of how the bug-like vehicles would perform could be made. Everything else is comparing known features of walker-bots with tracked vehicles, which has been done way to many times with the conclusions the other answers already offer: fine in heavy terrain, bad at running, worst in cross-section and maintenance of propulsion system.
[Answer]
This answer is in the 'why not' range...no clue how feasible any of this is.
>
> "what insectoid species from our world would best fit the roles of mechanised weapons systems: tank, transport, artillery, anti-aircraft, etc" from someone who can demonstrate knowledge of insectoid species and (bio?) engineering principles.
>
>
>
I'd assume 'swarm' attack tactics if we are going the insect route...they aren't manned and therefore losses are semi-acceptable.
Insect locomotion is going to be the big consideration here. One of your primary attributes of a tank is that it needs to take a hit and as such a tank is going to be heavily armoured. It's locomotion method on tracks allows it to support the heavy heavy armour. When we are speaking insect terms, the locomotion is on legs and this heavy armour option isn't really there. So we are going to go the heavy redundancy method instead...makes them more fun in a story sense too.
I'd replace the 'tank' with an army ant style vehicle, with the notable exception of more legs than an ant would have, and we are going to focus on redundancy. A 8 legged creature could feasibly lose half of it's legs and still be mobile...perhaps not as mobile as it could be, but considerably better off than a tank thats lost half of it's treads (at that point it's basically immobilized)..I'd actually aim for 12 legs with this in mind. It would have the three segments an ant normally has...the front 'head' component would be the sensors along with an anti-personal weapon, most likely a machine gun of some form. It's middle torso would house the engine, along with the mount of a heavier anti-armour weapon (cannon). It's back end would be a redundant engine, redundant sensors, bracing (think of a bulldozer end facing backwards), and another anti-personal weapon (grenade launcher maybe?). To compensate for the main weapons recoil, the ant would brace itself using this bulldozer end prior to firing (ya, I'm suggesting the ant crouches down to fire).
The key tactic here is numbers and redundancy. Any ant should be able to take a shot and still be mostly combat functional. A leg gone won't impact mobility sharply, the front segment lost means the backup sensors in the back take over, the middle segment lost would mean the back segment is now the only engine, etc. When attacking, these ant rely on their numbers and ability to compensate for damage to push forward.
A second smaller ant could also make an appearance for in-battle repairs...removing the 1 or 2 working legs from fully destroyed units and reattaching them to damaged ones. A downed ant with a functional back segment could be combined with a downed ant missing it's back segment to create a 'frankenstiened' army ant for the rest of the battle. Their task is simply to make the most out of the damaged and destroyed resources during the battle.
I would also suggest the army ant here could be outfitted for a few different functions and specialized a little. A smaller faster version could only have anti-personal weapons and specialize in going into underground areas or into buildings in search of squishy targets, while a much larger one could have additional bracing and be carrying a much larger anti-armour cannon.
For artillery (direct 'anti tank' fire and indirect fire) would fit a scorpions frame well. A narrow but wide profile with slanted armour hoping to deflect incoming attacks, along with a weapon mounted in the back (where it's tail would be). Instead of front facing claws, it would have pistons/pylons that brace itself when firing it's primary weapon.
The scorpion above would find itself a prime target for air assaults...your anti-air pieces would more resemble a grasshopper...a long narrow profile from above, with anti air weapons (preferably multiple) facing upwards from it's back. If it could, the ability to 'jump' like a grasshopper could mean it has a method of avoiding incoming airstrikes as well...but most likely it'll have lil tiny legs for motion...anti-air doesn't need to turn very often afterall.
Another anti-air option is a 'wasp' like creature...or bee if you prefer. More of a missile on wings, this suicidal creatures defence is to slam itself into enemy aircraft destroying itself and it's target in the same explosion.
My choice for troop transport would functionally be a centipede, however each segment of this centipede would be self sustaining and could detach/reattach to the larger whole as required. Damage from taking a hit would be minimized as the damaged section would be detached and then dropped off so the main whole could continue forward.
I'd use a much smaller and closer to the ground 'beetle' like creature for scouting...a mix of hiding and painting targets is really it's only value.
[Answer]
Insects sound like a great idea until the point where you scale them up; then they have problems.
## Problem 1:
Complexity. The wheels on the bus go round and round. The legs on the spiderbot have to go forwards and backwards, up and down in a relatively complex motion to get movement.
## Problem 2:
Spreading your weight. Tank tracks are wide and spread the weight of your heavy vehicle (relatively) evenly over quite a large area. Even an 6×6 truck spreads its weight a lot. Your spiderbot, even with 8 rather than the 6 legs of an insectbot is going to be spending a fair amount of time with legs off the ground and hence its weight focused on a small area. It's really going to struggle on soft ground.
However they also have advantages:
## Advantage 1:
Hard very rough ground, mountains and boulderfields, ruined urban environments, trenches and walls. Legs are going to have a real advantage here where wheels and tracks start to suffer. Wheels like to be on the ground all the time and if that can't be done they start spinning uselessly.
## Advantage 2:
Stability and Self righting. An insect bot is going to have a lot more degrees of movement along with greater stability. Its base will be a lot wider than its body, unlike a wheeled vehicle. This freedom of movement should also allow it to self right should it be capsized in the field.
## Advantage 3:
Less risk of hitting mines. Wheels and tracks have continuous ground coverage, if there's a mine in the track you're going to hit it. Legs have a reasonable chance of stepping over it without triggering it.
] |
[Question]
[
I’ve seen the terms *posthuman* and *transhuman* used in fairly generic ways. But given a setting with several types of beings, what consistent naming convention could be used? I suppose the vulgar terms might be less neat and careful than the official and legal names. I’m interested in both.
## 1
Human brains that have been scanned and ported to man-made computer architecture.
They might be gradually improved and extended: return to the nimble mind of youth; increase short-term memory; perfect recall when desired; but still very much human.
## 2
There is a spectrum of improvements both in type and in degree. More advanced “beyond old limits” would be full meta-manipulation. Audit the neural network for inconsistencies; edit for better optimal representations; build or prune links with *intent*. I think the big difference is not in how much incremental general improvement has been made, but in going meta.
## 3
Changes are made that cause a shift away from being a human mind and make it more alien. This might not be major, but has profound effects. E.g. the “Vulcan” faction prevents all inconsistencies among the neural net, even reworking what was in the mind before.
## 4
General capacity and capability are upgraded beyond human levels by substantial amounts. But he’s careful to remain human.
## 5
Forget backward compatibility with #4. Upgrade capacity and capability and eventually realize you’ve outgrown the human mind and transcend to a higher level of mind.
---
I suppose that all beings that came from human minds are of a class and might be called *post-human*. If the *transcendent* label is reserved for #5, what should we call the others?
[Answer]
The ***GURPS Transhuman Space*** tabletop RPG setting uses "infomorph" as a general term for all kinds of minds that run on computers instead of wetware. It also has "Ghosts" as uploaded human minds. The setting lacks the technology to upgrade its ghosts, so has no terminology for that.
[Answer]
The prefix *extra-* is generally used for things that are *outside* of normality - for example, extraterrestrial for being outside Earth-normal, or extracurricular for education outside of the normal curriculum.
Let's apply this to humans. If you're sort-of human, but not the original design, you could be known as *extrahuman*.
From here, you can take a major point from each of the levels of extrahumanity that you intend to create (5 of them, in your case), and prepend that to the general class name to come up with a specific name.
Your #1 could be *digital extrahumans*. Your #2 has a theme of meta-existence, so perhaps they're *meta extrahuman*. Your #3 doesn't have an obvious theme, but if there's something specific you're using, like a Vulcan faction - try *Vulcan extrahumans* on for size.
At #4 you're really moving out of the realm of humanity, so perhaps you need to change the base name entirely. What about *superhumans*, to take a cliché'd term literally? And #5 you've already decided on, but try adding the previous name to form *transcendent superhumans*.
[Answer]
One very important question is "Who is doing the name calling?"
If all of humanity is moving forward more or less in lockstep, they will call each other "human" at all stages. They might have other names for the previous stages, typically "pre-something humans".
However, knowing humanity, we will *not* move forward in lockstep. There will be conservatives, lagging behind, and there will be progressives, surging ahead.
These groups will have names for each other that will not be complimentary. "cave people" and "inhumans" is probably some of the kinder terms. On the other hand, they will have very complimentary terms for themselves, like "true humans" and "future humans".
Note that these names are all relative. One generations progressive "future human" can be the next generations conservative "true human".
Looking at history we find that group names can be very random, this will no doubt continue into the future. The founders of the group have some concept they think is very important and defines their philosophy. Later that concept falls by the wayside, but the name remains.
In summary, you can call these groups whatever you want, as long as it makes sense to the characters using the terms.
[Answer]
Human would be the correct broadbased word to use for all groups based on the simple logic of how evolution works...
Your groupings seem wrong...
* Group 1 - Humans that reject any modification may seem like they'd be called "human", but as time goes on more people will continue to move away from this and this group will eventually die one way or another. They're more than likely going to be called an insulting name, such as, "Trogs" while they might call themselves "Pure Humans"
* Group 2 - Humans that have had some modification, either through Cybernetics or DNA manipulations will likely be called "Humans" for the majority of their existence, but they might also be called "Mods", "Cybers", "Cyborgs", "Splicers", or "Mutants'. And this term will likely apply to anyone who hasn't digitized their brain in some way. That means that any modification beneath that point, including using brain linked cybernetics, will fit in this group.
* Group 3 - This group gets a bit harder to describe, but I call them "DigiHumans" and basically they are individuals who are sentient who are not permantly linked to a physical body.
Sub-group 1 - Humans who have digitized their brain in some way.
1a. Those who spend most of their time as some physical construct in the real world, such as they are made of nanites in human form, or are in a synthetically created body with the data for their brain encapsulated in this synthetic body.
1b. Same as 1a, but generally not in human form.
1c. This groups spend their time in virtual space and worlds and are more prone to not reside or consider that whatever the physical form in the real world is as their real form. They might be in a satellite in space all alone or they might be in a supercomputer on earth just one among millions of other sentients.
Sub-Group 2 - Synthetic Intelligences that are recognized as sentient. They are broken into the same sub-sub-groups as sub-group 1, but their origin is in software, rather than the "real world". This Sub-Group will become the majority of humans at some point in the future as Digihumans "reproduce" by creating new sentients and/or the Virtual worlds they create's inhabitants are allowed to see past their programming which allows them to become more and more like their creator and eventually maybe become their equal and surpass them. (This is subject to debate as to what to call these levels of progression of these intelligences, but this final level will exist if Digihumans exist).
By the time the 3rd group becomes the majority or only group of humans remaining a name will have been applied to them. I predict something like "Digis" because Digital Human is too long, Digihuman is too close to "Digimon". "Trans" has already been taken. "Posts" just will never catch on. So they'll likely be called Digis or something like that.
As far as Nomenclature for Digis beyond that... That's not going to happen. The difference between these groups are software or hardware. If you change the software they're not themselves any more and presumably you're trying to remain sentient so that's not going to happen. The differentiation there will be is in the difference of sub-subgroups, which is those who still associates with a given physical form and those who don't. What physical form or where they reside won't be some sort of weird categorization where somehow they've evolved into a different form. The distinction will only be in terms of personal Philosophy and wealth to get upgraded hardware, but they're not going to be looked at as some new species or different thing.
In other words, because you have a 2 Zhz Processor you're not a different thing than someone with 4 Yhz processor and one might distinguish based on wealth, but not in terms of "that's something else."
] |
[Question]
[
In a world where people can feel each other's thoughts and emotions, is it possible to lie? Is it possible to **think** something different from what you really think? It doesn't make sense...
When you lie in spoken language, you are aware that what you are saying is different from the truth. The process of forming a lie involves thinking: trying to make it sound plausible, avoiding the truth, even thinking about what you *don't* want to say. The only explanation I can think of is a natural instinct to say something, in which case you would think it before thinking about what you are thinking.
In this case however, it is not truly a lie, right?
The form of telepathy I envision is one where people can sense every thought, feeling, and process going on in your head. Everything that happens in your mind which you are aware of, other people are also aware of it.
If a civilisation such as this existed, would lying even be possible and how would it work?
Here are two plausible answers:
1: Making yourself believe something enough that you appear to be telling the truth. This would only work if after lying you can recover knowledge that it was in fact a lie, otherwise you are misleading yourself as well as the party being lied to. Possibly, training yourself not to think about the fact you **made** yourself believe something.
2: Misinterpretation. Saying part of the truth, but not the whole truth. This way, the other person/people may interpret your thoughts in a different way. This can be used to mislead others, while all the time what you appear sincere. This would only work if you don't think about the things you are missing out.
Both of these have disadvantages which need to be covered before you can successfully lie to another.
[Answer]
It really depends on the type of telepathy you as the author/creator envision. There could be telepathy that is purely intentional, akin to speaking or sign language. If others can always sense your thoughts or emotions, that might more properly be called mind reading or emotional empathy. In the latter, people still might be able to put up walls around their mind to pad or mute the effect. So ultimately, you get to choose.
Additional considerations:
First, on a communication level, what is truth? What separates truth from a lie? Whether I say the sky is blue or orange, there is nothing inherent in my communication that determines one or the other as real - truth is determined by the facts of life, regardless of what is communicated. The only exception with telepathy or mind reading would be sensing the *intention to deceive*, and intention is not the same thing as emotion.
You mentioned "evolved" telepathy, so consider what else might have evolved along with that - a subset of related functions that facilitate communication, including "blocking" thoughts or projecting only what is desired. Some might be better at communicating visual imagery, like artists, while musicians would have a much more detailed concept of audio information.
Some might not be good at this - you probably know people in real life who are terrible liars with just words. And anyone can run and jump, but watch the Olympics and tell me you can swim life Phelps. People can train and hone their natural skills to do amazing things, and as a natural ability, I can't imagine this would be an exception.
## Edit
In response to OP's comment defining his or her brand of telepathy:
Others have answered about "lying" to oneself, so I won't repeat those.
"Feelings" then, must be very precisely defined. Particularly, distinguish between:
* Emotions
* Intentions
* Motives
* Desire
* Memory
Now, some of these things are very low-level, subconscious functionality of the brain. While I always feel emotions and am usually conscious of them, I might not always be conscious of my own motives or intentions. Even if I am self-conscious enough to be aware of them, can I really articulate them, even to myself? Sometimes it takes weeks or months of introspection before one really understands some part of themselves. I personally think it would be unlikely for others to be able to sense those deep things "at a glance," as they aren't really feelings.
I might have strong emotional feelings for someone, but may have no intention of starting a relationship. Does the intent transfer, or just my warm fuzzies for them? Because unless I mentally articulate the intention, it could be a source of miscommunication, if not really a lie.
Memory - now this is a fun one! Memories might consist of thoughts and feelings, but in reality they are neither. Do others have access to only what I am remembering at the moment, or does everyone within telepathic range share a collective memory? But I'm digressing from the question of lying.
Based on what you describe, no, I don't think it's possible to intentionally deceive someone, which is usually via misinformation. Moreover, the social dynamic would be **extremely** different from ours. I don't think there would be cause for intentional communication - if everyone knows X, you can't articulate X any better to them. It would be redundant. I doubt there would be language or words - just a flow of abstract concepts. I don't think this society could even be aware of the concept of lying or deception, which makes an extremely interesting premise in itself.
[Answer]
People already tell lies to themselves in their minds.
I can stop whenever I want to. He loves me. I'll have better luck next time. This is not possible. Just five more minutes. Just this one more time.
If you could read people's minds, you'd actually have to spend some effort filtering truth from those kinds of lies.
And if you pick the mind of a professional liar, such as a con man or a polictician, you'd probably see that they are able to consciously lie to themselves by [doublethinking (from Orwell's 1984)](https://en.m.wikipedia.org/wiki/Doublethink):
>
> To know and not to know, to be conscious of complete truthfulness while telling carefully constructed lies, to hold simultaneously two opinions which cancelled out, knowing them to be contradictory and believing in both of them, to use logic against logic, to repudiate morality while laying claim to it, to believe that democracy was impossible and that the Party was the guardian of democracy, to forget whatever it was necessary to forget, then to draw it back into memory again at the moment when it was needed, and then promptly to forget it again, and above all, to apply the same process to the process itself – that was the ultimate subtlety: consciously to induce unconsciousness, and then, once again, to become unconscious of the act of hypnosis you had just performed. Even to understand the word 'doublethink' involved the use of doublethink.
>
>
>
[Answer]
I think the answer may be yes.
In this world, outright lies, or cynical lies (where people know that they're lying) are going to be much rarer (but still possible). But people lie to themselves, about all kinds of things - this is a lie that's quite possible in this world. People can use half-truths and omissions to paint an inaccurate picture - it will take a lot more skill, but it's doable.
How common this kind of lying is, and how much skill it takes to lie this way, will depend on exactly how telepathy works in your world - does it require active projecting/listening, is there often background emotional leakage, is everyone aware of what anyone else is thinking all the time, is it weakened or limited by distance, are there different strengths - they will all play a role. But if someone can lie to themselves, they can lie to others no matter how the telepathy works.
For more cynical lies, there are a range of techniques that can be used to manipulate one's mind. Meditation can be used to alter someone's mood even at a fairly basic level. Advanced techniques (I've seen attributed to shamanism and psycho-healing) include the healer "almost-really-nearly" convincing *themselves* that something is true, in order to convince or manipulate their patients with the right attitudes for healing. Such purely mental manipulations can be real enough to have physical effects, from stopping their heart to keeping warm in below-freezing temperatures to a host of psychosomatic effects, so they can probably be used, with a little preparation, for someone to lie by almost-convincing themselves during the conversation. In your telepathy-world, these techniques to control someone's mind won't be difficult exotic curiosities, they'll be as basic as toilet training, so kids learn not to project their moods all over the place.
People would probably figure out the 'pink elephant trick' - that is, once someone says the sentence "don't think of pink elephants", it's impossible not to think of them - in some stories this principle is used to dodge telepathy because characters thinking about the elephants (or any equivalent *fake*-secret), aren't thinking about their actual secrets. Or use mental organization techniques (like the liar's palace, mapping thoughts into mental rooms) to hide their thoughts under layers, so that those half-truths and omissions, seem like the really-real truth while someone is trying to deceive, and not when they actually need the truth. They might figure out crude hypnotism or self-directed mental conditioning to keep from "blurting out" secrets to the wrong people pretty early in history, and they have time to develop these techniques to an art form to hide secrets or confidential information or classified material.
And, people would be trying to figure out how to lie from prehistory. Even if, for whatever reason, there are no animals (*either* predators hunting for or prey fleeing from the wrong projection) which use similar techniques, and only other humans can listen in - there really hasn't been a period in history without conflict between human groups. The ability to keep secrets, ranging from where the good hunting grounds can be found, to where the winter stockpile is, would be a survival trait. So they will find what works, and run with it.
[Answer]
I'd say it would not be possible to technically lie to others.
As different answers have pointed out that you could convice yourself of believing a lie and then tell wrong things to others without them noticing, I'm currently lacking of a convincing explanation on how to return to the knowledge of your "lie".
So how about this:
A certain while after a relationship you can convince yourself you're over it but as it happens, you see your ex in the supermarket with a new lover and hurting heart realize you lied to yourself. If you predefined an external input, from which you know will snap back the state of your mind to before your "lie", you could actually realize that what you made yourself believe was in fact wrong and you knew before.
This could actually lead to potential psycho-thriller storylines.
] |
[Question]
[
I'm building a world which is broadly a [standard fantasy setting](http://tvtropes.org/pmwiki/pmwiki.php/Main/StandardFantasySetting) - similar to 15th to 16th century Europe in technology, government, growing urbanization and trade, etc., but with some magic. Very basic magic is common, but powerful magic is very rare. Somewhere on that spectrum is the ability to cure disease, and I'm wondering where I should put it to avoid completely overturning the setting. If most village wise women and hedge mages can [wipe away the Black Death with a few incantations](http://www.d20srd.org/srd/spells/removeDisease.htm), that would [change everything](https://en.wikipedia.org/wiki/Social_history_of_viruses#Middle_Ages). But what would be the impact if a select few had access to such magic?
For reference, [roughly half of the kings and queens of England died of natural causes, as opposed to violence or happenstance](https://en.wikipedia.org/wiki/List_of_monarchs_of_the_British_Isles_by_cause_of_death). However, I doubt that all of them would have led long lives even with a court magician on hand to cure their ails:
* The royal wizard may not *be* on hand; a monarch may travel or go hunting without his full court, or the wizard may be on vacation when plague hits. Some diseases can progress very quickly.
* *If* only a few and powerful mages can cure disease, a monarch will have little leverage over them. The vizier or high priest may decide not to bother healing his or her liege, if said liege has not been a good ruler/sinned before the gods.
* Assassinations are a little easier in this world, even with the presence of friendly defensive magic. Also, if there's little hope of one's enemies politely croaking off from syphilis, there's more reason to try to arrange for them to be overthrown or assassinated.
* Old people are more accident-prone, so an elderly king or queen who's not succumbed to any bugs may still slip in the bathtub.
A few notes on how magic works in this setting:
* There is normally no material cost in using magic; rare objects are useful in performing spells, but are not consumed. So the main limitation in getting a cure is having or finding an expert willing to devote some time, not cost *per se*.
* Powerful magic eventually warps the user in a variety of ways. This effect is much more pronounced for the most advanced spells; simple spells are mostly harmless, but a single act of creating life or de-aging a person may have a serious consequence for the caster. So more powerful spells are not only less available, but the people who can do them have good reason not to (and they have less interest in petty things like money, too).
* Relating to the warping effect, there's a cultural taboo against using magic on or for children, even to save a life. Even if curing magic is common, a prince or princess must survive childhood before he or she can benefit from it.
* Spells can be stored in potions or enchanted items, but this is not very practical for curing disease, as each type of infection would need a separate device.
* There are 13 schools of magic to be mastered separately. One includes infection diseases; basically, anything caused by microorganisms. Another covers non-infectious diseases and conditions like hereditary defects or cancer, as well as wounds and aging (a student of this school could help with those slippery bathtubs). So curing plague could be a relatively common spell, but curing heart disease could be rare, or vice versa.
To summarize, I'm asking "how would medieval-early Renaissance society be changed if the 1% were effectively immune to transmittable diseases?" The ultimate goal is to help decide how common to make *cure disease*-type magic.
Bonus points for answers which address the impact in a few different scenarios of rarity - e.g., only a few kings can afford it; most senior nobles can arrange for a cure; all non-impoverished nobles plus successful merchants have access to such magic.
[Answer]
## All the top of head no particular order
-) **Being able to survive disease would be spun as more evidence of the nobility's superior nature and right to rule.** This would delay or even block the evolution of democracy.
-) **Nobles might use the offer of magical cures as a means of controlling the upper tier of the population.** "Behave or when your kid gets sick, I won't help."
-) **If the world has a universal religion like Buddhism, Christianity, etc., then the hogging of cures might causes serious moral revulsion among the majority of the population.** "Death is the great leveler," and the idea that one's taxes went to pay for keeping the King's children alive but not your own might create political blowback.
***-) A mere taboo will not stop people from trying to heal their children.*** I can infer from you adding this to the list that you don't have children. I personally would do horrible things to almost anyone in any numbers if doing so would save the lives of my descendants. I wouldn't give a bleep about custom, tradition law, fairness, or the consequences to myself. All parents feel this way when it comes down to life or death for their children.
Steven Spielberg said of the ending of *Close Encounters of the Third Kind*, where Richard Dreyfuss's character left his wife and children to fly off with aliens, that it seemed credible when he was single and childless but, after he had his own kids, the character's action seemed wholly implausible.
So, if you want to prevent children from being treated, then you'll have to create an actual magical barrier that no one can get around otherwise your readers with children will be yanked out of the story.
## -) Greater political stability:
**-) Assured succession:** In the medieval world, kings functioned like the keystone in an arch, with the most powerful nobles being the stones pressing in from the side. The king had to be militarily powerful enough to bring the greatest nobles (e.g. dukes) to heel if they started private wars, refused to obey the law, or made foreign alliances. Moreover, kings were expected to be warriors who led from the front.
Basically, the medieval world was run like the mob and the king was the godfather or, more accurately, the mob is run like medieval kingdom. In either case, the guy at the top must have troops, military skill, and will to bust the heads of the most powerful when needed.
By the medieval age in Europe, the Germanic tradition of the legitimacy of a king being conferred by election had evolved to right by inheritance. If a king died before while his crown prince was still a child or, worse, died without heir, the kingdom lost its keystone and began to fall into internal war and disruption.
Improved medical care for royalty would provide greater stability by (1) increasing the lifespan of a monarch such that their heirs would be grown adults by the time the monarch died (this would also make policy more consistent and stable) and (2) would allow more heirs to survive, providing a greater talent pool from which to select an heir.
The best example of this phenomena would be the difference between Henry V and his son Henry VI. Henry V was the most effective political and military leader of his generation, accomplishing the feat of providing year-round logistics so his armies could campaign year round instead just through the summer months. It was that, more than his use of longbowmen, that allowed him to fight his way to the throne of France.
But he only reigned for the seven years 1415-1422, dying of dysentery while on campaign and leaving only his infant son as king. At first, the great magnates of the kingdom cooperated to keep things running smoothly and, for a decade, Henry V's brother was on hand over in France to slap nobles down when needed but, gradually, the English government became more dysfunctional.
Things got worse when Henry VI actually assumed the throne. Raised in a nightmare environment where he was constantly pulled this way and that by the most powerful men in the land, by his teens he was passive and likely to agree with the last person he talked to. He was a soft, unenergetic person with virtually no physical skills at all, much less a warrior. His inability to serve as as a keystone and contain the growing feud between the Duke of Somerset and the Duke of York triggered the War of the Roses.
Likewise, Edward IV managed to bring stability back to England but he died of natural causes, likely aggravated by his obesity and gluttonous living, leaving behind Edward V, a twelve-year-old. Edward V ended up murdered by Richard III by most accounts, triggering yet more instability which eventually led to Henry Tudor becoming Henry&bspVII.
If Henry V had been cured of his dysentery and survived another 20 or 30 years, his brilliance might have cemented an empire of England and France. Then either Henry VI would have assumed the thrown at middle-age, having had a less insane childhood or, if he still simply lacked the right temperament, could have become a monk (which he really wanted) and one of Henry V's other sons could have taken his place.
**-) More first sons,** raised to be kings would assume the thrown: In English history, there are two crown princes, both named Arthur, who died of disease thereby altering history.
The first was the son of Henry VII, who died shortly after marrying Catherine of Aragon, which triggered a whole avalanche of consequences when his younger brother, crowned Henry VIII, took the throne and Catherine as his wife.
The second Arthur was the first son of James II, the elder brother Charles II and his polar opposite in all regards. Charles was short, bowlegged from rickets, had a stutter, and had be raised in Scotland under the tutelage of radical Presbyterians whom he hated all his life. He was a Francophile with a Catholic wife who sought to become an absolute monarch. Arthur was raised largely in England, was an active Francophobe who probably would not have married a Catholic, and idolized the idea of a constitutional monarch. While Charles loathed such free-spirited men as Sir Francis Drake and other sea adventures, Arthur worshipped them. Had Arthur become king, it's unlikely the English Civil War would have occurred and that the transition of England to a stable constitutional monarchy might have occurred without violence.
Of course, then there would have never been the Dutch invasion under William III and, with it, the importation of Dutch innovations like insurance and banking, but it's likely enough that would have occurred by diffusion anyway.
**-) More surviving children means more alliances through political marriages**. In principle this would create more stability but, with more marriages and alliances, the value of each individual marriage alliance would decrease. You might see an effect common in medieval Islam in which a Sultan, Caliph, etc. had four wives, all owing to alliances. Each alliance was weaker than those formed in the monogamous culture in Christendom.
**-) No mad kings:** Henry V conquered France in large part because his opposite (IIRC, Charles II) had intermittent attacks of severe mental illness. A monarchial government can deal with a dead king, a child king, and an inept king to a degree, but one that goes utterly nuts is a nightmare as no legal means exist to remove him for incapacity. Henry VI lapsed into some sort of catatonia, a waking coma, for 18 months after learning of the fall of English France. England went to pieces during his incapacitation because nobody really had the authority to rule in his place.
## The downsides:
**-)Too many heirs not enough land:** With larger royal families, that would mean finding titles and lands for more sons. It would also mean more opportunity for jealousies to lead to arm conflict. A disturbing number of medieval nobles got whacked by their own first- or second-order kin.
Even worse, as the generations progressed, more and more people would have royal blood and thus some claim on the throne. If the immediate heirs of crown did all get killed by a sudden combination of accident and warfare, then the resulting scramble for the throne would be a dogfight.
It might lead to more expansionism, more crusading/jihad, or more exploration.
**-) Possibly more inbreeding:** Historical European nobility are so inbred they make the proverbial (and largely fictional) inbred hillbillies look like paragons of genetic diversity. With larger royal families, all intermarrying, the possibility of marrying too closely over successive generations increases. (Again, this was and is a problem in high status Islam. The wealthy produce a large number of half-siblings, who marry into similar families, producing another batch of half-siblings, and, since marrying cousins is still legal, genetic consequences can be severe.)
On the other hand, if you can fix those problem with magic, then maybe not.
**-) Mages who could heal would become viewed as assets to be captured and controlled.** Given the intense need for lineage and dynasty at all levels of society, a king is not going to bargain excessively with a mage or take "no" for an answer. He's going to say, "Cure my child and I'll let you live in a fancy estate as your prison. Don't, I'll torture and kill your entire family, all your friends and your little dog too." And he'll keep doing that until someone capitulates. Once he has such a mage, he won't let him out of his control and will probably keep him nearby.
It's likely that an institution would develop in which the mages would be considered automatic retainers or even slaves of the monarch with the innate duty to see to the royal family's health for the good of the realm. Those that didn't would be seen as traitors threatening not only the lives of the royal family but the peace and prosperity of the entire kingdom.
[Answer]
Culturally, very little would change. It was already believed that the [touch of a king could cure disease](https://en.wikipedia.org/wiki/Royal_touch).
That this was actually true rather than a convenient myth might prolong the reign of kings in the more revolutionary countries as it would be considered evidence of the divine right of kings to rule.
You've already limited magic to not be used on children, and the oft quoted statistics about average age at death is primarily about surviving childhood, not the actual age at which people died.
[Answer]
This is in some ways similar to the modern medical system in at least the United States, where the very rich can afford very advanced and expensive treatments of diseases that would otherwise eventually kill them or severely reduce quality of life.
This is an advantage given to those who are already quite advantaged, as a result of the fact that they are already quite advantaged. Magic or benefits like that serve to widen the gap between rich and poor (which, in the extreme, can be destabilizing to a society).
Reducing the leadership turnover rate could also reduce the rate of change and innovation, if the leaders are not open to new ideas.
The presence of this technology could reduce (but not eliminate) the incentive to develop biological warfare or infection-spreading weapons, like the smallpox-infected blankets that wiped out large numbers of American natives.
] |
[Question]
[
I know a tadpole can do this transformation, given enough time, so what about mermaids?
[Answer]
You either invoke magic, or they are really 'legs' that can 'velcro' together. It takes months for a small frog to change. On top of that frogs' [tails don't split into legs](http://allaboutfrogs.org/weird/general/cycle.html), legs grow out from the base of the tail and the tail shrinks back into the body.
A similar process for mermaids I would think would realistically take years.
Adding: Merfolk could be amphibious, so that the young are born with tails, 'teenagers' are growing legs and adults have full legs to leave the water with.
[Answer]
Give them legs. They could be separate from birth and just covered with a swimsuit. Or they could be joined at birth and separate during puberty. These follow somewhat from some...
# Real life precedents
## Sirenomelia
Tiffany Yorks, Shiloh Pepin, and Milagros Cerron were born with a rare condition called [sirenomelia](https://en.wikipedia.org/wiki/Sirenomelia) or "mermaid syndrome", where the legs did not separate in the womb. Though Shiloh could not undergo separation surgery because her legs' blood vessels were too tangled, Tiffany and Milagros had their legs successfully separated. Both needed extensive rehabilitation to walk, and Tiffany's continuing mobility issues echo the admonition of the Sea Witch in [H. C. Andersen's story](https://en.wikisource.org/wiki/Fairy_tales_of_Andersen_%28Paull%29/The_Little_Mermaid) that "at every step you take it will feel as if you were treading upon sharp knives."
## Monofin
A [monofin](https://en.wikipedia.org/wiki/Monofin) is a paddle that clips to a swimmer's feet, giving more surface area for a dolphin kick. This leads to improved performance in swimming and free diving. Cloth covers for the legs and monofin allow professional swimmers to [perform as mermaids](https://en.wikipedia.org/wiki/Mermaiding) in public. These covers are also sold commercially by firms such as Mermagica; others are custom-made.
## Sea Gypsies
The [Moken people](https://en.wikipedia.org/wiki/Moken_people) and [Sama people](https://en.wikipedia.org/wiki/Sama-Bajau_peoples) are two Austronesian ethnicities living seaborne nomadic lifestyles. These "Sea Gypsies" are known for [seeing underwater](http://www.cracked.com/article_21013_5-groups-people-who-developed-awesome-mutant-superpowers.html) and [holding their breath for several minutes](http://www.cracked.com/photoplasty_891_18-mutant-superpowers-you-wont-believe-real-humans-have/).
## Famous swimmers
Michael Phelps won a dozen Olympic golden medals for swimming in 2008 and 2012. In his autobiography *No Limits*, he attributes this to his long, thin torso, long arms, short legs, and large feet connected to hypermobile ankles. Pauli Poisuo of *Cracked* [called him "basically a seal."](http://www.cracked.com/blog/5-famous-athletes-who-may-be-superheroes/) Similarly, Icelandic fisherman Gudlaugur Fridthorsson [swam for six hours in freezing water](http://www.cracked.com/article_21518_5-epic-disasters-at-sea-survived-by-un-killable-badasses.html) in 1984. After his full recovery, it was discovered that his body fat resembled that of a seal more than a human.
# Suggestions
Francine DeGrood Taylor's answer that they are descended from humans who adapted to a semiaquatic lifestyle sounds like it's on the right track. But there are two ways this could go, even without any sort of magic.
One way leaning toward hard science is to make merpeople just a human ethnicity. This works well for "selkies," who can change between human and seal-like forms by putting on a sealskin wetsuit. Ethnic merpeople may resemble Sea Gypsies, with physiologic traits resembling those of Phelps and Gudlaugur, and wearing [bamboo-tech](https://allthetropes.miraheze.org/wiki/Bamboo_Technology) monofins with a covering to hold the legs together and reduce drag.
Another more extreme adaptation might be to have babies born with webbed legs, similar to sirenomelia. The children prefer to move through water, not straying far from the beach or the river, because moving on land requires placing one arm and the heel forward and then pulling the butt up to meet them. (Shiloh demonstrates this technique in one of the TV documentaries about her.) Around puberty, hormonal changes cause the webbing to retract, separating into legs over the course of the next few years. Puberty would be a pain, as adolescents would need to learn how to walk from scratch.
[Answer]
Add a few more joints to the legs so they can bend right when acting as a tail, then reintroduce our vestigial tail as a long thin muscled membrane which can be wrapped repeatedly around the waist and chest when in biped mode, or can encircle the legs and spread out at the feet when in aquatic mode.
Serious genetic engineering required, but it might work.
Also, if you make the membranous tail (or tails) pretty, they might serve as garments when wrapped around the torso and groin, explaining why mer-folk are usually depicted as topless when shown in fish form.
[Answer]
What if the mermaids actually had legs (although legs that were jointed a bit differently) and those legs provided the structural support for the flesh cover of the tail? Perhaps their evolutionary trail led in the opposite direction from humanity's; they started out as bipedal (or tripedal?) beings and moved into the water. In order to move more efficiently, they developed fleshy extrusions that grew longer, long enough to encompass their legs. So, in order for the legs to emerge, the skin of their tails must be shredded. This would make it very painful (hence the similarity to the HCA version of the mermaid, whose mobility caused her terrible, cutting pain).
Or possibly the tail skin requires immersion in order to stay alive. If the skin is dried out, it dies and turns brittle and is "shed" so that the legs separate and the mer-person can walk. Once they return to the water for long enough, their bodies start producing a mucus-like substance that grows down to cover the legs (and perhaps fingers as well, giving them webbing). The mucus could cover the entire body, providing insulation and protection from the inevitable battering of an environment that is often in violent motion.
] |
[Question]
[
This is of course not something that we can do at the moment, technologically speaking. But I was curious about the underlying principles of lasers and as they are, generally speaking, a form of concentrated,coherent, light radiation.
So this is for a fantasy project about another civilization that is very far advanced, with I guess what we might call "god-like powers".
Visible light is typically composed of a radiation that is a mixture of multiple wavelengths. In the universe we have other things that have a wave like presence/mode of propagation, such as:
1. sound
2. water
3. electricity
4. earthquakes
5. matter (as described e.g. [here](https://en.wikipedia.org/wiki/Matter_wave))
6. Cosmic Microwave Background (CMB) radiation
7. gravity (OK this may be more of a hypothesis at the moment)
The question is, would it in principle be possible, ***using the principles of lasers***, to create concentrated/coherent waves of any categories of "things" listed above?
[Answer]
## No
[Lasers](https://en.wikipedia.org/wiki/Laser) (no longer an acronym for "Light Amplification by Stimulated Emission of Radiation"), require a couple of phenomenon to provide the beam and the other waves that you mentioned don't have a means of providing one of more of these 3 items.
### [Design](https://en.wikipedia.org/wiki/Laser#Design)
**First**, you must have a ["lasing medium"](https://en.wikipedia.org/wiki/Active_laser_medium), this is a material that can contain atoms with electrons in an "excited" state (meaning electrons are not in the "ground" / lowest energy state) **AND** remain optically transparent to the lasing frequency.
**Second**, you must have an energy source capable of stimulating those atoms by pumping energy into the lasing medium (aka gain media). Ideally, you want the electrons to be bumped up to the same "non-ground" level state (so they release the same frequency of photon when they drop into the ground state).
This can be done through chemical reactions (e.g. $DF$, $OI$, etc.), electrical discharge (e.g. $CO\_2$), or by other non-coherent light sources.
**Third**, you must have a "resonator cavity" (usually a tube with a mirror on one side and a partially mirrored surface on the other).
### Operation
The order of operations is this:
1. The energy pump dumps energy into the gain media
2. The electrons in the gain media, jump into an excited state
3. At random one electron drops to the ground state, releasing a photon
4. The photon travels near another excited atom
5. This induces the second atom to release its energy in the form of a
photon of the same frequency and direction
6. Photons continue their voyage inducing more and more atoms to give
up their energy as photons of the same frequency
7. The photons reach the end of the resonator cavity and are either
reflected or released.
### Answer
As far as I know, no one has found a material to act as "gain media" for any of these other wave types.
### Details
Of the items in your list, #6 is a variation of em radiation. So it's possible that you could use the CMB as your energy pump. Just realize that there's not a lot of energy there so your laser will be very weak.
Items 1-4 on your list can participate in 1-3 different types of wave propagation
[P (Primary) waves](https://en.wikipedia.org/wiki/P-wave)
These are compression-rarefaction (pressure) waves. A "gain media" for this type of wave would need to be able to release a pressure wave in phase with another pressure wave and in a single direction.
P waves can travel through solids, liquids, and gases - but not vacuum.
We know of no such material.
[S (Secondary/shear) waves](https://en.wikipedia.org/wiki/S-wave)
These are transverse (side-side, like a wave on a rope) waves. A "gain media" for this type of wave would need to be able to release transverse motion in phase and in the same direction with another transverse wave.
S-waves can only travel through solids.
We know of no such material.
[Surface (aka L) waves](https://en.wikipedia.org/wiki/Surface_wave)
>
> a surface wave is a mechanical wave that propagates along the
> interface between differing media, usually as a gravity wave between
> two fluids with different densities.
>
>
>
In this case ["gravity wave"](https://en.wikipedia.org/wiki/Gravity_wave) does NOT mean a wave of gravity.
>
> In fluid dynamics, gravity waves are waves generated in a fluid medium
> or at the interface between two media when the force of gravity or
> buoyancy tries to restore equilibrium. An example of such an interface
> is that between the atmosphere and the ocean, which gives rise to wind
> waves.
>
>
>
Surface waves can only propagate along the boundary of two different materials (often two different phases of materials). Examples include ocean waves.
A gain media would need to operate on this same interface and provide a disturbance that only propagated along the material boundary.
We know of no such material.
For #5 & #7, we don't know how any of the components might work or have candidates for them. We know of nothing that would serve as gain media, energy pumping, or resonator cavity. We don't know how to reflect gravity, let along "pump up" gravity in an resonator.
[Answer]
Sadly: No.
An important thing about electromagnetic radiation is that is can pass through itself without causing interference. One 'wave' of light can be going up the body of the resonating cavity for the laser while another is going down, but the two won't meet. This means you can get their phase differences to match up just when you want them to in order to create a coherent (the waves are matching up and heading out of the laser) beam. Importantly, you can do this by just 'pouring' more light into the container.
Now consider a wavepool at a water park: You can't have both waves travelling through each other, they must interact, either constructively (you get a big splash as the two waves meet) or destructively (the waves just peter out, and it's rather disappointing). You can drive a single wave from either end of the pool and make it bigger, or you can throw more water into the pool to make a bigger wave, but you can't just keep adding water from one end and have the waves start to match up (be coherent) without the pool overflowing first.
**Edit for the sake of clarity:** The important point here is that physical waves can and must interact when passing through each other. EM radiation only causes increases in the likelihood of an interaction happening (photons don't hit photons). An antinode in a wavepool is always a huge wave, an antinode in a laser waveform is only a big thing if you stick something in it.
**Further edit for the sake of clarity:** For a solid material to have a signal-gain ratio of >1, you have to have a greater volume of material inside your laser than the volume of the laser. This isn't true of EM-radiation. That's the point I've been trying (and failing!) to illustrate.
If you have a physical phenomenon that can support waves travelling through each other, you can make a laser out of it. If it can't you just have to settle for resonant driving of the waveform. There's disagreement about which camp gravity falls into (if gravity is wavy at all).
What your super-beings could do is look at other methods of causing constructive resonance in various materials. Earthquakes would be a good example: If you can make three exactly calibrated earthquakes happen in precisely the right points in the earth, you could in theory have the shockwaves meet up at another point in such a way that they interfere constructively, and you get 3 times the earthquake at your target.
Supergenius aliens shouldn't have any problem with the maths for that, but sadly it isn't a ground-laser.
[Answer]
Many waves about which you are talking are long (human scale as opposed to fractions of micrometers for visible light) and coherent (actually this means that they are normal strong series of waves, not chaotic perturbations) by nature and laser action is hard to apply to them, but sufficiently (fantastically) advanced super-civilisation could create something like [laser](https://en.wikipedia.org/wiki/Laser) (*light amplification by stimulated emission of radiation*, modification of [maser](https://en.wikipedia.org/wiki/Maser) (*microwave amplification by stimulated emission of radiation*)) i.e. generators creating coherent waves with the use of amplification in the medium, even at the atom level. However, it would be sometimes funny.
1. Sound is usually coherent. Incoherent vibration of matter is heat. In a crystal, quanta of sound are called phonons. Physics of solid matter is well developed and I would not be surprised if somebody had already created laser-like generators of phonons. EDIT: I have just found it. There are [SASERs](https://en.wikipedia.org/wiki/Sound_amplification_by_stimulated_emission_of_radiation) since 2010. "In this active medium, a stimulated emission of phonons leads to amplification of the sound waves, resulting in a sound beam coming out of the device."
2. Waves on water can be created as single waves (that contain very many coherent quanta - human length means very low energy of one quantum - the weakest possible wave (such that smaller ones are impossible due to quantum uncertainty) is probably smaller than one atom) or whole series. It is weird to treat something as trivial from the quantum theory point of view, but it is possible and maybe our super-civilisation could make the energy of very many very slightly excited molecules (it is not so easy to find molecules with energy levels near enough to each other) transform into energy of waves of water. EDIT: On the other hand, [the way in which the wind is transferring its energy to waves](https://books.google.pl/books?id=RlhZc4HAS5oC&pg=PA7&lpg=PA7&dq=%22wind+waves%22+%22gain%22&source=bl&ots=qK5nhV4BqF&sig=NwtZRVOthSGyOQmsW6AccavuGsU&hl=pl&sa=X&ved=0ahUKEwjZ0sCa_KjJAhXDGCwKHRRoBy0Q6AEIHjAA#v=onepage&q=%22wind%20waves%22%20%22gain%22&f=false) amplifying them is somehow similar to laser action.
3. Electrical waves are more or less one-dimensional. They can also be created somehow similarly to laser action in electronic oscillators, but it is still not a full analogy. This would require something special.
4. Seismic waves could be amplified by causing explosions in the right places and moments, but to make it on a atomic level, would be again waird. They are mechanical vibrations like sound and also could be interpreted as coherent packs of phonons.
5. Coherent matter waves, like in [Bose-Einstein condensate](https://en.wikipedia.org/wiki/Bose%E2%80%93Einstein_condensate), are quite an achievement. However, the number of atoms (They can be treated as composed particles, as opposed to quasiparticles like phonons. Elementary particles building normal matter, electrons and quarks, as well as protons and neutrons, are always [fermions](https://en.wikipedia.org/wiki/Fermion), and there cannot be strong waves in the field connected with them - this would mean more than one particle/quantum in one state, and is impossible due to [Pauli exclusion principle](https://en.wikipedia.org/wiki/Pauli_exclusion_principle)) is conserved, ant this is one big difference between matter waves and for example light: we can create photons, but we can at most transfer atoms to one state from the other ones. Another difference is that atoms are massive.
6. As sanchises has explained, "CMB 'laser' is like saying 'traffic noise laser': CMB is *just there*". "Microwave laser", maser, on the other hand, is older than laser.
7. Gravity waves such that we observe results of their emission (we see that [binary pulsars](https://en.wikipedia.org/wiki/Binary_pulsar) change their orbital periods due to emission of this waves) are also coherent and have period of several hours, like the orbital period of the binary pulsars. Coherent gravitational waves with higher frequencies (from hertz to hundreds of terahertz (optical frequency) and further) would be something interesting and maybe could be somehow created with the use of stimulated emission, but currently we do not know any method to do it. Gravity radiation with energy of visible light would be very penetrating, but rather non-ionising. If the intensity were big enough, some gravitons would finally interact and heat the medium along the whole ray. Their interactions would be similar to the interactions of a photon of visible light, so could cause at most some chemical reactions and should not be very dangerous.
In modern physics, there are quasiparticles like phonons, composed particles like atoms and hypothetical fundamental particles like gravitons. **To summarise: we can try to apply quantum field theory to this particles and justify the possibility that super-civilisation will build something that emits corresponding waves and is analogous to a laser.** I tried to use my knowledge as graduate physics student and not to look at unorthodox ideas like a boring professional, but I am afraid that the result is not very clear. I hope that I did not do any serious mistakes and will be able to defend my ideas.
[Answer]
As a side note: Cosmic Background Radiation *is* light, but you wouldn't be able to turn it into a laser because there's no "container" for it. You could, however, "laserize" the radiation *in that spectrum.* I think you'd end up with [one of these](http://www.walmart.com/search/?query=microwave&).
Electricity is also sort of already the same thing as well. There's a reason its called the "electromagnetic spectrum": electricity, magnetism, and light are all closely bound. Electric charge is the "force in the electric field," electricity is "electric charge in motion," magnetism is "the repulsiveness of the electric field," and light is "the waves in this field produced by the back-and-forth motion of electrons." That is, physics is weird and I am not a physicist to properly explain the differences in English, but MinutePhysics has a few videos on it. Which either makes it "not a laser" or "exactly the same thing as a laser" depending on how you look at it (and probably also the particle-wave-duality ((quantum)physics is weird)).
Gravity *might* be possible to laserize, it also *might not.* The problem is that we (as the collective knowledge of the human species) doesn't really know how gravity works yet (heck, we're still not entirely sure that it propagates at the speed of light, slower, or faster although [experimental evidence](http://iopscience.iop.org/article/10.1086/378785/meta;jsessionid=5BCD8343545A84E1D4AC9736F0BCBEBA.c5.iopscience.cld.iop.org) suggests that it is exactly *c*). The main problem you'd have is moving a large enough mass around fast enough to make a difference (that or causing it to pop in and out of existence). It's kind of hard [citation needed] to pump more mass into something the same way you can pump energy in.
That said, a 'gravity laser' (a gaser? graser?) would probably just end up producing black holes (again, physics is weird). Which while certainly devastating (on a large scale), not exactly useful if it happens *inside* your [reflection chamber](https://en.wikipedia.org/wiki/Large_Hadron_Collider#Safety_of_particle_collisions).
[Answer]
>
> The question is, would it in principle be possible, using the
> principles of lasers, to create concentrated/coherent waves of any
> categories of "things" listed above?
>
>
>
Actually, yes. I think some people misunderstood and were trying to somehow convert any energy into a coherent light beam. That would be impressive, but is currently beyond our ken. But we already accomplish this feat on many different levels.
Back in the day, LASER was an acronym that stood for "**L**ight **A**mplification by **S**timulated **E**mission of **R**adiation". So naturally we old-timers don't simply apply that term to anything that presents a beam. (The term "X-Ray Laser" comes to mind - because it's actually a MASER, **M**icrowave **A**mplification by **S**timulated **E**mission of **R**adiation, but I guess the difference only means something to another physicist in today's world, so whatever...) That very thing is "yet another" application of creating a concentrated/coherent beam of waves - it just happens to be based on the principle of stimulated emission proposed by Albert Einstein. When atoms have been induced into an excited energy state, they can amplify radiation at a frequency particular to the element or molecule used as the medium (similar to what occurs in the lasing medium in a laser). Putting such an amplifying medium in a resonant cavity, feedback is created that can produce coherent radiation. How you release that radiation is relative to the wavelength/frequency of that radiation.
So you *could* effectively build a sound collimator device that produced a "beam" of concentrated sound (I think that would be devastating if deployed against a soft, fleshy target), or just about any commonly unfocused energy in existence. It's all in how you go about collecting, harmonizing, and focusing that energy into a coherent "stack" (or "beam") to be directed and released at your will.
tl/dr; Yes. It's do-able. Einstein said so, and I'm inclined to believe him.
] |
[Question]
[
The Wikipedia article on [Klemperer Rosettes](http://en.wikipedia.org/wiki/Klemperer_rosette) states that hexagonal rosettes are slightly more stable than other, non-hexagonal rosettes, due to the position of the orbital objects in the Lagrange points of their neighbors.
My question is this: How stable or unstable is it? That is, given a small push (say, changing the momentum of one of the bodies by 1 in 106 or thereabouts), would the system stay in an equilibrium or fall apart? If it falls apart, how fast will it do so?
[Answer]
A *Klemperer* Rosette is defined as a system of an even number of sets of bodies. The bodies in each set possess equal mass. All bodies are situated at the corners of a regular polygon (with or without a central mass).
A Klemperer Rosette:
[](https://i.stack.imgur.com/2yefd.gif)
It is common to describe a similar configuration of identical mass bodies at the points of a regular polygon as a Klemperer Rosette but this is a misuse of the term. This configuration was known before Klemperer identified Klepmerer Rosette.
[This picture from Cubist-Assassin64](http://cubist-assassin64.deviantart.com/art/Knuckles-Epic-Win-84946201) provides a good view of a rosette, but it is **NOT** Klemperer Rosette
[](https://i.stack.imgur.com/JNbQt.jpg)
>
> Such symmetry is also possessed by a peculiar family of geometrical
> configurations which may be described as 'rosettes'. In these an even
> number of 'planets' of two (or more) kinds, one (or some) heavier than
> the other, but all of each set of equal mass, are placed at the
> corners of two (or more) interdigitating regular polygons so that the
> lighter and heavier ones alternate (or follow each other in a cyclic
> manner).
>
>
>
[Klemperer Rosettes are unstable.](https://en.wikipedia.org/wiki/Klemperer_rosette#Instability)
More precisely, they are statically stable but dynamically unstable. Any tiny perturbation from this stable state leads to problems.
>
> Simulations of this system[2](https://i.stack.imgur.com/JNbQt.jpg) (or a simple linear perturbation
> analysis) demonstrate that such systems are definitely not stable: any
> motion away from the perfect geometric configuration causes an
> oscillation, eventually leading to the disruption of the system
> (Klemperer's original article also states this fact). This is the case
> whether the center of the Rosette is in free space, or itself in orbit
> around a star.
>
>
>
Although still unstable, a hexagonal Rosette (of either type), should possess some additional stability because the adjacent bodies of the Rosette will sit in each other's L4 & L5 points.
[Answer]
Not being a physicist but being able to read, it appears from the Wikipedia article you posted it's as stable as the Lagrangian points of the system.
Lagrangian points are where the centrifugal and gravitational force balance each other out. In the *hexagonal* rosettes the objects are all in Lagrangian points. This is particularly stable because that's where the objects "want" to be. The forces on them are balanced and are therefore stable.
The amount of energy required to push them out of balance is proportional to the size of the system and the mass of the objects in it and can probably be calculated using one of the equations [here](https://en.wikipedia.org/wiki/Lagrangian_point#Mathematical_details).
[Answer]
A Kemplerer Rosette is not stable in the sense you mean. Any perturbation will eventually kill the configuration. From [Kemplerer's paper](http://adsabs.harvard.edu/full/1962AJ.....67..162K) "While the rosette configurations here studied are capable of revolving as a whole in dynamical equilibrium, they are not stable against random perturbations."
[Answer]
I once played with an orbital simulator and they seemed to oscillate back and forth a bit until one got launched out of orbit and started a chain reaction.
That being said, I believe that the simulator was not simultaneously updating every point, but was doing so sequentially. However, this sequential updating would (unintentionally) introduce perturbations, which does show that once out of balance, the pattern collapses rather quickly.
---
Additionally, I'm not sure how valid using Lagrange Points is in this configuration. Lagrange Points, by definition, are solutions to adding a third, much smaller object, to a 2-body system. The 2 bodies are a single planet and the center of mass of all other planets.
The "3rd object" is identical in mass to the first object, and there are several additional masses in the system as well.
] |
[Question]
[
I am wondering, what mechanism would be needed to generate gravity on a space ship in interstellar space, like we see it on *Star Trek* or *Star Wars*? What is the most realistic hypothetical way what would be achieved?
[Answer]
Most realistic way is centripetal force, which is the rotating wheel that you see on space stations and ships in movies.
Linear acceleration also works, but requires you to maintain constant thrust.
Sci-fi ways to do it...
If you had room temperature super conductors, you could use super conducting magnets to produce [diamagnetic](https://en.wikipedia.org/wiki/Diamagnetism) fields. They have levitated a mouse that way. It would require a very strong magnetic field, and it is unknown what prolonged effects that would have on living organisms. (You can do it without room temperature super conductors, but it would be easier).
Gravitomagnetism might work, but that's kind of out there. Currently they've only generated 100 millionths of a g. With the right breakthroughs that could be improved...
`string theory predicts that gravity and electromagnetism unify in hidden dimensions`, so artificial is probably possible with the right knowledge.
Really, unless you want to go with the rotating ring or linear acceleration, you're going to have to hand wave a lot of stuff, so it's probably better to just say "It works" and not explain how, unless it's super important. Just like they do in Star Trek and Star Wars.
Silly Edit: One thing that we know works is mass. So if you were to weave fine neutronium filaments into the carpet, then the resulting mass could have enough gravity pull you down toward the floor...
**Edit 2:** So a less silly edit. I was thinking about it some more, and I remembered another possibility: The [Graviton](https://en.wikipedia.org/wiki/Graviton). It's a theoretical particle, but if they discover it, it will unite quantum theory with gravity. So let's say at some point in the near future that the Graviton is discovered\*, and then someone figures out how to generate them to create a (directed) gravitational field. This would also work for tractor beams, which could be a focused graviton laser, and repulsor fields to get an "Anti-Gravity" effect. Graviton drives could be used to take off from planets and for in-system propulsion by attracting or repulsing the planet's/sun's gravity.
\* Maybe using the first space particle accelerator, which rings Jupiter and uses the planets power to operate. It had to be a space based accelerator because earth's gravity pushes all generated gravitons away before they can be seen.
[Answer]
It sounds a bit mad - but I'm actually sure I got this idea from a film/series that I can't remember - basically you pair the magnetized floor/boots idea with a power harness which actively pulls you towards your boots, kind of like a puppet in reverse.
It lets you everything else gravity-free - like sleeping in a sleeping bag glued to the wall and drinks that float through the air - while keeping everyone firmly on their feet during normal operations.
Now that I think about it, the idea might have been used in the Defying Gravity (2009) series, how's that for irony.
[Answer]
I am not sure about it. It is rather a theoretical idea of mine. Everyone knows, that mass increases when a spaceship gets more near to the speed of light. Thats from Einsteins relativity theory. At leasts this aspect is always used to explain why it is impossible to reach speed of light: Because your spaceship will show more and more inertia because of increased mass.
<https://en.wikipedia.org/wiki/Mass_in_special_relativity#The_relativistic_mass_concept>
In the linked wikipedia section about relativistic mass they also denote that nowadays the term "relativistic mass" isn't welcome by some physicists. It is stated that people may thend to believe that increased velocity (or charge) causes a change of internal structure. Which is not the case in my model either. I build my idea upon the fact that a body becomes more and more heavy to accelerate as it reaches speed of light.
The idea is:
Place a solid ring below the mentioned carpet. The ring should rotate almost at the speed of light. First this would stabilize your ship and second the mass rotating at that very high speed would be that heavy that it generates enough gravitational force to act as articificial gravity for your travelers.
I am not sure about this use of relativity. Maybe I am getting it wrong. Is it known whether an object having its outside rotating almost at the speed of light seems to increase it's mass (and thus gravity) from a non-moving observer??
Of course you would have to find a materials which can take the high forces being caused by centripedal force on the disc.
I already tought a lot about this and if this maybe is even the reason why any particles are showing mass at all. Think of a proton having some quarks in it which oscillate at such a high frequency (and speed) that they are "relatively" heavy and cause gravity.
Thus mass would be a result of moving materia (particles).
[Answer]
Let's go completely Terry Pratchet / Hitchiker's Guide!
You attach a huge bladder containing some heavy, but fluid liquid to the underside of your ship and fill it with, say one earth mass of liquid to obtain 1 g of gravity.
However, this ship will, of course be impossible to move, so while accelerating or decelerating you suck the liquid into a pocket universe...
And for some, to us yet unknown physical reason, or perhaps quality of the pocket universe, the content of the pocket universe can be accelerated or decelerated along with the ship, however at much less mass... let's say one kilogram.
Then, when you've reached cruising speed, inflate the bladder and have a dance!
:)
[Answer]
Theoretically, if you can manipulate space and create a curved space within a small area below the floor (gravity well), you should be able to generate gravitational pull within that small area.
[Answer]
Not sure if someone else has already said this but here's my idea-
You have your ship, probably one or two levels. Each level has the same floor, so Bob can be walking on level 1, but to someone viewing on level 2 Bob is walking on the ceiling. How? The floor material is dense enough make a strong enough gravity field to hold humans to it. Going between levels is just walking through a big U to the other level so you end up upside down in relation to the other floor you were on. Your ship, or at least the interior where everyone is, will probably be a disk(but it could be any shape) with rounded edges so you can enter/exit other floors basically anywhere on the perimeter. This will definitely require some hand-waving to work, and I'm 99% sure we can't do this with today's technology.
] |
[Question]
[
[Hydrothermal vents](https://en.wikipedia.org/wiki/Hydrothermal_vent) are thought to exist on Europa. On Earth, these vents are surrounded by all manner of [freakish](http://www.deepseaphotography.com/vent_animals.html) and bizarre looking creatures, mainly various [worms](https://en.wikipedia.org/wiki/Pompeii_worm), [crabs](https://en.wikipedia.org/wiki/Hoff_crab) and [octopodes](https://en.wikipedia.org/wiki/Vulcanoctopus_hydrothermalis).
Europa's ocean(s) are much deeper than on Earth, I imagine that pressure might become an issue. Also, *Vulcanoctopus Hydrothermalis* (below) appears to have vestigial eyes. Europan life form's would also have never been exposed to light, would they evolve eyes? Perhaps eyes that see in a different part of the light spectum (eg: infrared?). What about bioluminescence?
From [here](http://eol.org/pages/3100246/details).
Assuming that would also evolve to live around Europa's vents, would it be similar to terrestrial vent life? Would most creatures have eyes and/or bioluminescence, or would feelers be more practical?
Would the pressure prevent the evolution of complicated organisms, i.e larger crabs, squid, etc.?
My own suspicion is that they would evolve many feelers and mostly be very slow in order to stretch out what little sustinence they can catch. Jelly-fish creatures might also be possible. Any other sugestions for adaptations are welcome.
[Answer]
Most of the Europan life forms would be analogues of bacteria which generate their energy from chemical reactions based on minerals that are heated and circulated through the hydrothermal vent. After that, a series of feeders who consume the bacterial creatures and extract energy and complex molecules from the bacteria should be assumed to exist, with most of the differentiation being based on how close they are to the vent and the density of the bacteria they can feed on (close to the vent will be very hot, but have a high concentration of bacteria, while farther away the temperatures will be more moderate, but the density of the bacteria will also be lower).
Depending on how energy intensive this sort of life is and the length of time thermal vents remain active, there is a possibility of more active "animal" life which feeds on the bacteria eaters, as well as a subset of ecological creatures which consume dead and decaying creatures as well. I would suspect that most of the life would be fixed in place by roots or anchors of some sort, to prevent it from being cast into the cold and lightless ocean, so we would see the analogues of corals, barnacles, sea anemones and so on, Predatory creatures might resemble millipedes, capable of hanging on in high currents and having some sort of proboscis to fish out corals and barnacles from their shelters.
While no creature would probably develop eyes, they may have some sort of sense linked to Jupiter's powerful magnetic field, as well as sensitive feelers to track the vibrations of their prey, possible earthquakes and the flow of current. I would picture creatures covered in fringes of antenna like sensors which can serve these functions, rather than smooth surfaces like we are accustomed to seeing. A creature which resembles a whiffle ball also has lots of tendrils to grab and feed on bacteria in the current, or possibly entangle larger prey. Giant creatures such as the one depicted in Arthur C Clarke's book 2010 are not very likely, since the available energy sources would be too small to support them.
I am not clear what the effects of the greater pressure would be, but unless the static column of water is so great that water changes into another form (like one of the 17 different forms of ice) and can no longer serve as a solvent and medium for chemical reactions necessary for life to occur, then I think that life may be possible on Europa.
[Answer]
**Possibilities**
-always dark==>**no eyes**, and **no bioluminescence** as this was developed to attract creatures with eyes. However like deep sea shrimp they might have **'light sensor'** on their backs, which can do little more than tell the creatures if there's a light source nearby. (Although their environment is pitch-black to human eyes, the hot vents emit an infrared glow.)
**A source of nutrition**-chemosynthesis or living off chemosynthesising organisms cf At their deep-sea homestead, the shrimp feed on gardens of bacteria they cultivate on their own bodies, a strategy also used by yeti crabs recently discovered at hydrothermal vents in the Antarctic.Then predators could live off these in turn.
-**a way of moving**-if strong currents exist a good description above of how they would need some (of the many possible) ways to hang onto the vent (claws, hooks, suckers etc)
-**a way of sensing**-most likely using vibration sense? or sound? (though I've no idea what happens to sound at huge depths and pressures). Likely is simple blind crawling around and feeling out for prey using touch organs. Also likely is simple slow-metabolism creatures lying in wait for someone to bump into them then ambush and snag and eat the unfortunate creature.
-also possible is **upside-down creatures**-as recently discovered in arctic-here underside of ice sheet-the 'roof' of their world is (as they swim 'upside down') now their 'ground'. Note 'upside down' is only our perspective, they are optimally orientated to their environment.
-**ignore terms such as very cold and very high pressure**-these terms mean nothing to a creature that has evolved in such an environment-for them this is perfectly normal.
-Equally when people say **very cold=slow metabolism** this is true of earth creatures, **it may not be true of alien creatures**. Earth has such 'weird' life-cycles just here that we can't begin to imagine how weird it will be elsewhere. Look at flabby whalefish and anglerfish for example.
-when people say **only enough oxygen for small amount of creatures to live** a) this is just an (educated) guess and b) **life will thus live off something else**, that seems to be the pattern here on Earth, complexity emerges out of whatever is there, under the right circumstances (which Europa seems to have).
-**likewise I don't see any reason why they couldn't float/swim etc in this giant ocean**, maybe **simple organism with incredibly slow metabolism or even on the cusp of dead/alive (think Resurrection plant**).
-creatures might also live off chemicals not just off the vent but those same chemicals released into the ocean eg not hunter/hunted but **chemosynthesising jelly fish** (who in turn might be prey for another creature/s)
-if large sea creatures existed, 'swimmingly' freely they would probably do so in a manner similar to our sea creatures-from simple drifting to guided activities **using all the various methods of aquatic locomotion (see wikipedia)** that have evolved here on Earth.
-if larger sea cretures existed as hunters they would very likely use a guided sensing method of hunting eg **smell, vibration sense or even echolocation.** Use of long (maybe very, very long) 'tendrils' that could act as a **aquatic spider web** also possible (why not?!)
-maybe **no communicative color or markings**-no eyes-no color needed, color on Earth has signalling function but there any color would be entirely random. Note how creatures around deep-sea vents (from what I know) are often color-free (white it seems) and have no markings.
-Other ideas, edited from Wikiepdia-'deep sea fish'...
...are **sedentary**, adapted to outputting minimum energy in a habitat with very little food or available energy.... Their bodies are elongated with weak, watery muscles and skeletal structures. **Since so much of the fish is water, they are not compressed by the great pressures at these depths**. They often have extensible, hinged jaws with recurved teeth. They are slimy, without scales. The central nervous system is confined to the lateral line and olfactory systems, the eyes are small and may not function, and gills, kidneys and hearts, and swimbladders are small or missing.
The swimbladders of deep sea fish are either absent or scarcely operational.
**The most important sensory systems are usually the inner ear, which responds to sound, and the lateral line, which responds to changes in water pressure. The olfactory system can also be important** for males who find females by smell.
Because food is so scarce, bathypelagic predators **are not selective in their feeding habits**, but grab whatever comes close enough.
It is not easy finding a mate in this zone....(some) are hermaphrodites, which doubles their chances of producing both eggs and sperm when an encounter occurs.
**Many forms other than fish live in the bathypelagic zone, such as squid, large whales, octopuses, sponges, brachiopods, sea stars, and echinoids, but this zone is difficult for fish to live in.**
[Answer]
I think the most important thing to remember is that most freakish life around thermal vents is an adaptation of already-existing life. Also, given Europa's distance from the sun and the depth of its vents in its (assumed) ocean, life would likely be either able to see and bioluminescent or sensitive in ways that don't require light. That said, it's *your world*, you can make your creatures however you wish.
Maybe there's bioluminescent plantlike life that makes it light as day around the vents. Maybe there are lifeforms that use echolocation or even psychic senses to see. Realism flies out the door; alien life may have support systems that allow them to expand despite the square/cube law. They may have systems that are completely unseen in our planet. They may be fourth dimensional.
[Answer]
I'm also making a Europa analogue, and my thinking was that if there's never been light for these creatures to evolve with, there'd be no reason for them to have eyes, so there'd be no reason to evolve bioluminescence. I thought about having them see infrared, but to me letting them have eyes to see infrared, when they can already feel the heat given off from an object or other creature, would be redundant. Also bioluminescence in the infrared spectrum would probably damage the creature creating the light, as it would need to be hot to produce that. It's hard to bring up evidence from Earth life to back any of that up, though, because all life on this planet had, at one point, access to sunlight.
] |
[Question]
[
There's a real fence that uses lasers to cut off the wings of insects to keep them out.
Is it possible to extend this technology to burn bullets into ash before they hit anything? Limit on minimum distance the bullet has to burn to stop?
[Answer]
There are two ways to stop the bullet using a laser, vaporisation (which will cause the bullet to lose its momentum due to air resistance) and ablation (which blasts material off the surface to slow it down).
For the purpose of this answer, we assume a bullet has a speed of 1000m/s and weighs 4 grams ([5.56mmx45 NATO](http://en.wikipedia.org/wiki/5.56%C3%9745mm_NATO)), and the bullet has to be stopped within a distance of 100m (0.1s)
## Vaporisation
Using the enthalpies of [vaporisation, melting and specific heat of lead](http://chempaths.chemeddl.org/services/chempaths/?q=book/General%20Chemistry%20Textbook/Solids%2C%20Liquids%20and%20Solutions/1406/enthalpy-fusion-and-enthalpy-vapo) from this page, it will take ~3400J to heat the bullet by 2000 degrees, and a further ~3.5kJ to melt and vaporise the bullet. A further amount of travel will probably be necessary for the lead vapor to dissipate its momentum.
This requires a power output of $\text{6.9kJ/0.1s = 69kW}$ of power delivered to the bullet. Actual laser power required will depend on the efficiency of the laser and how well the heat transfer occurs. If the lead vapor takes a long time to dissipate, it might be necessary to provide more power to allow it the time to dissipate.
## Ablation
[This paper](http://www.researchgate.net/profile/Claude_Phipps/publication/224511880_Impulse_coupling_to_targets_in_vacuum_by_KrF_HF_and_CO2_singlepulse_lasers/links/00463514caeb0b40bc000000.pdf) gives specific velocity changes for lasers ablating material. No values for copper (FMJ) or lead (hollow point) are given, so aluminium was used as the closest material for laser ablation.
[This paper](http://arxiv.org/ftp/arxiv/papers/1004/1004.0390.pdf) cites the previous paper, and suggests that the ablation rates were in the order of magnitude of 0.01 to 0.1 $\text{J m}^{-1} \text{ s g}^{-1}$ after unit conversion.
Therefore, assuming an ablation rate of 0.1 $\text{J m}^{-1} \text{ s g}^{-1}$, it will take $\text{40kJ/0.1s = 400kW}$ of total laser power to stop the bullet.
The actual mode of stopping the bullet appears to depend on the relative power of the laser. A high intensity pulse (MW range) will tend to favour ablation, while a relatively lower intensity pulse/higher material absorbance will tend to favour vaporisation.
[Answer]
With a powerful enough laser you can vaporize the bullet almost instantly.
There's not much to say besides that, someone else might try to calculate how much power you need to produce such effect on a beam with the diameter needed to cover the whole bullet. But instead of a fence you could try something like a small scale anti-projectile laser. You need a way to detect and track bullets and a laser on a gimbal with fast enough reaction time to track the bullet and sufficient power over range to vaporize it quickly. By using a fence, you need to cover the whole height with laser beams, stacking laser sources one over the other. This might not provide enough time for the laser to completely vaporize it, or this limitation might preclude the use of less powerful lasers.
] |
[Question]
[
As a child, I was always fascinated by the propensity of water going down a drain to form a vortex. I created a world with a global ocean where there was a narrow body of land running north-south which had a tunnel running under the land from one side to the other, connecting the sea on one side to the other (think a "Panama Tunnel"). My vision was that the difference in sea-level from one side to the other would cause water to flow through, and not being on the equator, Coriolis forces would supply the necessary angular momentum to form a vortex.
Is this a valid means by which a vortex big enough to swallow a ship could occur? Are there any other means by which this could be achieved, either created or natural, but requiring nothing more than geography to achieve, i.e. no artificial energy input.
On geological terms, such a feature need not last all that long - a few tens of thousands of years would be plenty.
[Answer]
No, this is not a valid means. (There **is** a valid means explained below)
The biggest water movement known with some certainty is the filling of the mediterranean basin through Gibraltar's strait (5.3 million years ago). It moved that mount of water in two years [[link]](http://www.elmundo.es/elmundo/2009/12/09/ciencia/1260382468.html) (link in spanish), so it did not last so long.
The key for any permanent water movement is that you somehow put more water upflow and drain it downflow. Why are rivers permanent? Because you have rain in the mountains, which puts water upflow, and evaporation in the ocean, which removes water downflow.
If there is no rain, rivers will dry and disappear. In the imaginary case in which there is no evaporation but there is still rain, sea level will raise more and more until a huge ocean covers everything.
So you can have a gigantic whirlpool if you happen to be lucky enough to have (or if you decide to create, as it is your world) a combination of several factors:
1. A tunnel at the bottom of a water body. It can not be the Ocean or any big Sea, since you need...
2. A lower water body to receive the drained water
3. Low depth over the upper tunnel mouth. Remember that a full bathtub creates almost no whirlpool, and the swirl gets stronger and stronger the lower the water level gets.
4. Constant supply of water to the upper water body.
As an imaginary example, just to get into some mental image: make it double or triple the flow of Colorado river at Hoover dam (by means of having some more rain upwards) and try to drain all that water through the current hole. You simply can not, so you will need a bigger tunnel. That bigger tunnel below the dam will cause exactly the kind of whirlpool you want.
[Answer]
One scenario that might cause this is if you had a large inland sea substantially above main sea level with a lot of rivers flowing into it.
The inland sea would drain out through an underwater hole feeding into a large river (some interesting geology would be needed but a soft limestone layer with granite over and some convenient fault lines might do it).
Above that drain into the underwater river would be the massive whirlpool you desire.
[Answer]
Well your example actually could work with some understanding. There are real vortexes/maelstroms out there though in the real world. All of them however are linked to the tides [some examples](http://en.wikipedia.org/wiki/Maelstrom). I've also seen a special case of this where the tides from one side of an island to the other will draw water through underground tunnels, so depending on the direction of the tide one side is upwelling water and on the other side of the island it is a dangerous vortex, when the tide switches the direction switches and they reverse rolls.
These particular ones are only big enough to be dangerous (on the vortex side) to people and maybe a canoe or surf board, people actually play in them when they are upwelling. so it could be theoretically possible to have something like that if is is tidally controlled with the perfect conditions. I'm still looking for a link about the island vortexes, I thought they were in Hawaii.
[Answer]
Whirlpools are formed whenever two currents for a shear owning to differences in velocity. In a bathtub style whirlpool, the sheer is caused by the water accelerating down the hole faster than the surrounding water. This causes friction which is resolved by the generation of an ordered structure in the form of a whirlpool.
However, the most common whirlpools are those that occur in lateral flowing bodies of water. In many cases, they form under the surface so that are not observed in proportion to how common they are. When water is flowing around a bend, the water on the inside of the curve slows and the water near the outside accelerates. This will create a shear wall between the two that dissolve in to chaotic turbulences of lots of little whirls. The energy builds up the turbulence until the ordered whirlpool forms.
The whirlpool directs the water downward and by accelerating it creates a lubricating layer between the streams.
Such whirlpools can form and last for years. Some produce ice rings when the water on top freezes over.
To produce a sustain whirlpool that could suck down a ship. You would need either a single powerful current being bent along one side to create the shear or two current flowing suddenly adjacent.
In theory, you could get a whirlpool that forms like a tornado. Tornado's start when air get loft high by thermals cools and falls very fast downward and gets sucked but the thermal again. The forms a fast rotating cylinder of air with it's axis parallel to the ground. At some point, the cylinder goes vertical, concentrates and becomes a tornado. In theory, cold, dense high saline water crossing on top of warm, less dense water (optimally fresh) would sink rapidly, mix, warm and rise, drawing more cold into the system. If that cylinder turned on the side, you could have a sustained whirlpool.
In this case, you likely wouldn't have as sustained whirlpool but a dangerous region where such whirlpools could form without warning. Kind of an aquatic tornado alley.
If you want to suck down a ship with a plausible mechanism, I suggest aerated water. Gas bubbles in water lower it's density and ships become no longer buoyant. It's happened with fairly large vessels around volcanos and gas from hydrate beds is suspected in a couple of others.
] |
[Question]
[
So it turns out that there’s billions of Coca Colas’ worth of sugar released into the rhizosphere beneath sea grasses.
<https://www.sciencedaily.com/releases/2022/05/220502120422.htm>
I have a race of humans/superhumans/merfolk that live exclusively in the sea and other aquatic habitats. They very, VERY rarely leave the sea/water unless they absolutely have to. They're very humanlike in appearance with only some visual quirks like webbed hands, long flexible feet, somewhat fatty foreheads to behave as melons, etc. and other internal traits like cetacean-like blood, collapsible ribs, etc.
At best they live in houseboats (of varying types) and make temporary living spaces on makeshift rafts, diving bells, etc. Being an amphibious species, their palette is limited (from a land-lubber’s point of view) outside of sea creatures and kelp/algae/seaweed. So I was looking into other foods and seasonings (besides salt) there could be and came across the sugar under the sea meadows. I wanted to know if there was a way for them to harvest the sugar there to add onto their cuisine.
Their technology is mostly with primitive materials at this stage. They make due with what they can with: seaweed/kelp, shells, bones, rocks, driftwood, sea glass, things salvaged from shipwrecks, reefs, coral, and whatever other things they can get in the ocean. They have also of course achieved very sophisticated free-range farms for their “vegetation”, numerous methods of fishing/hunting, and rearing of numerous sea creatures from krill to small whales. Some races advanced to where they could make primitive paddleboats as expensive as they may be.
With this info, how can they harvest sugar under the sea meadows with what they currently have?
If it helps, I’m looking at the sea grass meadows surrounding Australia in particular, but feel free to use other examples if it improves an answer.
(got approval from the Sandbox this time)
[Answer]
It might be better to instead breed the seagrass so that it retains more sugar in the rhizomes, then harvest and process these like sugarbeet.
[Answer]
I have an idea as to how this sea grass could be harvested, but I think it would be much easier to just use sugar cane. It is already a very water intensive crop, but unfortunately cannot grow in salt water. Your merfolk can squeeze the sugar cane, perhaps into a sponge, then put this into a clam shell, and bind it tightly with seaweed. This will slow the loss of the liquid to a minimum. If you want just crystal sugar, you would have to boil it. A sun cooker would be a monumental project, and likely would not suffice, and fire cannot be used for obvious reasons.
The seagrass' roots contain more pure sugar then the soil. It will be easier to harvest from there. Crush the roots into a powder, preferably in a area without water. Then seal it however you can, perhaps the clam wrapped in seaweed method might work. Add the powder as a sweetener, unfortunately you cannot purify it further without heat. Maybe if you have access to underwater vents you could place the container over it, heating the interior, but I doubt that will work.
Supposedly the mucus of a honeycomb moray eel is sweet, but this is undocumented. (This is entirely a theory based on fish behavior, supposedly the sweet taste lures the fish.)
Some mangrove trees produce edible fruit. These can be turned into sweeteners.
The sugar cane juices can be applied to food like a syrup, and the seagrass root powder, like a powder. Preferably you would place what you wanted sweetened in a container, like a barrel, then add in the sweetener, seal the barrel, then shake it or roll it. Hopefully the powder and/or 'syrup' will stick to your food, like a glaze.
[Answer]
The plants have been genetically engineered to store the sugar in the roots, and the roots have been engineered to work as a network to supply hungry "neighbours". Tapping the root network on site allows to extract the juice without killing the fields in a sustainable way.
Then a third genom was crafted on, resulting in cellulose coveredd sugar bladders forming on the roots. Given enough growth, the sugarbladders stem rips off and the whole thing drifts to the water surface.
Thus some droneboats just drive along, collecting floating sugar-bags. It was all good, till that faithfull day, a narco-sub crashed into a cliff, releasing a myriad of columbian snow packages.
People could not get enough of the real ocean grown "coca cola".
[Answer]
Harvest the seagrass, take it to a dry place (like a floating home or the shore). Let the seagrass dry, grind it to a powder, let it dry further. You will have a powder that has some quantities of sugar and salt in it.
A sea-dwelling species should not need to care about the high salt content in that powder. But if you wish to trade some of that sea-sugar with some hypertension-prone species, or increase the incidence of diabetes among your own people, you can refine that sugar further.
Get some booze - the stronger the stuff, the better. Aim for something that you could use to sterilize surgical instruments. You see, salt is not much soluble in alcohol, but sugar is. So you throw your powder into the booze, and most of the salt (both sea salt and lots of impurities) should settle in the bottom. Then you can transfer the liquid phase to another vessel. Drink some for your trouble and let the rest evaporate. You will end up with a very sweet powder that is mostly sugar.
] |
[Question]
[
Black holes were first seriously theorized in the early 20th century, but it took many decades before one could be observed; depending on your definition of "observe," this may have occurred as early as the 1998 research theorizing that only a black hole could explain the orbits of objects around Sagittarius A\*, or as late as the 2019 direct imaging of M87\*. And these observations were achieved by astronomers laboring under the consensus that black holes probably exist.
Assuming that scientific/engineering research progressed at about the same pace (up until this discovery, which would fork its development significantly), what are the *closest* and/or *furthest* locations where a black hole could be located such that it will be observed before it would be theorized in the 20th century, and how early would that observation happen? "Observe" being defined as "collect observations sufficient to convince astronomers that an object defying understood physics exists at the specific location of a real black hole," so something like the Sag A\* research would count.
Both the upper and lower limit on distance are interesting questions - a black hole as nearby as [the moon](https://worldbuilding.stackexchange.com/questions/237820/the-moon-turns-into-a-black-hole-of-the-same-mass-what-happens-next) would need to be small and lack an incandescent accretion disk in order to not disrupt life on Earth, which might make its optical lensing effect too small to observe with pre-20th century telescopes. Black holes further away can be larger and have incandescent accretion disks without cooking Earth, but they're harder to observe and you would need to be able to tell it apart from a normal star based on historical observation - just being bright isn't sufficient.
[Answer]
Although philosophers had suggested such things earlier, it wasn't until 1915 that Einstein provided us with a mathematical basis to bring the concept out of the realm of angels into the world of physics. Anything before then would then qualify.
# Not Actually Neptune
Anything within our solar system would be visible as an occasional flare when something passed too close. Neptune was spotted in 1846 based on its gravitational effects on the other planets. It could very well have been a black hole for all the effect it had on history.
Proxima Centauri is another of those that had to be spotted with a large telescope, but would have been a fun mystery if they looked and saw nothing or, even better, an accretion disk.
[Answer]
# A binary star system plus a black hole.
It is pretty easy to see stars which are fairly close. Your star system has a main solar system and a fairly close star which orbits with it. In that nearby star system there's a black hole pretty close to the star.
Fairly simple newtonian calculations should reveal to an astronomer that the gravity in the star near their sun is acting in a really funky way, that can only be explained by a large gravitational mass acting on the star and planets.
[Answer]
I don't think this can be answered properly.
>
> Observe" being defined as "collect observations sufficient to convince astronomers that an object defying understood physics exists at the specific location of a real black hole (...)
>
>
>
This is the bread and butter of scientists. When we run out of phenomena to explain they will all be out o job other than infotainment consultants.
As or black holes specifically: before relativity was a thing, there was a theory of [dark stars](https://en.wikipedia.org/wiki/Dark_star_(Newtonian_mechanics)), which will also be the name of metal band someday. This dates back to the 1783. So as soon as newtonian physics become a thing, people will be on the lookout.
And they will find a lot of stuff. Whenever something is amiss, someone will shout dark star/black hole. Even today, people are looking for a planet in the solar system beyond Pluto (the infamous Planet X), and some... unorthodox people are claiming it is actually a small black hole.
An earlier example: Mercury precedes differently than what would be expected under purely newtonian physics. Relativity resolves this, but before it became mainstream, there were still astronomers looking for a planet or something else orbiting really close to the sun and messing up with Mercury. I'm fairly sure dark stars were considered by some.
I think that for us to look at something and say "yep, this can only be either the gravitational effect of an invisible yet extremely massive body or otherwise the work of Satan" - and be right about it - without knowing what a black hole is, the thing would to be so close to our face that the Earth probably wouldn't last long.
] |
[Question]
[
I was thinking about a world where hot air rises to the extent that the top of the mountain is always warmer than the bottom. I guess this would be something like a permanent planet-wide inversion layer. What would be needed for this to happen? E.g., a very small planet, hot close parent star, very thick atmosphere of a specific composition?
[Answer]
**Titan style - the antigreenhouse effect.**
The hazy, opaque atmosphere of Titan reflects much of the incoming radiation from the SUn back into space. But it does not similarly reflect infrared heat coming from the planet surface. The result is that the surface is cooler than the atmosphere.
[https://en.wikipedia.org/wiki/Climate\_of\_Titan#:~:text=5%20Clouds-,Temperature,or%20%2D296.59%20%C2%B0F](https://en.wikipedia.org/wiki/Climate_of_Titan#:%7E:text=5%20Clouds-,Temperature,or%20%2D296.59%20%C2%B0F)).
>
> Haze in Titan's atmosphere contributes to an anti-greenhouse effect by
> reflecting sunlight back into space, making its surface significantly
> colder than its upper atmosphere.[3] This partially compensates for
> the greenhouse warming, and keeps the surface somewhat cooler than
> would otherwise be expected from the greenhouse effect alone...
>
>
>
I am suspicious that "upper atmosphere" might be fairly high up. The upper atmosphere (stratosphere) of Earth is also warmer than the troposphere layer next to the surface.
[](https://i.stack.imgur.com/l6M4H.gif)
<https://scied.ucar.edu/learning-zone/atmosphere/change-atmosphere-altitude>
Clearly, (opaquely?) a change in radiation absorbtion / reflection at altitude can cool the surface as is seen by [high altitude sulfur- containing dust clouds](https://en.wikipedia.org/wiki/Stratospheric_sulfur_aerosols) that are emitted by volcanoes - these clouds cool the surface for some years after the eruption.
So for your world: you will produce an antigreenhouse effect by parking highly reflective clouds in a layer not far above the surface or perhaps extending up from the surface. This white fog reflects both visible and infrared radiation. The fog layer stops a little higher than the highest mountains. I here assert that this will produce a thermocline with high temperatures at the top and above the clouds, and colder temperatures as one descends to the nearly lightless surface of the planet.
[](https://i.stack.imgur.com/JL00H.png)
<https://www.wikiwand.com/en/Thermocline>
[Answer]
**Put a small black hole in orbit**
This answer is highly speculative, but there are no science tags, so let's launch the idea.
Say you'd have a strong attractor, relatively near your planet, in elliptical orbit around the planet.
At two moments each "month", the attractor will be in perihelion, very close to the planet. There is no apocalypse and the planet itself remains near to its orbit around the star, but tidal forces will cause the atmosphere to bulge in the attractor's direction. Particles get accelerated while going up. As a result, you'd have friction forces which increase on higher altitudes compared to lower altitudes. This turbulence friction can warm up the upper atmosphere. Hence you'll get a temperature inversion where the attractor is. Mountain tops will warm up.
There is still conservation of energy: the planet rotates, the attractor will stay where it is. At some point, the air (cooled off in space) will be falling back to the planet, causing cooler weather on the opposite side.
[Answer]
# Polar mountain
One of the more idyllic backwaters of the future solar system is the North Mercury colony. Within the confines of the Gossamer Wall, an oxygen-rich atmosphere has been built up from the region's [once-frozen](http://public.media.smithsonianmag.com/legacy_blog/Mercury-n-pole-shadow-ice.jpg) lakes. Abundant plant life grows, fueled by carbon freely donated from Earth, that was flung from the boundary of space by the exospheric plows that used solar sails to sort gas molecules and end Earth's ancient climate crisis.
But the terrible chill of Mercury would never have been moderated, and the ice would never have melted at all, if it were not for the warmth of the [Kandinsky Mountains](https://www.planetary.org/space-images/kandinsky-crater-mercury). If you go climbing on one of the hot rims in summer, when the light of Ten Suns shines on your back, you'd better dress for the weather!
] |
[Question]
[
Dragonslayers are a common trope in fantasy, but mine are a bit different (please see [this](https://worldbuilding.stackexchange.com/questions/196004/balancing-bloodstones) and [that](https://worldbuilding.stackexchange.com/questions/195379/unconventional-rebirth-is-it-checked) for more on that). The problem is not with the dragonslayers but with the dragons themselves.
**Background:**
Yes, this is relevant, sorry it's so long. Long ago, there were only two dragons, Curse and Regis. Curse was the first Dark Dragon, and the first male; and Regis was the first Light dragon (and the first female). The two did *not* mate; for while Regis chose the way of peace, order, and virtue, Curse chose the way of violence, chaos, and evil.
These dragons soon came to two powerful magical constructs (formed of warped reality, or discord, which is the driving force behind magic): the Source Crystal and Neosis Gem. The Neosis Gem was a giant diamond capable of generating and harnessing creative energy (AKA creating more dragons), while the Source Stone was a giant stone that would channel the Neosis energies, making each dragon created by the Gem reflect its creator and yet be genetically unique.
To make a long story shorter, a third being, as powerful as Curse and Regis, also sought the Gem and Stone and when it couldn't have them it went kamikaze and killed not only the two (battling) dragons but itself as well. The subsequent release of magical essence inadvertently melded and went into both artifacts, and thus the dragons were born.
Each dragon reflected their harsh origins; since Curse and Regis were both forceful creatures and felt the need to fight for their beliefs (and to prove their dominance; they're *dragons* after all), so do their spawn. Because of this, the early dragons were very warlike creatures, and their world became a war zone. This belligerence was inherited by modern dragons, along with their ancestor's courtship rituals.
Since dragons prized power and fighting prowess, it didn't take long for dragons to unanimously decide that one's would-be mate would have to prove him- or her-self by defeating (read: subduing, overpowering) them. This led to dragons seeking powerful/skilled mates since no one wanted a weak mate; no, no, the thinking went; the harder the fight required to earn the right to mate with someone, the better they'll be as a mate!
This wouldn't really be a problem, but due to in-story reasons, all dragons are A) capable of becoming human and B) all learn they can become human from the moment puberty starts unless already informed.
**The Problem:**
Since dragonslayers are elite warriors who are employed for the sole purpose of subduing, overpowering or slaying dragons, they will (almost) inadvertently become attractive under the dragon's courtship rules. Sure, sensible dragons will stay away, but most dragons *aren't* sensible-natural selection favored those crazy enough to take on powerful members of the opposite gender, those who'd be difficult and even dangerous to court, and modern dragons reflect that.
Modern dragons have also inherited a martial code, which leads them to respect those who can rival or exceed their own level of power or skill, which only worsens the problem. "But wait," you say. "Is this really a problem?" YES.
1. Most Dragonslayers are Male
Due to this being (somewhat) realistic medieval fantasy, sexist attitudes and cultural expectations make men naturally more like to be dragonslayers. Being a dragonslayer also requires a certain amount of recklessness (AKA guts, courage), which I know from personal experience men are more likely to have. And men aren't exactly known for rejecting women's advances, in *any* era.
2. Veteran Dragonslayers *Aren't* Idiots
This is pretty much self-explanatory; in order to become a veteran dragonslayer, a "pro" if you will, one needs to have a certain amount of brains, common sense, foresight, and critical thinking ability. Accepting a dragon's advances comes with a lot of benefits, while rejecting them comes with very few benefits;
3. Having children with a dragon results in more powerful and capable children, and greatly increases the chance of said children having magic;
4. If one accepts a dragon's heart, they will gain the ability to do magic (Ex: pyromancy for a fire dragon), or gain stronger magic if they have magic already (see, 1 out of 14 dragonslayers are mages);
5. It usually results in one having a dragon companion, which is useful for obvious reasons (transportation, powerful backup, and so much more)....
and of course, "hell hath no fury like a woman scorned" applies tenfold to dragons. After learning all this from their seers, the king would like to know **How Can A King Best Deal With Draconic Courtship Practices?**
Clarification:
1. The king is looking for the best way to handle this, as it appears that this will put dragonslayers in a position of power and therefore make them a threat to the system (AKA him and his noble supporters). He specifically wants a solution that he can implement that will:
A. Ensure and maintain society's stability
*and*
B. Prevent dragonslayers from abusing this quirk of dragon culture to their benefit and his detriment; ie. balance this so they don't get overpowered.
2. If two half-dragons have a child, the result is a Dragonborn, a human who is both human *and* dragon and represents the full potential of each.
Basically 1/2 + 1/2 = 1. Thus Dragonborn + half-dragon =1 1/2, half-dragon + human= 1 1/2. That's not to say the results are the same, however.
A Dragonborn & half-dragon pairing results in a Dragonborn that's a little more (specially 1/2 more) human, making them more spontaneous, adaptive, artistic, and intellectual than a regular Dragonborn.
A half-dragon and human pairing results in a human that has 1/2 dragon thrown into the mix, making them more passionate, aggressive, impulsive, and stubborn than a regular Dragonborn.
As always, I appreciate your input and feedback, so if you decide to VTC or downvote, please let me know why so I can improve this question. Thank you!
[Answer]
If dragons can take human form then the problem already contains the solution: **Lizard Overlords**
The king and his nobles are themselves pure-blooded dragons. In the past a male dragon took on the guise of a human dragonslayer, found a suitable mate and with her help set up a new dynasty over the charred bones of the previous. Would-be dragonslayers now are mainly nominated by royal authority, and he only ever picks from the families of his fellow ruling dragons. After all, who best to overpower a dragon if not another dragon? Also, since dragons only want mates with sufficient power or skill, they can get rid of boring stuffy arranged marriages. The whole dragonslaying business would be how the dragons find a suitable match for their children. There may be some actual humans who try their luck without royal approval, but Sir Darwin will sort them out.
Thus, there is no conflict between dragon culture and that of the nobility, because they are the same thing. Societal stability is a nebulous thing, draconic rule can be done both overtly and covertly to that end. If your nobles are undeniably dragons, most rebellions can be nipped in the bud by the simple threat of dragonfire, thus maintaining peace and order. Otherwise, you can have a cabal of secret reptilian conspirators for maintaining the pretense of human rule.
Maybe you insist on having an actual pure-blooded human as king. A particularly martially inclined king could simply **pick up dragonslaying solely for himself**. The many benefits of picking up a dragon consort for a would be dragonslayer apply just the same to a king; even moreso, since the prestige acquired can be used to buffer his claim to the throne. Historical monarchies often justified their right to rule with the idea of a [divine mandate](https://en.wikipedia.org/wiki/Divine_right_of_kings) so yours is simply a variation involving dragons. Also, if there's anyone you can expect to be loyal to you it's yourself.
[Answer]
I see one problem here, from what I understand of your world: If Dragon A has been defeated by potential mate Dragon B, then while the defeated dragon A would be down for intercourse with B, B has no reason to mate with A, because B would want someone stronger than themself, which A has been proven to not be. And so on and so forth. If the "I want a stronger-than-me mate"-thing holds true to all dragons, that basically means all dragons would need to have mates from another species. Now, if "mate" includes "future parent of my offspring" the question is how the dragon species would propagate itself - IF you need two dragon parents to get a full-dragon child.
That problem would be solved if you needed only one parent of a full-dragon child to be a dragon as well (because something something magical mutation of human genes something).
This would potentially offer you one of the solutions you seek: Not everyone would be down with having your child be a whole different species than yourself.
I'm assuming that mate means something like lifelong sexual and romantic partner here.
Your king could do a few things, mostly simultaneously:
1. Not giving the dragon opportunity to court a Dragon Slayer or pull a "Hell Hath No Fury Like": No more orders for dragon-subduing, only for dragon-killing.
2. Only pair up male Dragon Slayers with male dragons, and female dragon slayers with female dragons: That's going to solve the problem of the heterosexual and heteroromantic dragons.
3. Only hire/train/send out married Slayers with children (has the downside of leaving more widowed spouses and orphans). Assuming cheating is culturally not accepted and being seen as morally wrong, and would if found out result in the cheater loosing their family (spouse and children) and reputation, then accepting a dragon's advances would be less tempting for a slayer. The king could codify some of these consequences in form of a law to be used in favour of the cheated-on spouse in court, for example.
4. Only send slayers out in groups. If defeating the dragon is a team effort, then no individual person is clearly stronger than the dragon, and no individual slayer will appear as an attractive mate to the dragon's eyes. Unless the dragon is down for polygamy.
5. Sterilisation or castration of some sort is also a possibility, but there would need to be massive benefits to becoming or staying a slayer to offset that large downside. Also, loosing your testicles means dropping natural testosterone levels and consequently muscle mass if I'm not mistaken, so the advantage male slayers would have over female slayers while training would largely disappear. Plus, introducing that would cost your king quite a few of his current slayers, who would not be down for loosing body parts to traditional castration methods.
[Answer]
>
> Assuming dragonslayers are male, how to keep them from mating with
> impressed lady dragons they are trying to kill?
>
>
>
1. Gelding dragonslayer. Might want to but can't.
2. Gay dragonslayer. Not interested even if the lady is.
3. Child dragonslayer. A couple of reasons no.
I think this would be a fine trio go out aslaying!
---
Three more: darker.
1. The monster. He is beautiful, seductive and terrible. He likes ladies but he likes them dead, or more than dead. He should be put down, but instead is put to use.
2. The other monster: a lady dragon, hating her dragon form, trained to kill in her human form. When she kills her own kind she symbolically kills the dragon that she is.
3. The paladin: he is the real thing, a rarity too pure to be seduced into relations with anyone but his wife.
These three would also be an excellent team, the paladin sent with the other two to watch them. Each one hates the other two.
[Answer]
**OPTION 1: PERSONAL DRAGON-HUNTER-HUNTERS**
The king could keep a loyal group of elite warriors paired up with an equally elite dragon, trained from the moment they fell for each other to be the ultimate anti-dragon and anti-dragon-slayer troops.
**OPTION 2: HOLY MATRIMONY BETWEEN KING AND DRAGON**
If you aren't afraid to drift into silly overtones, you can have some of the more egomaniacal kings become dragon-slayers themselves for the sole purpose of courting a dragon as a mate. I'm not referring to kings who assemble a group of warriors to professionally hunt them and take credit for the kills. I'm referring to kings who quite literally throw on some dragon-hunter gear and go out solo to fight and slay dragons.
[Answer]
Initially this works out in the favor of both species.
Dragons get mates. Humans get power.
The problem comes from Interbreeding! The offspring of such a pairing will only inherit half the power that a dragon normally gets. Stronger than a human but much, much weaker than a pureblood dragon.
Undoubtedly, this will create a few factions and conflicts around "pure bloodedness" versus "freedom to choose" around dragon mating. It would eventually cause class stratification.
If a King wants to they could claim superiority over the person they sent to defeat the dragon thus being the "greater mate" for the dragon. With later interbreeding and pure blooded issues, the pure blood faction might set up political marriages to create agreements to not hunt pure blood dragons and dilute the bloodline while simultaneously boosting the power of the royal bloodline.
] |
[Question]
[
I was thinking there might be a guest room for humans down in Atlantis. But this raises a question: how would they get enough oxygen for their guests?
Mines have various techniques for oxygenating themselves, including the use of fire, and horse-powered fans (sometimes the two together). So perhaps this could draw air down through a sort of chimney? That chimney would have to be pretty tall, though, and that would risk leaks or other damage.
It would be possible to collect air in water-proof containers, then pull it down to the city, then release the air. That would be quite a lot of work, but it's at least simple.
Does anyone have better ideas for how to keep landlubber envoys from suffocating?
[Answer]
Plants. They would need a lot of them, but the plants would remove the carbon dioxide and supply the oxygen, given enough appropriate water and light.
There would also need to be a process to get people back up if the city is very deep, owing to the bends.
[Answer]
The mermaids could split water molecules using electrolysis. It's a relatively simple process and it's the same way that astronauts make oxygen. However, the mermaids would have to split a lot of water molecules to supply an entire hotel.
[Answer]
They could use some sort of reverted [bucket-wheel excavator](https://en.wikipedia.org/wiki/Bucket-wheel_excavator), where the bucket-wheel would capture air from above the water and would convey it to an underwater central storage.
[](https://i.stack.imgur.com/LQ8yg.jpg)
From there it can be distributed to the local users with a system of piping and pumps, not much different than what happens with gas.
And don't forget that, apart from providing oxygen, they also need to remove the accumulated CO2 from the environments: even though there is plenty of oxygen left in the air, high levels of CO2 are lethal for humans.
[Answer]
## Algae
80% of the earth's free oxygen comes from photosynthesizing algae.
The mermaids could "plant" it in an airtight room, and then place a pipe at the top which goes to a storage reservoir.
Used air would be pumped back into the algae farm to restore the oxygen.
One caveat: they might want to mix some used air into the fresh air; while oxygen is necessary for life, *pure* oxygen is poisonous.
[Answer]
Electrolyze water to produce a mixture of oxygen and hydrogen for breathing.
Purification and other processing may be required to prevent inhalation of halogen gas.
[Answer]
The King of the merpeople has [power over the creatures of the sea](https://www.denofgeek.com/wp-content/uploads/2018/07/aquaman-arthur-curry-aquarium.jpg). He simply commands whales to take a deep breath at the surface and breath out beneath the giant seashell cupola grown for the landpeople's convenience.
] |
[Question]
[
Horse were originally native to north america but between 13,000 and 11,000 years ago they went extinct likely due to expanding glaciers into their territory. The question I propose is how could I make it so horses don't go extinct in the new world allowing for Native Americans to domesticate them?
NOTE: magic does not exist in my story
[Answer]
**Domesticate Them**
This is really your only option. A bit of history lesson on horse domestication: wild horses (here defined as horses in the subgenus *Equus* (*Equus*), rather than counting donkeys or zebras) weren't just wiped out in the New World, they were almost wiped out across their entire range in Eurasia as well. Horses are big (producing a lot of meat per individual) and apparently taste good, and so are prime targets for hunter-gatherer societies just like any other megafauna. It just turns out that they are more useful to people as mounts and draft animals than as food.
Humans basically hunted horses to extinction across all of Eurasia except for a few remnant populations in the northern steppes of what is now Kazakhstan and the Caucasus. These northern steppes (including nearby areas like present-day Mongolia) probably held horses longer because it would have been harder for humans to corral or hunt them on foot. A handful of cultures started to keep horses in captivity, mostly for meat and milk (possibly for kumis), and only later found out horses are useful for carrying people or things. At least some of these cultures may be some of the proto-Indo-Europeans (especially given the center of domestication of the horse is the same place that they are theorized to have come from) and their domestication of the horse may have contributed to them being able to spread their cultural ideas everywhere.
These peoples may have domesticated some of the last herds of wild horses, with the species going extinct in the wild shortly thereafter. [It was once thought that Przewalski's Horse and the Tarpan represented remnant populations of wild horses, but it turns out that these horses are likely descended from secondarily wild individuals that escaped from captivity thousands of years ago](https://www.nationalgeographic.com/news/2018/02/przewalski-wild-horses-botai-kazakhstan-spd/) This may not be the only domestication event of the horse, some people have suggested multiple domestication events or even one domestication of the horse combined with new genes added from bringing in wild mares from local populations, but it's very telling that herds of wild horses are pretty much gone after the Neolithic. And that a lot of other wild equid species other than the plains zebra and kiang aren't doing so well.
Notably something similar happened with a lot of Native American groups when horses were reintroduced to North America. A lot of groups (mostly peoples with more sedentary habits) saw horses as most useful for food, but a few of them like the Comanche and the Sioux found that riding horses was a lot more effective (likely because most of these cultures lived on the open plains) and leveraged it into becoming big political powers of the region (*Empire of the Summer Moon* talks a bit about this).
The best way to keep horses alive in the New World would be to have some culture domesticate them somewhere in either North or South America. Maybe twice if you want horses in both places, as llamas despite being domesticated in South America never seemed to become popular in Mesoamerican cultures like the Aztecs, Maya, or Toltecs, and the rainforests of South and Central America might make horses less useful and therefore less likely to be traded between continents. Wild horses might still exist, but as secondarily feral herds descended from domesticated escapees, similar to the modern Przewalski's horse or the mustangs in North America today.
EDIT: Looking up tarpans a bit more it's possible wild horses survived a bit longer based on historical documentation, though it's not clear whether they were actually wild or descended from escaped domestic animals because historical observers usually didn't make the distinction. Observations seem to be pretty rare. Nevertheless "wild" horses were persecuted a lot because they were perceived as good food and competition with domestic horses for grass, and they only did well where large groups of people generally weren't.
[Answer]
Have aliens use their spaceships to kidnap a herd of horses early on and keep them in cryogenic storage. Every time the horse goes extinct, the aliens descend and repopulate. Let them breed a bit, then take a subset back on board. The repopulation can continue until the aliens get bored or their tech breaks down.
] |
[Question]
[
Humans developed technology from sticks and stones to computers and rockets in thousands of years. However most of this is only possible given access to certain elements like iron, copper and the like. **So the question is what environment would prevent technology from developing? What should the planet be made of to not allow electronics from being invented?**
Due to this the planet would only be able to make use of physical or chemical properties of materials, for building houses or making medicines. To a space traveler this would be "primitive" but the natives would not be stupid. They are intelligent, good at craftsmanship but can't make electronics for some reason.
Saying that they aren't evolved enough or have no desire to develop technology is beyond the point. I also get a lot of comments on my creature design posts that say that humans are ultimately superior and that adaptations are unnecessary. So getting a good reason to why that can't happen would be perfect.
[Answer]
**There are places on earth where metals and even rocks are hard to reach**
The plot of *The Gods Must Be Crazy* (great flick, IMHO) was based on the claim that in the Kalahari desert, the soil is so soft and free of rocks that a glass Coke bottle was the hardest object that a certain bushman had ever seen. I don't know if that's really true of that particular desert, but there are certainly other places where people cannot access rocks. I live in a place where the last Ice Age deposited rocks of all sizes, everywhere, so it seems strange to me, but there are prairies in the USA where you can dig a hole or plow a field without hitting a rock. There are also tropical islands where ancient people made fish-hooks out of seashells because there was no other hard material, and there may be people who live on the tundra and never know what's beneath the ice.
Your world could just be a scaled-up version of one of those type of land forms on Earth: maybe it's a coral archipelago world, or a tundra world, or a vast, eroded prairie that doesn't have tectonic activity to create new mountains.
[Answer]
Basically, for devices identifiable as electronics to be possible in a similar manner as the technology's progression on Earth, you need the following to be common on the planet:
* A ferromagnetic metal (preferably iron, nickel or cobalt if you must)
* At least one Group 11 transition metal (copper, silver, gold)
* At least one post-transition metal (tin, zinc, indium, aluminum)
* At least one noble transition metal with a high melting temperature (tungsten, rhenium, osmium)
* At least one metalloid (silicon, germanium, boron)
* A gas that is chemically inert even at relatively high temperatures (noble gases mainly; neon, argon etc)
If you have all of these, you can at least get to the vacuum-tube era of electronics. Progressing beyond this level requires a wider variety of "rare-earth metals" and other substances, but you can get to a basic electronic computer if you have a relatively plentiful supply of at least one of all the above options. If you have a basic idea of why they're needed, skip the next section, otherwise keep reading.
---
Ferromagnetism is a requisite for the efficient generation of electricity. Moving a magnet within a coil of wire is how about 97% of the world's grid electricity is originated (photovoltaic solar power, the most common non-inductive generation method, produces only about 2.5% of infrastructural power, even taking replacement of actual grid power with roof-mounted systems into account). Iron is the ideal candidate for a ferromagnetic metal useful to humans, and is pretty easy to find on Earth. Nickel and cobalt metals and their alloys are magnetic too, but these happen to be ridiculously toxic to human biochemistry, so sleeper-ship colonists reduced to "off-the-grid" tech wouldn't want to be anywhere near an open-air smelter of any ore containing either metal. Neodymium is not itself magnetic, but in a crystalline alloy with iron it boosts iron's potential to be magnetized, thus allowing stronger magnets with less material. It would be nice to have but isn't critical.
With the basic material to induce electric current, a soft, ductile, highly-conductive but nonmagnetic metal is what we tend to induce that current in. Copper is one of the first metals to be harnessed by humanity, and fairly plentiful on Earth (though our demand for it in industrial and post-industrial economies is making it a more expensive commodity of late). Metals in the same elemental group are rarer on Earth, to the point of being stores of value, but on a planet where gold was very common, that would do many of copper's jobs better than copper itself (copper would be relatively lighter and a little more durable, offset by gold's natural corrosion resistance reducing required maintenance). Silver's closer to copper in most of its properties (including unfortunately that it oxidizes or tarnishes easily) and again if relatively common on some new planet it could do most of copper's jobs, but silver's commonly found alongside copper in a number of metallic ores.
Having generated and conducted electricity, you need to use it. Resistive emission ("intentionally wasting" electrical power to generate heat and light through electrical resistance) was one of the first discovered uses of the technology, closely followed by inductive motion (using current to generate a magnetic field that pushes or pulls another magnet); heating and lighting filaments and inductive coil transducers (motors, solenoids, speakers/microphones) remain the two largest classes of electrical "doers" on the planet (even as a much more efficient alternate form of light emission using semiconductors has become the most common form of light generation).
While Group 11 metals work well for induction as they conduct electricity very well, that same conductivity (and their low melting points) means that they're relatively poor at resistive applications. Iron, especially as a high-carbon steel alloy, is a passable resistor especially for heat generation, but it's relatively inefficient at generating light (the "color temperature scale" of room light is calibrated based on the spectral emissions of iron heated to the prescribed temperature, giving you some idea how hot iron has to be to glow white and how much power that takes), and the heat involved speeds corrosive oxidation. Various organic compounds like graphite make good low-power resistors, but turn up the voltage too much and they'll literally explode. The generation of electric light involves forcing electrical current through something that does not conduct well, but is also not physically or chemically altered by the electricity flowing through it or the heat it's producing. The best such element we have in what we'd call a plentiful supply is tungsten, a member of the "refractory group" that also includes metals commonly alloyed with iron to produce stainless steel, including vanadium, chromium and molybdenum. The platinum group is another good area of the Periodic Table to have available, with rhenium having the second-highest melting temperature after tungsten, and being very corrosion-resistant. Platinum itself is used in PCBs, though it's not a critical requirement.
A low-melting-point post-transition metal has a number of uses in electronics, for instance as a solder material to form high-continuity wire junctions. These post-transition metals are also valuable as fuses, as resistive heat eventually exceeds the melting point and breaks the connection. Tin's a very common choice nowadays, replacing lead especially in plumbing for what should be obvious reasons. Aluminum has a number of uses for conductivity of heat and electricity in electronic devices, however at its actual melting point it will also burn readily, and its dissociation temperature (where it will separate from the oxygen and become a useful metal) is ridiculously high, making aluminum a precious metal until the Bayer and Hall-Heroult processes made aluminum refinement commercially viable by WWII. More exotic ones include indium, which you can melt in a glass beaker over a Bunsen burner (or even a good hotplate) and is very rare on Earth.
The metalloids have several uses. Primary among them is that most are dielectrics; they do not conduct electricity (at least not below an arbitrarily high voltage not typically relevant to benchtop electronics), but they can become polarized by electric charge, and by so doing allow electrical interaction to occur through them. This property, especially of silicon (one of the most plentiful elements on Earth) has led to a wealth of uses in semiconductors, from capacitors to transistors. The development of germanium- and then silicon-based solid-state transistors is what enabled the proliferation of modern electronic devices. However, and earlier and more primitive, but no less critical, use for metalloids is as glass. Glass containers are airtight, nonconducting and non-magnetic materials with relatively high melting temperatures, making them very useful for containing high-temperature air-sensitive components like charged plates and filaments. Modern electronics would not have been enabled by the MOSFET solid-state transistor if it had not been preceded a generation earlier by the vacuum-tube triode transistor, and that in turn required the relatively simple but deceptively difficult artisan skill of glass forming to have been developed and refined beginning before the Renaissance and proceeding into the 20th Century.
I've hinted at uses for inert gases, but to be clear, if you don't have an inert gas, a lot of things become a lot harder to do, because your "vacuum tubes" have to have a true vacuum, and this shortens the life of the electronic elements as the metal literally evaporates into the vacuum under heat and electrical excitement, and deposits onto the inner walls of the glass (a process called sublimation, which we have since harnessed to produce electronic components by etching circuits into layers of sublimated "thin film"). Argon is the main such gas we use, krypton would work just as well but is relatively rarer on Earth and is prized for use in light-generating equipment for its multi-spectral pattern under electrical excitement. Nitrogen, the most abundant gas in Earth's atmosphere, works well enough at "normal" temperatures to exclude oxygen from a volume of space as a blanket, but when you get into the high hundreds of degrees it starts becoming reactive (the Haber process for synthesis of ammonia starts becoming favorable around 400\*C, though high pressures and a metal catalyst are also required).
---
So, if you have a sufficient selection of all of these materials, you can fashion rudimentary electronic components up to and including early 50s-era computers. To progress further, you need the MOSFET, which requires gallium or boron for P-doped transistors and phosphorous or arsenic for N-doped transistors, in addition to either silicon or germanium as the body material. That gets you to printed circuits, allowing progressively smaller amounts of miniaturization. Other elements, reasonably common on earth but not often in the combinations we use them, are used in modern electronic processes, including chlorine trifluoride which is used as a cleaning reagent for thin film equipment (at which it undoubtedly excels; it's the most vigorous oxidizer known to modern chemistry, so nasty to handle even the Nazis had second thoughts about weaponizing the stuff).
A planetary environment lacking significantly in either iron or copper would dramatically inhibit the natural development of electricity-based technologies similar to our own. Of the two, iron deficiency would also inhibit multi-systematic life forms as we know them; a dearth of iron would preclude the popular development of iron complexes like hemoglobin for oxygen capture and transport, which on Earth would have stunted eukaryotic life at the plant level. Sentient plants have been sci-fi fodder for a while, but at least on Earth the energy reserves and transportation mechanisms of even the very largest or most energy-dense plants are far too low and too slow to fuel the more complex neural networks found in animal life.
**So, making copper an impractically rare trace element would be the most likely way that life forms we'd recognize as such could develop to sentience, but which would limit the development of modern technology as we know it.** In fact, without an easy-to-smelt and economically-useful metal, such a civilization would likely be trapped in the Neolithic era of human development.
Which, as we know from our own history, is a totally valid steady-state; the Mayans, Incans, Aztecs, Pacific Islanders and other New World cultures managed to develop quite advanced civilizations and technology based around stone and organic materials, with little if any knowledge of metallurgy. However, again evidenced by the fate of New World native civilizations, carving stone only gets you so far, and New World knowledge of forming and using metal was relatively limited.
The most common metal known to be commonly worked by New World civilizations, rather ironically, was gold, whose ore is basically the raw metal with impurities that are fairly trivial to separate, and is relatively easy to melt and to work. These same properties, however, make it less useful as an infrastructure metal even if plentiful; it's not a very strong or stiff metal, and it's dense (#8 on the periodic table overall, out of all elements we've been able to accumulate a cubic centimeter of at one time and place for an empiric test). Copper would have been known, but its relatively higher rate of corrosion (not to mention the higher difficulty and inherent hazards of smelting copper out of the higher sulfur- and arsenic-containing ores) would have made it less economically viable than in Europe. The relative dearth of zinc (most plentiful source in the Americas was thousands of miles northeast of the Aztecs' widest range, in the Mississippi and Tennessee River valleys) and of tin (currently mined in Peru, but with modern methods of extraction and refinement not developed until the Industrial Age) would have limited the New World's knowledge of alloying, giving Europeans about 4,000 years' head start including about 2500 years' experience with iron and eventually with steel as of when the conquistadors first set foot on continental South America.
This lack of knowledge and of available materials also meant that New World civs, much like any hypothetical extraterrestrial race developing on a similarly-deprived planet, would have less opportunity to discover electrochemistry and start connecting the dots. The generation of static charges is the most commonly-identified early source of harnessed electricity, however it was Alessandro Volta's invention of the "voltaic pile", a copper-zinc metal-acid cell, that produced enough sustained electric current to enable focused scientific study. This would lead to Oersted's accidental but repeatable discovery of electromagnetic fields, in turn leading to Farraday's laws of electromagnetic induction which fully link electricity and magnetism as a unified theory of a fundamental physical force, not to mention powering the world as we know it.
[Answer]
Electromagnetic pulses would be the first to come to mind, those can be caused by heavy lightning, objects passing through the plants atmosphere or solar flares.
If they are powerful/frequent enough they could disrupt the development process so much that the alternatives become more attractive with this becoming an obsolete industry.
Those would not be the healthiest circumstances but seeing your "humans" developed on the planet their biology should have adapted to it.
[Answer]
No metal ores, neither common metals nor rare metals. Without metals whole civilization progress would be much slower, and some technologies would almost certainly didn't exist, electronics would be main candidate to this.
[Answer]
You might consider not only changing the planet they develop on, but the actual universe. If you don't want your humans to be able to develop electronics, consider removing the electromagnetic force. It will definitely affect a lot more than just whether or not your people can use electronics, although I'm not sure what the side effects would be. The other advantage of this is that they would still be able to use metal, which is an important part of civilization and the absence of which would affect a lot more than just the developement of electronics.
[Answer]
Get rid of the rubber trees. Unless they are ludicrously simple, electrical components need insulating materials.
Historically, this was rubber, as other materials available (e.g. glass) would be rigid, rather than flexible. I'm struggling to think of a natural material that could replace it.
] |
[Question]
[
How long will a 400 km wide 30 km deep pit (trench or crater) with a relatively shallow (for stability) gradient of slope of 20 degrees from the edge to the surface of the planets crust be expected to last on [Mars](https://en.wikipedia.org/wiki/Mars) before geological & climate processes close it.
*Rock plasticity under the [weight & pressure](https://courses.lumenlearning.com/wmopen-geology/chapter/outcome-stress-and-strain/) of the rocks above is one potential concern that's been identified for me, I think only 30 km depth may avoid that but I'd like to be sure.*
*I'd prefer 41 km deep (as that should give us an atmospheric pressure roughly equivalent to a height of 6 km on Earth [where our highest plants grow](https://www.newscientist.com/article/2114856-worlds-highest-plants-discovered-growing-6km-above-sea-level/)) & with an average crust thickness of 50 km thought that should be OK .. until it was suggested to me anything lower than 30 km would slowly fill back up from the bottom to a depth of 30 km, but at least 30 km should still put us below the [Armstrong limit](https://en.wikipedia.org/wiki/Armstrong_limit).*
How long could we expect the structure to remain viable & retain a depth of at least 29 km?
[Answer]
Since nothing exactly like this exists on Mars, let's look at the best real-life example of what you're describing: A crater.
## On Mars
[Hellas Planitia](https://en.wikipedia.org/wiki/Hellas_Planitia) is one of the oldest and largest craters on Mars. It was formed during the Late Heavy Bombardment, which started around 4.1 BYA. At more than 7 km deep, it's one of the deepest craters in the solar system.
This crater has survived nearly all of Mars' volcanic history, atmospheric conditions, erosion from wind and water, has even been dumped into by a few volcanoes, and is still this large after billions of years. Assuming you maintain a similar grade (maybe even steeper depending on your timeframe), your pit could theoretically last as long as the history of the planet.
Since you also mentioned atmospheric pressure, it's worth noting that at the bottom of the crater the atmosphere is already 103% more dense than at the surface of the surrounding topology.
**Edit** based on comments: Since nothing of the dimensions described exists in the solar system, let's check out some examples of rock slopes here on earth.
## Above Ground
[Trango Towers](https://en.wikipedia.org/wiki/Trango_Towers) in Pakistan is home to some of the steepest rock faces in the world. They range up to more then 7 km tall, and have nearly-vertical drops, so the downward pressure of gravity is much more significant than the outward pressure of the rock. That being said, you're talking about something below the surface, so let's look at perhaps a closer example.
## Below Ground
The [Mariana Trench](https://en.wikipedia.org/wiki/Mariana_Trench) dips down to 11 km below sea level, over a third of the value we're targeting, so it should be a decent model for how these things work on a large scale. [According to studies](https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2003TC001581) of the trench, the deepest parts still maintain an incline of up to 34 degrees in places. Consider that the trench is entirely submerged, is subjected to massive erosive currents, and violent earthquakes, and it has survived for [180 million years](https://www.nationalgeographic.com/news/2012/4/120405-james-cameron-mariana-trench-deepsea-challenger-oceans-science/) and counting.
# In Summary
As long as you stick to a gradient of ~30 degrees (to be *very very* safe), I think any depth that does not break the crust would be fine. Just be careful to also [consider temperature](https://what-if.xkcd.com/135/) at that depth, as you'll be getting close to the mantle.
[Answer]
[Valles Marineris](https://en.wikipedia.org/wiki/Valles_Marineris) reaches a depth of 11 km, while [Olympus mons](https://en.wikipedia.org/wiki/Olympus_Mons) reaches 25 km of height, together they make the gap you envision.
Olympus mons is thought to be 200 million years old, while Valles Marineris should count 3 billion years. Therefore the lower limit for existence of such a height difference seems to be at least 200 million years.
[Answer]
What I should have been looking at is the [Geoid](https://en.wikipedia.org/wiki/Geoid) of [Mars](https://en.wikipedia.org/wiki/Mars) & the depth from it to the [mantle](https://en.wikipedia.org/wiki/Mantle_(geology))
The thickness of the [crust](https://en.wikipedia.org/wiki/Crust_(geology)) varies between 50 km & 22 km due to the Geography & features (rock layers) above the Geoid while the distance from it to the mantle should be reasonably uniform.
I presume the putative Geoid of Mars is the altitude used for measuring atmospheric density.
According to some sources the crust of Mars is [10 km thick at its thinnest](https://solarsystem.nasa.gov/planets/mars/in-depth/) points which is presumably to be found in those places furthest below the Geoid like the [Hellas Planitia](https://en.wikipedia.org/wiki/Hellas_Planitia) .. which means the mantle is around 17 km below the Geoid & may mean we can't go much deeper than 7 km without lava flows.
So the crust beneath the Hellas Planitia is probably only 10 km thick.
I found this [KSP compatible Mars Heightmap](https://forum.kerbalspaceprogram.com/index.php?/topic/136993-ksp-compatible-mars-heightmap/)
[](https://i.stack.imgur.com/tDKKv.png)
& this map of the [topography of Mars](https://upload.wikimedia.org/wikipedia/commons/2/2c/Mars_topography_%28MOLA_dataset%29_with_poles_HiRes.jpg) (useful as you can zoom in & out on features)
The [Interactive Mars map](https://en.wikipedia.org/wiki/Atmosphere_of_Mars) at the bottom of WikipediA's 'Atmosphere of Mars' page is also useful as it names features you hover the cursor on & links you directly to their page if you click on them.
***What I think this means is a 30 km deep hole either pops straight through the crust into the mantle or will be just fine almost indefinitely, depending on where you dig it.***
*It also means we probably can't achieve a depth below the standard atmospheric pressure of Mars of much more than a few kilometers beyond 7 km without being in danger of getting magma .. the 0.168 PSI of Hellas Planitia ([air pressure at the summit of Mount Everest](https://www.google.com/search?rlz=1C1NHXL_enGB711GB711&sxsrf=ACYBGNQkFfUoXg_5CybqMa7DRUXGqsvCgA%3A1574977824572&ei=IEHgXcDHIoSs1fAPz-qE2AU&q=Hellas%20Planitia%20everest%20atmospheric%20pressure%20&oq=Hellas%20Planitia%20everest%20atmospheric%20pressure%20&gs_l=psy-ab.12...601466.607285..608548...0.3..0.90.254.3......0....1j2..gws-wiz.......0i71j35i39j0i22i30j33i10.-Sgk_9Hu5Wc&ved=0ahUKEwjA14zO8Y3mAhUEVhUIHU81AVsQ4dUDCAs) (the highest point on Earth) is 4.89 PSI) is probably not that far from as good as we can get on Mars by digging holes .. not what I hoped.*
[Answer]
A possible side effect: displacing such huge amount of material could perceptibly shift the planet's rotation axis. It is believed to have actually happened on our Moon due to volcanism moving the material.
So it should not be done haphazardly. If this causes the artificial crater to end up closer to pole after the excavation, it will have colder climate than planned. Even worse, if the rotation axis is destabilized and starts to precess, large temperature variations. I'm not sure if planetary precession with short period of ~few years is mathematically feasible but in a story, why not.
] |
[Question]
[
In a [previous question](https://worldbuilding.stackexchange.com/questions/156617/can-a-scaled-up-whipple-shield-protect-from-hypervelocity-rounds/156722#156722), I asked about using a scaled-up whipple shield to protect against a 250kg tungsten round traveling at about 60 km/s. The round in question is 'about' 10 cm in diameter and 'about' 1 meter long. The conclusion was that, no, the whipple shield would be ineffective because it would only shave off a small part of the tungsten round, which would continue on mostly unscathed to the main hull, fair enough. But what happens if you hit the incoming round with another fairly sizable shot going the other direction?
Say you fire a 10kg steel round at the incoming tungsten round at a comparatively paltry 3 km/s. The combined velocity is about 63 km/s, and by my back-of-the-envelope calculations the impact should release more than ten times the energy needed to vaporize the tungsten round (if the numbers I gave aren't actually quite enough, assume that the mass and velocity of the interceptor round are sufficient to get about this value for kinetic energy). The steel round is gone completely... but is the tungsten round? Will this impact just shave off about 10kg from the tungsten round and leave the rest to continue on to target? Will the tungsten round be vaporized? Will it be blown to fist-sized chunks?
What exactly is left of the incoming round makes a big difference to the target being shot at. A cloud of plasma can be dealt with by a magnetic shield; a cloud of dust can be dealt with by a whipple shield. Fist-sized chunks? You need some pretty hefty armor. Mostly-intact round? Good luck.
[Answer]
In space conditions, tungsten is very brittle. Even monocrystalline tungsten is likely to shatter completely upon impact. This is not so bad for an impactor, unless you're shooting a hardened target (actually it might be *desirable*, also because tungsten is pyrophoric and a cloud of tungsten shrapnel in a pressurized starship's oxygen atmosphere will supply a decent imitation of a thermobaric bomb).
So if you can hit it, I don't expect pure tungsten impactors to be a problem at all. They will disgregate into dust, *and* that dust will probably miss the ship by a wide margin.
The impactor might then be made of *impactor alloys* (tungsten-nickel-iron with 90% of tungsten, or tungsten carbide-doped porous matrix of tungsten - nickel - iron - cobalt with 90% tungsten). The latter [has shown](https://aip.scitation.org/doi/pdf/10.1063/1.5065263) a much improved penetrating power against hardened targets, which translates into good resistance to impacts from iron counterimpactors.
The likely outcome is that the front part of the impactor explodes, while the rear section remains mostly unscathed. Even so, in almost all circumstances the projectile will be subject to a significant lateral thrust, which at any realistic distance should ensure it will miss the target.
Much depends about the distance the impactor gets intercepted at.
The impact would surely alter the impactor's trajectory even if it does nothing else; even a small deflection might spell the difference between an impact and the round flying harmlessly by, missing the target. And at a sufficient distance (say, 600 kilometers), a second counterimpactor could maybe still hit the projectile while still .3 seconds from impact.
(I don't know whether a "layered" impactor - an impactor that has been thinned in two points along its length, to divide it into three sections - could be expected to fare better; whether the collision thrust would shatter the link between the sections, leaving the back section almost unchanged in its trajectory while the foremost disintegrated. Better a third of the projectile to make it to the target, than nothing. Probably any attacking ship would have several kinds of impactors to choose from).
[Answer]
>
> Say you fire a 10kg steel round at the incoming tungsten round at a comparatively paltry 3 km/s
>
>
>
This is no different to having a static steel Whipple shield, and an incoming projectile travelling at 63km/s. The problem is still that hypervelocity impacts do not behave like low velocity ones, and as a result the effects of collisions are counterintuitive. This is why more sedate collisions (say, 15km/s) are modelled as jets of fluid splashing off each other, for example... intermolecular bonds don't mean anything given the impact forces involved.
This means that all the blurb below is just as applicable to whipple shields as it is to interceptor projectiles.
>
> Will the tungsten round be vaporized? Will it be blown to fist-sized chunks?
>
>
>
It isn't entirely clear what will happen to it. Worst case scenario is that a short length of the impactor is ablated off, and the rest just carried on coming. Using the same hydrodynamic penetration approximation [as I did last time](https://worldbuilding.stackexchange.com/a/156623/62341)... if your steel projectile has the same diameter as the incoming projectile it'll be 4cm thick, and ablated about 2.5cm off the front of the impact. That's not so good, from the target's point of view.
I've recently been reading up on "crater strength", a notion that handles the expansion of a crater in a solid object. I'm not entirely certain how this applies to hypervelocity impactors... it doesn't gel nicely with the idea of hydrodynamic jets, that's for sure, but does handle the notion of something exploding, as you might expect releasing an awful lot of energy in a short period of time. It was also suggested by Luke Campbell, who knows a fair bit more about this sort of thing than I do, and has put more thought into it. So with all that said, **take this with a small pinch of salt**.
The cratering approximation define crater volume $V\_c = E\_p/S\_c$ where $E\_p$ is the kinetic energy of the projectile and $S\_c$ is the cratering strength of the material involved, handwaved to be three times its yield strength. The yield strength of tungsten is 750MPa, so its cratering strength is defined as 2.25GJ/m3. If we imaging the tungsten impactor as stationary, and the steel interceptor is coming in at 63km/s, it'll have a kinetic energy of nearly 20GJ. That gives a cratering volume of 8.82m3, and hence a cratering depth (as defined as the radius of a sphere with that crater volume) of about 2.1m.
With *that* approximation, the impactor is indeed blown to pieces. Hooray! (it also suggests your whipple shielding in the previous question is better than originally anticipated, so I'll revisit that at some point).
*However*.
Given the hydrodynamic penetration depth assumption, the steel interceptor will be more or less "used up" in the front couple of centimetres of the impactor. The energy of the collision must, therefore, be transmitted along the impactor by plain old atoms bumping together. If that happens at the speed of sound in tungsten, 5.2km/s, it'll take 1/5200th of a second for the impactor to fully disintegrate, during which time it will have travelled 11m. If the interceptor hits the impactor any closer to the ship than that, you're still in big trouble (this also suggests your 50m whipple shielding gap in your previous answer is probably a sensible spacing). I'm not sure what speed the debris will expand at, as that requires working out energy budgets and things and I'm feeling too lazy for that. The speed at which the projectile expands should inform you as to how far away you must intercept the projectile, and how much armour you'll need to mop up the bits.
Next, there's a *lot* of momentum in a quarter-tonne slug travelling at 60km/s. Your little steel projectile may deliver enough energy to break it up, but those bits are going to be quite big and will maintain most of their original speed and direction. This isn't so much "spalling" as a terrifying shotgun blast of doom. Not as much doom as a metre long rod of tungsten, but you might still need to deal with a cloud of fist-sized 60km/s projectiles (it won't matter if they're solid or melted, incidentally).
>
> A cloud of plasma can be dealt with by a magnetic shield; a cloud of dust can be dealt with by a whipple shield. Fist-sized chunks? You need some pretty hefty armor. Mostly-intact round? Good luck.
>
>
>
I don't *think* it will be dust. And remember, even if it *was* dust, a quarter tonne of dust travelling at 60km/s requires a pretty substantial whipple shield, and that whipple shield will have a pretty substantial hole in it afterwards.
As for dealing with plasma via a magnetic shield... again, the remnants of the impactor will have considerable momentum, and you have a short period of time in which to exert a considerable force on it in order to deflect it. I'm not going to try and work this out here (magnet maths is *hard* :-() but it sounds a little dubious.
Finally though, let's revisit those fist sized chunks. At the end of my last answer, I said this:
>
> the simplest countermeasure from the attacker's point of view is to fire multiple smaller projectiles, slightly separated along their trajectory.
>
>
>
This still holds true. Colinear kinetic penetrators will be excellent at defeating defense in depth, though sufficient interceptor railgun fire might be able to swat all the projectiles before they reach the target. The other alternative, many long, slender projectiles (a sort of parallel impactor instead of serial) would require one railgun round *each*, which may very very quickly overwhelm any plausible defense. A combination of the two approaches sacrifices the sheer one-hit-kill ability of the monolithic tungsten slug for a huge cloud of kinetic death which will be impractical to defend against.
[Answer]
Try **not** to hit the incoming projectile dead-on. If you hit it slightly off-axis, you will nudge the trajectory slightly. And then the incoming round will miss.
This is similar to some [asteroid defense proposals](https://en.wikipedia.org/wiki/Asteroid_impact_avoidance#Kinetic_impact).
] |
[Question]
[
Some follow-up thoughts on [this question](https://worldbuilding.stackexchange.com/q/151405/2800)...
Hydrogen isn't very soluble in water. Oxygen is more so, but still sufficiently insoluble that most oxygen-breathing Earth creatures use special oxygen carrying proteins (most famously, haemoglobin) to move oxygen through their blood rather than just relying on its solubility in said blood. Ergo, it would seem that hydrogen-breathing animals would also be in great need of some gas-transport assistance.
As explored in that other question, ammonia is likely to also be quite common in a hydrogen-breather's environment, and can also be used as an electron donor for respiration, and doing so seems like a good strategy for aquatic organisms, which would therefore not need to care about efficient hydrogen transport; however, a land creature would be well advised to minimize its metabolic destruction of ammonia so as not to upset the pH and osmotic balance of its own bodily fluids.
So, what would make a good equivalent for the red-blood-cell mechanism that we use to transport oxygen for a hydrogen-breathing creature? Do they use a reversibly-binding metal-protein complex like us? Do they rely on dissolving hydrogen in non-polar vesicles? Or something else entirely?
[Answer]
Another thread ([Other blood colors](https://worldbuilding.stackexchange.com/questions/28276/other-blood-colors)) had a user Jim2B post a very in depth post on possible blood colours for binding oxygen, but also referenced this gem:
Chloro-carbonyl-bis(tri phenylphosphine)-iridium
An excerpt from the book Xenology (An Introduction to the Scientific Study of Extraterrestrial Life, Intelligence, and Civilization, by Robert A. Freitas Jr. <http://www.xenology.info/Xeno/10.4.htm>) had this to say:
>
> Another interesting though less likely possibility is iridium-based blood. One simple compound with an absolutely horrible name (chloro-carbonyl-bis(tri phenylphosphine)-iridium) has recently been shown to undergo reversible oxygenation. This substance is insoluble in water and other polar media such as liquid ammonia and alcohols, but this presents no barrier to its use in blood. The vanadium chromagen found in ascidians is also insoluble in water.
>
>
> In solution, the compound takes up one atom of oxygen per molecule to change from brilliant yellow to sullen orange. The reaction is not quite as fast as with the cobalt complexes, so a more convoluted lung would be necessary.
>
>
> In the oxygenated condition, the iridium-based blood of extraterrestrials would have to be protected from light because it is very photosensitive. The pigment slowly decomposes over a period of days or weeks when exposed to strong light, gradually changing color from orange to green and finally to a deep bluish-black. Such aliens would therefore either have very dark skin, or would inhabit a dimly lit world. (In the absence of light, the molecule is stable for years.)
>
>
> The iridium complex has one additional property which is extremely fascinating to xenobiologists. In addition to oxygen, the molecule is also capable of reversibly binding hydrogen as well!
>
>
>
So, if you were looking for a a transport protein that could potentially work for your species that breathes hydrogen, and wanted a metal-protein complex like we have, this could do the job. You'd have the restrictions of the photosensitivity I'm afraid, but you wouldn't need to change much from protein blood carriers beyond having organisms living in the dark or protecting their skin from light. Plus you get the cool effect of the blood being coloured something more exotic than red - yellow when oxygenated and dull orange when not.
Hope this tiny bit of into might be able to play a part in figuring out your problem!
[Answer]
Carrying hydrogen gas directly would be difficult, and perhaps not useful. In real biology, the oxygen isn't carried as a gas, but as oxygen radicals attached to the iron atoms in the heme molecule.
However, it *is* possible. Your best approach would be to use a chelated compound with palladium at its core.
You can think of a chelated compound as a sort of organic "claw" molecule that "grabs" and holds a metal ion. The claw part is called a ligand.
These kinds of compounds are very common in biology, actually. The aforementioned heme (part of hemoglobin) uses iron as its metal, which of course is why blood is red (it is literally rust).
Similar compounds include hemocyanin, which uses copper as its metal instead of iron. This gives blood made of hemocyanin a blue color, as opposed to red (hence the name).
Another example is vitamin B-12, which uses cobalt as the chelated metal.
In chelated compounds, the metal is generally the active site for the molecule as a whole, and the ligands are used to control the reactions associated with it. You can think of the metal as a kind of "power core" in this case.
So we've established, based on real biology, that you most likely want some sort of chelated compound. So why palladium? Palladium is a precious metal of the noble metals group. It has the interesting property of acting like a "sponge" for hydrogen atoms, being able to pack them much closer together than in their gaseous form.
However, the use of palladium and hydrogen here over iron and oxygen introduces its own problems:
In the two heme examples, the molecule is designed to carry highly reactive oxygen radicals that can be passed on to other proteins for chemical reactions. They aren't carrying oxygen gas directly.
Secondly, palladium's "sponge effect" comes from the lattice structure of its metallic crystals. This means you need not just a single metal atom or ion, as in the previously mentioned cases, but hundreds, probably thousands, of palladium atoms in crystalline form. This won't fit into a simple ligated molecule.
Another problem with palladium is that it requires heating to release the hydrogen it's captured. Your creature will have to have differing temperatures across its body; essentially a "cold section" where it breathes in the hydrogen, and a "hot section" where it releases it.
The last problem is palladium's rarity. As a dense and heavy metal, it would sink to the core of any planet its on, and not easily be available to life to use. On Earth, it's about 3 times as common as gold, but iron is literally millions of times more prevalent. Palladium is present in Earth's crust at 15 parts per billion, but iron is present at 63 parts per THOUSAND. There is on average literally more iron in the crust of the Earth than there is salt in the ocean (about twice as much). This will make it difficult for your creatures to find and consume in any kind of meaningful biocycle.
But your question is "how would it work," not "would it work," so let's try and create a scenario where we can use it:
Your creature's blood would need specialized cells, these cells contain small granules of palladium, let's call them "pallophores." Rather than lungs, your creature could breathe through its skin, which is covered thousands of tiny ruffles packed with pallophores in order to maximize surface area. This effectively increases the surface area for respiration, allowing your creature to pump its blood slower. The fact that the pallophores are pumped close to the skin surface allows them to be better cooled for hydrogen uptake.
Because your creature's pallophores are quite literally like little grains of sand in its blood cells, they couldn't be very flexible, and so your creature would need to have relatively large blood vessels, especially capillaries. The tradeoff is that you could get more density of hydrogen atoms packed into the pallophores than you would be able to for oxygen packed into heme.
Now, we need a way to get the hydrogen back out of the pallophores. Probably the easiest option here is for the creature to have "nodes" in its blood stream where pallophore rich blood cells gather, perhaps little sacs of some sort. These sacs are heated, allowing the hydrogen gas in the pallophores to diffuse out into the surrounding tissue. Your creature will need a lot of these pallosacs in order to provide for its hydrogen needs.
The hydrogen gas is reduced with some other chemical, presumably *NOT* oxygen, into an easily removed (preferably liquid or ionic) waste product. This waste is carried through a second blood loop where it's excreted by a kidney-like organ.
Because of all the biological limitations we've had to place on the creature, its metabolism will necessarily be slow, so in order to survive, the creature must be large and slow. We can use this ecological niche to solve our rarity problem: Let's assume that there are some kind of plant-like organisms that pull palladium out of the soil and concentrate it in their bodies, and your creature eats the plants in order to get the palladium.
[Answer]
Alright, I'm gonna **frame challenge *myself***.
In three different ways, in fact.
First: hydrogen may have low solubility in water, but it also diffuses much faster than oxygen, due to both its lower mass and physically smaller size. That means tracheal tubes delivering air directly to internal tissues, without the need for blood transport, will be more efficient for hydrogen breathers, and support creatures of larger size than that system can on Earth. But, it gets even better: if we assume that glucose is the primary food molecule used for energy, only one gaseous waste molecule (methane) is produced for every *two* dihydrogen molecules consumed (cf. aerobic respiration of glucose, which produces CO2 waste in one-to-one ratio with O2 consumed). That means there is half as much volume of waste gas being expelled into the trachea as there is hydrogen being taken up, which in turn means that, even without active pumping, the trachea will be operating at constant negative pressure just due to regular metabolic processes, thus further improving the efficiency of hydrogen transport from the environment! So, we may not need blood to transport hydrogen at all.
Second: There are ways for land creatures to make use of ammonia after all: rather than primarily *breathing* their metabolic reducer, they can *drink* it. Using up ammonia internally will screw with the chemical balance in their cells, but metabolizing proteins does that for us as well, and we have a perfectly good means of dealing with it: urine. So, "hydrogen"-breathing land creatures could in fact avoid having to breathe hydrogen after all, as long as they always have ready access to a supply of drinking "water" (water/ammonia solution) to replenish their ammonia stores. They would then concentrate and expel hydroxic acid (i.e., pure water) in the equivalent of a kidney to maintain a consistent water/ammonia ratio in their bodies.
Third: Even if they do breathe hydrogen, and they do need to transport chemical reducing potential in their blood, their blood doesn't necessarily need to transport the same complete dihydrogen molecules that they breathe in. As L.Dutch pointed out in the comments, any acid will do as a proton carrier; I initially dismissed this idea, as it's not really the protons that we care about carrying, it is the chemical reducing potential--i.e., the *electrons*. But there is the seed of a workable idea there! Because, you see, as long as suitable electrons can be delivered to metabolic reaction sites, there will be plenty of free protons (or at least hydronium and ammonium ions) floating around to recombine with them, and we need not bother with guaranteeing that any particular electron stays with the same proton that it was inhaled with. Thus, the lung and/or blood tissue of a hydrogen breather can take in atmospheric hydrogen and use it to reduce an intermediate molecule like NAD+ or NADP+ into NADH/NADPH, and then transport those molecules throughout the body, with hydrogen being reconstituted "on the spot" when the intermediate molecule is used in reduction metabolism.
] |
[Question]
[
Assume that an alien starship pops into existence at the [L2 Lagrange point](https://en.wikipedia.org/wiki/Lagrangian_point) of the Earth-Moon system, behind the Moon as seen from Earth.
**When and how is the starship detected and recognized as extraterrestrial?**
* For purposes of the story, Earth has real-world, present-day science and technology.
* The starship has a cross-section of 1,000 to 10,000 square metres, depending on the aspect. It consists of steel and composites with a matte-black paint job and no lights or radio beacons, but no deliberate stealth technology.
* How the starship arrives behind the Moon is space opera technobabble, the means are not detectable by real-world science. It cannot be seen on arrival.
* I'm aware that [space debris is tracked](https://en.wikipedia.org/wiki/Space_debris#Tracking_from_the_ground) by various agencies, but I don't know if they have means to look at L2.
* I'm aware that there is a [satellite at L2](https://en.wikipedia.org/wiki/Lagrangian_point#Spacecraft_at_Earth%E2%80%93Moon_L2). No idea if it has navigation sensors or if it is watched by relays off the direct line.
* L2 is unstable. The starship can maneuver to stabilize a [halo orbit](https://en.wikipedia.org/wiki/Halo_orbit) or park on L2, again by means not detectable by Earth science. It has collision-avoidance systems to dodge satellites already there.
* Assuming that somehow the presence of an "anomaly" was detected, what assets could be used to take pictures of the object "behind" the Moon?
For narrative purposes, the best answer would be a civilian scientists detecting "weird" readings, followed by an attempt to get a peek with civilian instruments, followed by civilians telling one or more air forces about "something big-but-fuzzy at L2," followed by hectic activity in various capitals. What can be done to make this plausible, if it isn't?
[Answer]
There are space telescopes sensitive to various frequencies in various orbits. Even a telescope in low Earth orbit would be at a right angle to the direction between Earth and the Moon twice in each 90 minute orbit. And at that angle a low orbit telescope (and one on the ground below it) should almost be able to see the L2 position.
According to a rough scale diagram I drew a low orbit telescope might possibly be able to see the exact L2 point when the Moon is at perigee, it's closest distance. And an object, like your alien space ship, at the L2 point should have a halo orbit around the L2 point and sometimes be thousands of miles from the L2 point. If any of that movement is perpendicular to the line between the L2 point and the centers of the Earth and the Moon, the alien spaceship should sometimes be in line of sight as seen from low Earth orbit or even the surface of the Earth.
Any telescope able to view L2 with enough resolution at the right wavelength - like the infrared wavelengths of the heat emitted by the space ship - should detect the space ship.
This looks like a job for the James Webb Space Telescope!
It is scheduled to launch in March, 2021 into an orbit near the Sun-Earth L2 position. It will be near the L2 point 1,500,000 kilometers (930,000 mi) from Earth, directly opposite to the Sun. Actually it will be in a sort of halo orbit around the L2 point, an orbit with a radius of kilometers or 500,000 miles. So the Earth-Moon L2 point should almost always be visible from the James Webb Space Telescope.
And the James Webb Space Telescope is designed to detect infrared wavelengths, and all objects in outer space emit infrared radiation based on their temperatures.
<https://en.wikipedia.org/wiki/James_Webb_Space_Telescope>[1](https://en.wikipedia.org/wiki/James_Webb_Space_Telescope)
If there are aliens in that spaceship that come from an Earth-like environment the spaceship will have an earth-like temperature and emit Earth-like infrared radiation.
And even if the aliens come from a planet so cold their bio chemistry uses liquid ammonia or liquid methane instead of water, that planet - and thus their spaceship - will still have a temperature above absolute zero and will glow in some infrared wavelengths due to that temperature.
And if the alien spaceship is only occupied by machines, those machines will have an optimum working temperature, and the spaceship will need to be at that optimum working temperature, which will be above absolute zero, and so the spaceship will emit infrared radiation at that temperature.
At the present time the Spitzer Space Telescope, launched in 2009, is orbiting the Sun and some of its infrared instruments are still working. The Earth-Moon L2 point would only rarely be hidden behind the Earth or the Moon from the Spitzer Space Telescope, so if it has enough resolution at the right wavelengths it could detect the infrared light emitted by the alien spaceship.
<https://en.wikipedia.org/wiki/Spitzer_Space_Telescope>[2](https://en.wikipedia.org/wiki/Spitzer_Space_Telescope)
Someone more familiar with those infrared space telescopes might be able to calculate if they could accidentally detect the alien spaceship in the L2 position or confirm its existence if accidentally detected by other methods.
[Answer]
The Queqiao satellite parked at the Earth-Moon L2 point may detect the appearance of the object if there is an accompanying radiation spike in the 80 kilohertz to 80 megahertz range as the satellite hosts the Netherlands-China Low-Frequency Explorer which is running astrophysical studies focused on that frequency range. It's also possible that the ship may break said satellite on arrival.
Alternately there are several other satellites planned for that area one of which may observe or impact on the ship. In terms of visual observation from Earth, no that's not going to happen.
Also depending on the mass of the ship in question very finely calibrated satellite systems such as [GRACE](https://en.wikipedia.org/wiki/GRACE_and_GRACE-FO) may detect it purely due to gravitational anomaly.
I believe that in order to make a good visual observation we would need to launch a new asset.
[Answer]
Your preference is for initial observation by Mr. Average Joe. We can see how plausible this is by creating some categories of how likely Average Joe is to have access to certain vantage points.
From most plausible to least plausible (list is not exhaustive):
* **Surface of Earth** - *very easy, just walk outside*
* **Low Earth Orbit (hudreds of km up)** - *not as easy but still plausible; Average Joe can get viewing time on such telescopes*
* **Geosynchronous Orbit (10s of thousands of km up)** - *even less likely, possibly implausible; can Average Joe get viewing time on such satellites? Not that I know of, but I'm not an expert*
* **Lunar Orbit** - *Not unless Average Joe has some special job, connections, or story plot hook*
* **Something else farther away**, such as Earth-Sun L-points instead of Earth-Moon L-points, or other non-Earth/Moon-bound objects - *Not feasible for Average Joe*
Now let's do some simple, rough trig estimations to see how far from Earth you'd need to be to see around the moon to that point.
Distances in thousands of km:
```
+ < Moon edge
+
+ ~2
+ ~61
+++++++++++++++++++++++++++++
^Moon center ^L2
```
All we have to do is scale that triangle up by multiplying the sides. We know that the distance Earth-to-Moon is ~384000km, so the distance Earth-to-Lunar-L2 is ~(384000+61000)km = ~445000km. That is a factor of ~7.3 increase from 61000km, so...
(again distances in 1000s of km)
```
+ < X (which is where we want to be at or past to see Earth-Moon-L2)
+
+ + < Moon edge ~2
+ +
++++++++++++++++++++++++++++++++++++++++++
^ Earth center ~445 ^Moon center ~61 ^L2
```
This has now become a "Solve for X" math problem. `X / 2 = 445 / 61` After solving for X by shifting the "/2" over, we have `X = 14`
So that is 14000km from the center of the Earth, so for orbit distance about half that number of km from the surface of the Earth. A calculation that I did shortly before writing this answer put it at a 6000km orbit, and I think that quick calculation was slightly more accurate than this one.
Roughly, 6000km is about 10 times farther than low earth orbit, but is only about one-tenth as much as geosynchronous orbit. So Average Joe cannot view L2 from his backyard, nor from a low earth orbit telescope. Average Joe would need to beg, borrow, steal, or pay for time on something farther out. Possible, but not quite as feasible.
It might still work for your story if this is Academic Astronomer Joe or Wealthy Hobby Astronomer Joe rather than just Average Joe. Either that, or maybe a plot hook that gets Average Joe some experience and some time on the appropriate telescope. Plot hooks could include being a college astronomy major or having a friend or relative that can get Joe the telescope time.
>
> As Joe rode his bike past the observatory, he saw the last car leave
> their parking lot. Joe had wanted to get back into there ever since he
> got a tour of the place for a 9th grade STEM event. They even had a
> computer in there that has access to a telescope in geostationary
> orbit that they got to play with for a few minutes - it was as if they
> were sitting out in space and looking out at the cosmos!
>
>
> Joe couldn't shake the feeling. Despite being on detention *again*
> this week for breaking into the high school's science lab after hours,
> he just could not pass this opportunity up. With the holiday tomorrow,
> nobody would be back at the observatory for days. It's decided! The
> only question now is where to hide the bike from street view for the
> next hour.
>
>
> (break away to another set of characters, then next chapter come back
> to...)
>
>
> Joe could hardly believe it, the password was written down on a sticky
> note in a drawer nearby! Didn't these guys ever get a computer
> security lesson when they were in school? Oh that's right, that wasn't
> a thing when they were Joe's age.
>
>
> After punching in the password, Joe was in. Luckily, Joe was paying
> close attention on the tour when the astronomers were controlling the
> orbiting satellite. Hmm, it's trained on one of Saturn's moons - so
> far away, so tiny, so pixelated... so boring. Let's look at something
> closer. The moon should be easy to find. What is that tiny patch
> there? It's black, but it still stands out, just barely...
>
>
>
[Answer]
We do have a telescope observing the Earth from beyond the Moon, the [Deep Space Climate Observatory](https://en.wikipedia.org/wiki/Deep_Space_Climate_Observatory). It orbits itself at Earth-Sun L1 point. When moon aligned right it already [captured the moon's far side](https://www.nasa.gov/feature/goddard/from-a-million-miles-away-nasa-camera-shows-moon-crossing-face-of-earth), potentially revealing any objects above it or at Earth-Moon L2.
However, 10000 square metres means diameter of about 100 metres. This is roughly 0,00005 of moon's diameter, so should the alien object be visible as 1 pixel, the image of the moon must have at least 20k\*20k pixels.
Sadly DSCOVR with its 90's technology downlinks only 1024x1024 pixels. Launching another satellite with muchly improved resolution telescope is technically fully feasible.
[Answer]
I just got a crazy idea reading at people answers.
What if a meteorite or comet is about to pass really close to the Earth (and thus, the Moon), and, as so many people are looking at it, they detect the shadow of the alien starship when it goes between the Sun and the meteorite?
I know is pretty impossible that it just happen to align for the shadow to hit on the meteorite, but that way a lot of people with their telescopes would see it, and with the professional ones even calculate the size of the starship.
Maybe too crazy for your question, but I think is somewhat plausible.
Hope I inspired something!
[Answer]
I think the sudden gravitational influence of a very large ship would impact the stability of every geostationary satellite orbiting the Earth. Since these satellites have limited maneuvering fuel for correcting minor perturbations to their orbit, the corrections are applied very judiciously.
So, a sudden perturbation to every satellite would cause people to look for a reason. And they’d all point to something massive at L2. So, they’d go look using telescopes, spacecraft, or whatever was handy. It's reasonable to assume they’d ask NASA and other global space agencies for help figuring out what happened.
I think after that point, the discovery of the Thing at L2 would be inevitable.
Edit --------------------------------------------
Based on an estimate of 100E6 tons for the mass of the spaceship and a distance of 1E6 miles between L2 and Earth, the spaceship would exert 1E-14 Newtons on a satellite. In a week of the additional gravity field, the satellites could experience as much as a ~1E-3 m/s delta-V -- which is very small. But, after a month it would be significantly greater at just under 0.1 m/s and after a year > 1 m/sec to delta-V.
] |
[Question]
[
How large (in terms of height and radius) would an *outdoor* circular wall (like a city wall on a colossal scale) need to be before a casual observer would perceive the wall as "straight"? I found "[What is the minimum radius of a circular corridor for the walls to appear straight?](https://worldbuilding.stackexchange.com/questions/76346/what-is-the-minimum-radius-of-a-circular-corridor-for-the-walls-to-appear-straig)" and based on [this answer](https://worldbuilding.stackexchange.com/a/76356/3311):
>
> ...the tunnel must bend less than 0.01 degrees over the proposed 20 meters visual range. Therefore, the tunnel would need to be (360/0.01)\*20 meters in length, or 720 kilometers. This will put the inner radius at about 115 kilometers.
>
>
>
some [examples of distance to the horizon](https://en.wikipedia.org/wiki/Horizon#Examples) courtesy of Wikipedia, and some hasty back-of-the-envelope math I came up with a minimum diameter of ~53,000km which seems... high, given that the Earth itself only has a diameter of ~13,000km. Is my math just completely off, is this formula incorrect for this problem, or is a wall that big just not possible?
[Answer]
Relevant facts and formulas:
* [Horizon distance on Earth](https://en.wikipedia.org/wiki/Horizon#Distance_to_the_horizon): $d \approx 3.57\sqrt{h}$
* [Normal visual acuity](https://en.wikipedia.org/wiki/Visual_acuity#%22Normal%22_visual_acuity): 1 minute of arc
In order for a circular wall to appear straight, the wall needs to deviate from straight by no more than one minute of arc over the course of the visible section. Since we're dealing with small sections of absurdly huge structures, we can use the [small-angle approximation](https://en.wikipedia.org/wiki/Small-angle_approximation) and treat the arc of the circle as a straight line. This gives a formula for the radius of the circle as $r \approx 3400 d$
The absolute limiting factor on how far you can see is the atmospheric opacity, not the horizon distance. Under exceptional seeing conditions, you can see high-contrast objects about 300 km away. Plugging that into the formula gives a circular wall with a radius of around a million km. You're going to need a medium-large star to build that wall on (maybe build it at night?).
But let's say we don't care about a full circle, we just want an arc that disappears over the horizon without looking horizontally curved. Assume a two-meter-tall observer trying to spot the curvature of a two-meter-high wall: the top of the wall disappears below the horizon at a distance of 10 km (5 km observer-to-horizon + 5 km horizon-to-wall). You'll need a radius of curvature greater than 34000 km.
[Answer]
The simple answer is that your wall should curve *downwards* rather than *around*, and thereby form a Great Circle with the same diameter as the planet/moon it's built on but still appearing perfectly straight.
If you build it on the Moon, its diameter would be smaller than if you build it on Earth.
You can actually stretch this technique slightly to have your wall form a Small Circle, such as one of the lines of latitude. In this case the wall would technically curve slightly to one side as seen from the surface, but it might not be noticeable.
[Answer]
First suggestion:
My answer in this question [What is the minimum radius of a circular corridor for the walls to appear straight?](https://worldbuilding.stackexchange.com/questions/76346/what-is-the-minimum-radius-of-a-circular-corridor-for-the-walls-to-appear-straight)[1](https://worldbuilding.stackexchange.com/questions/76346/what-is-the-minimum-radius-of-a-circular-corridor-for-the-walls-to-appear-straig) discussed various architectural methods to trick someone into thinking that a circular corridor was actually straight. Most of those methods that might work indoors wouldn't work so well for an outdoor wall, but possibly something similar might work to some degree out side.
What if the wall is not perfectly circular?
Perhaps the wall has semicircular towers no higher than the wall itself attached to it at regular intervals. So when the viewer of the wall looks to right or left the sections of straight wall between towers will look shorter and shorter with increasing distance until the viewer will only see the front edges of the semicircular towers one behind the other in the distance. And the farther away each tower is from the one nearer to the viewer, the less the front of it will seem to project beyond the front of the tower near to the viewer. Finally the farthest off towers will be impossible to tell one from the other.
Or perhaps the wall will have independent bastions in front of it at regular intervals, connected to the main wall by bridges or walls. So as a traveler gets closer and closer to the wall and is closer to being able to sight along the length of the wall to see if it is straight or curved, the traveler will have to look through any openings that might be in the bridges or wall connecting the bastions to the main wall.
If there are no openings in walls connecting the bastions to the main wall, each space between two bastions will be a separate bay of the wall structure. Once a traveler is closer than the outer edge of the bastions he will be able to see only a short stretch of the main wall.
Possibly a traveler reaching the city or country enclosed by the wall will travel across a plain and the wall will slowly appear as a dark line on the horizon and appear taller and taller as the traveler approaches.
The wall might have a moat many miles wide in front so the traveler will have to approach along a causeway or bridge for miles, with the nearest other causeway or bridge miles away over the horizon to the right or the left. Thus the traveler will be unable to walk around the outside of the wall and notice from the sun in the day and the stars at night that the wall is curved.
Second suggestion:
If your story is a fantasy you can set it on a flat world that could be as large as needed and your wall can be as many thousands or millions of miles or kilometers in diameter as it needs to be to be circular and appear straight. And in a science fiction setting you might be able to create an analog of a flat Earth in some gigantic artificial construct in space built by a highly advanced society. Something like some of the constructions discussed in Larry Niven's "Bigger Than Worlds": <http://www.isfdb.org/cgi-bin/title.cgi?133302>
] |
[Question]
[
Since different planets have different gravity, atmospheric pressure, air density and composition, it's obvious that a definition of operational altitude based on earth sea level is inadequate for a hypothetical aircraft that can be deployed on different worlds.
Leaving aside the question of how such an aircraft could be designed, I'm interested to know if there might be some way to define an absolute operational altitude, perhaps by specifying at which atmospheric pressure the number holds true and allowing one to adjust the figure by doing some simple math depending on the condition of the planet in question.
[Answer]
(Do you need it to be strictly an *absolute* operational altitude?)
The easiest approach (no pun intended) might be to go with something similar to what airliners on Earth do. While for the passengers it will be translated to "we're cruising today at 36,000 feet", that's a simplification.
What airliners do is that they cruise *at a particular ambient (static) air pressure level*, or *maintain a static isobar*.
[Wikipedia offers](https://en.wikipedia.org/wiki/Altitude#In_aviation) a decent illustration:
[](https://en.wikipedia.org/wiki/File:Vertical_distances.svg)
When the pilots on a commercial flight tell the passengers "we're cruising at 36,000 feet", what they *really mean* is "we're cruising at Flight Level 360". When the altimeter is set to consider an air pressure of 1013.25 hPa as "0 ft", known as a standard setting (because 1013.25 hPa is the surface air pressure in the International Standard Atmosphere), this shows on their instruments as 36,000 feet.
An *isobar* is, basically, a line of identical (static) air pressure.
This is all useful because it means that pilots don't need to concern themselves with the ground below them, as long as they are well clear of it (for which they have charts and maps and ground proximity warning systems and all kinds of fancy gadgets; on some flights, it's even possible to use a pair of good old Mark I eyeballs), and Air Traffic Control can simply instruct the pilots to maintain a particular flight level. As long as everyone has their altimeters set correctly, everyone on "flight level 360" will be flying on the same isobar, regardless of how that isobar relates to the ground below them. Only near the ground (below the transition level) do pilots switch their altimeters to the current local air pressure setting, at which point they are flying at a particular altitude measured not as static air pressure, but one measured *by way of static air pressure* in feet or, rarely in the case of aviation, meters.
Aircraft and low-orbiting spacecraft both need to concern themselves with ambient air pressure; aircraft primarily for lift, spacecraft primarily for drag. Since the flight level is essentially a way of specifying an ambient air pressure, this provides pilots of both with a crucial piece of information packed into a convenient, bite-sized chunk.
Now, you can define things like operational envelopes in terms of what static (or dynamic, which is static plus e.g. accounting for the effect of relative movement) air pressure range is required to maintain flight (or freefall), and translate this directly into your corresponding concept of "levels".
And you don't even need to define them in terms of absolute altitudes, let alone height, unless you really want to. If you want to do that, then you can apply whatever pressure gradient you have in your atmosphere to your concept of levels and end up with a measurement in your preferred unit of length or distance.
[Answer]
You have to consider the reasons why an aircraft has an operational altitude range. Primarily that's related to the air pressure and the type of engine and wing size on the aircraft.
Hence you're on the right path by looking at the atmospheric pressure range and extrapolating from that to get appropriate altitude ranges for any given planet. The median altitude and the available range of altitude will change based on local conditions, gravity, atmospheric density etc.
All you need to do next is define the datum you're calculating from for navigation purposes as not every planet will have something equivalent to "sea level" to work from.
[Answer]
You won't have a "one size fits all" solution. All will depend on the planet.
In general you want to define an arbitrary reference level which can be easily used to determine the height.
If the planet has an atmosphere, you can use, for example:
* The quota at which the stellar constant (amount of light power per unit surface) has dropped by a given factor with respect to outer space at same distance from the star
* The quota at which the atmospheric pressure is at a given value (i.e. 1 bar)
If the planet has no atmosphere, you cannot use any of the above.
Moreover, all of the above are not really constant, so they might be hard to be used as real references. Atmospheric pressure changes with meteorological conditions, atmosphere opacity is affected by many factors...
Therefore you might want to use, as reference, some orbital parameter which depends only on the mass of the planet, like the planet-stationary orbit. That being your 0, you can refer heights to that level.
As added bonus, you can set this up without having to explore the planet and probe its atmosphere, so it is pretty convenient if you start from scratch.
[Answer]
Air pressure might be a good idea as it helps to give you an idea of efficiency and drag.
But you would need to correct it for the local gravity as higher differences would mean a different gradient.
And of course things like safety margins would still be in the original distances.
So you would have some sort of lookup table to recalculate your heights, and if you would need to recalculate.
] |
[Question]
[
I've been playing with the idea of living nests for insects for a while now to help populate my worlds. The idea is that they don't build a static nest out of wood pulp and other material but have a literal living and breathing creature that they call their home in a symbiotic relationship. This isn't a simple cooperation where one creature allows the nest to be build on top of him for mutual protection, this is a full-blown "we share DNA" type of cooperation.
There's several things that I would like to know. Ignoring any evolutionary processes to get there, there's things like shape, who would ideally nourish who + how they do that, procreation, keeping the hive together and more.
This question focuses on the optimal shape, based on existing creatures right now. Such a cooperation would have some advantages and disadvantages. Having a warm nest that can find food and protect part of the hive during winter is great and can give a big advantage over hibernating queens that need to find a spot and build up their numbers. On the other hand having to help sustain this living and breathing hive is going to take a lot more work and the creature itself needs the space for the hive to function.
With rambling half-fluff out of the way, for an answer I'm looking for the following factors:
* Space for most of the insects to reside for a short period of several days to survive extended travel or harsh weather.
* Space for a small portion of the insects to live for a long period of several months during winter, only to be temporarily roused for short forages when the hive finds something (the remainder could simply die naturally or be absorbed for food).
* The hive is based off a currently living creature to minimize the amount of guesswork necessary. In order to make the choice of creature less subjective: More space for the insects rules.
* The insects offer an obvious advantage in the finding of food for the creature chosen. For clarification these insects can fly (walking insects would be interesting but change the answer).
* The choice of the insects and creature being herbivores, omnivores or carnivores is yours.
* The chosen creature offers an obvious advantage in the finding of food and survival of the insects it supports.
[Answer]
# A tortoise
Tortoises are protected by a thick shell, which would also protect a small hive. While this would require an expansion of the tortoise's shell it's not implausible for the turtle to be a bit underdeveloped for the shell size.
Even though tortoises are slow, its escort of insects is fast enough to kill flighty prey if carnivorous, can reach very tall fruits if herbivorous, or both if omnivorous.
## Who nourishes who?
Well, it's probably preferable for the insects themselves to have their own digestive tracts. If the hive dies then the insects can continue to survive until they find/grow/morph another hive. However, feeding the hive directly would require a lot of effort on the part of the swarm. Also during winter or other weather (like storms) the hive may be more mobile than the swarm.
It'd be easiest and most reliable for the swarm to bring food into the reach of the hive and then the hive just walks over and eats it. So that's gnawing down fruit or bringing down prey so the hive just plods over and eats it.
## Procreation
The swarm would obviously lay eggs in the spaces in the hive where they rest. Simple and effective.
## Keeping the hive together
If insects can navigate back to the starting location, they could follow a scent trail left by the hive. There are already sun-based mechanisms used by bees for navigating - return to starting point is a solved problem for insects.
[Answer]
Sloths.
[There are already insects that live inside the fur of sloths:](https://en.wikipedia.org/wiki/Sloth_moth)
>
> A sloth moth is a coprophagous moth which has evolved to exclusively inhabit the fur of sloths (...)
>
>
>
But I think you want eusocial insects such as bees, right?
Imagine that insteaf of moths, sloths were home to wasps. Those [refacted due to be nice policy] are vicious and, unlike bees, are comfortable with spartan, minimalistic nests (when they don't use some living bug as nest + food).
The sloth will provide shelter, warmth, home mobility, and love (which wasps don't have on their own).
Wasps will pay their rent by stinging anyone and anything that threatens the sloth. Any few species that still hunt sloths will evolve to not hunt them anymore. I have never been stung by a wasp by I've been told it is extremely painful. In fact, [some species have their stings on levels three and four of the Schmidt sting pain index:](https://en.wikipedia.org/wiki/Schmidt_sting_pain_index)
>
> Schmidt describes the sting of the warrior wasp as *"Torture. You are chained in the flow of an active volcano. Why did I start this list?"*
>
>
>
There is also risk of death to the allergic.
[Answer]
I think a **land-based coral-like creature** (might also be a plant) would work well as an symbiotic insect hive.
Similarly to corals this (stationary) creature lives of organic matter, which it gathers from its surroundings: using a paralyzing venom against (small) creatures that come near it, it can obtain food. It might also be able to digest other plants, using vines similar to poison ivy, and of course being poisonous is also a good way to prevent being eaten by bigger animals.
The insects using this creature as a hive are of course immune to the paralysing venome (as clownfish are immune to sea annemones), which allows them to hide and nest within the plant.
This tendency to nest in the plant over time evolved into a full blown symbiotic relationship:
* the insects gather food (like bees) and store it in their hive, if the plant doesn't get other food it can also live of these reserves
* The insects can drag dead animals (like mice or small birds) or other large food itens they find to the hive. This secures the food from any other competitors that like to feed on them (once in/on the hive only the insects and the hive can feed on it).
* Additionally and predators chasing the insects can be lured to hive and thereby become food themselves (since the hive will paralyze and slowly kill them, also the insects can now grab a bite from the former predator).
This might even evolve so far that the hive recognises not the insects but specifically the (female/worker) descendants of a particular insect queen (by DNA/pheromones) and doesn't even allow any other swarms of the same species in.
* In case of short last bad weather or other conditions the insects can live of the reserves the accumulated, or also on not fully digested prey of the hive.
* The hive gives the insects almost impenetrable protection: smaller animals, other insects and so on are food for the hive and most bigger animals ignore the hive and anything in it since its poisonous. This allows the insects to also leaves food storages and eggs or not fully developed newborns without in the hive without having to worry about predators.
* The size of the hive creature can range from very small to huge - mostly depending on how much (extra) food the insects can gather. If they are able to gather extra food the hive will thrive and in turn the swarm can grow. If may insects die or the hive gets damaged than the other partner starts dying of until they both match capacity again and can regrow together.
* In case of long (several months) winters both the insects and the hive probably won't see a lot of food for a long time. In this case the queen and small part of the insects can retreat into the core of the hive and life of reserves. Any other insects that can't get enough food, can serve as nutrients for the hive (the hive only consumes dead animals, the insects are the only ones normally surviving contact); but the hive will likely also loose biomass and wither until only the core with the incest queen & associates remains.
* Without insects the hive can only grow passively and very slowly. However every time a new queen is born (or an insect swarm needs to relocated) the queen takes a part of the plant with it to grow a new hive from the seedling.
* Further symbiotic evolution might lead to a heat regulated central chamber / core for the hive queen (or eggs)
While you said you'll ignore evolution of the hive / symbiosis for now, I think it's pretty clear how it might have worked here:
* the insects somehow developed immunity to the hive paralysis venom and started nesting there
* the insects figure out that any food stored / dragged to the hive is protected from all other creatures that would compete over it
* from this point onwards the hive gains a huge benefit from the insects nesting in it, leading to symbiotic evolution
[Answer]
## **Some kind of sponge-like creature**
This is *Synalpheus regalis*, the world's only eusocial crustacean. Colonies of this snapping shrimp spends their entire lives living and feeding inside their host nests: sponges.
Sponges present a naturally convoluted and tunnel-filled structure which serves as a ready made equivalent to an ant or termite nest. Suppose your world has a creature much like a sponge, perhaps even more appropriate for a network of passageways, only it breathes air and is fully terrestrial. Your insects could use these as living nests.
For the other end of the symbiosis, consider that the insects will defecate and die inside the sponge frequently. This organic matter would be absorbed by the host nest and provide welcome nutrition.
[Answer]
Denigan
I believe Renan has the right example for you. Sloths are basically a mini-ecosystem. The flies that inhabit the sloths live off of the algae that live in the hair of the sloths. The flies help to fertilize the algae with their feces as I recall. There is a positive feedback loop of sorts. You'll need an organism that provides an ecosystem that sustains multiple species that support each other with the host being the keystone species.
You have an organism with micro-environments temperature differentials lots of nooks and crannies (spaces to hide) hence lots of diverse habitats.
] |
[Question]
[
So I have a scene where someone gets poisoned. I want the poison to have a couple qualities:
1. It works fast, with in the span of a meal be to exact
2. It can be put in food or drink, either covered up or without a taste or smell
3. It has noticeable effects that people would assume is poison and not say an illness, i.e. choking or foaming out the mouth or something like that, leading up to death.
4. It's easy to get a hold of.
5. Preferably, but not as important, it should be available/has been invented/discovered by 1920
I'm already aware of cyanide, which works for most of this, but I'm looking for other possible options so I'm not constrained to one thing. So does anyone know any poisons that fit this description?
[Answer]
A readily available reference is the works of Agatha Christie. People have even made on-line lists of the poisons she used in her works, e.g. <https://owlcation.com/humanities/The-Poisons-of-Agatha-Christe>
Perhaps the most obvious is strychnine "Strychnine blocks motor neuron post-synaptic receptors in the spinal cord’s central horn, antagonising inhibitory tone. Uncontrollable muscle contractions result, classically beginning with trismus and risus sardonicus, then spreading distally, with contractions increasing in frequency and intensity. Death occurs some two - three hours after exposure..."
Good old reliable arsenic can be used in high dosage to cause rapid death, with fairly obvious symptoms. It can also be used in lower doses for a chronic poisoning.
Monkshood and hemlock act fairly quickly, and have the additional advantage of being readily available if one gardens. There are many other garden plants that are poisonous, with more or less immediate & obvious symptoms. Yew is quite common, as is oleander in climates warmer & wetter than mine.
[Answer]
# [Strychnine](https://en.wikipedia.org/wiki/Strychnine#History)
It's been known since the 18th century. It's got well-known dramatic effects. It takes effect quickly. It's easy enough to get ahold of, if you have access to the right plants.
Seems like it fits the bill.
[Answer]
If you can stretch the date a little, go with a nerve agent like VX. It's usually used in gas form but there's no reason you couldn't put liquid VX in someone's drink. It's deadly even just from skin contact, so even if it tastes bad and they spit it out, they will likely still die. 10 milligrams is lethal. The symptoms are pretty obvious if you know what you're looking for, I won't link to any videos of it because they're pretty gruesome, but you should be able to find them. VX is also deadly very quickly, symptoms start in seconds, respiratory and cardiac arrest in minutes. Antidotes do exist, but a bunch of party guests at a fancy gala aren't likely to have them. They won't be able to do much of anything but watch as the target loses control of his bodily functions, starts seizing uncontrollably, then stops breathing.
One big downside is that since it is lethal just from skin contact and in such small doses means it may be difficult to avoid collateral damage. The chefs and waiters who prepared that food might die too. I think the whole kitchen staff collapsing might tip off the target that something was amiss.
[Answer]
Ambroise Pare is called the "Father of Surgery". He recounts in in [Apologie and Treatise](https://archive.org/stream/in.ernet.dli.2015.64006/2015.64006.The-Apologie-And-Treatise-Of-Ambroise-Pare_djvu.txt) an experiment he did to prove to the King that bezoar was not an antidote to all poison. The poison is "sublimate" or **sublimate of mercury**. It sticks in my mind as a pretty graphic account of rapid poisoning.
>
> ...it was an easy matter to make trial hereof on such as were
> condemned to be hanged. The motion pleased the King; there was a
> Cooke brought by the Jailor who was to have been hanged within a
> while after for stealing two silver dishes out of his masters house.
> Yet the King desired first to know of him, whether he would take the
> poison on this condition, that if the Antidote which was predicated
> to have singular power against all manner of poisons, which should be
> presently given him after the poison, should free him from death,
> that then he should have his life saved. The Cooke answered
> chearfuUy, that he was "willing to undergo the hazzard, yea, and
> greater matters. not only for to save his life, but to shun the
> infamy of the death he was like to be adjudged to.
>
>
> Therefore he then
> had poyson given him by the Apothecarie that then waited, and
> presently after the poyson, some of the Bezahar brought from Spain,
> which being taken down, within a while after he began to vomit, and
> to void much by stoole with grievous torments, and to cry out that
> his inward parts were burnt with fire. Wherefore, being thirsty, and
> desiring water, they gave it him; an houre after, with the good leave
> of the Jaylor, I was admitted to him; I find him on the ground going
> like a beast upon hands and feet, with his tongue thrust forth of his
> mouth, his eyes fierie, vomiting, with store of cold sweats, and
> lastly, the bloud flowing forth by his eares, nose, mouth, fundament
> and yard. I gave him eight ounces of oile to drinke, but it did him
> no good, for it came too late. Wherefore at length he died with great
> torment and exclamation, the seventh houre from the time that he
> tooke the poison being scarcely passed. I opened his body in the
> presence of the Jailor and foure odiers, and I found the botome of
> his stomacke blacke and dry, as if it had beene burnt with a
> Cautery; whereby I understood he had sublimate given him; whose force
> the Spanish Bezahar could not represse, wherefore the King commanded
> to burn it.
>
>
>
[Answer]
There is a type of spider that you may have heard of that has very potent venom: The Black Widow. This Spiders' venom is a neurotoxin that, within minutes of ingesting or being bitten, show: Stiffness of muscles, nausea, difficulty breathing, excessive sweating,Rash and itching, swollen eyelids, weakness or tremors, and sometimes, paralysis. this all happens between the range of minutes to hours, depending on the symptom. If you could harvest it, it would be very potent for use in warfare. I hope this answers your question.
] |
[Question]
[
I want to use Teslapunk weapons in my semi-realistic science fantasy RPG that behave somewhat like flamethrowers, in the aspect that they fire out a branching arc of raw electricity. It would obviously use batteries, cells, or something else instead of traditional fuel that flamethrowers use.
How would these compare to flamethrowers? According to AlexP, batteries have a much lower energy density when compared to gasoline. I would think that death by electrocution would be more humane in terms of pain than that of death by burning. I'm not fluent when it comes to electricity in scientific terms, so it's maybe far worse than a simple flamethrower.
I was inspired by this thread [here](https://worldbuilding.stackexchange.com/questions/22312/handheld-weapons-plasma-vs-laser), that asked about plasma and laser based weaponry.
[Answer]
Are handheld flamethrower like electrical weapons realistic? No not at all. Flamethrowers have a simple purpose, they're area denial weapons. The fill a trench or bunker, making it impossible for the enemy to remain there. Even if you block the flames it burns away the local oxygen. Your electrical weapons will completely fail at this job. So what's left is a short range weapon that can kill in a wide path. There it will compete with a shotgun (with a duckbill barrel).
It serves no practical purpose unless it's about overloading some sort of mechanical contraption. If it's about killing people they're not realistic. Electrocution isn't more humane then burning alive. I'd argue it's the other way around. Electrocution cramps up your muscles. Either you get a heart attack or you cook from the inside out. It's not a pleasant way to go.
Now neither is burning alive but something that happens rather fast with burning alive is your nerves burn away. Within seconds the outer layer of nerves is destroyed beyond having the ability to signal pain. While it's utterly distressing to smell yourself burning. To feel your skin tighten and crack. It doesn't hurt as much, the painful period has already passed.
Regardless of that your weapons lack a realistic purpose. They're cool but not realistic.
[Answer]
I agree with most of what Mormacil said but differ on a few points.
With enough power (Volts\*Amps) then it could instantly kill someone, so it would be humane. The effects would be as, if not more, grisly than a flame throws since with enough power you could vaporize their innards causing them to split open like a potato in the microwave.
For a Tesla weapon to be useful, there would need to be a strong magnetic field to confine the electrons to travel in a specific direction. Otherwise, the arc generated by the weapon would seek the nearest ground potential -- read as dirt, water, walls. But with a helical magnetic field radiating from the weapon towards the target, the electrons in the arc would be confined by a Lorentz force.
This would also provide means of defending against the weapon, powered iron would cause the magnetic field to be distorted in wild ways, making the aim unreliable.
Conductive fluids like salt water sprayed in the air would attract the arc and dissipate some of its energy be being turned into steam, rendering the arc less dangerous.
Any conductive and grounded metal would act as a lightning rod and pull the arc towards it. So a shield or a suit of armor that was grounded would protect the wearer until the metal got too hot as the arc melted a hole through it. But, thick enough and sufficiently grounded metal could last indefinitely.
And lastly, as pointed out in previous answers, battery technology used in laptops and cell phones would not have the power density required for a dangerous weapon. But, a fuel cell and one-use chemical batteries used for missiles generate tremendous power for the length of the weapon's flight time -- 20 minutes to 2 hours. These kinds of batteries are called primary cells.
It is not unreasonable to think that either of these power sources could be used. Fuel cells would require refueling. And chemical batteries only last for a specific time period after activation. Activation, in this case, means mixing the chemicals. Both aspects provide interesting limitations for gaming.
[Answer]
This probably should be a comment instead of an answer but if you go by the "flame throwers are area denial weapons" logic, we can assume you want a battery powered area denial weapon instead of a literal electric flame thrower and that is doable. And such weapons are in use or testing IIRC even.
**Maser**
A microwave frequency laser. When it hits something with lots of water, human body for example, it makes the water heat up. This causes the nerves in the skin think you are on fire. So this is actually surprisingly close to electric flame thrower in that it fairly effectively simulates one with good energy efficiency and low collateral damage.
Still the good energy efficiency still doesn't really allow "hand held" weapons and it is fairly easy to protect yourself from as the microwaves will not penetrate lots of cheap and easily obtainable things.
IIRC this has been tested but I do recall seeing the actual results.
**IR lasers**
These are used to blind people. Add small rotating mirror, camera, processor, and a program that directs the laser at moving targets within the field of view and you have an area denial weapon. I think modern software fairly reliably recognizes the eyes even.
I've been toying this idea for a while and I think it might be a feasible short range weapon. Being blinded is very distracting and the energy needed is fairly low. So using one when assaulting or receiving an assault might make sense.
Again the low powered nature means it is fairly simple to protect your eyes if you are expecting this and have the time and resources to prepare. And you would not carry it in your hand, your hand would carry a gun, this toy would strap onto your shoulder.
Blinding lasers are used by military forces but in far longer ranged and non-automated version not the fancy smart short range version here.
[Answer]
Electric weapons basically won't work as you describe (like a flamethrower). Electricity requires a conductive path to its target. (Even static electricity, like lightning bolts, which create their own path to the "nearest" oppositely-charged point.) A weapon that just creates a high, lightning-like charge is most likely to hit you :-)
So you have two possibilities. Either you use a Taser-like mechanism that shoots a thin wire to the target, or you make it a contact weapon like a cattle prod or stun gun.
[Answer]
**Combine your electrical charge weapon with a particle beam.**
The problem with a bolt of electricity is that it will seek the quickest path the ground in the vicinity. That might be your target, or a tree, or you. How to make sure that your target is the quickest path to ground for the electrical charge, which is presumably coming from your backpack of batteries?
First shoot a proton beam at your target. Protons can be calibrated to drop their energy at a specified distance from discharge. This makes them useful for radiation therapy too.
<http://www.proton-therapy-today.com/what-is-proton-therapy/why-is-proton-therapy-a-preferable-option-and-what-is-the-bragg-peak/>
>
> On the contrary, the proton is a heavy and charged particle that
> gradually loses its speed as it interacts with human tissue. It is
> easily controlled and delivers its maximum dose at a precise depth,
> which is determined by the amount of energy it was given by the
> cyclotron (via acceleration), and can go as far as 32 cm. The proton
> is very fast when it enters the patient’s body and deposits only a
> small dose on its way. The absorbed dose increases very gradually with
> greater depth and lower speed, suddenly rising to a peak when the
> proton is ultimately stopped. This is known as the Bragg peak. The
> behavior of the proton can be precisely determined and the beam can be
> directed so the Bragg peak occurs exactly within the tumor site.
> Immediately after this burst of energy, the proton completely stops to
> irradiate.
>
>
>
Air is a great insulator. In a bolt of electricity, the electrical charge must ionize the air into plasma so that it becomes conductive. In this weapon, your plasma beam ionizes the path and then the charge is happy to take it.
One might protest that if you have a proton shooting particle beam, you could shoot your enemies with that. This particle beam only needs to ionize a hair-thin pathway through the air. Using the beam to deposit energy in your target comparable to an electrical bolt will take a long time, and even then, it might just result in your target getting sick later in the day, or developing cancer some years later.
---
A cool side effect of this approach - there are free sources of charge to be had. If your target is insulated from the ground but you charge it up with your device, eventually charge might arc across from your charged target to something else in its vicinity. Or you could pull charge down from the sky as a real lightning bolt. One could use the proton ray conduit for exactly this purpose, opening a path between sky and target. The proton ray is invisible and would need to be big to keep the path charged up (or many working in concert) but real naturally occurring lightning bolts are pretty awesome.
That said, you could defend against those too with a portable lightning rod - perhaps a copper spike on your helmet and a trailing cable to ground.
] |
[Question]
[
I have created a life form that is based on the element boron. As a substitute for DNA it instead uses Diborane as a building block. I've come across a problem however that I can't seem to get around. This problem is what would these Boron cells use to obtain energy?
[](https://i.stack.imgur.com/9dAQZ.png)
The atmosphere of the planet this creature lives in is heavily reducing. This means most of the oxidizing agents are locked up in bonds with other elements. This creature mainly breathes methane to power chemical reactions in a process of cellular respiration that looks like this.
4CONHNH2NOHN2 + 22CH4 = 20NH3 + 11C2H4 + 4CO2
Methane is used to break down a chemical similar to carbohydrazide and is turned into ammonia, ethylene and carbon dioxide.
In carbon based biochemistry, the energy that allows this process to happen comes from ATP which is broken down in the process of hydrolysis, giving the cell energy. However, ATP is mostly carbon and oxygen based, which this boron based life form doesn't have a lot of. Knowing this, what could these boron based creatures use as an alternative to ATP?
[Answer]
The important part of ATP for energy storage isn't the carbon-based part: it's the phosphate chain. The adenosine part is essentially a nucleobase (adenine) bonded to a sugar--i.e., a fragment of an RNA molecule. That's a pretty suspicious coincidence, no? It seems likely that ATP derives from the ancient use of RNA as a catalyst, analogous to proteins, in addition to an information carrier.
So, what would be the analogous, ubiquitous structural base molecule in your boron biochemistry? I'd pick either a nucleobase or an amino-acid-equivalent (or something which can be both, like adenosine), and just stick a phosphate chain on it.
Edit: A reducing environment shouldn't be a problem for evolving phosphate chains... but a general lack of oxygen, or water for hydrolytic energy reactions, probably is!
However, these creatures do have lots of ammonia available, and -NH- groups are isoelectronic with -O- groups, so... This is considerably more speculative, but rather than HPO3 groups with an OH terminal, maybe P(NH)2(NH2) groups with an -NH2 terminal.
The ammonia equivalent of ATP hydrolysis and dehydration synthesis would be:
(NH2)-P(NH)(NH2)-(NH)-P(NH)(NH2)-(NH)-R + NH3 <-> P(NH)(NH2)3 + (NH2)-P(NH)(NH2)-(NH)-R
Where R is whatever "organic" base molecule you have to carry those phosphorus chains around.
[Answer]
**2 carbon molecules.**
@Logan R. Kearsley's idea of taking a page from your own fictional biochemistry makes sense. Here is another idea that will make sense to readers with only high school chemistry.
[](https://i.stack.imgur.com/evsYH.png)
<https://brilliant.org/wiki/common-types-of-organic-reactions/>
The idea with ATP is that it takes energy to add that phosphorus and it will yield energy when you release it: energy currency.
Carbon-carbon bonds are the same way. It takes energy to expel that hydrogen and bond carbon to carbon. There is more energy in acetylene than in ethane, which is why we use acetylene for welding and ethane / methane for gas grills. On removing hydrogen, energy is stored. On adding hydrogen back to the carbon, energy is released.
[Answer]
## Frame Challenge: Your organism will still be Carbon Based
When you say an organism is Carbon Based you are referring to the element that forms the core building block in your organic molecules.
Removing Carbon in favor of Boron Based Biochemistry has a whole slew of problems bigger than finding a solution for ATP, and it all leads back to the number of covalent bonds it can form. Carbon can form 4 covalent bonds whereas Boron can only form 3 without becoming unstable and negatively charged. This makes carbon far more useful in the construction of complex molecules. So much so, that evolution of your world would choose the carbon based path over the Boron based path, even if Carbon is less available.
Furthermore, your world actually has plenty of Carbon to work with. Organic carbon in our world mostly comes from the CO2 in our atmosphere; so, if your organisms are already relying on atmospheric methane in any substantial way, then the primary producers on your world can simply breath in methane, and breath out hydrogen gas as a way to bring carbon into your organism's natural life cycles.
The only reason for life to evolve not to be carbon based is if carbon is extraordinarily rare. Not just sequestered, but non-existent on your planet, and if Carbon in unavailable, the next logical step is the next densest element which can form 4 covalent bonds, that being Silicon. Even Germanium, Tin, or Lead based life may be more common that Boron based life because of how important that 4th covalent bond is in creating complex systems.
That said, Carbon based life is almost certainly the norm since we can prove it wins out, even against more prevalent options. Here on Earth, Carbon makes up only 0.02% of the elements in the crust whereas Silicon, the next best thing, makes up 28.2% of the crust. This demonstrates that life prefers the elements that work best over those that are just more common.
[](https://i.stack.imgur.com/bHpy9.png)
] |
[Question]
[
So, I've been designing an alien species, actually a redesign of something from childhood. However, I've recently come into an issue with its limbs.
The creature possesses two arms. The right arm is roughly humanoid, ending in a prehensile hand. Currently, there are eight digits, although this may be subject to change. However, the left arm ends in a hand that has been modified into a weapon. Currently, four digits have been adapted into spikes, similar to *Iguanodon*, and the remaining four have modified into a thickened, blunt structure, leaving the entire hand to somewhat resemble a spiked mace.
However, this is where I've run into a roadblock. This is a naturally evolved creature, but I'm struggling to figure not only the circumstances for this adaptation but also if this level of asymmetry is really realistic.
EDIT - A few additional points to help clarify things. The species is sapient and civilization-faring. The eight digits are an attempt to get around the dexterity problem of only one functional hand, essentially putting two hands on one arm. Secondly, both genders possess this feature. Part of me is thinking to just go the Hellboy route.
Preliminary (and very low-quality) sketch -
[](https://i.stack.imgur.com/cdHl6.jpg)
Any answers would be greatly appreciated.
[Answer]
You see limb asymmetry in fiddler crabs.
[](https://i.stack.imgur.com/r3dnH.jpg)
<https://www.azgardens.com/product/mini-algae-eating-fiddler-crab/>
It seems to me that a creature with prehensile limbs probably uses tools, and so it does not make sense functionally for a tool user to have a limb differentiated into a tool. It could pick up a spiked club with both hands like humans do.
A fiddler crab would probably do better with 2 little claws. It cannot feed itself with that stupidly large claw. **But it evolved that way because the ladies like it.** There are many other examples of male phenotypes which seem burdensome or less than useful, but exist because they are attractive to the opposite sex. Maybe because a male able to tote around such a useless appendage must be vigorous?
Crabs also use the big claws for conspecific combat (read: showing off / intimidating competitor males). That could also be a use of the club hands - which also boils down to sexual selection.
[Answer]
One other way to do this is to look at the classic SF novel: "[The Mote in God's Eye](https://infogalactic.com/info/The_Mote_in_God%27s_Eye)", where an intelligent alien species has evolved both asymmetry in their limbs, but also a biological caste system where various sub species exist to carry out specialist tasks.
The "Moties" were descended from a six limbs species, but due to high levels of radiation a mutation was passed down which caused the limbs on one side to fuse into a much larger and stronger arm, with the resulting Moties having five limbs. The "Warrior" caste is even more extreme, with all the appendages having sharp claws, spikes on the joints and even the doubled arm being somewhat devolved, with a sharp "claw" like cutting limb tucked under the "armpit" when not extended for fighting.
[](https://i.stack.imgur.com/YVLKQ.png)
*Rendering of a Motie <https://www.deviantart.com/yoggurt/art/White-brown-motie-220557951>*
The real issue here isn't that something like this isn't possible, but rather to create a clear backstory as to *why* your creature evolved to look the way you intend. Sexual selection is one possible way, or living in some sort of very dangerous environment where requiring a smashing weapon attached to your arm is advantageous (perhaps the other use is to smash open a coconut sized husk to extract food). Frankly, the level of specialization seems a bit much, since an actual hand on each limb would be far more useful for survival. An asymmetric arm ending in a giant fist, analogous to a Fiddler crab seems to be a more realistic evolutionary adaptation, and the extra large hand will also be far more useful to the creature. Perhaps in addition to the obvious sign of virility, the large hand also assists in both hunting and gathering, or building giant sized [structures](https://www.wired.com/2016/02/absurd-creature-of-the-week-meet-the-bird-that-lies-and-tricks-its-way-into-sex/) to attract mates much like the [Bower bird](https://infogalactic.com/info/Bowerbird)
[](https://i.stack.imgur.com/H1gpY.jpg)
*Male Bower bird inside his courtyard*
Evolution works in wonderful ways, repurposing existing structures to squeeze the most out of the environments your creature is living in. Have some fun thinking about your back story.
[Answer]
Its like a fiddler crab, where one side is for fighting and display and the other side is for sexual competition. Anyways I'm going to say it's fine so long as there's a clear evolutionary path.
] |
[Question]
[
This is a submission for the [Anatomically Correct Series](https://worldbuilding.meta.stackexchange.com/questions/2797/anatomically-correct-series/2798#2798])
[](https://i.stack.imgur.com/aRnJr.png)
The [snallygaster](https://en.wikipedia.org/wiki/Snallygaster) is a cryptid from Maryland. It is often described as resembling a half bird/half reptile like creature with large wings, a metal beak, tentacles like an octopus (sometimes depicted as emerging from its beak) and is known for snatching prey and draining them of their blood. Could something like this evolve naturally?
[Answer]
**TL;DR: You are probably looking at a featherless therizinosaur with steering wings derived from shoulder blades, an internal bladder of lighter-than-air gas, a metallic-looking beak and a multi-appendaged, oversized tongue.**
Well, I'm going to use this picture as a reference:
[](https://i.stack.imgur.com/mhdjM.jpg)
The first thing that strikes me here is that there are four limbs along with a pair of wings. This either means that it is a hexapod (Perhaps from an alternate Earth timeline where a six-finned lobe-finned fish colonized the land?), or that the wings are not developed from forelimbs.
Seen as the latter option is consistent with real-life evolutionary history, I'll go with that one. Instead, the wings can be in fact modified shoulder blades.
So, we now know that this is not a bird. Overall, its body plan is quite evocative, for me, of a therizinosaur:
[](https://i.stack.imgur.com/yMH1n.jpg)
The above depiction is currently outdated, as we now know that they had feathers, but it is entirely plausible that a therizinosaur could lose its plumage due to environmental pressures (Stable temperatures? Semi-aquatic habits?). The feathers on the wings could stay though, as they are far more aerodynamic than any other biological wing on Earth. Also, therizinosaurs were extant at the time of the K-Pg impact, so they could have been potential survivors.
That being said, it is obvious that the snallygaster could not be supported in the air by these tiny shoulder-blade wings. The illustration depicts it as airborne, so I imagine that the wings could be used for steering (and display, too) if it had some other method of buoyancy.
As for what that method of buoyancy would be, perhaps it fills an internal bladder/sac with hydrogen or methane, making it lighter than air? I'm not sure how plausible this is given the apparent large size of the snallygaster, but it's something to consider, certainly.
As for the beak, some therizinosaurs had beaks, so that's okay. The metal part is tricky though, but not impossible. Technically, steel is made from iron and carbon - elements which are both found in animal bodies, but I'm not really sure if it could form some kind of sheath over the keratinous bill. There are plenty of birds with shiny, grey beaks, though, and since the snallygaster is a cryptid, accounts will inevitably be exaggerated.
Lastly, the tentacles. Since they emerge from the mouth, the most plausible option for me is that they are derived from the tongue. If the tongue was to split into multiple appendages, which would be quite feasible evolutionarily, engorge those appendages and gain limited independent control of the members, it would resemble tentacles in every way.
Why would this evolve? Well, while therizinosaurs do have grasping hands, many have long claws which make any kind of dexterous use of the forelimbs quite clumsy. As such, the tongue could have evolved its tentacle-like properties as a means of attaining a prehensile organ. The prehensile forepaws are very important to how big cats hunt, and is in part why they can tackle such massive prey more than virtually any other predator. I imagine that the tongue could start out as being one, long, serpentine appendage, and then going on to split into more members to grapple with prey better.
[Answer]
I believe almost anything can evolve naturally. Life on Earth is incredibly varied, and organisms come in all different forms.
It is not too difficult to conceive of all the attributes of your creature evolving as they have evolutionarily occurred in other organisms:
* Half bird/half reptile: Sounds similar to a relation to dinosaurs
* Large wings: in the above example Pterodactyls are dinosaurs (birds) that have large wing spans.
* A metal beak: Metals are difficult to form part of a body as it does not lend itself well to growth over time, and organic materials such as cartilage and bones are much more malleable biologically.
* tentacles like an octopus: tentacles are a flexible version of limbs to other creatures. Again, this can evolve.
* Draining them of their blood: Many organisms need to eat other organisms to survive. Yours might need the nutrients found in blood, much like mosquitos, vampire bats and others.
So the only difficult one to achieve is a truly metal beak - although keep in mind beaks in current birds are quite strong and adequate for most purposes already.
[Answer]
A snallygaster could have evolved from a toothed ornithuran. It would most likely eat fish. At some point, some fish would start to eat huge amounts of plant matter, which they would store in a crop. The snallygasters would evolve to consume this plant matter, by entering symbiosis with methanogenic microorganisms similar to what is found in ruminants. They may store the methane they produce in the blind-ended portions of their respiratory system. This would reduce their weight, leading them to increase in size and density, and also to increase the size in the body of the methane-storing respiratory organs. They might switch diets to become predators, and develop scaly armour over their body, to protect against prey. It may become larger, and start to hunt large prey like an eagle. The snallygasters could at some point rapidly shrink in population, causing a genetic drift effect leading to many snallygasters having Cyclopia. These snallygasters, while not as intelligent, may be able to have larger, and better at focusing eyes, as the resources and space for eyes is not split between two eyes. The snallygasters may evolve an extremely loud shriek, in order to find mates over a large area.
In the ocean, there may be large, long-lived, intelligent octopodes, that live near the coast and are hematophagous. In order to avoid the snallygasters and other predators, they may become toxic and gain warning colours. A drop in oxygen levels could lead to these octopodes gaining simple lungs. These octopodes would be vulnerable to human hunters, who could cook their meat and make it edible, and so the octopodes would learn to hide in the nests of the man-eating snallygasters, using their warning signals to avoid being eaten. These octopodes would create tools, to help the snallygasters get the most meat out of each kill, as they benefit from having many snallygaster nests to hide in. Soon, the snallygasters would learn to keep the octopodes around, and start to protect them by hiding them in the top of their oesophagus. The octopodes would create tools for the snallygaster, such as a helmet to protect their eyes, ears, and other weak-spots.
[Answer]
The main issue of a real snallygaster is the half-bird/half-reptile thing. Any animal like that would be long dead once humans came, and likely too unlike the snallygaster for the realms of plausibility
However, the world is full of tiny distant branches on the tree of life, and evolution can be a powerful thing, so let's continue
Firstly, we need an ancestor: To best fulfill the snallygaster, we'd ideally get something primitive with pennaceous feathers. Unfortunately, pennaceous feathers are restricted to the maniraptors, with true flight feathers themselves even more limited in scope. Taking this into account, we can make the snallygaster as a small primitive oviraptor, with wings and beak, but a long tail and teeth as well
This oviraptor is still far from the snallygaster, and there's a mass extinction heading its way. We could make progress with both issues if this species were to adapt to arboreal life. This would give us many changes useful to our ends; It could likely gain grasping feet and wings, and perhaps even become flighted. All these traits would bring it one step closer to the snallygaster
Being smaller, this species could likely survive the mass extinction just as well as the various avian clades. However, like all animals, it will need to change first. Firstly, it will likely have to lose its arboreal adaptations for the lack of trees (while their were some trees, they were rare and ground-dwellers often had the advantage). Given that all their limbs were in use in the trees, it seems reasonable that the same would stay true on the surface
These terrestrial creatures would benefit from some protection, both from the rough ground and from predators. Scales would be quite useful to this end. One plausible arrangement could be having the head, chest, and wings be feathered for aerodynamics, with the feet, legs, and tail being scaly to maximize protection. This would make these proto-snallygasters much more reptilian
After the extinction, there would be many niches to fill, especially for fliers. A good niche for this proto-snallygaster would be a piscivore. This would motivate adaptations like a long beak and sharp teeth, like a snallygaster. These piscivores, given the right environment, could become rather large. This shouldn't be an obstacle to flight: *Argentavis*, a flighted bird, was heavier than a human being
Piscivores need not subsist solely on fish. They would likely add other foods to their diet, if possible. Perhaps these snallygasters (or at least some of them) could take on a more eagle-like lifestyle, to supplement their diet if there aren't enough fish. While they won't be able to pick up human-sized beasts, small children and other similar-sized creatures would be more than light enough
They will need some way to hold their prey, however, as unlike birds they would only have 3 forward-facing toes. They could grasp small prey between the hindfeet, but they will need a better solution. One such possibility could be a large hooked claw like that of the dromaeosaurs, which could be turned out like a thumb to grab prey
Now we have made quite a snallygaster, but there are still some obstacles to the complete picture. Some traits could be considered as display; Reflective colouration could account for the metallic beak and steely claws, and a locomotive-like whistle could be an effective mating call. However, the other remaining traits are hard to justify
Tentacles, especially those of the octopus, are full-fledged limbs, which would be hard to add to such an advanced tetrapod. We can still do something similar, though
While reptiles and birds do not have cartilages on their face, it isn't totally implausible for the snallygaster to have them. A set of cartilaginous display nubs around the mouth would be a good origin for tentacles. These nubs could likely extend out as a Fisherian runaway, forming long flexible structures that would seem remarkably close to tentacles
The central eye would be another issue. Cyclopia, while it has the desired effect, is always accompanied by many other deleterious features. However eyespots (or fake eyes) are very common in nature
A single scaly eyespot in the forehead would be a useful feature, as it would resist attacks more than a feather eyespot, and it is where attackers would expect an eye. This could adapt into a large, shell-like eye-dome in the centre of the forehead
Finally, we must discuss its hematophagy. A large animal like the snallygaster could not subsist on blood alone, but other animals can
If the snallygasters are capable of withstanding hematophagous worms and bugs (which shouldn't be implausible with their thick skin and scales), then they could use these bugs as a defense, going to dense areas and even cultivating their numbers. This would inevitably result in any meat they store ending up wholly drained of blood before they go to eat it. This won't be much of a downside for the snallygaster, as there are still a lot of nutrients left over, as our own diets can attest
Overall, these changes would lead to an animal very much like the snallygaster of folklore
[Answer]
The metallic beak and claws are hard to swallow, but not quite as farfetched as one might think. There is one real-life animal, the [scaly-foot gastropod](https://en.wikipedia.org/wiki/Scaly-foot_gastropod), a deep-sea snail which incorporates metallic iron into its physiology in order to produce a functional metallic shell. But the snail lives around deep-sea vents which pump out vast quantities of free molecular iron sulfide, and contains symbiotic chemosynthetic bacteria which eat the iron sulfide and provide the snail with both energy and free iron atoms. The snail was getting iron as a waste product before it evolved something to do with it. It's a lot harder to imagine a similar evolutionary path happening in a terrestrial avian.
However, it is noted that the Snallygaster has a taste for blood. While it's unlikely that a large predator would subsist entirely on blood, it is possible that it evolved from a much smaller creature that did. Animals that drink blood need to have some means of removing the excess iron to avoid iron poisoning. So, perhaps the evolutionary path looked something like this:
1. Small birdlike predator evolves to occasionally drink blood
2. Small birdlike predator learns to extract iron from blood in order to tolerate a blood-based diet
3. Small birdlike hemovore learns to incorporate the excess iron into its hard body parts, assisting in its offensive capabilities - perhaps allowing it to slice open veins like a living scalpel
4. Small birdlike hemovore can now kill larger animals more easily and returns to a predatory lifestyle
5. Snallygaster grows to its current size to tackle larger prey, but retains its taste for blood and ability to incorporate iron into its beak and claws
Half-bird half-reptile isn't too farfetched, as birds are pretty reptilian already and this could easily be a member of a living fossil clade that branched off around the time of the dinosaurs. An additional set of dragon-like wings, such as those in your picture, are less plausible on an Earth tetrapod, but if we modify the design a bit we could get clawed wings such as one might find on a primitive avian, and that's fine.
The mouth tentacles could be highly modified tongue (tongues are basically tentacles already, and snakes show that it is possible for them to split into multiple branches). I'm not sure what its function could be, but "mating display" is always an easy choice when all else fails.
] |
[Question]
[
Historical accounts of battles sometimes talk of rivers running red with the blood of fallen combatants.
>
> Many Lancastrians were killed while fleeing; some trampled each other and others drowned in the rivers, which are said to have made them run red with blood for several days. ([Wikipedia](https://en.wikipedia.org/wiki/Battle_of_Towton))
>
>
> The ensuing massacre of the Parliamentarians is said to have been of such magnitude that the beck ran crimson with blood. ([Wikipedia](https://en.wikipedia.org/wiki/Battle_of_Seacroft_Moor))
>
>
>
This seems implausible, given that a river’s water is flowing, therefore clearing the water of blood eventually. But, it would make a good scene in my story. **What is the minimum plausible number of dead bodies it takes to cause a river to be stained in red for days**?
Notes:
* Technology is early medieval, so arrows, stab wounds, and drowning are primary causes of death.
* The river is medium-size: large enough to drown people but small enough to have people try to flee over it, similar to the [Namsen River](https://en.m.wikipedia.org/wiki/Namsen), in Norway at GPS (64.4464433N,11.8602026E). It is only 130 m across, meriting (failed) attempts by the wounded to swim to safety.
* The definition of "stained red" is that the water is a solid reddish hue when looked at from above.
* The stain must last for at least twenty-four hours, over at least a 1km stretch of the river.
* The river's water color is blue or blue-greenish most of the time.
Other cool numbers:
* 5 L of blood per person (estimate, usually between 4.7 and 5.7 L)
* The river speed is about 4-5 mph
* Blood density is 1060 kg/m³, so it will sink to the bottom eventually.
[Answer]
So I was going to add this as a comment, but I don't have the required reputation for that yet; I will try to increase the number of considered factors and variables later.
Based on @candied\_orange's anwer and the average discharge rate of $285\:m^3/s$ provided in the link for the river (the German Wikipedia states varying rates between $155\:m^3/s$ and $1000\:m^3/s$), a blood flow of $71,250\:l/s$ is required.
Assuming all of the bodies bleed out entirely, this would require the blood of $14,250$ people to taint the water that flows through the river in a second.
With a speed of $5\:mph$ this would suffice for a stripe of blood-red water that is $2.235\:m$ wide. In order for the taint to be $1\:km$ long, $447.39$ times as much blood would be needed, which would be from roughly $6,375,269$ corpses.
Maintining this over a $24\:h$ period would respectively increase this number.
Keep in mind this is a preliminary calculation that assumes the entire water of the river flowing during that time will be tainted with blood to a sufficient degree. What you actually want is probably just the upper layer and enough blood to maintain this before the blood sinks too low to be visible. In general however I recommend using a much, much smaller river, and I don't believe the historic accounts you mentioned refer to a river anywhere near that size either.
Another tip is to utilise dead horses to increase the amount of blood available (1 horse has as much blood as about 8 humans).
[Answer]
It all depends on how red is red enough for you.
[](https://i.stack.imgur.com/H0sL2.png)
>
> blood 4-times diluted with water was light red (3)
>
>
>
So if light red is the limit of red enough then you need people bleeding at least one fourth as much blood as the water the river is passing, all over however long you want this to last.
You can find [studies](https://www.researchgate.net/figure/Blood-thickness-1-mL-blood-1-2-mL-blood-2-4-mL-blood-3-Blood_fig3_23451448) about the darnest things.
] |
[Question]
[
There is a background planet in this story that is important due to character back story however we never visit it in this book.
It is describe as a mostly jungle planet, with regular heavy rains or monsoons but little to no bodies oceans or large bodies of water.
How feasible is this? What other conditions would need to be added to allow the monsoons without much water surface water?
The planet would have to have been stable long enough for life to have evolved there.
**EDIT**
The answeres provided gave me the info I needed to do further research. An acer of water evaproates about 10,000 gallons a day. An acer of corn can lose 8,000 gallons a day through evapotranspiration.
Through this I can imagine a world with minimum to no handwavium with these characteristics. So the correct answer goes to @SJuan76. Thanks go out to @JBH and their excellent answer as it gave me the terms I needed to further my search.
<http://www.ncga.com/upload/files/documents/pdf/water_movement_in_corn_production.pdf>
<https://www.tractorbynet.com/forums/rural-living/81477-how-much-water-evaporates-per.html>
[Answer]
**Sand, lots of it**
Sand is permeable, which means that rain water falling on it will sink down (at least, until the lower layers are soaked).
So you have a planet with lots of sand, let's say some 20 meters minimum all around1. When it rains, water sinks down until it finds an impermeable layer, and it remainst trapped there.
And now you have to get the water out...
**Trees, lots of them**
But those trees have to dig *hard* to get the water. They roots go deep in the sand1 until it reachs the water (the phreatic level). Roots will suck water and send it towards the leaves; where it will evaporate (respiration and photosyntesis) and return to the atmosphere.
Considerations:
* A new tree will need a lot of water to build its initial root; if they use seeds those are going to be huge and full of water. Or maybe they do not use seeds and new trees appear as an outgrown of other trees roots, or the trees can "drink" from the roots of older trees while growing their roots.
* There may be a need for a mechanism to "process" dead tree remains. Otherwise, they will decompose and will form, little by little, fertile soil. Maybe the soil is pushed down by the rain?
* No tectonic activity will help, as no new rocks will be pushed to the surface and no new soil will be created.
---
1Which also gives them structural support, because, you know, they are literally built on sand.
[Answer]
**This is not feasible**
Atmospheric water must come from somewhere, and it cannot come from underground springs. The one and only option to do it in bulk is evaporation.
You don't describe your planet in detail, but let's assume that it's close enough to the sun to keep the poles melted. They won't be tropical (or the rest of the planet would be a blazing desert), let's assume they're arid.
That makes the rest of the planet fairly hot. Good. We need rapid evaporation. We have tons of trees and low tectonic activity so the water has worn most of the land fairly flat. (That's a problem by itself, BTW, because erosion is no small thing, but let's ignore that.)
You do get a ton of water into the atmosphere via transpiration (the plant form of sweating), but not nearly enough to create monsoons. For that you need open water to evaporate.
Could you do it with a swamp planet? Well... maybe, but if you're looking for no surface water, soggy swamp may not solve the problem. If soggy swamp *could* solve the problem, then you're looking at basically 100% humidity planet-wide. Yuck. Good for plants. Hard for critters (like humans) that need to breathe. (But, then again, [sapient bipedal fish](https://upload.wikimedia.org/wikipedia/en/thumb/4/4b/Abesap2.jpg/220px-Abesap2.jpg) aren't unheard of.)
In reality, though, a planet with monsoons will have oceans, if only because an entirely flat planet (the only way you don't get oceans) is pretty unrealistic. Give a little altitude anywhere, even a few feet, and the water from those monsoons begins to puddle and gather. And you need them to evaporate enough water to create those tropical monsoons.
Think of Earth. 67% surface water, and we're NOT a tropical planet with regular monsoons. And yet you're looking to do it with 0% surface water. That's why I'm voting for not feasible.
**But that's not the same as "don't use it in your story"**
Having said that, IGNORE ME COMPLETELY. Oftimes authors get too bogged down in the details. The number of people who read your story and think to themselves, "that jungle planet with lots of rain and no oceans is *sooo* unrealistic!" compared to the number of people who think "This is the most awesome book in the world!" is *so honking low* that it's statistically zero. Up theirs (if you'll excuse my french). Have fun with your story and forget everything I said.
Cheers.
[Answer]
Oh, it's quite feasible.
But it would be an inferno: a Venus-like planet, minus the chemical craze, where it is so hot that ALL of the world's water has evaporated and stays in the atmosphere. And when it rains, it evaporates *before* touching the surface, thus keeping the cycle at a higher level over the surface -which would be totally dry and subjected to an enormous pressure.
If plants had a chance to survive, they'd need to live on mountains, be *very* tall and have the thickest bark to retain water and survive the surface temperature. Like baobabs, their roots would be propelled upside to collect all humidity from the suspended atmosphere water
] |
[Question]
[
# Background Info
So a humanoid species has been found in the arctic. Or rather, a humanoid subspecies. That subspecies is ***Humanoidus Keplerianus Arcticus***. They have dense hair all over, sort of like a yeti which also has dense hair all over its body. Their urine is very concentrated but not as concentrated as that of desert surviving humanoids. They primarily eat meat but they also eat edible plants during the summer. This subspecies and other subspecies want to build cities in the arctic.
# Question
Now I'm wondering, with it being so cold in the arctic that you either need geothermal heat, warm clothes, or dense hair all over, how would electricity be generated? Also could yearly power outages be prevented?
I'm thinking there would be these sources:
* Solar(but only like right where the building is and even then, there would be at least 1 day with no sun at all)
* Water and Tidal(but only during months when there is liquid water on the surface)
* Geothermal(Obviously, although it isn't very efficient, it is a relatively stable source and would be used the entire year)
Wind would be complicated. Yes there is plenty of wind in the arctic but the turbines could accumulate ice and be stuck not working. So wind power, while theoretically possible, is practically impossible in the arctic.
Ice is actually my main concern for any non-geothermal power source and for geothermal plants. Since there would be wires outside for quite a few of these sources and for geothermal plants, these wires could accumulate ice and then bring all the power lines down causing a winter-long power outage. For water and tidal, this can't be avoided but can it be avoided with the geothermal plants and the wires coming from them?
With solar, it isn't the wires per se but rather the reflectivity of the ice. Bare ice reflects 50% of the light that hits it. So half as much power from the photovoltaic cells. Ice with snow on top of it reflects 90% of the light that hits it. Solar would be practically useless when there is snow on top of the ice. Then there is meltwater. This would also mean less than optimal power but meltwater only reflects 30% of the light that hits it. So more power than when there was ice on the solar panels.
**So how could yearly power outages be prevented and would the solar power that they get in the winter just be stored in batteries until spring comes and solar power is useful again?**
[Answer]
Your people could generate electricity in the Arctic the way regular nonfictional people generate electricity in the Arctic, and elsewhere.
**Burn coal**.
[](https://i.stack.imgur.com/pnkGE.jpg)
<https://www.mapsofworld.com/business/industries/coal-energy/world-coal-deposits.html>
Note the coal deposits in Siberia and the Russian Far East, and northern Alaska. Those are all in the Arctic.
Regular generators burn coal to turn a turbine and generate electricity. You can do that anywhere you have coal. Or you can burn coal in a fire to stay warm, as people do all over the world. You can have a thick coat of hair too, and whip it back and forth.
It is not the sexiest of fictional ideas, burning coal to generate power.
[Answer]
**Nuclear Powered Snowmen**
**"Renewable" energy kinda sucks-** Solar is only viable when you have the panels made in near slave labor conditions in china where the toxic byproducts of the manufacture can be legally dumped into a river, then heavily subsidize their sale once they arrive in the wealthier nation. If the panels were made in a developed nation with adequate environmental controls and well paid workers and the government didn't use taxes to subsidize their sale they would cost more than they would ever produce in electrical output during their entire lifetime. Did I mention that solar panels require lots of fossil fuels and massive amounts of energy to manufacture? IF a solar panel produces at optimum output for its entire lifespan it might, MIGHT break even on how much energy was required to produce, transport, install and maintain it. No system will ever operate at optimum output at all times, thus most solar panels you see haven't even made up the deficit created by their construction yet and wont for another 15 to 20 years, by which time they will need to be replaced.
Wind is an unpredictable source of power and only works to supplement a power grid's output. A grid ran entirely off of wind power would not be a reliable and viable option, wind turbines are how power companies convince you to ignore the coal powered steam turbines that perform the majority of the workload. They are also only really viable to build cost effectively when using cheap 3rd world slave labor and massive government subsidies.
Geothermal is cost prohibitive anywhere that geothermal activity is not occurring close to the surface. This means you really can't choose where you are building them, and the locations where geothermal activity is accessible is not going to necessarily be where you want to build a city or power plant. Tidal is periodic output, it only produces power during tidal activity. Like wind, it is only going to useful to augment an existing grid, not replacing it entirely. Also you have all that ice stopping you from using it for long periods of the year.
**Nuclear reactors kinda don't-** Nuclear reactors are actually quite safe and efficient now days. The old fashioned reactors were more dangerous due to possessing more primitive computers and were based on older theories of nuclear physics. Why not thorium reactors? Thorium is a lot more common than uranium or plutonium, more stable and easier to control, less expensive to refine, and cannot be weaponized into nuclear bombs. The best part of a nuclear reactor using thorium is that it does not have complicated control rods as saftey measures. The idea that a computer could fail or something could get stuck and cause a meltdown doesn't exist. Thorium reactors keep the thorium suspended in a pool of molten salt. Pull the plug and drain the molten salt and thorium into a series of sub-critical mass tanks and that's it. Fission stops. No melt down. Stopping a thorium reactor is basically just as simple as pulling the plug on a giant bathtub.
Nuclear power being depicted as "that crazy thing we can't believe we were into back in the 50's" is kinda mostly due to petroleum company lobbyists trying to justify why we ought to keep burning their products like we have been since the 1800's. Also apparently coal miners are heroic blue collar patriotic figures that require constant protection from evil communists. Said coal miners could just be used to mine thorium instead. "green" energy lobbyists also attack nuclear power to serve their own goals and hide their own shortcomings and schemes. I'm all or renewable energy, but the people aren't really renewable, aren't really producing much energy, cant make profits without being given our tax money, and are actively obstructing more viable clean power options. Your more pragmatic snow-men see this and develop measures that don't just politically advertise well, but work well too.
[Answer]
You might want to check my answer here:
[Giving Tolkien Architecture a Reality Check: Dwarvish Kingdoms](https://worldbuilding.stackexchange.com/questions/100380/giving-tolkien-architecture-a-reality-check-dwarvish-kingdoms/100413#100413)
It describes a city within a mountain, or what can be considered a city within a single building.
See ckersch's answer here:
[How many people can you feed per square-kilometer of farmland?](https://worldbuilding.stackexchange.com/questions/9582/how-many-people-can-you-feed-per-square-kilometer-of-farmland)[1](https://worldbuilding.stackexchange.com/questions/9582/how-many-people-can-you-feed-per-square-kilometer-of-farmland)
It seems to me that a multistory city within a single building would be easier to keep warm in cold climates since the waste heat produced by lower floors would rise and help warm the higher floors. If solar panels and/or wind turbines were placed on top of the city waste heat rising from the city might warm them enough to keep them free of ice and snow.
And if the electricity source is inside the multistory single building city the power lines will be protected from the wind and weather outside.
Maybe the electricity would be generated by generators powered by imported diesel fuel.
Maybe a nearby waterfall would power electric generators.
Maybe during the arctic summer solar panels would generate electricity.
Maybe wind turbines would generate electricity.
Maybe nuclear reactors would generate electricity.
Maybe in the future fusion reactors would generate electricity.
Maybe if several cities are built in the arctic region several different methods would be used to generate electricity.
Note that I don't discuss geothermal energy because that will probably be unimportant unless the cities are built near specific geothermal hot spots, and I don't know if there are any in the Arctic.
>
> Wind would be complicated. Yes there is plenty of wind in the arctic but the turbines could accumulate ice and be stuck not working. So wind power, while theoretically possible, is practically impossible in the arctic.
>
>
>
Use some of the electricity generated by the electric turbines to heat up the most important parts to keep them ice free so the turbines can turn. And waste heat rising from a multi story single building city could warm up wind turbines on top of the city. And if the wind turbines are designed to use rising currents of air, the air warmed up by waste heat from the city will provide a steady wind for them to use.
>
> Ice is actually my main concern for any non-geothermal power source and for geothermal plants. Since there would be wires outside for quite a few of these sources and for geothermal plants, these wires could accumulate ice and then bring all the power lines down causing a winter-long power outage. For water and tidal, this can't be avoided but can it be avoided with the geothermal plants and the wires coming from them?
>
>
>
Why would arctic people be stupid enough to string their power lines from pole to pole above the surface, when they could dig channels through the dirt and/or ice and lay down well insulted power cables in the channels and fill up the channels again?
Aerial power cables have always been a silly idea, at least within densely populated cities that are being newly built from the ground up, and even more so where the weather can be as bad as in the arctic.
And if the electricity source is inside the multistory single building city the power lines will be protected from the wind and weather outside.
>
> With solar, it isn't the wires per se but rather the reflectivity of the ice. Bare ice reflects 50% of the light that hits it. So half as much power from the photovoltaic cells. Ice with snow on top of it reflects 90% of the light that hits it. Solar would be practically useless when there is snow on top of the ice. Then there is meltwater. This would also mean less than optimal power but meltwater only reflects 30% of the light that hits it. So more power than when there was ice on the solar panels.
>
>
>
What difference does it make how much light is reflected from snow, ice, or water? Are the solar panels going to be facing the snow, ice, or water, or are they going to be facing the Sun?
And if the solar panels are facing the Sun, of course occasional storms may coat them with snow or ice. But once the snow or ice gets too thick, it will be opaque anyway and let zero light get through to the solar panels. Since the Sun is usually at a low angle in the arctic regions the solar panels would be almost vertical, and thus rainwater would run off them and they would quickly dry from rain. So snow and ice would be the problem.
And the answer to that would be to turn the solar panels parallel to the wind when it is raining, snowing, sleeting, or hailing, so that as little precipitation as possible is blown onto the solar panels. And then heat up the solar panels so the ice and snow closest to them melts, and slides off the almost vertical solar panels, which will disconnect the remaining ice and snow from the panels, and thus the remaining ice and snow will also slide off.
And waste heat rising from a multi story single building city could warm up solar panels on top of the city.
>
> So how could yearly power outages be prevented and would the solar power that they get in the winter just be stored in batteries until spring comes and solar power is useful again?
>
>
>
Energy experts may be able to answer that question.
The Arctic region is defined as lands north of the Arctic Circle.
Here is a map of the Arctic.
>
> <https://en.wikipedia.org/wiki/File:Political_Map_of_the_Arctic.pdf>
>
>
>
Note that there are settlements within the Arctic Circle.
Here is a link to a map of the Antarctic Circle.
<https://en.wikipedia.org/wiki/Antarctic_Circle#/media/File:Antarctic_circle.svg>[2](https://en.wikipedia.org/wiki/Antarctic_Circle#/media/File:Antarctic_circle.svg)
Note that there are research bases within the Antarctic Circle.
The settlements and research bases within the Arctic and Antarctic Circles generate electricity. Have you researched how they do that?
[Answer]
Somebody already tried to put down renewables but actually it can be an option.
For example, there are extreamly strong and constant winds around Cape Denison in Antarctica. It is such a good place for wind energy that there are projects of putting wind turbines there and [transmitting power via microwave beam, reflected by a giant "space kite"(see the link for details)](http://www.islandone.org/LEOBiblio/SPBI135.HTM).
[Answer]
Depending on how close the arctic city is to volcanic activity, you can have geothermal power.
[](https://i.stack.imgur.com/TafdU.png)
Some of the volcanoes near Iceland and the fault line leading to the arctic region can be potentially utilized for geothermal energy. However, one way to help prevent outages could be to use two or three different forms of power at the same time. [Raidioisotope thermoelectric](https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator) generators could be used in case the geothermal power method is temporarily offline. It is a simple form of nuclear power with no moving parts that uses the Seebeek effect to generate electricity from radioactive decay.
[](https://i.stack.imgur.com/OUGaZ.png)
Each generator could provide a few hundred watts of power for a long time and was used by the Soviet Union to power lighthouses in the Arctic Circle. Finally, you could have Humanoidus Keplerianus Arcticus be energy conscious and use very little power. They still utilize electricity, but maybe have them live like an arctic eco village or spend most of their time living like the Inuit here on Earth: they might use electric power for parts of their daily life, but most of their lifestyle doesn't require using electricity all the time.
] |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.